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1. The impact of aerosol fluorescence on long-term water vapor monitoring by Raman lidar and evaluation of a potential correction method

Author: Fernando Chouza, Thierry Leblanc, Mark Brewer, Patrick Wang, Giovanni Martucci, Alexander Haefele, Hélène Vérèmes, Valentin Duflot, Guillaume Payen, Philippe Keckhut, Laboratory Studies and Atmospheric Observations, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH)-NASA-California Institute of Technology (CALTECH), Federal Office of Meteorology and Climatology MeteoSwiss, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), This research has been supported by the Jet Propulsion Laboratory (grant no. 80NM0018D0004)., and European Project: 1343583(2013)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science
Abstract: The impact of aerosol fluorescence on the measurement of water vapor by UV (355 nm emission) Raman lidar in the upper troposphere and lower stratosphere (UTLS) is investigated using the long-term records of three high-performance Raman lidars contributing to the Network for the Detection of Atmospheric Composition Change (NDACC). Comparisons with co-located radiosondes and aerosol backscatter profiles indicate that laser-induced aerosol fluorescence in smoke layers injected into the stratosphere by pyrocumulus events can introduce very large and chronic wet biases above 15 km, thus impacting on the ability of these systems to accurately estimate long-term water vapor trends in the UTLS. In order to mitigate the fluorescence contamination, a correction method based on the addition of an aerosol fluorescence channel was developed and tested on the water vapor Raman lidar TMWAL located at the JPL Table Mountain Facility in California. The results of this experiment, conducted between 27 August and 4 November 2021 and involving 22 co-located lidar and radiosonde profiles, suggest that the proposed correction method is able to effectively reduce the fluorescence-induced wet bias. After correction, the average difference between the lidar and co-located radiosonde water vapor measurements was reduced to 5 %, consistent with the difference observed during periods of negligible aerosol fluorescence interference. The present results provide confidence that after a correction is applied, long-term water vapor trends can be reasonably well estimated in the upper troposphere, but they also call for further refinements or use of alternate Raman lidar approaches (e.g., 308 nm or 532 nm emission) to confidently detect long-term trends in the lower stratosphere. These findings may have important implications for NDACC's water vapor measurement strategy in the years to come.
Published: 2022

2. Early Evolution of the Stratospheric Aerosol Plume Following the 2022 Hunga Tonga‐Hunga Ha'apai Eruption: Lidar Observations From Reunion (21°S, 55°E)

Author: A. Baron, P. Chazette, S. Khaykin, G. Payen, N. Marquestaut, N. Bègue, V. Duflot, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), NOAA Chemical Sciences Laboratory (CSL), National Oceanic and Atmospheric Administration (NOAA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Chimie Atmosphérique Expérimentale (CAE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)
Subjects: Geophysics, [SDU]Sciences of the Universe [physics], General Earth and Planetary Sciences
Abstract: International audience
Published: 2023

3. Bio-physicochemistry of tropical clouds at Maïdo (Réunion Island, Indian Ocean): overview of results from the BIO-MAÏDO campaign

Author: Leriche, Maud, Tulet, Pierre, Deguillaume, Laurent, Burnet, Frédéric, Colomb, Aurélie, Borbon, Agnès, Jambert, Corinne, Duflot, Valentin, Houdier, Stéphan, Jaffrezo, Jean-Luc, Vaïtilingom, Mickaël, Mouchel-Vallon, Camille, Dominutti, Pamela, Rocco, Manon, Gdachi, Samira, Brissy, Maxence, Fathalli, Maroua, Maury, Nicolas, Verreyken, Bert, Amelynck, Crist, Schoon, Niels, Gros, Valérie, Pichon, Jean-Marc, Ribeiro, Mickael, Pique, Eric, Leclerc, Emmanuel, Bourrianne, Thierry, Roy, Axel, Moulin, Eric, Barrie, Joël, Metzger, Jean-Marc, Péris, Guillaume, Guadagno, Christian, Bhugwant, Chatrapatty, Tibere, Jean-Mathieu, Tournigand, Arnaud, Freney, Evelyn, Sellegri, Karine, Delort, Anne-Marie, Amato, Pierre, Joly, Muriel, Baray, Jean-Luc, Renard, Pascal, Bianco, Angelica, Réchou, Anne, Payen, Guillaume, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Centre ESCER, Université du Québec à Montréal = University of Québec in Montréal (UQAM), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Laboratoire de Recherche en Géosciences et Energies [UR2_1] (LARGE), Université des Antilles (UA), Institut de Chimie de Clermont-Ferrand (ICCF), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA), Department of Chemistry, University of Ghent, Ghent, Belgium, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Departement of Chemistry, University of Ghent, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), ATMO-Réunion, ANR, BIO-MAÏDO, OCTAVE, European Project: 654109,H2020,H2020-INFRAIA-2014-2015,ACTRIS-2(2015), and ANR-18-CE01-0013,BIO-MAIDO,Bio-physicochimie des nuages tropicaux au Maïdo (Île de la Réunion) : processus et impacts sur la formation des aérosols organiques secondaires(2018)
Subjects: Atmospheric chemistry, Field campaign, tropical atmosphere, [SDU]Sciences of the Universe [physics], COV, Réunion Island, cloud, aerosols
Abstract: The BIO-MAÏDO (Bio-physicochemistry of tropical clouds at Maïdo (Réunion Island): processes and impacts on secondary organic aerosols formation) campaign was conducted from the 13th of March to the 4th of April 2019 on the tropical Réunion Island and implied several scientific teams and state-of-the-art instrumentation. The campaign was part of the BIO-MAÏDO project with the main objective is to improve our understanding of cloud impacts on the formation of secondary organic aerosols (SOA) from biogenic volatile organic compounds (BVOC) precursors in a tropical environment. Instruments were deployed at five sites: a receptor site, the Maïdo observatory (MO) at 2165 m asl, and four sites along the slope of the Maïdo mountain. The obtained dataset includes measurements of the gas-phase mixings ratio of volatile organic compounds (VOC), the characterization of the physical, chemical, and biological (bacterial diversity) properties of aerosols and the characterization of the physical, chemical and biological (identification of viable bacteria through culture-based approaches) properties of the cloud water. In addition, the turbulent parameters of the boundary layer, radiative fluxes, and emissions fluxes of BVOC from the surrounding vegetation were measured to help with the interpretation of the observed chemical concentrations in the different phases. Dynamical analyses using back-trajectories show two preferred trajectories routes for air masses arriving at MO during the daytime both corresponding to the return branches of the trade winds associated with the up-slopes thermal breezes, and both influenced by marine boundary layer and endemic forest below the Maïdo observatory. Additional analysis based on a high-resolution Meso-NH simulation for a typical cloudy day indicates that air masses sampled at MO likely encountered cloud processing during its transport along the slope. The highest mixing ratio of oxygenated VOC (OVOC) were measured above the site located in the endemic forest and the highest contribution of OVOC to total VOC at MO. Chemical composition of particles during the daytime shows that organic aerosol is more oxidized at MO than at other sites along the slope. This is a signature of photochemical aerosols aging along the slope. A higher concentration of oxalic acid at a site below MO indicates this oxidation occurs potentially through cloud processing. Despite an in-depth analysis of organic compounds in cloud water, around 80% on average of dissolved organic compounds is undefined highlighting the complexity of the cloud organic matter. The BIO-MAÏDO project is focusing on the analysis of observations and processes using numerical simulations: a 0D cloud chemistry model including biodegradation by bacteria in cloud water and a high-resolution 3D model coupling dynamical, microphysical and chemical processes.
Published: 2023

4. Seasonality of the particle number concentration and size distribution: a global analysis retrieved from the network of Global Atmosphere Watch (GAW) near-surface observatories

Author: C. Rose, M. Collaud Coen, E. Andrews, Y. Lin, I. Bossert, C. Lund Myhre, T. Tuch, A. Wiedensohler, M. Fiebig, P. Aalto, A. Alastuey, E. Alonso-Blanco, M. Andrade, B. Artíñano, T. Arsov, U. Baltensperger, S. Bastian, O. Bath, J. P. Beukes, B. T. Brem, N. Bukowiecki, J. A. Casquero-Vera, S. Conil, K. Eleftheriadis, O. Favez, H. Flentje, M. I. Gini, F. J. Gómez-Moreno, M. Gysel-Beer, A. G. Hallar, I. Kalapov, N. Kalivitis, A. Kasper-Giebl, M. Keywood, J. E. Kim, S.-W. Kim, A. Kristensson, M. Kulmala, H. Lihavainen, N.-H. Lin, H. Lyamani, A. Marinoni, S. Martins Dos Santos, O. L. Mayol-Bracero, F. Meinhardt, M. Merkel, J.-M. Metzger, N. Mihalopoulos, J. Ondracek, M. Pandolfi, N. Pérez, T. Petäjä, J.-E. Petit, D. Picard, J.-M. Pichon, V. Pont, J.-P. Putaud, F. Reisen, K. Sellegri, S. Sharma, G. Schauer, P. Sheridan, J. P. Sherman, A. Schwerin, R. Sohmer, M. Sorribas, J. Sun, P. Tulet, V. Vakkari, P. G. van Zyl, F. Velarde, P. Villani, S. Vratolis, Z. Wagner, S.-H. Wang, K. Weinhold, R. Weller, M. Yela, V. Zdimal, P. Laj, Institute for Atmospheric and Earth System Research (INAR), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Federal Office of Meteorology and Climatology MeteoSwiss, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), National Oceanic and Atmospheric Administration (NOAA), Norwegian Institute for Air Research (NILU), Université Bourgogne Franche-Comté [COMUE] (UBFC), Leibniz Institute for Tropospheric Research (TROPOS), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Institute of Environmental Assessment and Water Research (IDAEA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Centre for Energy, Environment and Technology (CIEMAT), Universidad Mayor de San Andrés (UMSA), Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Bulgarian Academy of Sciences (BAS), Paul Scherrer Institute (PSI), Saxon State Office for Environment, Agriculture and Geology, German Federal Environmental Agency / Umweltbundesamt (UBA), North-West University [Potchefstroom] (NWU), Universidad de Granada = University of Granada (UGR), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), Environmental Radioactivity Lab, Institute of Nuclear and Radiological Sciences & Technology, Energy & Safety, NCSR 'Demokritos' (NCSR 'Demokritos'), Institut National de l'Environnement Industriel et des Risques (INERIS), Meteorological Observatory Hohenpeissenberg (MOHp), University of Utah, Environmental Chemical Processes Laboratory [Heraklion] (ECPL), Department of Chemistry [Heraklion], University of Crete [Heraklion] (UOC)-University of Crete [Heraklion] (UOC), Vienna University of Technology (TU Wien), CSIRO Oceans and Atmosphere, CISRO Oceans and Atmosphere, National Institute of Meteorological Sciences (NIMS), Seoul National University [Seoul] (SNU), Division of Nuclear Physics, Lund University [Lund], Finnish Meteorological Institute (FMI), National Central University [Taiwan] (NCU), CNR Institute of Atmospheric Sciences and Climate (ISAC), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), European Commission - Joint Research Centre [Ispra] (JRC), University of Puerto Rico at Rio Piedras Campus (UPR-RP), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), National Observatory of Athens (NOA), Institute of Chemical Process Fundamentals of the ASCR, Czech Republic, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Chimie Atmosphérique Expérimentale (CAE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Environment and Climate Change Canada, Zentralanstalt für Meteorologie und Geodynamik (ZAMG), Appalachian State University, University of North Carolina System (UNC), Atmospheric Sounding Station 'El Arenosillo', Instituto Nacional de Técnica Aeroespacial (INTA), State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, 4S Company, Leibniz-Institut für Troposphärenforschung (TROPOS), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), European Project: 654109,H2020,H2020-INFRAIA-2014-2015,ACTRIS-2(2015), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of Helsinki, University of Granada [Granada], Consiglio Nazionale delle Ricerche (CNR), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Atmospheric Science, Global Atmosphere Watch (GAW), 010504 meteorology & atmospheric sciences, Planetary boundary layer, QC1-999, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, 010501 environmental sciences, Spatial distribution, Atmospheric sciences, 114 Physical sciences, 01 natural sciences, Atmosphere, medicine, Cloud condensation nuclei, 14. Life underwater, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, QD1-999, Diel vertical migration, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Physics, Seasonality, medicine.disease, Aerosol, Chemistry, 13. Climate action, Environmental science, Climate model, Trollobservatoriet
Abstract: This research was supported by the European Commission's Horizon 2020 Framework Programme (ACTRIS2 (grant agreement no. 654109)), the University of Helsinki, the Finnish Meteorological Institute, the Department of Science and Innovation of South Africa, the Academy of Finland Centre of Excellence programme (project no. 272041), the Academy of Finland project Greenhouse gas, aerosol and albedo variations in the changing Arctic (project no. 269095), the Novel Assessment of Black Carbon in the Eurasian Arctic: From Historical Concentrations and Sources to Future Climate Impacts (NABCEA, project no. 296302), the Korea Meteorological Administration Research and Development Program "Development of Monitoring and Analysis Techniques for Atmospheric Composition in Korea" (grant no. KMA2018-00522), the National Research Foundation of Korea (grant no. 2017R1D1A1B06032548), the Korea Meteorological Administration Research and Development Program (grant no. KMI2018-01111), the Taiwan Environmental Protection Administration, the China Meteorological Administration, the National Scientific Foundation of China (41675129, 41875147), the National Key R&D Program of the Ministry of Science and Technology of the People's Republic of China (grant no. 2016YFC0203305 and 2018YFC0213204), the Chinese Academy of Meteorological Sci-ences (2020KJ001), the Innovation Team for Haze-fog Observation and Forecasts of MOST and CMA, CNRS-INSU, the French Ministry for Research under the ACTRIS-FR national research infrastructure, the French Ministry of the Environment, MeteoSwiss (GAW-CH aerosol monitoring programme), the Swiss State Secretariat for Education, Research and Innovation (SERI), the Ministry of Education, Youth and Sports of CR within National Sustainability Program I (NPU I, grant no. LO1415), ERDF "ACTRISCZ RI" (grant no. CZ.02.1.01/0.0/0.0/16_013/0001315), CRISOL (CGL2017-85344-R MINECO/AEI/FEDER, UE), TIGAS-CM (Madrid Regional Government Y2018/EMT-5177), AIRTECCM (Madrid Regional Government P2018/EMT4329), REDMAAS2020 (RED2018-102594-T CIENCIA), Red de Excelencia ACTRIS-ESPANA (CGL2017-90884-REDT), the Spanish Ministry of Economy, Industry and Competitiveness, FEDER funds (project HOUSE, grant no. CGL2016-78594-R), the Generalitat de Catalunya (AGAUR 2017 SGR41 and the DGQA), the National Institute for Aerospace Technology, the Ministerio Espanol de Economia, Industria y Competitividad (MINECO), the Spanish Ministry of Economy and Competitiveness (projects no. CGL2016-81092-R, CGL2017-90884-REDT, RTI2018-097864-BI00 and PGC2018-098770-B-I00), the Andalusia Regional Government (project no. P18-RT-3820), the PANhellenic infrastructure for Atmospheric Composition and climate change (MIS 5021516), Research and Innovation Infrastructure, Competitiveness, Entrepreneurship and Innovation (grant no. NSRF 20142020), the Italian Ministry of Research and Education, the Norwegian Environment Agency, Swedish FORMAS, the Swedish Research Council (VR), the Magnus Bergvall foundation, the Marta och Erik Holmberg foundation, and the Swedish EPA., Aerosol particles are a complex component of the atmospheric system which influence climate directly by interacting with solar radiation, and indirectly by contributing to cloud formation. The variety of their sources, as well as the multiple transformations they may undergo during their transport (including wet and dry deposition), result in significant spatial and temporal variability of their properties. Documenting this variability is essential to provide a proper representation of aerosols and cloud condensation nuclei (CCN) in climate models. Using measurements conducted in 2016 or 2017 at 62 ground-based stations around the world, this study provides the most up-to-date picture of the spatial distribution of particle number concentration (N-tot) and number size distribution (PNSD, from 39 sites). A sensitivity study was first performed to assess the impact of data availability on N-tot's annual and seasonal statistics, as well as on the analysis of its diel cycle. Thresholds of 50% and 60% were set at the seasonal and annual scale, respectively, for the study of the corresponding statistics, and a slightly higher coverage (75 %) was required to document the diel cycle. Although some observations are common to a majority of sites, the variety of environments characterizing these stations made it possible to highlight contrasting findings, which, among other factors, seem to be significantly related to the level of anthropogenic influence. The concentrations measured at polar sites are the lowest (similar to 10(2) cm(-3)) and show a clear seasonality, which is also visible in the shape of the PNSD, while diel cycles are in general less evident, due notably to the absence of a regular day-night cycle in some seasons. In contrast, the concentrations characteristic of urban environments are the highest (similar to 10(3)-10(4) cm(-3)) and do not show pronounced seasonal variations, whereas diel cycles tend to be very regular over the year at these stations. The remaining sites, including mountain and non-urban continental and coastal stations, do not exhibit as obvious common behaviour as polar and urban sites and display, on average, intermediate N-tot (similar to 10(2)-10(3) cm(-3)). Particle concentrations measured at mountain sites, however, are generally lower compared to nearby lowland sites, and tend to exhibit somewhat more pronounced seasonal variations as a likely result of the strong impact of the atmospheric boundary layer (ABL) influence in connection with the topography of the sites. ABL dynamics also likely contribute to the diel cycle of N-tot observed at these stations. Based on available PNSD measurements, CCN-sized particles (considered here as either >50 nm or >100 nm) can represent from a few percent to almost all of N-tot, corresponding to seasonal medians on the order of similar to 10 to 1000 cm(-3), with seasonal patterns and a hierarchy of the site types broadly similar to those observed for N-tot. Overall, this work illustrates the importance of in situ measurements, in particular for the study of aerosol physical properties, and thus strongly supports the development of a broad global network of near surface observatories to increase and homogenize the spatial coverage of the measurements, and guarantee as well data availability and quality. The results of this study also provide a valuable, freely available and easy to use support for model comparison and validation, with the ultimate goal of contributing to improvement of the representation of aerosol-cloud interactions in models, and, therefore, of the evaluation of the impact of aerosol particles on climate., European Commission's Horizon 2020 Framework Programme (ACTRIS2) 654109, University of Helsinki, Finnish Meteorological Institute, Department of Science and Innovation of South Africa, Academy of Finland 272041, Academy of Finland project Greenhouse gas, aerosol and albedo variations in the changing Arctic 269095, Novel Assessment of Black Carbon in the Eurasian Arctic: From Historical Concentrations and Sources to Future Climate Impacts (NABCEA) 296302, Korea Meteorological Administration Research and Development Program "Development of Monitoring and Analysis Techniques for Atmospheric Composition in Korea" KMA2018-00522, National Research Foundation of Korea 2017R1D1A1B06032548, Korea Meteorological Administration Research and Development Program KMI2018-01111, Taiwan Environmental Protection Administration, China Meteorological Administration, National Natural Science Foundation of China (NSFC) 41675129 41875147, National Key R&D Program of the Ministry of Science and Technology of the People's Republic of China 2016YFC0203305 2018YFC0213204, Chinese Academy of Meteorological Sciences 2020KJ001, Innovation Team for Haze-fog Observation and Forecast of MOST Innovation Team for Haze-fog Observation and Forecast of CMA Innovation Team for Haze-fog Observation and Forecast of CNRS-INSU, French Ministry for Research under the ACTRIS-FR national research infrastructure, French Ministry of the Environment, MeteoSwiss (GAW-CH aerosol monitoring programme), Swiss State Secretariat for Education, Research and Innovation (SERI), Ministry of Education, Youth and Sports of CR within National Sustainability Program I (NPU I) LO1415, ERDF "ACTRISCZ RI" CZ.02.1.01/0.0/0.0/16_013/0001315, CRISOL CGL2017-85344, TIGAS-CM (Madrid Regional Government) Y2018/EMT-5177, AIRTECCM (Madrid Regional Government) P2018/EMT4329, REDMAAS2020 RED2018-102594-T, Red de Excelencia ACTRIS-ESPANA CGL2017-90884-REDT, Spanish Ministry of Economy, Industry and Competitiveness, FEDER funds CGL2016-78594-R, Generalitat de Catalunya, General Electric AGAUR 2017 SGR41, National Institute for Aerospace Technology, Ministerio Espanol de Economia, Industria y Competitividad (MINECO) Spanish Government CGL2017-90884-REDT CGL2016-81092-R RTI2018-097864-BI00 PGC2018-098770-B-I00, Andalusia Regional Government P18-RT-3820, PANhellenic infrastructure for Atmospheric Composition and climate change MIS 5021516, Research and Innovation Infrastructure, Competitiveness, Entrepreneurship and Innovation NSRF 20142020, Ministry of Education, Universities and Research (MIUR), Norwegian Environment Agency, Swedish FORMAS, Swedish Research Council, Magnus Bergvall foundation, Marta och Erik Holmberg foundation, Swedish EPA
Published: 2021

5. Seismic Signature of Rain and Wind Inferred From Seismic Data

Author: E. J. Rindraharisaona, A. Réchou, F. R. Fontaine, G. Barruol, P. Stamenoff, B. Boudevillain, F. Rigaud‐Louise, E. Delcher, Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Observatoire volcanologique et sismologique de martinique (OVSM), Institut de Physique du Globe de Paris (IPG Paris), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)
Subjects: [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, General Earth and Planetary Sciences, Environmental Science (miscellaneous)
Abstract: International audience
Published: 2022

6. Measurement report: Source apportionment of volatile organic compounds at the remote high-altitude Maïdo observatory

Author: Nicolas Kumps, Jean-Marc Metzger, Jean-François Müller, Niels Schoon, Christian Hermans, Trissevgeni Stavrakou, Aurélie Colomb, Crist Amelynck, Jerome Brioude, Bert Verreyken, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Météo-France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de Météorologie Physique (LaMP), and Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)
Subjects: Atmospheric Science, Daytime, METHYL VINYL KETONE, Formic acid, QC1-999, Troposphere, chemistry.chemical_compound, RATE CONSTANTS, Altitude, Observatory, QD1-999, Diel vertical migration, Isoprene, Physics, IN-SITU, 55-DEGREES E, TECHNICAL NOTE, Chemistry, DIMETHYL SULFIDE, REUNION ISLAND, chemistry, [SDU]Sciences of the Universe [physics], Earth and Environmental Sciences, Environmental chemistry, Environmental science, Dimethyl sulfide, REACTION MASS-SPECTROMETRY, ISLAND 21-DEGREES S, PARTICLE DISPERSION MODEL
Abstract: We present a source apportionment study of a near-continuous 2-year dataset of volatile organic compounds (VOCs), recorded between October 2017 and November 2019 with a quadrupole-based high-sensitivity proton-transfer-reaction mass-spectrometry (hs-PTR-MS) instrument deployed at the Maïdo observatory (21.1∘ S, 55.4∘ E, 2160 m altitude). The observatory is located on La Réunion island in the southwest Indian Ocean. We discuss seasonal and diel profiles of six key VOC species unequivocally linked to specific sources – acetonitrile (CH3CN), isoprene (C5H8), isoprene oxidation products (Iox), benzene (C6H6), C8-aromatic compounds (C8H10), and dimethyl sulfide (DMS). The data are analyzed using the positive matrix factorization (PMF) method and back-trajectory calculations based on the Lagrangian mesoscale transport model FLEXPART-AROME to identify the impact of different sources on air masses sampled at the observatory. As opposed to the biomass burning tracer CH3CN, which does not exhibit a typical diel pattern consistently throughout the dataset, we identify pronounced diel profiles with a daytime maximum for the biogenic (C5H8 and Iox) and anthropogenic (C6H6, C8H10) tracers. The marine tracer DMS generally displays a daytime maximum except for the austral winter when the difference between daytime and nighttime mixing ratios vanishes. Four factors were identified by the PMF: background/biomass burning, anthropogenic, primary biogenic, and secondary biogenic. Despite human activity being concentrated in a few coastal areas, the PMF results indicate that the anthropogenic source factor is the dominant contributor to the VOC load (38 %), followed by the background/biomass burning source factor originating in the free troposphere (33 %), and by the primary (15 %) and secondary biogenic (14 %) source factors. FLEXPART-AROME simulations showed that the observatory was most sensitive to anthropogenic emissions west of Maïdo while the strongest biogenic contributions coincided with air masses passing over the northeastern part of La Réunion. At night, the observatory is often located in the free troposphere, while during the day, the measurements are influenced by mesoscale sources. Interquartile ranges of nighttime 30 min average mixing ratios of methanol (CH3OH), CH3CN, acetaldehyde (CH3CHO), formic acid (HCOOH), acetone (CH3COCH3), acetic acid (CH3COOH), and methyl ethyl ketone (MEK), representative for the atmospheric composition of the free troposphere, were found to be 525–887, 79–110, 61–101, 172–335, 259–379, 64–164, and 11–21 pptv, respectively.
Published: 2021

7. Evaluation of the Sources, Precursors, and Processing of Aerosols at a High-Altitude Tropical Site

Author: Dominutti, Pamela, Chevassus, Emmanuel, Baray, Jean-Luc, Jaffrezo, Jean-Luc, Borbon, Agnès, Colomb, Aurélie, Deguillaume, Laurent, El Gdachi, Samira, Houdier, Stephan, Leriche, Maud, Metzger, Jean-Marc, Rocco, Manon, Tulet, Pierre, Sellegri, Karine, Freney, Evelyn, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Centre ESCER, Université du Québec à Montréal = University of Québec in Montréal (UQAM), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), ANR-18-CE01-0013,BIO-MAIDO,Bio-physicochimie des nuages tropicaux au Maïdo (Île de la Réunion) : processus et impacts sur la formation des aérosols organiques secondaires(2018), and European Project: 654109,H2020,H2020-INFRAIA-2014-2015,ACTRIS-2(2015)
Subjects: Atmospheric Science, Cloud processing, Positive matrix factorization, Space and Planetary Science, Geochemistry and Petrology, ToF-ACSM, [SDE.IE]Environmental Sciences/Environmental Engineering, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, [SDE.MCG]Environmental Sciences/Global Changes, Secondary organic aerosols, Aqueous-phase chemistry, Southern Hemisphere, [SDE.ES]Environmental Sciences/Environmental and Society
Abstract: International audience; This work presents the results from a set of aerosol- and gas-phase measurements collected during the BIO-MAIDÖ field campaign in Reunion ́ between March 8 and April 5, 2019. Several offline and online sampling devices were installed at the Maidö Observatory (MO), a remote high-altitude site in the Southern Hemisphere, allowing the physical and chemical characterization of atmospheric aerosols and gases. The evaluation of short-lived gas-phase measurements allows us to conclude that air masses sampled during this period contained little or no anthropogenic influence. The dominance of sulfate and organic species in the submicron fraction of the aerosol is similar to that measured at other coastal sites.Carboxylic acids on PM10 showed a significant contribution of oxalic acid, a typical tracer of aqueous processed air masses, increasing at the end of the campaign. This result agrees with the positive matrix factorization analysis of the submicron organic aerosol, where more oxidized organic aerosols (MOOAs) dominated the organic aerosol with an increasing contribution toward the end of the campaign. Using a combination of air mass trajectories (model predictions), it was possible to assess the impact of aqueous phase processing on the formation of secondary organic aerosols(SOAs). Our results show how specific chemical signatures and physical properties of air masses, possibly affected by cloud processing, can be identified at Reunion. ́ These changes in properties are represented by a shift in aerosol size distribution to large diameters and an increased contribution of secondary sulfate and organic aerosols after cloud processing.
Published: 2022

8. Aerosol Characterization of the Stratospheric Plume From the Volcanic Eruption at Hunga Tonga 15 January 2022

Author: Corinna Kloss, Pasquale Sellitto, Jean‐Baptiste Renard, Alexandre Baron, Nelson Bègue, Bernard Legras, Gwenaël Berthet, Emmanuel Briaud, Elisa Carboni, Clair Duchamp, Valentin Duflot, Patrick Jacquet, Nicolas Marquestaut, Jean‐Marc Metzger, Guillaume Payen, Marion Ranaivombola, Tjarda Roberts, Richard Siddans, Fabrice Jégou, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de physique de l'atmosphère (LPA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de physique et chimie de l'environnement (LPCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), OPAR is presently funded by CNRS (INSU), ANR-10-LABX-0100,VOLTAIRE,Geofluids and Volatil elements – Earth, Atmosphere, Interfaces – Resources and Environment(2010), and ANR-21-CE01-0007,ASTuS,Tourbillons de fumées s'élevant dans la stratosphère(2021)
Subjects: in situ observations, aerosol size distribution, Geophysics, aerosol plume, [SDU]Sciences of the Universe [physics], stratosphere, General Earth and Planetary Sciences, Hunga Tonga, aerosol typology
Abstract: International audience; Following the Hunga Tonga eruption (20.6°S, 175.4°W, mid-January 2022), we present a balloon-borne characterization of the stratospheric aerosol plume one week after its injection (on 23 and 26 January 2022, La Réunion island at 21.1°S, 55.3°E). Satellite observations show that flight (a) took place during the overpass of a denser plume of sulfate aerosols (SA) compared to a more diluted plume during flight. (b) Observations show that the sampled plumes (at around 22, 25 and 19 km altitude, respectively) consist exclusively of very small particles (with radius
Published: 2022

9. Analysis of CO2, CH4, and CO surface and column concentrations observed at Réunion Island by assessing WRF-Chem simulations

Author: Callewaert, Sieglinde, Brioude, Jérôme, Langerock, Bavo, Duflot, Valentin, Fonteyn, Dominique, Müller, Jean-François, Metzger, Jean-Marc, Hermans, Christian, Kumps, Nicolas, Ramonet, Michel, Lopez, Morgan, Mahieu, Emmanuel, de Mazière, Martine, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), ICOS-RAMCES (ICOS-RAMCES), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Liège
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Abstract: Réunion Island is situated in the Indian Ocean and holds one of the very few atmospheric observatories in the tropical Southern Hemisphere. Moreover, it hosts experiments providing both ground-based surface and column observations of CO2, CH4, and CO atmospheric concentrations. This work presents a comprehensive study of these observations made in the capital Saint-Denis and at the high-altitude Maïdo Observatory. We used simulations of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), in its passive tracer option (WRF-GHG), to gain more insight to the factors that determine the observed concentrations. Additionally, this study provides an evaluation of the WRF-GHG performance in a region of the globe where it has not yet been applied. A comparison of the basic meteorological fields near the surface and along atmospheric profiles showed that WRF-GHG has decent skill in reproducing these meteorological measurements, especially temperature. Furthermore, a distinct diurnal CO2 cycle with values up to 450 ppm was found near the surface in Saint-Denis, driven by local anthropogenic emissions, boundary layer dynamics, and accumulation due to low wind speed at night. Due to an overestimation of local wind speed, WRF-GHG underestimates this nocturnal buildup. At Maïdo, a similar diurnal cycle is found but with much smaller amplitude. There, surface CO2 is essentially driven by the surrounding vegetation. The hourly column-averaged mole fractions of CO2 (XCO2) of WRF-GHG and the corresponding TCCON observations were highly correlated with a Pearson correlation coefficient of 0.90. These observations represent different air masses to those near the surface; they are influenced by processes from Madagascar, Africa, and further away. The model shows contributions from fires during the Southern Hemisphere biomass burning season but also biogenic enhancements associated with the dry season. Due to a seasonal bias in the boundary conditions, WRF-GHG fails to accurately reproduce the CH4 observations at Réunion Island. Furthermore, local anthropogenic fluxes are the largest source influencing the surface CH4 observations. However, these are likely overestimated. Furthermore, WRF-GHG is capable of simulating CO levels on Réunion Island with a high precision. As to the observed CO column (XCO), we confirmed that biomass burning plumes from Africa and elsewhere are important for explaining the observed variability. The in situ observations at the Maïdo Observatory can characterize both anthropogenic signals from the coastal regions and biomass burning enhancements from afar. Finally, we found that a high model resolution of 2 km is needed to accurately represent the surface observations. At Maïdo an even higher resolution might be needed because of the complex topography and local wind patterns. To simulate the column Fourier transform infrared (FTIR) observations on the other hand, a model resolution of 50 km might already be sufficient.
Published: 2022

10. Remote-sensing of aerosol atmospheric rivers over the southwest Indian Ocean in September 2017: origins, evolution and impacts

Author: Alexandre Baron, Valentin Duflot, Patrick Chazette, Marco Gaetani, Cyrille Flamant, Juan Cuesta, Guillaume Payen, Philippe Keckhut, Philippe Goloub, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Centre National d'Études Spatiales [Toulouse] (CNES), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Istituto Universitario di Studi Superiori (IUSS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), TROPO - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), STRATO - LATMOS, Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: Aerosols, Remote Sensing, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Smoke Plumes, Troposphere, Southwest Indian Ocean, aerosol atmospheric river (AAR), Southern Hemisphere, Biomass, Spaceborne Lidar, Fires, Spectro-radiometer
Abstract: In the southern hemisphere, the dry season from June to October coincides with the occurrence of significant fires especially located along the tropical belt in Africa and South America. This fire activity is an important source of aerosols in the tropical troposphere and results in smoke plumes transported across long distances toward area generally aerosol-free. The atmospheric composition over the Indian Ocean is often influenced by biomass burning plumes shaped by the synoptic atmospheric circulation with high pressure over southern Africa and the movement of westerly waves that may embedded cut-off lows. The propagation over the Indian Ocean is then dependent on the position of the Mascarene High. The meandering shape of the plumes is then associated with an aerosol atmospheric river (AAR). Such a phenomenon has been sampled by spaceborne lidars and spectro-radiometers, and even observed above La Réunion (21.1°S, 55.3°E) during September 2017 by a ground-based lidar and a sun-photometer. The Li1200, an operational lidar in the frame of the Atmospheric Physics Reunion Observatory (OPAR), recorded the passage of an AAR during two nights. These measurements allow us to derive both the vertical structures of the plume and some vertically resolved aerosol optical properties. This information was used to constrain Lagrangian modelling tools to identify the pathways and origins of the biomass burning plume. These results have been corroborated by the spaceborne observations of CALIOP and CATS, and the passive sensor MODIS. Reanalysis of ECMWF with atmospheric composition outputs from the Copernicus Atmosphere Monitoring Service (CAMS) supports the understanding of the synoptic conditions leading to the formation of this aerosol plume configuration. We will present our scientific approach and discuss the environmental impact of these AARs in the southwest Indian Ocean.
Published: 2022

11. ReNovRisk: a multidisciplinary programme to study the cyclonic risks in the South-West Indian Ocean

Author: Alicia Gonzalez, Sabine Garabedian, Claire Rault, Kevin Samyn, David Nortes-Martinez, Dominique Mekies, Soline Bielli, Guillaume Payen, Gwenaëlle Pennober, Florian Jouvenot, Fabrice R. Fontaine, Christelle Barthe, Joris Pianezze, E. J. Rindraharisaona, Julien Cattiaux, Jean-Lambert Join, Idriss Fontaine, Jean-Pierre Cammas, Pascal Mouquet, Bertrand Aunay, Remi Belon, Fabrice Chauvin, Pierre Tulet, Callum Thompson, François Bonnardot, Franck Gabarrot, Olivier Bousquet, Guilhem Barruol, Hélène Vérèmes, Christophe Révillion, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Météo France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Centre d'Économie et de Management de l'Océan Indien (CEMOI), Université de La Réunion (UR), UMR 228 Espace-Dev, Espace pour le développement, Université de Guyane (UG)-Université des Antilles (UA)-Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Météo-France Direction Interrégionale Sud-Est (DIRSE), Météo-France, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM)-Université de Guyane (UG)-Université des Antilles (UA)
Subjects: Tropical cyclone, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, 010504 meteorology & atmospheric sciences, Climate change, Structural basin, 010502 geochemistry & geophysics, 01 natural sciences, Interdisciplinary programme, Indian ocean, Geography, 13. Climate action, Multidisciplinary approach, Natural hazard, Earth and Planetary Sciences (miscellaneous), Cyclone, 14. Life underwater, Cyclonic hazards, Resilience (network), Indian Ocean, Environmental planning, 0105 earth and related environmental sciences, Water Science and Technology
Abstract: Today, resilience in the face of cyclone risks has become a crucial issue for our societies. With climate change, the risk of strong cyclones occurring is expected to intensify significantly and to impact the way of life in many countries. To meet some of the associated challenges, the interdisciplinary ReNovRisk programme aims to study tropical cyclones and their impacts on the South-West Indian Ocean basin. This article is a presentation of the ReNovRisk programme, which is divided into four areas: study of cyclonic hazards, study of erosion and solid transport processes, study of water transfer and swell impacts on the coast, and studies of socio-economic impacts. The first transdisciplinary results of the programme are presented together with the database, which will be open access from mid-2021.
Published: 2021

12. Aerosol characterization in an oceanic context around Reunion Island (AEROMARINE field campaign)

Author: Raphaël Peroni, Bert Verreyken, Pierre Tulet, Jerome Brioude, Troy Thornberry, Philippe Goloub, Thierry Podvin, Valentin Duflot, Luc Blarel, Faustine Mascaut, Olivier Pujol, Jean Marc Metzger, Karine Sellegri, Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), LEFE-INSU, ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011), Laboratoire de physique de l'atmosphère (LPA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Atmospheric Science, geography, Southern indian Ocean, AEROMARINE field Campaigs, geography.geographical_feature_category, Chemical transport model, Mesoscale meteorology, AEROMARINE field Campaign, Context (language use), Atmospheric sciences, AERONET, Aerosol, Troposphere, [SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, Environmental science, Oceanic basin, Sea salt aerosols, Sea level, Pristine conditions, General Environmental Science
Abstract: International audience; This article presents the results of the AEROMARINE field campaign which took place between February and April 2019 off the coast of Reunion Island in the South West Indian Ocean basin. The Southern Indian Ocean is of major interest for the study of marine aerosols, their distribution and variability. Six instrumented light plane flights and a ground-based microwave radiometer were used during the field campaign. These measurements were compared with the long-term measurements of the AERONET sun-photometer (based in St Denis, Reunion Island) and various instruments of the high altitude Maïdo Observatory (2.2 km above sea level, Reunion Island). These results were also analyzed using different model outputs: (i) the AROME mesoscale weather forecast model to work on the thermodynamics of the boundary layer, (ii) the FLEXPART-AROME Lagrangian particle dispersion model to assess the geographical and vertical origin of air masses, and (iii) the chemical transport model CAMS (Copernicus Atmosphere Monitoring Service) to work on the aerosol chemical composition of air masses. This allowed to highlight two points: (1) the atmospheric layer above 1.5 km is mainly composed of aerosols from the regional background; (2) the local environment (ocean or island) has little impact on the measured concentrations. Marine aerosols emitted locally are mostly measured below 0.5 km. The daytime marine aerosol distributions in the free troposphere measured by the aircraft were compared to the night-time aerosol distributions measured at the high altitude Maïdo Observatory when the Observatory is located in the free troposphere. The results indicate that this high altitude site of measurements is representative of the marine aerosol concentrations in the free troposphere. We also found that the CAMS reanalyses overestimated the aerosol optical depth in this region. Finally, our study strongly suggests that the AERONET station in St Denis (Reunion Island) can be considered as a representative marine station under the Tropics.
Published: 2022

13. Insights into tropical cloud chemistry at Reunion Island (Indian Ocean): results from the BIO-MAÏDO campaign

Author: Martin Leremboure, P. Renard, Jean-Luc Jaffrezo, Agnès Borbon, Muriel Joly, Aurélie Colomb, Anthony Vella, T. Bourianne, Laurent Deguillaume, Mickael Ribeiro, Jean-Marc Metzger, Mickaël Vaitilingom, Stephan Houdier, Valentin Duflot, Pierre Tulet, Jean-Marc Pichon, Manon Rocco, Frédéric Burnet, Jean-Luc Baray, Angelica Bianco, Anne-Marie Delort, Pamela Dominutti, Maud Leriche, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire de Recherche en Géosciences et Energies [UR2_1] (LARGE), Université des Antilles (UA), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Clermont-Ferrand (ICCF), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, UNIVERSITE GRENOBLE ALPES CNRS IRD GRENOBLE INP UMR IGE FRA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre pour l’étude et la simulation du climat à l’échelle régionale (ESCER), Département des sciences de la terre et de l’atmosphère, Université du Québec à Montréal, Laboratoire de Recherche en Géosciences et Energies (LARGE), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: Supersaturation, gas/aqueous phase partitioning, tropical atmosphere, business.industry, Cloud computing, Cloud chemical composition, Vegetation, 15. Life on land, Atmospheric sciences, complex mixtures, dissolved organic carbon, Indian ocean, 13. Climate action, [SDU]Sciences of the Universe [physics], Dissolved organic carbon, [CHIM]Chemical Sciences, business, Scavenging, Chemical composition, air mass influence, Field campaign
Abstract: We present here the results obtained during an intensive field campaign conducted in the framework of the French “BIO-MAÏDO” (Bio-physico-chemistry of tropical clouds at Maïdo (Réunion Island): processes and impacts on secondary organic aerosols’ formation) project. This study integrates an exhaustive chemical and microphysical characterization of cloud water obtained in March–April 2019 at Reunion Island (Indian Ocean). Fourteen cloud samples have been collected along the slope of this mountainous island. A comprehensive chemical characterization of these samples is performed, including inorganic ions, metals, oxidants, and organic matter (organic acids, sugars, amino acids, carbonyls, and low-soluble volatile organic compounds (VOCs)). Cloud water presents high molecular complexity with elevated water-soluble organic matter content partly modulated by microphysical cloud properties. As expected, our findings show the presence of compounds of marine origin in cloud water samples (e.g., chloride, sodium) demonstrating ocean–cloud exchanges. However, the non-sea salt fraction of sulphate varies between 38 and 91 %, indicating the presence of other sources. Also, the presence of amino acids and for the first time in cloud waters of sugars, clearly indicates that biological activities contribute to the cloud water chemical composition. A significant variability between events is observed in the dissolved organic content (25.5 ± 18.4 mgC L−1), with levels reaching up to 62 mgC L−1. This variability was not similar for all the measured compounds, suggesting the presence of dissimilar emission sources or production mechanisms. For that, a statistical analysis is performed based on back-trajectory calculations using the CAT (Computing Atmospheric Trajectory Tool) model associated with land cover registry. These investigations reveal that air mass origins and microphysical variables do not fully explain the variability observed in cloud chemical composition, highlighting the complexity of emission sources, multiphasic transfer, and chemical processing in clouds. Additionally, several VOCs (oxygenated and low-soluble VOCs) were analysed in both gas and aqueous phases. Significant levels of biogenic low-soluble VOCs were detected in the aqueous phase, indicating the cloud-terrestrial vegetation exchange. Cloud scavenging of VOCs is assessed and compared to Henry’s law equilibrium to evaluate potential super or sub saturation conditions. The evaluation reveals the supersaturation of low-soluble VOCs from both natural and anthropogenic sources. Our results depict even higher supersaturation of terpenoids, suggesting their importance in the aqueous phase chemistry in highly impacted tropical areas.
Published: 2021

14. Impact of Tropical Cyclones on Inhabited Areas of the SWIO Basin at Present and Future Horizons. Part 2: Modeling Component of the Research Program RENOVRISK-CYCLONE

Author: Fabrice Chauvin, Olivier Bousquet, Jonas Zucule, Frauke Fleischer-Dogley, Quoc-Phi Duong, Edouard Lees, Romain Husson, Alexis Mouche, Callum Thompson, Emmanuel Cordier, François Bonnardot, Radiance Calmer, Navalona Manitriniana Ravoson, Guilhem Barruol, Vincent Amelie, M. Singh, Julien Cattiaux, Bruno Razafindradina, Nicolas Marquestaut, Sylvie Malardel, Alberto Mavume, Chia-Lun Tsai, Stéphane Ciccione, Dominique Mekies, Soline Bielli, Joris Pianezze, M Claeys, E. J. Rindraharisaona, Christelle Barthe, Lova Zakariasy, Gregory Roberts, Pierre Tulet, Jonathan Durand, Marie-Noëlle Bouin, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Institute for Coastal Marine Research (CMR), Nelson Mandela University, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Center for Atmospheric REmote Sensing (CARE), Kyungpook National University [Daegu], Direction Interrégionale de Météo-Franc pour l'océan Indien, Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Seychelles Meteorological Authority, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, National Snow and Ice Data Center (NSIDC), University of Colorado [Boulder], Kélonia - Observatoire des tortues marines, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Seychelles Islands Foundation (SIF), Collecte Localisation Satellites (CLS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National d'Études Spatiales [Toulouse] (CNES), Eduardo Mondlane University, Institut et Observatoire de Géophysique d’Antisiranana (IOGA), Institut Supérieur de Technologie d’Antisiranana, Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California, Mauritius Oceanography Institute, University of Mauritius, Instituto Nacional de Meteorologia (INAM), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Kyungpook National University [Daegu] (KNU), Direction Interrégionale de Météo-France pour l'océan Indien (DIROI), Météo-France, Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Scripps Institution of Oceanography (SIO - UC San Diego), and University of California (UC)-University of California (UC)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, tropical cyclone, ocean-wave-atmosphere coupling, Climate change, Context (language use), Environmental Science (miscellaneous), 01 natural sciences, Meteorology. Climatology, 14. Life underwater, climate modeling, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, cloud-resolving model, geography.geographical_feature_category, Microphysics, 010505 oceanography, Global warming, ocean–wave–atmosphere coupling, 13. Climate action, Climatology, Archipelago, south-west Indian ocean, Environmental science, Cyclone, Climate model, Tropical cyclone, QC851-999
Abstract: International audience; The ReNovRisk-Cyclone program aimed at developing an observation network in the south-west Indian ocean (SWIO) in close synergy with the implementation of numerical tools to model and analyze the impacts of tropical cyclones (TC) in the present and in a context of climate change. This paper addresses the modeling part of the program. First, a unique coupled system to simulate TCs in the SWIO is developed. The ocean–wave–atmosphere coupling is considered along with a coherent coupling between sea surface state, wind field, aerosol, microphysics, and radiation. This coupled system is illustrated through several simulations of TCs: the impact of air–sea flux parameterizations on the evolution of TC Fantala is examined, the full coupling developed during the program is illustrated on TC Idai, and the potential of novel observations like space-borne synthetic aperture radar and sea turtles to validate the atmosphere and ocean models is presented with TC Herold. Secondly, the evolution of cyclonic activity in the SWIO during the second half of the 21st century is assessed. It was addressed both using climate simulation and through the implementation of a pseudo global warming method in the high-resolution coupled modeling platform. Our results suggest that the Mascarene Archipelago should experience an increase of TC related hazards in the medium term.
Published: 2021

15. Impact of Tropical Cyclones on Inhabited Areas of the SWIO Basin at Present and Future Horizons. Part 1: Overview and Observing Component of the Research Project RENOVRISK-CYCLONE

Author: Joris Pianezze, M Claeys, E. J. Rindraharisaona, Pierre Tulet, Bruno Razafindradina, Guilhem Barruol, Romain Husson, Callum Thompson, François Bonnardot, Chia-Lun Tsai, Frauke Fleischer-Dogley, Christelle Barthe, Lova Zakariasy, M. Singh, Julien Cattiaux, Nicolas Marquestaut, Alberto Mavume, Fabrice Chauvin, Stéphane Ciccione, Jonas Zucule, Dominique Mekies, Gregory Roberts, Jonathan Durand, Olivier Bousquet, Emmanuel Cordier, Edouard Lees, Alexis Mouche, Radiance Calmer, Vincent Amelie, Soline Bielli, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Institute for Coastal Marine Research (CMR), Nelson Mandela University, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), National Snow and Ice Data Center (NSIDC), University of Colorado [Boulder], Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Scripps Institution of Oceanography (SIO - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), Seychelles Meteorological Authority, Seychelles Islands Foundation (SIF), Eduardo Mondlane University, Institut Supérieur de Technologie d’Antisiranana, Direction Interrégionale de Météo-France pour l'océan Indien (DIROI), Météo-France, Mauritius Oceanography Institute, University of Mauritius, Collecte Localisation Satellites (CLS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Kélonia - Observatoire des tortues marines, Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Scripps Institution of Oceanography (SIO), University of California-University of California, Direction Interrégionale de Météo-Franc pour l'océan Indien, and Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, tropical cyclone, gliders, Satellite system, Environmental Science (miscellaneous), Structural basin, sea turtles, 010502 geochemistry & geophysics, 01 natural sciences, seismic data, biologging, Meteorology. Climatology, 14. Life underwater, south-west Indian Ocean, unmanned airborne system, 0105 earth and related environmental sciences, Atmospheric sounding, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, global satellite navigation system, ReNovRisk, austral and cyclonic swells, numerical modelling, climate modelling, Drone, Swell, 13. Climate action, GNSS applications, Cyclone, Environmental science, QC851-999, Tropical cyclone
Abstract: International audience; The international research program “ReNovRisk-CYCLONE” (RNR-CYC, 2017–2021) directly involves 20 partners from 5 countries of the south-west Indian-Ocean. It aims at improving the observation and modelling of tropical cyclones in the south-west Indian Ocean, as well as to foster regional cooperation and improve public policies adapted to present and future tropical cyclones risk in this cyclonic basin. This paper describes the structure and main objectives of this ambitious research project, with emphasis on its observing components, which allowed integrating numbers of innovative atmospheric and oceanic observations (sea-turtle borne and seismic data, unmanned airborne system, ocean gliders), as well as combining standard and original methods (radiosoundings and global navigation satellite system (GNSS) atmospheric soundings, seismic and in-situ swell sampling, drone and satellite imaging) to support research on tropical cyclones from the local to the basin-scale.
Published: 2021

16. Investigation of several proxies to estimate sulfuric acid concentration under volcanic plume conditions

Author: C. Rose, M. P. Rissanen, S. Iyer, J. Duplissy, C. Yan, J. B. Nowak, A. Colomb, R. Dupuy, X.-C. He, J. Lampilahti, Y. J. Tham, D. Wimmer, J.-M. Metzger, P. Tulet, J. Brioude, C. Planche, M. Kulmala, K. Sellegri, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institute for Atmospheric and Earth System Research (INAR), University of Helsinki, University of Tampere [Finland], Helsinki Institute of Physics (HIP), NASA Langley Research Center [Hampton] (LaRC), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, INAR Physics, Helsinki Institute of Physics, Polar and arctic atmospheric research (PANDA), Tampere University, Physics, Helsingin yliopisto = Helsingfors universitet = University of Helsinki, and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France
Subjects: Atmospheric Science, Daytime, 010504 meteorology & atmospheric sciences, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Atmospheric sciences, 114 Physical sciences, 01 natural sciences, Proxy (climate), lcsh:Chemistry, 03 medical and health sciences, chemistry.chemical_compound, Mixing ratio, Relative humidity, Sulfur dioxide, 030304 developmental biology, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 0303 health sciences, geography, geography.geographical_feature_category, Vulcanian eruption, lcsh:QC1-999, Plume, lcsh:QD1-999, Volcano, chemistry, 13. Climate action, Environmental science, lcsh:Physics
Abstract: Sulfuric acid (H2SO4) is commonly accepted as a key precursor for atmospheric new particle formation (NPF). However, direct measurements of [H2SO4] remain challenging, thereby preventing the determination of this important quantity, and, consequently, a complete understanding of its contribution to the NPF process. Several proxies have been developed to bridge the gaps, but their ability to predict [H2SO4] under very specific conditions, such as those encountered in volcanic plumes (including, in particular, high sulfur dioxide mixing ratios), has not been evaluated so far. In this context, the main objective of the present study was to develop new proxies for daytime [H2SO4] under volcanic plume conditions and compare their performance to that of the proxies available in the literature. Specifically, the data collected at Maïdo during the OCTAVE (Oxygenated organic Compounds in the Tropical Atmosphere: variability and atmosphere–biosphere Exchanges) 2018 campaign, in the volcanic eruption plume of the Piton de la Fournaise, were first used to derive seven proxies based on knowledge of the sulfur dioxide (SO2) mixing ratio, global radiation, condensation sink (CS) and relative humidity (RH). A specific combination of some or all of these variables was tested in each of the seven proxies. In three of them (F1–F3), all considered variables were given equal weight in the prediction of [H2SO4], whereas adjusted powers were allowed (and determined during the fitting procedure) for the different variables in the other four proxies (A1–A4). Overall, proxies A1–A4 were found to perform better than proxies F1–F3, with, in particular, improved predictive ability for [H2SO4] > 2 × 108 cm−3. The CS was observed to play an important role in regulating [H2SO4], whereas the inclusion of RH did not improve the predictions. A last expression accounting for an additional sink term related to cluster formation, S1, was also tested and showed a very good predictive ability over the whole range of measured [H2SO4]. In a second step, the newly developed proxies were further evaluated using airborne measurements performed in the passive degassing plume of Etna during the STRAP (Synergie Transdisciplinaire pour Répondre aux Aléas liés aux Panaches volcaniques) 2016 campaign. Increased correlations between observed and predicted [H2SO4] were obtained when the dependence of predicted [H2SO4] on the CS was the lowest and when the dependence on [SO2] was concurrently the highest. The best predictions were finally retrieved by the simple formulation of F2 (in which [SO2] and radiation alone were assumed to explain the variations in [H2SO4] with equal contributions), with a pre-factor adapted to the STRAP data. All in all, our results illustrate the fairly good capacity of the proxies available in the literature to describe [H2SO4] under volcanic plume conditions, but they concurrently highlight the benefit of the newly developed proxies for the prediction of the highest concentrations ([H2SO4] > 2–3 × 108 cm−3). Moreover, the contrasting behaviours of the new proxies in the two investigated datasets indicate that in volcanic plumes, like in other environments, the relevance of a proxy can be affected by changes in environmental conditions and that location-specific coefficients do logically improve the predictions.
Published: 2021

17. Validation of the TROPOspheric Monitoring Instrument (TROPOMI) surface UV radiation product

Author: K. Lakkala, J. Kujanpää, C. Brogniez, N. Henriot, A. Arola, M. Aun, F. Auriol, A. F. Bais, G. Bernhard, V. De Bock, M. Catalfamo, C. Deroo, H. Diémoz, L. Egli, J.-B. Forestier, I. Fountoulakis, K. Garane, R. D. Garcia, J. Gröbner, S. Hassinen, A. Heikkilä, S. Henderson, G. Hülsen, B. Johnsen, N. Kalakoski, A. Karanikolas, T. Karppinen, K. Lamy, S. F. León-Luis, A. V. Lindfors, J.-M. Metzger, F. Minvielle, H. B. Muskatel, T. Portafaix, A. Redondas, R. Sanchez, A. M. Siani, T. Svendby, J. Tamminen, Space and Earth Observation Centre [Sodankylä], Finnish Meteorological Institute (FMI), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Aristotle University of Thessaloniki, Biospherical Instruments Inc., Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute (IRM), Aosta Valley Regional Environmental Protection Agency (ARPA), CNR Institute of Atmospheric Sciences and Climate (ISAC), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Physical-Meteorological Observatory/World Radiation Center, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Atmospheric Optics Group of the University of Valladolid (GOA-UVA), Universidad de Valladolid [Valladolid] (UVa), Australian Radiation Protection and Nuclear Safety Agency, Norwegian Radiation and Nuclear Safety Authority, Izaña Atmospheric Research Center (IARC), Agencia Estatal de Meteorología (AEMet), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Israel Meteorological Service, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Norwegian Institute for Air Research (NILU), The UV-Indien programme has been supported by the European Union through the PO INTERREG V, by the Reunion Island Council and by the French Government. The OPAR station (Observatoire de Physique de l’Atmosphèrede La Réunion) and the OSUR activities are funded by the Université de LaRéunion and CNRS. Measurements of French spectroradiometers are supported by CNES (within the French programme TOSCA), the Région Hauts-de-France and the Ministère de l’Enseignement Supérieur et de la Recherche (CPER Climibio), and the European Fund for Regional Economic Development. GUV measurements at Blindern, Ny-Ålesund and Andøya are funded by the Norwegian Environment Agency. Kaisa Lakkala is supported by the CHAMPS project (grant no. 329225) of the Academy of Finland under the CLIHE programme., Institut Royal Météorologique de Belgique [Bruxelles] (IRM), Consiglio Nazionale delle Ricerche (CNR), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, and Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome]
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Brewer spectrophotometers, QUALITY-ASSURANCE, Irradiance, GROUND-BASED MEASUREMENTS, SOLAR ULTRAVIOLET IRRADIANCE, TOTAL OZONE, SATELLITE ESTIMATION, SPECTRAL IRRADIANCE, THESSALONIKI, TRACEABILITY, SODANKYLA, COLUMN, Atmospheric sciences, 01 natural sciences, UV radiation, Latitude, 010309 optics, Troposphere, Atmosphere, 0103 physical sciences, Nadir, Ozone column, lcsh:TA170-171, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:TA715-787, lcsh:Earthwork. Foundations, Albedo, Snow, lcsh:Environmental engineering, 13. Climate action, Tropospheric Monitoring Instrument, Satellite
Abstract: The TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor (S5P) satellite was launched on 13 October 2017 to provide the atmospheric composition for atmosphere and climate research. The S5P is a Sun-synchronous polar-orbiting satellite providing global daily coverage. The TROPOMI swath is 2600 km wide, and the ground resolution for most data products is 7.2×3.5 km2 (5.6×3.5 km2 since 6 August 2019) at nadir. The Finnish Meteorological Institute (FMI) is responsible for the development of the TROPOMI UV algorithm and the processing of the TROPOMI surface ultraviolet (UV) radiation product which includes 36 UV parameters in total. Ground-based data from 25 sites located in arctic, subarctic, temperate, equatorial and Antarctic areas were used for validation of the TROPOMI overpass irradiance at 305, 310, 324 and 380 nm, overpass erythemally weighted dose rate/UV index, and erythemally weighted daily dose for the period from 1 January 2018 to 31 August 2019. The validation results showed that for most sites 60 %–80 % of TROPOMI data was within ±20 % of ground-based data for snow-free surface conditions. The median relative differences to ground-based measurements of TROPOMI snow-free surface daily doses were within ±10 % and ±5 % at two-thirds and at half of the sites, respectively. At several sites more than 90 % of cloud-free TROPOMI data was within ±20 % of ground-based measurements. Generally median relative differences between TROPOMI data and ground-based measurements were a little biased towards negative values (i.e. satellite data < ground-based measurement), but at high latitudes where non-homogeneous topography and albedo or snow conditions occurred, the negative bias was exceptionally high: from −30 % to −65 %. Positive biases of 10 %–15 % were also found for mountainous sites due to challenging topography. The TROPOMI surface UV radiation product includes quality flags to detect increased uncertainties in the data due to heterogeneous surface albedo and rough terrain, which can be used to filter the data retrieved under challenging conditions.
Published: 2020

18. Solar UV Radiation in the Tropics: Human Exposure at Reunion Island (21° S, 55° E) during Summer Outdoor Activities

Author: Cadet, Jean-Maurice, Bencherif, Hassan, Cadet, Nicolas, Lamy, Kévin, Portafaix, Thierry, Belus, Matthias, Brogniez, Colette, Auriol, Frédérique, Metzger, Jean-Marc, Wright, Caradee, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, University of KwaZulu-Natal (UKZN), Université de La Réunion - Faculté de Lettres et Sciences humaines (UR FLSH), Université de La Réunion (UR), Conseil Régional de La Réunion, Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Medical Research Council [South African], This research was funded jointly by the CNRS (Centre National de la Recherche Scientifique) and the NRF (National Research Foundation) in the framework of the IRP ARSAIO and by the South Africa/France PROTEA Program (project No 42470VA). CYW receives funding from the South African Medical Research Council and the National Research Foundation. This research is also part of the activities of the UV-Indien program, which funded some of the materials used in this study. UV-Indien Network is funded jointly by European cooperation programme PO InterregV and Regional Council of Reunion Island., Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Ultraviolet Rays, solar UV radiation, lcsh:R, mountain, hike, lcsh:Medicine, Environmental Exposure, human health, Article, tropics, UV exposure, volcano, Solar Energy, Sunlight, Humans, Recreation, beach, Seasons, Reunion
Abstract: Reunion Island is a popular tourist destination with sandy beaches, an active volcano (Piton de la Fournaise), and Piton des Neiges, the highest and most dominant geological feature on the island. Reunion is known to have high levels of solar ultraviolet radiation (UVR) with an ultraviolet index (UVI) which can reach 8 in winter and 16 in summer (climatological conditions). UVR has been linked to skin cancer, melanoma, and eye disease such as cataracts. The World Health Organization (WHO) devised the UVI as a tool for expressing UVR intensity. Thresholds ranging from low (UVI 1&ndash, 2) to extreme (UVI &gt, 11) were defined depending on the risk to human health. The purpose of the study was to assess UVR exposure levels over three of the busiest tourist sites on the island. UVR was measured over several hours along popular hiking trails around Piton de la Fournaise (PDF), Piton des Neiges (PDN), and St-Leu Beach (LEU). The results were compared with those recorded by the local UV station at Saint-Denis. In addition, cumulative standard erythemal dose (SED) was calculated. Results showed that UVI exposure at PDF, PDN, and LEU were extreme (&gt, 11) and reached maximum UVI levels of 21.1, 22.5, and 14.5, respectively. Cumulative SEDs were multiple times higher than the thresholds established by the Fitzpatrick skin phototype classification. UVI measurements at the three study sites showed that Reunion Island is exposed to extreme UVR conditions. Public awareness campaigns are needed to inform the population of the health risks related to UVR exposure.
Published: 2020
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19. Mesoscale simulations of tropical cyclone Enawo (March 2017) and its impact on TTL water vapor

Author: Stephanie Evan, Karen H. Rosenlof, Thibaut Dauhut, Christelle Barthe, Damien Héron, Joris Pianezze, Jerome Brioude, Vincent Noel, Jean-Pierre Cammas, Soline Bielli, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Mercator Océan, Société Civile CNRS Ifremer IRD Météo-France SHOM, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, National Oceanic and Atmospheric Administration (NOAA), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Troposphere, Convection, 13. Climate action, Mixing ratio, Mesoscale meteorology, Environmental science, Tropical cyclone, Tropopause, Atmospheric sciences, Stratosphere, Water vapor
Abstract: In early March 2017, tropical cyclone (TC) Enawo formed north of Réunion Island and moved westward toward Madagascar. Enawo evolved from a tropical depression on 2 March to an intense TC on 6 March. This study explores the water vapor transport into the tropical tropopause layer (TTL) throughout TC Enawo's development. High-resolution (2 km) mesoscale simulations using the Meso-NH model were performed to cover TC Enawo's lifecycle over the ocean for the period 2–7 March 2017. The simulated convective cloud field agrees with geostationary satellite infrared observations. Compared to the Global Precipitation Measurements (GPM) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite observations, the simulation seems to reproduce well both location and amplitude of the observed precipitation. Simulated and observed ice water content have similar ranges in the upper troposphere but simulated ice above the tropopause is overestimated by a factor 10. Balloon-borne measurements of water vapor, temperature and horizontal winds are also used to validate the Meso-NH simulations in the upper-troposphere and TTL regions. The simulations reveal that the maximum water vapor transport into the TTL occurred on 4 March, when deep (cold) convective clouds were observed. As a result, the lower stratospheric water vapor is increased by ~50 % when compared to pre-storm conditions. An increase of ~2 ppmv in water vapor mixing ratio was simulated in the lower stratosphere within a 700-km region surrounding Enawo's center. Our simulation of TC Enawo suggests that TCs over the Southwest Indian Ocean (0–30° S, 30–90° E) could produce a moistening of 0.4 ppmv. We extended our results to the global tropics (30° S–30° N) using the estimates from published work (Allison et al., 2018; Preston et al., 2019) and by calculating statistics on TC numbers and durations using the International Best Track Archive for Climate Stewardship (IBTrACS) dataset. We estimated a global impact of TC induced tropical lower stratospheric moistening of 0.3 to 0.5 ppmv. Our results suggest that TCs may play an important role in the moistening of the TTL/lower stratosphere via direct injection of ice particles and subsequent sublimation.; In early March 2017, tropical cyclone (TC) Enawo formed north of Réunion Island and moved westward toward Madagascar. Enawo evolved from a tropical depression on 2 March to an intense TC on 6 March. 15 This study explores the water vapor transport into the tropical tropopause layer (TTL) throughout TC Enawo's development. High-resolution (2km) mesoscale simulations using the Meso-NH model were performed to cover TC Enawo's lifecycle over the ocean for the period 2-7 March 2017. The simulated convective cloud field agrees with geostationary satellite infrared observations. Compared to the Global Precipitation Measurements (GPM) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite observations, the 20 simulation seems to reproduce well both location and amplitude of the observed precipitation. Simulated and observed ice water content have similar ranges in the upper troposphere but simulated ice above the tropopause is overestimated by a factor 10. Balloon-borne measurements of water vapor, temperature and horizontal winds are also used to validate the Meso-NH simulations in the upper-troposphere and TTL regions. The simulations reveal that the maximum water vapor transport into the TTL occurred on 4 March, when deep (cold) convective 25 clouds were observed. As a result, the lower stratospheric water vapor is increased by ~50% when compared to pre-storm conditions. An increase of ~2ppmv in water vapor mixing ratio was simulated in the lower stratosphere within a 700-km region surrounding Enawo's center. Our simulation of TC Enawo suggests that TCs over the Southwest Indian Ocean (0-30°S, 30-90°E) could produce a moistening of 0.4 ppmv. We extended our results to the global tropics (30°S-30°N) using the estimates from published work (Allison et al., 2018; Preston et al., 2019) 30 and by calculating statistics on TC numbers and durations using the International Best Track Archive for Climate Stewardship (IBTrACS) dataset. We estimated a global impact of TC induced tropical lower stratospheric moistening of 0.3 to 0.5 ppmv. Our results suggest that TCs may play an important role in the moistening of the TTL/lower stratosphere via direct injection of ice particles and subsequent sublimation.
Published: 2020

20. A global analysis of climate-relevant aerosol properties retrieved from the network of Global Atmosphere Watch (GAW) near-surface observatories

Author: P. Laj, A. Bigi, C. Rose, E. Andrews, C. Lund Myhre, M. Collaud Coen, Y. Lin, A. Wiedensohler, M. Schulz, J. A. Ogren, M. Fiebig, J. Gliß, A. Mortier, M. Pandolfi, T. Petäja, S.-W. Kim, W. Aas, J.-P. Putaud, O. Mayol-Bracero, M. Keywood, L. Labrador, P. Aalto, E. Ahlberg, L. Alados Arboledas, A. Alastuey, M. Andrade, B. Artíñano, S. Ausmeel, T. Arsov, E. Asmi, J. Backman, U. Baltensperger, S. Bastian, O. Bath, J. P. Beukes, B. T. Brem, N. Bukowiecki, S. Conil, C. Couret, D. Day, W. Dayantolis, A. Degorska, K. Eleftheriadis, P. Fetfatzis, O. Favez, H. Flentje, M. I. Gini, A. Gregorič, M. Gysel-Beer, A. G. Hallar, J. Hand, A. Hoffer, C. Hueglin, R. K. Hooda, A. Hyvärinen, I. Kalapov, N. Kalivitis, A. Kasper-Giebl, J. E. Kim, G. Kouvarakis, I. Kranjc, R. Krejci, M. Kulmala, C. Labuschagne, H.-J. Lee, H. Lihavainen, N.-H. Lin, G. Löschau, K. Luoma, A. Marinoni, S. Martins Dos Santos, F. Meinhardt, M. Merkel, J.-M. Metzger, N. Mihalopoulos, N. A. Nguyen, J. Ondracek, N. Pérez, M. R. Perrone, J.-E. Petit, D. Picard, J.-M. Pichon, V. Pont, N. Prats, A. Prenni, F. Reisen, S. Romano, K. Sellegri, S. Sharma, G. Schauer, P. Sheridan, J. P. Sherman, M. Schütze, A. Schwerin, R. Sohmer, M. Sorribas, M. Steinbacher, J. Sun, G. Titos, B. Toczko, T. Tuch, P. Tulet, P. Tunved, V. Vakkari, F. Velarde, P. Velasquez, P. Villani, S. Vratolis, S.-H. Wang, K. Weinhold, R. Weller, M. Yela, J. Yus-Diez, V. Zdimal, P. Zieger, N. Zikova, INAR Physics, Institute for Atmospheric and Earth System Research (INAR), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Università degli Studi di Modena e Reggio Emilia = University of Modena and Reggio Emilia (UNIMORE), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Norwegian Institute for Air Research (NILU), Federal Office of Meteorology and Climatology MeteoSwiss, Leibniz Institute for Tropospheric Research (TROPOS), Norwegian Meteorological Institute [Oslo] (MET), Institute of Environmental Assessment and Water Research (IDAEA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), School of Earth and Environmental Sciences [Seoul] (SEES), Seoul National University [Seoul] (SNU), JRC Institute for Environment and Sustainability (IES), European Commission - Joint Research Centre [Ispra] (JRC), Universidad Mayor de San Andrés (UMSA), Centro de Investigaciones Energéticas Medioambientales y Tecnológicas [Madrid] (CIEMAT), Finnish Meteorological Institute (FMI), Paul Scherrer Institute (PSI), Laboratory of Atmospheric Chemistry [Paul Scherrer Institute] (LAC), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), Iinstitute of Environmental Protection - National Research Institute (IOS-PIB), Environmental Radioactivity laboratory (ERL), Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research 'Demokritos' (NCSR)-National Center for Scientific Research 'Demokritos' (NCSR), National Centre for Scientific Research Demokritos, Institut National de l'Environnement Industriel et des Risques (INERIS), Deutscher Wetterdienst [Offenbach] (DWD), Department of Computer Science and Engineering [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Swiss Federal Laboratories for Materials Science and Technology [Dübendorf] (EMPA), Arctic Space Centre [Helsinki], Bulgarian Academy of Sciences (BAS), University of Crete [Heraklion] (UOC), Institute for Chemical Technologies and Analytics, Vienna University of Technology (TU Wien), Environmental Chemical Processes Laboratory [Heraklion] (ECPL), Department of Chemistry [Heraklion], University of Crete [Heraklion] (UOC)-University of Crete [Heraklion] (UOC), Department of Environmental Science and Analytical Chemistry [Stockholm] (ACES), Stockholm University, South African Weather Service (SAWS), Department of Medicine [New York], Icahn School of Medicine at Mount Sinai [New York] (MSSM), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens (NOA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Chimie Atmosphérique Expérimentale (CAE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), NERC National Centre for Earth Observation (NCEO), Natural Environment Research Council (NERC), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Institute for Applied Environmental Research [Stockholm], Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Instituto Nacional de Técnica Aeroespacial (INTA), European Project: 654109,H2020,H2020-INFRAIA-2014-2015,ACTRIS-2(2015), 10092390 - Beukes, Johan Paul, European Commission, Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), CNR - National Research Council of Italy, University of Helsinki, Università degli Studi di Modena e Reggio Emilia, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Laj, P., Bigi, A., Rose, C., Andrews, E., Lund Myhre, C., Collaud Coen, M., Lin, Y., Wiedensohler, A., Schulz, M., A. Ogren, J., Fiebig, M., Gliss, J., Mortier, A., Pandolfi, M., Petaja, T., Kim, S. -W., Aas, W., Putaud, J. -P., Mayol-Bracero, O., Keywood, M., Labrador, L., Aalto, P., Ahlberg, E., Alados Arboledas, L., Alastuey, A., Andrade, M., Artinano, B., Ausmeel, S., Arsov, T., Asmi, E., Backman, J., Baltensperger, U., Bastian, S., Bath, O., Paul Beukes, J., T. Brem, B., Bukowiecki, N., Conil, S., Couret, C., Day, D., Dayantolis, W., Degorska, A., Eleftheriadis, K., Fetfatzis, P., Favez, O., Flentje, H., I. Gini, M., Gregoric, A., Gysel-Beer, M., Gannet Hallar, A., Hand, J., Hoffer, A., Hueglin, C., K. Hooda, R., Hyvarinen, A., Kalapov, I., Kalivitis, N., Kasper-Giebl, A., Eun Kim, J., Kouvarakis, G., Kranjc, I., Krejci, R., Kulmala, M., Labuschagne, C., Lee, H. -J., Lihavainen, H., Lin, N. -H., Loschau, G., Luoma, K., Marinoni, A., Martins Dos Santos, S., Meinhardt, F., Merkel, M., Metzger, J. -M., Mihalopoulos, N., Anh Nguyen, N., Ondracek, J., Perez, N., Rita Perrone, M., Pichon, J. -M., Picard, D., Pont, V., Prats, N., Prenni, A., Reisen, F., Romano, S., Sellegri, K., Sharma, S., Schauer, G., Sheridan, P., Patrick Sherman, J., Schutze, M., Schwerin, A., Sohmer, R., Sorribas, M., Steinbacher, M., Sun, J., Titos, G., Toczko, B., Tuch, T., Tulet, P., Tunved, P., Vakkari, V., Velarde, F., Velasquez, P., Villani, P., Vratolis, S., Wang, S. -H., Weinhold, K., Weller, R., Yela, M., Yus-Diez, J., Zdimal, V., Zieger, P., and Zikova, N.
Subjects: Earth's energy budget, 1171 Geosciences, Atmospheric Science, Eearth radiation balance, PARTICLE NUMBER, 010504 meteorology & atmospheric sciences, Particle number, Meteorology, VISIBLE-LIGHT ABSORPTION, 010501 environmental sciences, 01 natural sciences, Atmosphere, PARTICULATE MATTER, Solar radiation, Cloud condensation nuclei, lcsh:TA170-171, ORGANIC AEROSOL, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], SIZE DISTRIBUTIONS, lcsh:TA715-787, Global Atmosphere Watch, REGIONAL BACKGROUND SITES, lcsh:Earthwork. Foundations, Aerosol particles, OPTICAL-PROPERTIES, Albedo, Particulates, RADIATIVE PROPERTIES, Aerosol, lcsh:Environmental engineering, 13. Climate action, Greenhouse gas, FILTER-BASED MEASUREMENTS, BLACK CARBON, Environmental science, Trollobservatoriet, Global Climate Monitoring System
Abstract: Aerosol particles are essential constituents of the Earth’s atmosphere, impacting the earth radiation balance directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei. In contrast to most greenhouse gases, aerosol particles have short atmospheric residence times, resulting in a highly heterogeneous distribution in space and time. There is a clear need to document this variability at regional scale through observations involving, in particular, the in situ near-surface segment of the atmospheric observation system. This paper will provide the widest effort so far to document variability of climate-relevant in situ aerosol properties (namely wavelength dependent particle light scattering and absorption coefficients, particle number concentration and particle number size distribution) from all sites connected to the Global Atmosphere Watch network. High-quality data from almost 90 stations worldwide have been collected and controlled for quality and are reported for a reference year in 2017, providing a very extended and robust view of the variability of these variables worldwide. The range of variability observed worldwide for light scattering and absorption coefficients, single-scattering albedo, and particle number concentration are presented together with preliminary information on their long-term trends and comparison with model simulation for the different stations. The scope of the present paper is also to provide the necessary suite of information, including data provision procedures, quality control and analysis, data policy, and usage of the ground-based aerosol measurement network. It delivers to users of the World Data Centre on Aerosol, the required confidence in data products in the form of a fully characterized value chain, including uncertainty estimation and requirements for contributing to the global climate monitoring system., European Commission Joint Research Centre 654109, European ERDF funds through different Spanish R&D projects of the Spanish Ministerio de Economia, Industria y Competitividad, NorthWest University, University of Helsinki, Academy of Finland 272041, Academy of Finland project Greenhouse gas 269095 296302, Korea Meteorological Administration Research and Development Program "Development of Monitoring and Analysis Techniques for Atmospheric Composition in Korea KMA2018-00522, National Research Foundation of Korea 2017R1D1A1B06032548, Korea Meteorological Administration Research and Development Program KMI2018-01111, Taiwan Environmental Protection Administration, Ministry of Research, France, French Ministry of the Environment, United States Environmental Protection Agency, MeteoSwiss (GAW-CH aerosol monitoring programme), Swiss State Secretariat for Education, Research and Innovation (SERI), Ministry of Education, Youth and Sports of CR within National Sustainability Program I (NPU I) LO1415, ERDF "ACTRISCZ RI" CZ.02.1.01/0.0/0.0/16_013/0001315 CGL2017-85344-R MINECO/AEI/FEDER, TIGAS-CM (Madrid Regional Government) Y2018/EMT-5177, AIRTECCM (Madrid Regional Government) P2018/EMT4329 REDMAAS2020 RED2018-102594-T CIENCIA, Spanish Ministry of Economy, Industry and Competitiveness, European Union (EU) CGL2016-78594-R, Generalitat de Catalunya AGAUR 2017 SGR41, National Institute for Aerospace Technology, Ministerio Espanol de Economia, Industria y Competitividad (MINECO) MIS 5021516, Competitiveness, Entrepreneurship and Innovation, NSRF, Ministry of Education, Universities and Research (MIUR), Norwegian Environment Agency, Swedish FORMAS; Swedish Research Council (VR), Magnus Bergvall foundation, Marta och Erik Holmberg foundation, Swedish EPA
Published: 2020

21. Cézeaux-Aulnat-Opme-Puy De Dôme: a multi-site for the long-term survey of the tropospheric composition and climate change

Author: J.-L. Baray, L. Deguillaume, A. Colomb, K. Sellegri, E. Freney, C. Rose, J. Van Baelen, J.-M. Pichon, D. Picard, P. Fréville, L. Bouvier, M. Ribeiro, P. Amato, S. Banson, A. Bianco, A. Borbon, L. Bourcier, Y. Bras, M. Brigante, P. Cacault, A. Chauvigné, T. Charbouillot, N. Chaumerliac, A.-M. Delort, M. Delmotte, R. Dupuy, A. Farah, G. Febvre, A. Flossmann, C. Gourbeyre, C. Hervier, M. Hervo, N. Huret, M. Joly, V. Kazan, M. Lopez, G. Mailhot, A. Marinoni, O. Masson, N. Montoux, M. Parazols, F. Peyrin, Y. Pointin, M. Ramonet, M. Rocco, M. Sancelme, S. Sauvage, M. Schmidt, E. Tison, M. Vaïtilingom, P. Villani, M. Wang, C. Yver-Kwok, P. Laj, Laboratoire de physique de l'atmosphère (LPA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), Institut de Chimie de Clermont-Ferrand (ICCF), SIGMA Clermont (SIGMA Clermont)-Institut de Chimie du CNRS (INC)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), ICOS-RAMCES (ICOS-RAMCES), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), MeteoSwiss, Federal Office of Meteorology and Climatology MeteoSwiss, CNR Institute of Atmospheric Sciences and Climate (ISAC), Consiglio Nazionale delle Ricerche (CNR), Laboratoire d'étude et d'expertise sur la radioactivité de l'environnement [Saint-Paul-Lez-Durance] (PSE-ENV/SEREN/LEREN), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, École des Mines de Douai (Mines Douai EMD), Institut Mines-Télécom [Paris] (IMT), Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Lille Douai), ICOS-ATC (ICOS-ATC), Institut des Géosciences de l’Environnement (IGE), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Laboratoire d'étude et d'expertise sur la radioactivité de l'environnement (IRSN/PSE-ENV/SEREN/LEREN), Service d'expertise et d'étude en radioprotection des populations et de la radioactivité dans l'environnement (IRSN/PSE-ENV/SEREN), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: Atmospheric Science, Ice cloud, 010504 meteorology & atmospheric sciences, lcsh:TA715-787, lcsh:Earthwork. Foundations, Climate change, Orography, Context (language use), 010501 environmental sciences, Atmospheric sciences, 7. Clean energy, 01 natural sciences, Trace gas, Aerosol, lcsh:Environmental engineering, Troposphere, Altitude, 13. Climate action, [SDU]Sciences of the Universe [physics], Environmental science, [CHIM]Chemical Sciences, lcsh:TA170-171, 0105 earth and related environmental sciences
Abstract: For the last 25 years, CO-PDD (Cézeaux-Aulnat-Opme-puy de Dôme) has evolved to become a full instrumented platform for atmospheric research. It has received credentials as a national observing platform in France and is internationally recognized as a global station in the GAW (Global Atmosphere Watch) network. It is a reference site of European and national research infrastructures ACTRIS (Aerosol Cloud and Trace gases Research Infrastructure) and ICOS (Integrated Carbon Observing System). The site located on top of the puy de Dôme mountain (1465 m a.s.l.) is completed by additional sites located at lower altitudes and adding the vertical dimension to the atmospheric observations: Opme (660 m a.s.l.), Cézeaux (410 m), and Aulnat (330 m). The integration of different sites offers a unique combination of in situ and remote sensing measurements capturing and documenting the variability of particulate and gaseous atmospheric composition, but also the optical, biochemical, and physical properties of aerosol particles, clouds, and precipitations. Given its location far away from any major emission sources, its altitude, and the mountain orography, the puy de Dôme station is ideally located to sample different air masses in the boundary layer or in the free troposphere depending on time of day and seasons. It is also an ideal place to study cloud properties with frequent presence of clouds at the top in fall and winter. As a result of the natural conditions prevailing at the site and of the very exhaustive instrumental deployment, scientific studies at the puy de Dôme strongly contribute to improving knowledge in atmospheric sciences, including the characterization of trends and variability, the understanding of complex and interconnected processes (microphysical, chemical, biological, chemical and dynamical), and the provision of reference information for climate/chemistry models. In this context, CO-PDD is a pilot site to conduct instrumental development inside its wind tunnel for testing liquid and ice cloud probes in natural conditions, or in situ systems to collect aerosol and cloud. This paper reviews 25 years (1995–2020) of atmospheric observation at the station and related scientific research contributing to atmospheric and climate science.
Published: 2020

22. Inter-Comparison Campaign of Solar UVR Instruments under Clear Sky Conditions at Reunion Island (21 • S, 55 • E)

Author: Cadet, Jean-Maurice, Portafaix, Thierry, Bencherif, Hassan, Lamy, Kévin, Brogniez, Colette, Auriol, Frédérique, Metzger, Jean-Marc, BOUDREAULT, Louis-Etienne, Wright, Caradee Yael, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), ReuniWatt, University of Pretoria [South Africa], Medical Research Council [South African], Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, University of KwaZulu-Natal (UKZN), and Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, UV instruments, solar ultraviolet radiation, clear sky, UV index, La Réunion
Abstract: International audience; Measurement of solar ultraviolet radiation (UVR) is important for the assessment of potential beneficial and adverse impacts on the biosphere, plants, animals, and humans. Excess solar UVR exposure in humans is associated with skin carcinogenesis and immunosuppression. Several factors influence solar UVR at the Earth's surface, such as latitude and cloud cover. Given the potential risks from solar UVR there is a need to measure solar UVR at different locations using effective instrumentation. Various instruments are available to measure solar UVR, but some are expensive and others are not portable, both restrictive variables for exposure assessments. Here, we compared solar UVR sensors commercialized at low or moderate cost to assess their performance and quality of measurements against a high-grade Bentham spectrometer. The inter-comparison campaign took place between March 2018 and February 2019 at Saint-Denis, La Réunion. Instruments evaluated included a Kipp&Zonen UVS-E-T radiometer, a Solar Light UV-Biometer, a SGLux UV-Cosine radiometer, and a Davis radiometer. Cloud fraction was considered using a SkyCamVision all-sky camera and the Tropospheric Ultraviolet Visible radiative transfer model was used to model clear-sky conditions. Overall, there was good reliability between the instruments over time, except for the Davis radiometer, which showed dependence on solar zenith angle. The Solar Light UV-Biometer and the Kipp&Zonen radiometer gave satisfactory results, while the low-cost SGLux radiometer performed better in clear sky conditions. Future studies should investigate temporal drift and stability over time.
Published: 2020

23. Analysis of volatile organic compounds during the OCTAVE campaign: sources and distributions of formaldehyde on Reunion Island

Author: Rocco, Manon, Colomb, Aurélie, Baray, Jean-Luc, Amelynck, Crist, Verreyken, Bert, Borbon, Agnès, Pichon, Jean-Marc, Bouvier, Laetitia, Schoon, Niels, Gros, Valérie, Sarda-Estève, Roland, Tulet, Pierre, Metzger, Jean-Marc, Duflot, Valentin, Guadagno, Christian, Peris, Guillaume, Brioude, Jérôme, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Department of Inorganic and Physical Chemistry [Ghent], Universiteit Gent = Ghent University [Belgium] (UGENT), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Chimie Atmosphérique Expérimentale (CAE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Observatoire réunionnais de l'Air (ORA), This study was supported by the project OCTAVE of the Belgian Research Action through Interdisciplinary 5 Networks (BRAIN-be) research program (2017–2021) through the Belgian Science Policy Office (BELSPO) under the contract number BR/175/A2/OCTAVE., Laboratoire de météorologie physique (LaMP), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Équipe Troposphère, Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB)-Université libre de Bruxelles (ULB), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Université Libre de Bruxelles [Bruxelles] (ULB)-Université Libre de Bruxelles [Bruxelles] (ULB), Universiteit Gent = Ghent University (UGENT), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France
Subjects: volatile organic compounds (VOCs), formaldehyde sources, ISOPRENE EMISSION, COMPOUNDS VOC, BIOGENIC EMISSIONS, ANTHROPOGENIC SOURCES, IN-SITU, [SDE.MCG]Environmental Sciences/Global Changes, lcsh:QC851-999, RATIOS, TROPOSPHERE, factorization (PMF), Chemistry, positive matrix factorization (PMF), positive matrix, [SDE]Environmental Sciences, lcsh:Meteorology. Climatology, MARINE BOUNDARY-LAYER, ATMOSPHERIC CHEMISTRY, ACETALDEHYDE, kinetic chemical equations
Abstract: The Oxygenated Compounds in the Tropical Atmosphere: Variability and Exchanges (OCTAVE) campaign aimed to improve the assessment of the budget and role of oxygenated volatile organic compounds (OVOCs) in tropical regions, and especially over oceans, relying on an integrated approach combining in situ measurements, satellite retrievals, and modeling. As part of OCTAVE, volatile organic compounds (VOCs) were measured using a comprehensive suite of instruments on Reunion Island (21.07° S, 55.38° E) from 7 March to 2 May 2018. VOCs were measured at a receptor site at the Maïdo observatory during the entire campaign and at two source sites: Le Port from 19 to 24 April 2018 (source of anthropogenic emissions) and Bélouve from 25 April to 2 May 2018 (source of biogenic emissions) within a mobile lab. The Maïdo observatory is a remote background site located at an altitude of 2200 m, whereas Bélouve is located in a tropical forest to the east of Maïdo and Le Port is an urban area located northwest of Maïdo. The major objective of this study was to understand the sources and distributions of atmospheric formaldehyde (HCHO) in the Maïdo observatory on Reunion Island. To address this objective, two different approaches were used to quantify and determine the main drivers of HCHO at Maïdo. First, a chemical-kinetics-based (CKB) calculation method was used to determine the sources and sinks (biogenic, anthropogenic/primary, or secondary) of HCHO at the Maïdo site. The CKB method shows that 9% of the formaldehyde formed from biogenic emissions and 89% of HCHO had an unknown source; that is, the sources cannot be explicitly described by this method. Next, a positive matrix factorization (PMF) model was applied to characterize the VOC source contributions at Maïdo. The PMF analysis including VOCs measured at the Maïdo observatory shows that the most robust solution was obtained with five factors: secondary biogenic accounting for 17%, primary anthropogenic/solvents (24%), primary biogenic (14%), primary anthropogenic/combustion (22%), and background (23%). The main contributions to formaldehyde sources as described by the PMF model are secondary biogenic (oxidation of biogenic VOCs with 37%) and background (32%). Some assumptions were necessary concerning the high percentage of unknown HCHO sources of the CKB calculation method such as the biogenic emission factor resulting in large discrepancies between the two methods.
Published: 2020

24. Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the south-west Indian Ocean

Author: Theodore K. Koenig, Nicolas Kumps, Jerome Brioude, Aurélie Colomb, Niels Schoon, Crist Amelynck, Jean Marc Metzger, Trissevgeni Stavrakou, Christopher F Lee, Jean-François Müller, Rainer Volkamer, Bert Verreyken, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Royal Belgian Institute for Space Aeronomy, Universiteit Gent = Ghent University (UGENT), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), University of Colorado [Boulder], This research has been supported by the Belgian Federal Science Policy Office (grant no. BR/175/A2/OCTAVE), the Horizon 2020 (ACTRIS-2, grant no. 654109), and the National Science Foundation, Division of Atmospheric and Geospace Sciences (grant no. AGS-1620530)., Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, and Universiteit Gent = Ghent University [Belgium] (UGENT)
Subjects: FORMIC-ACID, Atmospheric Science, Ozone, DISPERSION MODEL FLEXPART, 010504 meteorology & atmospheric sciences, Formic acid, TRACE GASES, MAX-DOAS, VOLATILE ORGANIC-COMPOUNDS, 010501 environmental sciences, Atmospheric sciences, 01 natural sciences, lcsh:Chemistry, chemistry.chemical_compound, Nitrogen dioxide, Benzene, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, IN-SITU, SEASONAL-VARIATIONS, lcsh:QC1-999, Trace gas, Plume, REUNION ISLAND, chemistry, lcsh:QD1-999, 13. Climate action, Earth and Environmental Sciences, Environmental science, Methanol, REACTION MASS-SPECTROMETRY, ISLAND 21-DEGREES S, lcsh:Physics, Carbon monoxide
Abstract: We present an investigation of biomass burning (BB) plumes originating from Africa and Madagascar based on measurements of a suite of volatile organic compounds (VOCs), carbon monoxide (CO), ozone (O3) and nitrogen dioxide (NO2) obtained during the dry season of 2018 and 2019 at the high-altitude Maïdo observatory (21.1∘ S, 55.4∘ E, 2160 ma.s.l.), located on the remote island of La Réunion in the south-west Indian Ocean (SWIO). Biomass burning plume episodes were identified from increased acetonitrile (CH3CN) mixing ratios. Enhancement ratios (EnRs) – relative to CO – were calculated from in situ measurements for CH3CN, acetone (CH3COCH3), formic acid (HCOOH), acetic acid (CH3COOH), benzene (C6H6), methanol (CH3OH) and O3. We compared the EnRs to emission ratios (ERs) – relative to CO – reported in the literature in order to estimate loss or production of these compounds during transport. For CH3CN and CH3COOH, the calculated EnRs are similar to the ERs. For C6H6 and CH3OH, the EnR is lower than the ER, indicating a net sink of these compounds which was found to be in line with the expected atmospheric lifetime. For CH3COCH3 and HCOOH, the calculated EnRs are larger than the ERs. The discrepancy reaches an order of magnitude for HCOOH (18–34 pptv ppbv−1 compared to 1.8–4.5 pptv ppbv−1). This points to significant secondary production of HCOOH during transport. The Copernicus Atmospheric Monitoring Service (CAMS) global model simulations reproduce the temporal variation of CO mixing ratios well at the observatory but underestimate O3 and NO2 mixing ratios in the plumes by on average 16 ppbv and 60 pptv respectively. This discrepancy between modelled and measured O3 mixing ratios was attributed to (i) large uncertainties in VOC and NOx (NO+NO2) emissions due to BB in CAMS and (ii) misrepresentation of NOx recycling in the model during transport. Finally, transport of pyrogenically emitted CO is calculated with FLEXPART in order to (i) determine the mean plume age during the intrusions at the observatory and (ii) estimate the impact of BB on the pristine marine boundary layer (MBL). By multiplying the excess CO in the MBL with inferred EnRs at the observatory, we calculated the expected impact of BB on CH3CN, CH3COCH3, CH3OH and C6H6 concentrations in the MBL. These excesses constitute increases of ∼20 %–150 % compared to background measurements in the SWIO MBL reported in the literature.
Published: 2020

25. Validation of the Water Vapor Profiles of the Raman Lidar at the Maïdo Observatory (Reunion Island) Calibrated with Global Navigation Satellite System Integrated Water Vapor

Author: Vérèmes, Hélène, Payen, Guillaume, Keckhut, Philippe, Duflot, Valentin, Baray, Jean-Luc, Cammas, Jean-Pierre, Evan, Stéphanie, Posny, Françoise, Körner, Susanne, Bosser, Pierre, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lindenberg Meteorological Observatory - Richard Assmann Observatory (MOL-RAO), Deutscher Wetterdienst [Offenbach] (DWD), Lab-STICC_ENSTAB_CID_PRASYS, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), Institut Mines-Télécom [Paris] (IMT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-Institut Mines-Télécom [Paris] (IMT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), and Institut Mines-Télécom [Paris] (IMT)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], gnss iwv, maïdo observatory, water vapor, reunion island, raman lidar, lcsh:Meteorology. Climatology, lcsh:QC851-999, calibration
Abstract: The Ma&iuml, do high-altitude observatory located in Reunion Island (21 ∘ S, 55.5 ∘ E) is equipped with the Lidar1200, an innovative Raman lidar designed to measure the water vapor mixing ratio in the troposphere and the lower stratosphere, to perform long-term survey and processes studies in the vicinity of the tropopause. The calibration methodology is based on a GNSS (Global Navigation Satellite System) IWV (Integrated Water Vapor) dataset. The lidar water vapor measurements from November 2013 to October 2015 have been calibrated according to this methodology and used to evaluate the performance of the lidar. The 2-year operation shows that the calibration uncertainty using the GNSS technique is in good agreement with the calibration derived using radiosondes. During the MORGANE (Ma&iuml, do ObservatoRy Gaz and Aerosols NDACC Experiment) campaign (Reunion Island, May 2015), CFH (Cryogenic Frost point Hygrometer) radiosonde and Raman lidar profiles are compared and show good agreement up to 22 km asl, no significant biases are detected and mean differences are smaller than 9% up to 22 km asl.
Published: 2019

26. Solar UV Radiation in Saint-Denis, La Réunion and Cape Town, South Africa: 10 years Climatology and Human Exposure Assessment at Altitude

Author: Cadet, Jean-Maurice, Bencherif, Hassan, du Preez, David, Portafaix, Thierry, Sultan-Bichat, Nathalie, Belus, Matthias, Brogniez, Colette, Auriol, Frédérique, Metzger, Jean-Marc, Ncongwane, Katlego, Coetzee, Gerrie, Wright, Caradee, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), University of Pretoria [South Africa], Centre Hospitalier Ouest Réunion, Conseil Régional de La Réunion, Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), South African Weather Service (SAWS), Medical Research Council [South African], Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, University of KwaZulu-Natal (UKZN), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), and Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], South Africa, La Reunion, UV dose, hiking, lcsh:Meteorology. Climatology, ddc:610, lcsh:QC851-999, solar ultraviolet radiation, UV assessment, UV index, altitude
Abstract: Solar ultraviolet radiation (UVR) monitoring is important since it depends on several atmospheric parameters which are associated with climate change and since excess solar UVR exposure and has significant impacts on human health and wellbeing. The objective of this study was to investigate the trends in solar UVR during a decade (2009−2018) in Saint-Denis, Reunion Island (20.9°S, 55.5°E, 85 m ASL) and Cape Town, South Africa (33.97°S, 18.6°E, 42 m ASL). This comparison was done using total daily erythema exposure as derived from UVR sensors continuously at both sites. Climatology over the 10-year period showed extreme UVR exposure for both sites. Slight changes with opposite trends were found, +3.6% at Saint-Denis and −3.7% at Cape Town. However, these two sites often experience extreme weather conditions thereby making the trend evaluation difficult. Human exposure assessment was performed for hiking activities at two popular high-altitude hiking trails on the Maïdo−Grand Bénare (Reunion) and Table Mountain (Cape Town) with a handheld radiometer. Extreme exposure doses of 64 SED and 40 SED (Standard Erythemal Dose, 1 SED = 100 J.m−2) were recorded, respectively. These high exposure doses highlight the importance of raising public awareness on the risk related to excess UVR exposure at tourist sites, especially those at high altitude.
Published: 2019

27. Spatio‐temporal variability of rainfall in a high tropical island: Patterns and large‐scale drivers in Réunion Island

Author: Guillaume Jumaux, François Bonnardot, Anne Réchou, Chloé Pouppeville, Valentin Duflot, Olivier Bousquet, Olivier Flores, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Peuplements végétaux et bioagresseurs en milieu tropical (UMR PVBMT), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université de La Réunion (UR), Météo France [Sainte-Clotilde], Météo France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Overseas Ministry, EROVEG program. Réunion University, Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Météo France, Direction interrégionale de La Réunion,France, Direction Régionale de Météo-France pour l'Océan Indien, Institut de Recherche pour le Développement (IRD)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de La Réunion (UR)-Institut National de la Recherche Agronomique (INRA), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Direction Interrégionale de Météo-France pour l'océan Indien (DIROI), and Météo-France
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Atmospheric Science, 010504 meteorology & atmospheric sciences, Rain gauge, Weather forecasting, Elevation, Geopotential height, Context (language use), Inversion (meteorology), 15. Life on land, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, computer.software_genre, 01 natural sciences, 010305 fluids & plasmas, 13. Climate action, Climatology, 0103 physical sciences, Environmental science, Canonical correlation, Scale (map), computer, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience; Weather forecasting is challenging because of the complex interplay between local conditions and regional atmospheric forcings. In this article, we analyse the relationships between local daily rainfall and large‐scale synoptic patterns in the geographical context of Réunion Island, a high volcanic island in the southwestern Indian Ocean basin. Given the critical role of trade winds on weather conditions at island scale, we analyse those relationships across seasons defined with respect to yearly trade‐wind regimes. The analysis of the distribution of inversion events' elevation and frequency allows us to characterize the trade‐wind inversion layer (TWIL) and identify four seasons with homogeneous distributions. We characterize the spatio‐temporal variability of rainfall measured at island scale by a dense network of rain‐gauges over 37 years and relate it to large‐scale weather regimes identified using geopotential height meteorological data. After seasonal signal removal using Fourier transforms and dimension reduction via Principal Component Analysis, we perform Canonical Correlation Analysis to identify canonical variables relating rainfall and geopotential height patterns at the two different studied spatial scales. We then combine Ascending Hierarchical Classification and partitioning k‐means methods to identify homogeneous large‐scale synoptic conditions within each season. From this information, we build composite maps of geopotential height that characterize weather regimes and further analyse rainfall patterns at island scale in each regime. Elevation and orientation are used as descriptive variables at island scale as they strongly structure the patterns. Overall, four homogeneous seasons were identified based on trade‐wind regimes, within which six large‐scale weather regimes were identified for summer, the most variable season, and four for the others. Finally, rainfall patterns at island scale are described in relation to the highlighted synoptic regimes and local descriptive variables.
Published: 2019

28. Clear-sky ultraviolet radiation modelling using output from the Chemistry Climate Model Initiative

Author: Lamy, K., Portafaix, T., Josse, B., Brogniez, C., Godin-Beekmann, S., Bencherif, H., Revell, L., Akiyoshi, H., Bekki, S., Hegglin, M. I., Jöckel, Patrick, Kirner, O., Liley, B., Marecal, V., Morgenstern, O., Stenke, A., Zeng, G., Abraham, N. L., Archibald, A. T., Butchart, N., Chipperfield, M. P., Di Genova, G., Deushi, M., Dhomse, S. S., Hu, R.-M., Kinnison, D., Kotkamp, M., McKenzie, R., Michou, M., O'Connor, F. M., Oman, L. D., Pitari, G., Plummer, D. A., Pyle, J. A., Rozanov, E., Saint-Martin, D., Sudo, K., Tanaka, T. Y., Visioni, D., Yoshida, K., Laboratoire de l'Atmosphère et des Cyclones (LACy), Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), School of Chemistry and Physics [Durban], University of KwaZulu-Natal (UKZN), Institute for Atmospheric and Climate Science [Zürich] (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), School of Physical Chemical Sciences [Christchurch], University of Canterbury [Christchurch], Bodeker Scientific, National Institute for Environmental Studies (NIES), Department of Meteorology [Reading], University of Reading (UOR), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Steinbuch Centre for Computing [Karlsruhe] (SCC), Karlsruher Institut für Technologie (KIT), National Institute of Water and Atmospheric Research [Wellington] (NIWA), National Centre for Atmospheric Science [Leeds] (NCAS), Natural Environment Research Council (NERC), Department of Chemistry [Cambridge, UK], University of Cambridge [UK] (CAM), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], School of Earth and Environment [Leeds] (SEE), University of Leeds, Department of Physical and Chemical Sciences [L'Aquila] (DSFC), Università degli Studi dell'Aquila (UNIVAQ), Meteorological Research Institute [Tsukuba] (MRI), Japan Meteorological Agency (JMA), National Center for Atmospheric Research [Boulder] (NCAR), NASA Goddard Space Flight Center (GSFC), Environment and Climate Change Canada, Centre for Atmospheric Science [Cambridge, UK], Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), Graduate School of Environmental Studies [Nagoya], Nagoya University, Sibley School of Mechanical and Aerospace Engineering (MAE), Cornell University [New York], Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), Università degli Studi dell'Aquila = University of L'Aquila (UNIVAQ), and Météo France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], EMAC, ozone, Atmospheric physics and chemistry, MESSy, CCMI, Erdsystem-Modellierung, clear-sky, ultraviolot radiation, chemistry-climate modelling
Abstract: We have derived values of the ultraviolet index (UVI) at solar noon using the Tropospheric Ultraviolet Model (TUV) driven by ozone, temperature and aerosol fields from climate simulations of the first phase of the Chemistry-Climate Model Initiative (CCMI-1). Since clouds remain one of the largest uncertainties in climate projections, we simulated only the clear-sky UVI. We compared the modelled UVI climatologies against present-day climatological values of UVI derived from both satellite data (the OMI-Aura OMUVBd product) and ground-based measurements (from the NDACC network). Depending on the region, relative differences between the UVI obtained from CCMI/TUV calculations and the ground-based measurements ranged between −5.9 % and 10.6 %. We then calculated the UVI evolution throughout the 21st century for the four Representative Concentration Pathways (RCPs 2.6, 4.5, 6.0 and 8.5). Compared to 1960s values, we found an average increase in the UVI in 2100 (of 2 %–4 %) in the tropical belt (30∘ N–30∘ S). For the mid-latitudes, we observed a 1.8 % to 3.4 % increase in the Southern Hemisphere for RCPs 2.6, 4.5 and 6.0 and found a 2.3 % decrease in RCP 8.5. Higher increases in UVI are projected in the Northern Hemisphere except for RCP 8.5. At high latitudes, ozone recovery is well identified and induces a complete return of mean UVI levels to 1960 values for RCP 8.5 in the Southern Hemisphere. In the Northern Hemisphere, UVI levels in 2100 are higher by 0.5 % to 5.5 % for RCPs 2.6, 4.5 and 6.0 and they are lower by 7.9 % for RCP 8.5. We analysed the impacts of greenhouse gases (GHGs) and ozone-depleting substances (ODSs) on UVI from 1960 by comparing CCMI sensitivity simulations (1960–2100) with fixed GHGs or ODSs at their respective 1960 levels. As expected with ODS fixed at their 1960 levels, there is no large decrease in ozone levels and consequently no sudden increase in UVI levels. With fixed GHG, we observed a delayed return of ozone to 1960 values, with a corresponding pattern of change observed on UVI, and looking at the UVI difference between 2090s values and 1960s values, we found an 8 % increase in the tropical belt during the summer of each hemisphere. Finally we show that, while in the Southern Hemisphere the UVI is mainly driven by total ozone column, in the Northern Hemisphere both total ozone column and aerosol optical depth drive UVI levels, with aerosol optical depth having twice as much influence on the UVI as total ozone column does. ISSN:1680-7375 ISSN:1680-7367
Published: 2019

29. Transition from stable column to partial collapse during the 79 cal CE P3 Plinian eruption of Mt. Pelée volcano (Lesser Antilles)

Author: Stephen Tait, Allan Fries, Audrey Michaud-Dubuy, Edouard Kaminski, Guillaume Carazzo, Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Dynamique des Fluides Géologiques (DFG - IPGP), Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris, Laboratoire Magmas et Volcans (LMV), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement et la société-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Jean Monnet [Saint-Étienne] (UJM), Univ Geneva, Sect Earth & Environm Sci, Geneva, Switzerland, Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut National des Sciences de l'Univers -Centre National de la Recherche Scientifique progamme CT3-ALEA INSU-CNRS Artemis 2016 INSU-CNRS Artemis 2017 French National Research Agency (ANR)ANR-09-ANR-RISK-002French National Research Agency (ANR)ANR-16-CE030002IdEx project 'Universite de Paris' ANR-18-IDEX-0001, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Dynamique des fluides géologiques, Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE03-0002,RAVEX,Développement d'une approche intégrée pour la réduction des Risques Associés au Volcanisme EXplosif, de la recherche sur l'aléa aux outils de gestion de crise : le cas de la Martinique(2016), and ANR-18-IDEX-0001,Université de Paris,Université de Paris(2018)
Subjects: Radiocarbon dating, 010504 meteorology & atmospheric sciences, Partial collapse, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Pyroclastic rock, Eruption column, 010502 geochemistry & geophysics, Tephra fallout, 01 natural sciences, Volcanic Gases, Magmatic water, Geochemistry and Petrology, Pumice, event, Tephrostratigraphy, Petrology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, event.disaster_type, geography, geography.geographical_feature_category, Geophysics, Dense-rock equivalent, Volcano, [SDU]Sciences of the Universe [physics], 13. Climate action, Mt. Pelee volcano, Plinian eruption, Martinique, Geology
Abstract: Explosive volcanic eruptions commonly form sustained Plinian columns that collapse at some stage producing dangerous pyroclastic density currents (PDC) on the ground. Numerical and laboratory models of volcanic plumes show that the conditions leading to total column collapse are strongly controlled by the amount of exsolved gas at the source and the mass eruption rate. However, column collapse is rarely total and the volcanic jet often separates in a dense collapsing part feeding PDC and a buoyant rising plume spreading volcanic gases and pyroclasts in the atmosphere. This transitional regime has been directly observed and/or inferred from the structure of the deposits for several past eruptions, but the number of cases for which the partial collapse regime is described in detail, including the 79 CE Vesuvius, and the 186 CE Taupo eruptions, remains too small to fully constrain physical models. Here, we present a detailed reconstruction of the time evolution of the P3 eruption at Mt. Pelee volcano (Martinique, Lesser Antilles) that underwent partial column collapse in order to discuss the mechanisms controlling the eruption dynamics and improve the volcanological database on transitional eruptions. The P3 eruptive succession consists of seven major phases that produced a total of 1 km3 dense rock equivalent (DRE) of deposits (i.e., VEI 5 event), starting with a thick pumice fall deposit (0.1 km3 DRE) overlain by alternating pyroclastic density current (PDC) (0.7 km3 DRE) and pumice fall deposits (0.2 km3 DRE). We use physical models together with field data on deposit dispersal, thickness, and grain-size distribution to reconstruct the dynamical evolution of the volcanic column. Our results show that the mass eruption rate (MER) increased from 1.2 × 108 to 1.7 × 108 kg s−1 during the initial phase producing a 28 to 30 km-high Plinian plume. The MER later reached up to 2.5 × 108 kg s−1 and the column entered the partial collapse regime characterized by the formation of a small (i.e., 12 to 17 km-high) ash plume and contemporaneous PDCs mainly channelized in three paleo-valleys. These estimates are used together with published data on magmatic water contents in glass inclusions to decipher the mechanisms leading to partial collapse. The P3 eruption column collapsed due to an increase in mass eruption rate and a decrease in gas content. A similar evolution was also inferred for the 1300 CE P1 and 280 CE P2 eruption deposits, revealing a systematic behavior in the recent Plinian eruptions of Mt. Pelee volcano. The comparison of model predictions of column collapse and field data reveals a good agreement for the P1, P2, P3 and Taupo eruptions, but not for the 79 CE Vesuvius eruption where thermal disequilibrium between gas and pyroclasts most likely strongly affected the column dynamics.
Published: 2020

30. Cloud Occurrence Frequency at Puy de Dôme (France) Deduced from an Automatic Camera Image Analysis: Method, Validation, and Comparisons with Larger Scale Parameters

Author: Karine Sellegri, Guillaume Payen, Geneviève Sèze, Valentin Duflot, Nadège Montoux, Laurent Deguillaume, Vincent Noel, Franck Gabarrot, Jean-Marc Pichon, Asmaou Bah, Jean-Luc Baray, Philippe Cacault, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, cloud occurrence frequency, Cloud cover, Dome, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Cloud computing, 010501 environmental sciences, Environmental Science (miscellaneous), Atmospheric sciences, 01 natural sciences, Altitude, Diurnal cycle, Camera image, automatic camera image analysis, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [CHIM.ORGA]Chemical Sciences/Organic chemistry, business.industry, Cloud fraction, Astrophysics::Instrumentation and Methods for Astrophysics, 13. Climate action, Computer Science::Computer Vision and Pattern Recognition, Environmental science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Scale (map), business
Abstract: We present a simple algorithm that calculates the cloud occurrence frequency at an altitude site using automatic camera image analysis. This algorithm was applied at the puy de D&ocirc, me station (PUY, 1465 m. a.s.l., France) over 2013&ndash, 2018. Cloud detection thresholds were determined by direct comparison with simultaneous in situ cloud probe measurements (particulate volume monitor (PVM) Gerber). The cloud occurrence frequency has a seasonal cycle, with higher values in winter (60%) compared to summer (24%). A cloud diurnal cycle is observed only in summer. Comparisons with the larger scale products from satellites and global model reanalysis are also presented. The NASA cloud-aerosol transport system (CATS) cloud fraction shows the same seasonal and diurnal variations and is, on average, 11% higher. Monthly variations of the ECMWF ERA-5 fraction of cloud cover are also highly correlated with the camera cloud occurrence frequency, but the values are 19% lower and up to 40% for some winter months. The METEOSAT-SEVIRI cloud occurrence frequency also follows the same seasonal cycle but with a much smaller decrease in summer. The all-sky imager cloud fraction (CF) presents larger variability than the camera cloud occurrence but also follows similar seasonal variations (67% in winter and 44% in summer). This automatic low-cost detection of cloud occurrence is of interest in characterizing altitude observation sites, especially those that are not yet equipped with microphysical instruments and can be deployed to other high-altitude sites equipped with cameras.
Published: 2019

31. Water vapor observations up to the lower stratosphere through the Raman lidar during the Maïdo Lidar Calibration Campaign

Author: Y. Courcoux, Guillaume Payen, Alain Hauchecorne, Jean-Luc Baray, J. Leclair de Bellevue, Franck Gabarrot, Jean-Pierre Cammas, Philippe Keckhut, Rémy Decoupes, Davide Dionisi, Hélène Vérèmes, Jacques Porteneuve, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de météorologie physique (LaMP), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, lcsh:TA715-787, lcsh:Earthwork. Foundations, 01 natural sciences, lcsh:Environmental engineering, law.invention, 010309 optics, Microwave Limb Sounder, Troposphere, Lidar, 13. Climate action, law, 0103 physical sciences, Radiosonde, Calibration, Environmental science, Cirrus, lcsh:TA170-171, Stratosphere, Water vapor, 0105 earth and related environmental sciences, Remote sensing
Abstract: A new lidar system devoted to tropospheric and lower stratospheric water vapor measurements has been installed at the Maïdo altitude station facility of La Reunion Island, in the southern subtropics. The main objectives of the MAïdo LIdar Calibration Campaign (MALICCA), performed in April 2013, were to validate the system, to set up a calibration methodology, to compare the acquired water profiles with radiosonde measurements and to evaluate its performances and capabilities with a particular focus on the UTLS measurements. Varying the characteristics of the transmitter and the receiver components, different system configuration scenarios were tested and possible parasite signals (fluorescent contamination, rejection) were investigated. A hybrid calibration methodology has been set up and validated to insure optimal lidar calibration stability with time. In particular, the receiver transmittance is monitored through the calibration lamp method that, at the moment, can detect transmittance variations greater than 10–15%. Calibration coefficients are then calculated through the hourly values of IWV provided by the co-located GPS. The comparison between the constants derived by GPS and Vaisala RS92 radiosondes launched at Maïdo during MALICCA, points out an acceptable agreement in terms of accuracy of the mean calibration value (with a difference of approximately 2–3%), but a significant difference in terms of variability (14 vs. 7–9%, for GPS and RS92 calibration procedures, respectively). We obtained a relatively good agreement between the lidar measurements and 15 co-located and simultaneous RS92 radiosondes. A relative difference below 10% is measured in low and middle troposphere (2–10 km). The upper troposphere (up to 15 km) is characterized by a larger spread (approximately 20%), because of the increasing distance between the two sensors. To measure water vapor in the UTLS region, nighttime and monthly water vapor profiles are presented and compared. The good agreement between the lidar monthly profile and the mean WVMR profile measured by satellite MLS has been used as a quality control procedure of the lidar product, attesting the absence of significant wet biases and validating the calibration procedure. Thanks to its performance and location, the MAIDO H2O lidar is devoted to become a reference instrument in the southern subtropics, allowing to insure the long-term survey of the vertical distribution of water vapor, and to document scientific themes such as stratosphere–troposphere exchange, tropospheric dynamics in the subtropics, links between cirrus clouds and water vapor.
Published: 2018

32. A new coupled ocean-waves-atmosphere model designed for tropical storm studies : example of tropical cyclone Bejisa (2013-2014) in the South-West Indian Ocean

Author: Pianezze, Joris, Barthe, Christelle, Bielli, Soline, Tulet, Pierre, Jullien, S., Cambon, G., Bousquet, Olivier, Claeys, Marine, Cordier, Emmanuel, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract: International audience; Ocean-Waves-Atmosphere (OWA) exchanges are not well represented in current Numerical Weather Prediction (NWP) systems, which can lead to large uncertainties in tropical cyclone track and intensity forecasts. In order to explore and better understand the impact of OWA interactions on tropical cyclone modeling, a fully coupled OWA system based on the atmospheric model Meso-NH, the oceanic model CROCO, and the wave model WW3 and called MSWC was designed and applied to the case of tropical cyclone Bejisa (2013–2014). The fully coupled OWA simulation shows good agreement with the literature and available observations. In particular, simulated significant wave height is within 30 cm of measurements made with buoys and altimeters. Short-term (< 2 days) sensitivity experiments used to highlight the effect of oceanic waves coupling show limited impact on the track, the intensity evolution, and the turbulent surface fluxes of the tropical cyclone. However, it is also shown that using a fully coupled OWA system is essential to obtain consistent sea salt emissions. Spatial and temporal coherence of the sea state with the 10 m wind speed are necessary to produce sea salt aerosol emissions in the right place (in the eyewall of the tropical cyclone) and with the right size distribution, which is critical for cloud microphysics.
Published: 2018

33. High occurrence of new particle formation events at the Maïdo high-altitude observatory (2150 m), Réunion (Indian Ocean)

Author: Foucart, Brice, Sellegri, Karine, Tulet, Pierre, Rose, Clémence, Metzger, Jean-Marc, Picard, David, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, and Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology
Abstract: International audience; This study aims to report and characterise the frequent new particle formation (NPF) events observed at the Maïdo observatory, Réunion, a Southern Hemisphere site located at 2150 m (a.s.l.) and surrounded by the In-dian Ocean. From May 2014 to December 2015, continuous aerosol measurements were made using both a differential mobility particle sizer (DMPS) and an air ion spectrometer (AIS) to characterise the NPF events down to the lowest particle-size scale. Carbon monoxide (CO) and black carbon (BC) concentrations were monitored, as well as meteorological parameters, in order to identify the conditions that were favourable to the occurrence of nucleation in this specific environment. We point out that the annual NPF frequency average (65 %) is one of the highest reported so far. Monthly averages show a bimodal variation in the NPF frequency , with a maximum observed during transition periods (autumn and spring). A high yearly median particle growth rate (GR) of 15.16 nm h −1 is also measured showing a bi-modal seasonal variation with maxima observed in July and November. Yearly medians of 2 and 12 nm particle formation rates (J 2 and J 12) are 0.858 and 0.508 cm −3 s −1 , respectively , with a seasonal variation showing a maximum during winter, that correspond to low temperature and RH typical of the dry season, but also to high BC concentrations. We show that the condensation sink exceeds a threshold value (1.04 × 10 −3 s −1) with a similar seasonal variation than the one of the NPF event frequency, suggesting that the occurrence of the NPF process might be determined by the availability of condensable vapours, which are likely to be transported together with pre-existing particles from lower altitudes .
Published: 2018

34. Two-year operation of the lidar 1200: from fine-scale tropospheric structures to lower stratospheric water vapor detection

Author: Françoise Posny, Franck Gabarrot, Guillaume Payen, Valentin Duflot, Jimmy Leclair de Bellevue, Holger Vömel, Nicolas Marquestaut, Philippe Keckhut, Jean-Marc Metzger, Hélène Vérèmes, Susanne Meier, Jean-Luc Baray, Jean-Pierre Cammas, Stephanie Evan, Ruud Dirksen, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lindenberg Meteorological Observatory - Richard Assmann Observatory (MOL-RAO), Deutscher Wetterdienst [Offenbach] (DWD), Earth Observing Laboratory [Boulder] (EOL), National Center for Atmospheric Research [Boulder] (NCAR)-University Corporation for Atmospheric Research (UCAR), Observatoire des Sciences de l'Univers de La Réunion ( OSU-Réunion ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de la Réunion ( UR ), Laboratoire de l'Atmosphère et des Cyclones ( LACy ), Météo France-Université de la Réunion ( UR ) -Centre National de la Recherche Scientifique ( CNRS ), SHTI - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Météorologie Physique - Clermont Auvergne ( LaMP ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Lindenberg Meteorological Observatory - Richard Assmann Observatory ( MOL-RAO ), Deutscher Wetterdienst [Offenbach] ( DWD ), Earth Observing Laboratory [Boulder] ( EOL ), National Center for Atmospheric Research [Boulder] ( NCAR ) -University Corporation for Atmospheric Research ( UCAR ), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Time delay and integration, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, Meteorology, Hygrometer, QC1-999, 0211 other engineering and technologies, 02 engineering and technology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Atmospheric sciences, 01 natural sciences, Troposphere, Lidar, [ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 13. Climate action, Observatory, Scale (map), Stratosphere, Water vapor, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences
Abstract: International audience; The 2-year lidar water vapor database (November 2013 - October 2015) of the Maïdo Observatory (Reunion Island / 21°S,55.5°E) is now calibrated. The performance of the lidar to provide accurate vertical structures are shown to be good. The ability of measuring quantities of a few ppmv in the lower stratosphere is demonstrated up to 22 km (based on Cryogenic Frostpoint Hygrometer sondes/lidar profiles comparisons) for an integration time period of 48 hours and a vertical resolution of 1.3 km.
Published: 2018

35. Ultraviolet radiation modelling from ground-based and satellite measurements on Reunion Island, southern tropics

Author: Lamy, Kévin, Portafaix, Thierry, Brogniez, Colette, Godin-Beekmann, Sophie, Bencherif, Hassan, Morel, Béatrice, Pazmino, Andrea, Metzger, Jean-Marc, Auriol, Frédérique, Deroo, Christine, Duflot, Valentin, Goloub, Philippe, Long, Charles N., Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), School of Chemistry and Physics [Durban], University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), Energy Lab (ENERGY Lab), Université de La Réunion (UR), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Observatoire de Physique de l’Atmosphère à la Réunion (OPAR)Université de la RéunionINSU, Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), University of KwaZulu-Natal (UKZN), and Laboratoire d'Energétique, d'Electronique et Procédés (LE2P)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract: International audience; Surface ultraviolet radiation (SUR) is not an increasing concern after the implementation of the Montreal Protocol and the recovery of the ozone layer (Morgenstern et al., 2008). However large uncertainties remain in the prediction of the future changes of SUR (Bais et al., 2015). It has long been known that its variability depends on ozone levels and also on clouds, aerosol and albedo. It is therefore essential to monitor its evolution in the context of global change. Unfortunately there are 5 few ground-based stations measuring surface UV irradiance in the southern tropics and particularly in the Indian Ocean, and long-term time series are required to study SUR variability and its relationship to ozone and to detect trends.Reunion Island is located in the tropics (21S, 55E), in a part of the world where the amount of ozone in the ozone column is naturally low. In addition, this island is mountainous and the marine atmosphere is often clean with low aerosol concentrations. Thus, measurements show much higher SUR than at other sites at the same latitude or at mid-latitudes. Several studies 10 pointed out that UV-B impacts the biosphere (Erickson III et al., 2015), especially aquatic system, which plays a central part in biogeochemical cycle (Hader et al., 2007). It can affect phytoplankton productivity (Smith and Cullen, 1995). This influence can result in either positive or negative feedback on climate (Zepp et al., 2007). In order to quantify the future evolution of SUR in the tropics, it is necessary to validate a model against present observations. This study is designed to be a preliminary parametric and sensitivity study of SUR modelling in the tropics.Ground-based measurements of SUR have been performed at Reunion Island by a BENTHAM DTMc300 spectroradiometer since 2009. This instrument is part of the Network for the Detection of Atmospheric Composition Change (NDACC). In this study, we used the UltraViolet Index in order to quantify SUR radiation integratively.
Published: 2018
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36. Ship detection and tracking from single ocean-bottom seismic and hydroacoustic stations

Author: Alister Trabattoni, Guilhem Barruol, Richard Dréo, Abdel Boudraa, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Géosciences Azur, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut de Recherche de l'Ecole Navale (IRENAV), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), Ecole Doctorale STEP'UPDirection Générale de l'Armement (DGA), and ANR-11-BS56-0013,RHUM-RUM,Imagerie mantellique du point chaud de La Réunion(2011)
Subjects: Acoustics and Ultrasonics, Arts and Humanities (miscellaneous), [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
Abstract: International audience; We report in this study how ocean-bottom seismometers (OBS) can be used as passive sonars to automatically detect, localize, and track moving acoustic sources at the ocean surface. We developed single-station methods based on direction of arrival and on multi-path interference measurements capable of handling continuous erratic signals emitted by ships. Based on a Bayesian mathematical framework, we developed an azimuthal detector and a radial detector and combined them into a fully automatic tracker. We tested the developed algorithm on seismic and hydroacoustic data recorded in the Indian Ocean by an OBS deployed at 4300 m depth, 200 km west of La R eunion Island. We quantified the performances using archives of commercial-vessel trajectories in the area provided by the Automatic Identification System. Detectors demonstrate capabilities in the detection range up to 100 km from the OBS with azimuthal accuracies of a few degrees and with distance accuracies of a few hundred of meters. We expect the method to be easily transposed to any other kind of sources (such as marine mammals).
Published: 2023

37. Unsuspected explosive activity of Montagne Pelée (Lesser Antilles) during the 25–10 ka period

Author: Michaud-Dubuy, Audrey, Carazzo, Guillaume, Balcone-Boissard, Hélène, Boudon, Georges, Kaminski, Edouard, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut des Sciences de la Terre de Paris (iSTeP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE03-0002,RAVEX,Développement d'une approche intégrée pour la réduction des Risques Associés au Volcanisme EXplosif, de la recherche sur l'aléa aux outils de gestion de crise : le cas de la Martinique(2016), and ANR-18-CE03-0010,V-CARE,Sensibilisation précoce aux éruptions volcaniques : Développement, test et étude de l'impact psychosociologique de nouveaux indicateurs en vue d'une meilleure gestion des crises volcaniques.(2018)
Subjects: hazard assessment, Montagne Pelée volcano, eruptive dynamics, Plinian eruption, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, dome-forming eruption, Eruptive history
Abstract: The recent eruptive history of Montagne Pelée volcano was dominated by a period of vigorous basaltic andesitic magma production (36-25 ka) followed by a long period of lower activity (i.e., with less frequent and less voluminous eruptions) and a renewal of felsic magma production in the last 10 ka. The temporal succession of volcanic events that occurred during the 25-10 ka period and the timing of felsic magma production are currently poorly constrained. This study focuses on the stratigraphy and eruptive dynamics of the pyroclastic deposits emplaced immediately after 25 ka. New on-land stratigraphic correlations and radiocarbon dating measurements allow us identifying six major explosive eruptions. We use field data on tephra dispersal, thickness and grain-size distribution together with physical models of explosive volcanic plumes to estimate the eruption source parameters. Our results show that these events are VEI 4 eruptions with intermediate magnitudes (from M = 4.2 to M = 5.1) and intensities (from I = 10.6 to I = 11.6). These eruptions share several characteristics with the most recent Plinian eruptions of Montagne Pelée volcano (i.e., mass eruption rate, maximum column height, runout of pyroclastic density currents, glass composition). The tephra succession documents two phases of magma production rates. The first phase from 25 to 14 ka corresponds to a period of low activity with a magma production rate of 0.04 km3 kyr-1. The second phase from 14 to 10 ka is characterized by a significant increase of the volcanic activity with a magma production rate of 0.4 km3 kyr-1, consistent with previous estimates.
Published: 2023

38. The isotopic composition of near-surface water vapor at the Maïdo observatory (Reunion Island, southwestern Indian Ocean) documents the controls of the humidity of the subtropical troposphere

Author: Guilpart, Etienne, Vimeux, Françoise, Evan, Stéphanie, Brioude, Jérôme, Metzger, Jean-Marc, Barthe, Christelle, Risi, Camille, Cattani, Olivier, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Hydrosciences Montpellier (HSM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), This study was supported by Institut de Recherche pour le Développement, Commissariat à l’énergie atomique et aux énergies alternatives, CNRS-INSU, and by the ANR proposal 12-BS06-001., Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract: We present a 1 year long record of the isotopic composition of near-surface water vapor (delta O-18(v)) at the Maido atmospheric observatory (Reunion Island, Indian Ocean, 22 degrees S, 55 degrees E) from 1 November 2014 to 31 October 2015, using wavelength-scanned cavity ring down spectroscopy. Except during cyclone periods where delta O-18(v) is highly depleted (-20.5%), a significant diurnal variability can be seen on both delta O-18(v) and q(v) with enriched (depleted) water vapor (mean delta O-18(v) is -13.4% (-16.6%)) and moist (dry) conditions (mean q(v) is 9.7 g/kg (6.4 g/kg)) during daytime (nighttime). We show that d18Ov diurnal cycle arises from mixing processes for 65% of cases with two distinct sources of water vapor. We suggest that delta O-18(v) diurnal cycle is controlled by an interplay of thermally driven land-sea breezes and upslope-downslope flows, bringing maritime air to the observatory during daytime, whereas at night, the observatory is above the atmospheric boundary layer and samples free tropospheric air. Interestingly, delta O-18(v) record also shows that some nights (15%) are extremely depleted (mean delta O-18(v) is -21.4%). They are among the driest of the record (mean q(v) is 2.9 g/kg). Based on different modeling studies, we suggest that extreme nocturnal isotopic depletions are caused by large-scale atmospheric transport and subsidence of dry air masses from the upper troposphere to the surface, induced by the subtropical westerly jet.
Published: 2017

39. Recent changes in stratospheric aerosol budget from ground-based and satellite observations

Author: Khaykin, Sergey, Godin-Beekmann, Sophie, Keckhut, Philippe, Hauchecorne, Alain, Portafaix, Thierry, Bègue, Nelson, Vernier, Jean-Paul, DeLand, Matthew, Bhartia, Pawan K., Leblanc, Thierry, TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), STRATO - LATMOS, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Langley Research Center [Hampton] (LaRC), NASA Goddard Space Flight Center (GSFC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Cardon, Catherine, Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract: International audience; Stratospheric aerosol budget plays an important role in climate variability and ozone chemistry. Observations of stratospheric aerosol by ground-based lidars represent a particular value as they ensure the continuity and coherence of stratospheric aerosol record. Ground-based lidars remain indispensable for complementing and validating satellite instruments and for filling gaps between satellite missions. On the other hand, geophysical interpretation of local observations is complicated without the knowledge of global distribution of stratospheric aerosol, which calls for a combined analysis of ground-based and space-borne observations.The present study aims at characterizing global and regional variability of stratospheric aerosol over the last 5 years using various sets of observations. We use the data provided by three lidars operated within NDACC (Network for Detection of Atmospheric Composition Change) at Haute-Provence, (44◦ N), Mauna Loa (21◦ N) and Maido (21◦ S) sites together with quasi-global-coverage aerosol measurements by CALIOP and OMPS satellite instruments. The local and space-borne measurements are shown to be in good agreement allowing for their synergetic use.Since the late 2012 stratospheric aerosol remained at background levels throughout the globe. Eruptions of Kelud volcano at 4◦ S in February 2014 and Calbuco volcano at 41◦ S in April 2015 resulted in a remarkable enhancement of stratospheric AOD at a wide latitude range. We explore meridional dispersion and lifetime of volcanic plumes in consideration of global atmospheric circulation. A focus is made on the poleward transport of volcanic aerosol and its detection at the mid-latitude Haute-Provence observatory. We show that the moderate eruptions in the Southern hemisphere leave a measurable imprint on the Northern mid-latitude aerosol loading. Having identified the volcanically-perturbed periods from local and global observations we examine the evolution of non-volcanic (background) aerosol by comparing the recent observations with historical data available from 23-yr observations at Haute-Provence and Mauna-Loa.
Published: 2017

40. High occurrence of new particle formation events at the Maïdo high altitude observatory (2150 m), Reunion Island (Indian Ocean)

Author: Foucart, Brice, Sellegri, Karine, Tulet, Pierre, Rose, Clémence, Metzger, Jean-Marc, Picard, David, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Physique (LaMP), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de météorologie physique (LaMP), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 13. Climate action, 14. Life underwater
Abstract: This study aims to report and characterize the frequent new particle formation (NPF) events observed at the Maïdo observatory, Reunion Island, a Southern Hemisphere site located at 2200 m and surrounded by the Indian Ocean. In 2014 and 2015, continuous aerosol measurements were made using both a Differential Mobility Particle Sizer (DMPS) and an Air Ion Spectrometer (AIS) to characterize the NPF events down to the lowest particle size scale. Carbon monoxide (CO) and sulfur dioxide (SO2) concentrations were monitored, as well as meteorological parameters, in order to identify the conditions that were favourable to the occurrence of nucleation in this specific environment. We point out that the annual NPF frequency average (65 %) is one of the highest reported so far. Monthly averages show a bimodal variation of the NPF frequency, with a maximum observed during off-season periods (March to May and September to December). A high yearly median particle Growth Rate (GR) of 15.16 nm.h−1 is also measured, occasionally peaking at values of the order of 100 nm.h−1 and showing a bimodal seasonal variation with maxima observed in July and November. Yearly medians of 2 and 12 nm particle formation rates (J2 and J12) are 0.858 and 0.508 cm−3.s−1 respectively, with a seasonal variation similar to that of the GR. The seasonal variations of GR and J correspond to the seasonal variation of radiation, which may be responsible for more efficient photochemistry and also for a higher influence of the boundary layer, as shown by the CO seasonal variation. Multiple sources can contribute to the NPF frequency and intensity, including marine, biogenic from vegetation, and anthropogenic sources.
Published: 2017
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41. Long-range isentropic transport of stratospheric aerosols over Southern Hemisphere following the Calbuco eruption in April 2015

Author: Bègue, Nelson, Vignelles, Damien, Berthet, Gwenaël, Portafaix, Thierry, Payen, Guillaume, Jégou, Fabrice, Bencherif, Hassan, Jumelet, Julien, Vernier, Jean-Paul, Lurton, Thibault, Renard, Jean-Baptiste, Clarisse, Lieven, Duverger, Vincent, Posny, Françoise, Metzger, Jean-Marc, Godin-Beekmann, Sophie, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), School of Chemistry and Physics [Durban], University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), NASA Langley Research Center [Hampton] (LaRC), Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), Agence Nationale de la Recherche (ANR), ANR-10-LABX-0100,VOLTAIRE,Geofluids and Volatil elements – Earth, Atmosphere, Interfaces – Resources and Environment(2010), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, and University of KwaZulu-Natal (UKZN)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract: International audience; After 43 years of inactivity, the Calbuco volcano which is located in the southern part of Chile erupted on 22 April 2015. The space-time evolutions (distribution and transport) of its aerosol plume are investigated by combining satellite (CALIOP, IASI, OMPS), in situ aerosol counting (LOAC OPC) and lidar observations, and the MIMOSA advection model. The Calbuco aerosol plume reached the Indian Ocean 1 week after the eruption. Over the Reunion Island site (21° S; 55.5° E), the aerosol signal was unambiguously enhanced in comparison with "background" conditions with a volcanic aerosol layer extending from 18 km to 21 km during the May–July period. All the data reveal an increase by a factor of ~ 2 in the SAOD (Stratospheric Aerosol Optical Depth) with respect to values observed before the eruption. The aerosol e-folding time is approximately 90 days. Microphysical measurements obtained before, during and after the eruption reflecting the impact of the Calbuco eruption on the lower stratospheric aerosol content have been analyzed over Reunion site. During the passage of the plume, the volcanic aerosol was characterized by an effective radius of 0.16 ± 0.02 µm with an unimodal lognormal size distribution and the aerosol number concentration appears 20 times higher than before and one year after the eruption. A tendency toward "background" conditions has been observed about one year after the eruption, by April 2016. The volcanic aerosol plume is advected eastward in the Southern Hemisphere and its latitudinal extent is clearly bounded by the subtropical barrier and the polar vortex. The transient behavior of the aerosol layers observed above Reunion Island between May and July 2015 reflects an inhomogeneous geographical distribution of the plume which is controlled by the latitudinal motion of these dynamical barriers.
Published: 2017

42. Tropospheric ozone profiles by DIAL at Maïdo Observatory (Reunion Island): system description, instrumental performance and result comparison with ozone external data set

Author: Duflot, Valentin, Baray, Jean-Luc, Payen, Guillaume, Marquestaut, Nicolas, Posny, Françoise, Metzger, Jean-Marc, Langerock, Bavo, Vigouroux, Corinne, Hadji-Lazaro, Juliette, Portafaix, Thierry, de Mazière, Martine, Coheur, Pierre-François, Clerbaux, Cathy, Cammas, Jean-Pierre, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de météorologie physique (LaMP), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), European Space Agency (EUMETSAT O3M-SAF project , O3-CCI), CNES, CNRS, Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Sociologie politique
Abstract: In order to recognize the importance of ozone (O3) in the troposphere and lower stratosphere in the tropics, a DIAL (differential absorption lidar) tropospheric O3 lidar system (LIO3TUR) was developed and installed at the Université de la Réunion campus site (close to the sea) on Reunion Island (southern tropics) in 1998. From 1998 to 2010, it acquired 427 O3 profiles from the low to the upper troposphere and has been central to several studies. In 2012, the system was moved up to the new Maïdo Observatory facility (2160-l. - metres above mean sea level) where it started operation in February 2013. The current system (LIO3T) configuration generates a 266 beam obtained with the fourth harmonic of a Nd:YAG laser sent into a Raman cell filled up with deuterium (using helium as buffer gas), generating the 289 and 316 beams to enable the use of the DIAL method for O3 profile measurements. The optimal range for the actual system is 6-19ga.m.s.l. depending on the instrumental and atmospheric conditions. For a 1gh integration time, vertical resolution varies from 0.7gkm at 6ga.m.s.l. to 1.3gkm at 19ga.m.s.l. and mean uncertainty within the 6-19gkm range is between 6 and 13g%. Comparisons with eight electrochemical concentration cell (ECC) sondes simultaneously launched from the Maïdo Observatory show good agreement between data sets with a 6.8g% mean absolute relative difference (D) between 6 and 17ga.m.s.l. (LIO3T lower than ECC). Comparisons with 37 ECC sondes launched from the nearby Gillot site during the daytime in a ±24gh window around lidar shooting result in a 9.4g% D between 6 and 19ga.m.s.l. (LIO3T lower than ECC). Comparisons with 11 ground-based Network for Detection of Atmospheric Composition Change (NDACC) Fourier transform infrared (FTIR) spectrometer measurements acquired during the daytime in a ±24gh window around lidar shooting show good agreement between data sets with a D of 11.8g% for the 8.5-16gkm partial column (LIO3T higher than FTIR), and comparisons with 39 simultaneous Infrared Atmospheric Sounding Interferometer (IASI) observations over Reunion Island show good agreement between data sets with a D of 11.3g% for the 6-16gkm partial column (LIO3T higher than IASI). ECC, LIO3TUR and LIO3T O3 monthly climatologies all exhibit the same range of values and patterns. In particular, the Southern Hemisphere biomass burning seasonal enhancement and the ozonopause altitude decrease in late austral winter-spring, as well as the sign of deep convection bringing boundary layer O3-poor air masses up to the middle-upper troposphere in late austral summer, are clearly visible in all data sets., SCOPUS: ar.j, info:eu-repo/semantics/published
Published: 2017

43. Validation of 10-year SAO OMI Ozone Profile (PROFOZ) product using ozonesonde observations

Author: Tristan J. Hall, Bertrand Calpini, Bogumil Kois, Roeland Van Malderen, René Stübi, Marion Marchand, Marc Allaart, Masatomo Fujiwara, Thierry Leblanc, Anne M. Thompson, M.B. Tully, Richard Querel, Everette Joseph, Françoise Posny, Ghassan Taha, Kai Yang, Zhaonan Cai, Giovanni Laneve, Michael J. Newchurch, Manvendra K. Dubey, Gary A. Morris, Hugo De Backer, Rinus Scheele, Xiong Liu, Jacquelyn C. Witte, Kenneth R. Minschwaner, Nozomu Ohkawara, Ankie Piters, Kelly Chance, Shin-Ya Ogino, Margarita Yela, Ninong Komala, Emilio Cuevas-Agulló, H. B. Selkirk, Sophie Godin-Beekmann, Guanyu Huang, Manuel Cupeiro, Valérie Thouret, Holger Vömel, Russell C. Schnell, Gerrie Coetzee, Pawan K. Bhartia, Masato Shiotani, Gérard Ancellet, Otto Schrems, Bryan J. Johnson, Gert König-Langlo, Rigel Kivi, F. J. Schmidlin, Peter von der Gathen, P. Skrivankova, David W. Tarasick, Henry E. Fuelberg, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Department of Atmospheric and Oceanic Science [College Park] (AOSC), University of Maryland [College Park], University of Maryland System-University of Maryland System, NASA Goddard Space Flight Center (GSFC), Royal Netherlands Meteorological Institute (KNMI), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Payerne Aerological Station, Federal Office of Meteorology and Climatology MeteoSwiss, South African Weather Service (SAWS), Izaña Atmospheric Research Center (IARC), Agencia Estatal de Meteorología (AEMet), National Meteorological Service [Ushuaia], Institut Royal Météorologique de Belgique [Bruxelles] (IRM), Los Alamos National Laboratory (LANL), Department of Earth, Ocean and Atmospheric Science [Tallahassee] (FSU | EOAS), Florida State University [Tallahassee] (FSU), Faculty of Environmental Earth Science [Sapporo], Hokkaido University [Sapporo, Japan], STRATO - LATMOS, ESRL Global Monitoring Laboratory [Boulder] (GML), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA), Atmospheric Sciences Research Center (ASRC), University at Albany [SUNY], State University of New York (SUNY)-State University of New York (SUNY), Finnish Meteorological Institute (FMI), Institute of Meteorology and Water Management - National Research Institute (IMGW - PIB), Indonesian National Institute of Aeronautics and Space (LAPAN), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Earth Observation Satellite Images Applications Laboratory (EOSIAL), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Physics [Socorro], New Mexico Institute of Mining and Technology [New Mexico Tech] (NMT), St. Edward's University, Department of Atmospheric Science [Huntsville], University of Alabama in Huntsville (UAH), Department of Coupled Ocean-Atmosphere-Land Processes Research (DCOP), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Global Environment and Marine Department [Tokyo], Japan Meteorological Agency (JMA), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), National Institute of Water and Atmospheric Research [Lauder] (NIWA), Universities Space Research Association (USRA), Research Institute for Sustainable Humanosphere (RISH), Kyoto University [Kyoto], Czech Hydrometeorological Institute (CHMI), Environment and Climate Change Canada, Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Australian Bureau of Meteorology [Melbourne] (BoM), Australian Government, Earth Observing Laboratory [Boulder] (EOL), National Center for Atmospheric Research [Boulder] (NCAR)-University Corporation for Atmospheric Research (UCAR), Science Systems and Applications, Inc. [Lanham] (SSAI), Instituto Nacional de Técnica Aeroespacial (INTA), Harvard University-Smithsonian Institution, Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute (IRM), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Kyoto University, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Cloud cover, 0211 other engineering and technologies, 02 engineering and technology, 01 natural sciences, Latitude, Troposphere, Ozone layer, lcsh:TA170-171, Stratosphere, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, validation, Ozone Monitoring Instrument, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:TA715-787, Anomaly (natural sciences), OMI, lcsh:Earthwork. Foundations, ozone, lcsh:Environmental engineering, Trace gas, 13. Climate action, Climatology, Environmental science
Abstract: We validate the Ozone Monitoring Instrument (OMI) Ozone Profile (PROFOZ) product from October 2004 through December 2014 retrieved by the Smithsonian Astrophysical Observatory (SAO) algorithm against ozonesonde observations. We also evaluate the effects of OMI row anomaly (RA) on the retrieval by dividing the dataset into before and after the occurrence of serious OMI RA, i.e., pre-RA (2004–2008) and post-RA (2009–2014). The retrieval shows good agreement with ozonesondes in the tropics and midlatitudes and for pressure ∼ 50 hPa after applying OMI averaging kernels to ozonesonde data. The MBs of the stratospheric ozone column (SOC, the ozone column from the tropopause pressure to the ozonesonde burst pressure) are within 2 % with SDs of ∼ 50 hPa. The SOC MBs increase up to 3 % with SDs as great as 6 % and the TOC SDs increase up to 30 %. The comparison generally degrades at larger solar zenith angles (SZA) due to weaker signals and additional sources of error, leading to worse performance at high latitudes and during the midlatitude winter. Agreement also degrades with increasing cloudiness for pressure > ∼ 100 hPa and varies with cross-track position, especially with large MBs and SDs at extreme off-nadir positions. In the tropics and midlatitudes, the post-RA comparison is considerably worse with larger SDs reaching 2 % in the stratosphere and 8 % in the troposphere and up to 6 % in TOC. There are systematic differences that vary with latitude compared to the pre-RA comparison. The retrieval comparison demonstrates good long-term stability during the pre-RA period but exhibits a statistically significant trend of 0.14–0.7 % year−1 for pressure
Published: 2017

44. Interdisciplinary strategy to assess the impact of meteorological variables on the biochemical composition of the rain and the dynamics of a small eutrophic lake under rain forcing

Author: Fanny Noirmain, Jean-Luc Baray, Frédéric Tridon, Philippe Cacault, Hermine Billard, Guillaume Voyard, Joël Van Baelen, Delphine Latour, Service d'Ingénierie Moléculaire pour la Santé (ex SIMOPRO) (SIMoS), Médicaments et Technologies pour la Santé (MTS), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Laboratoire Microorganismes : Génome et Environnement (LMGE), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), University of California [Berkeley] (UC Berkeley), University of California (UC), Université Clermont Auvergne (UCA), Institut de Chimie de Clermont-Ferrand (ICCF), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA), Laboratoire de l'Atmosphère et des Cyclones (LACy), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France
Subjects: impact of meteorological variables, [SDE]Environmental Sciences, biochemical composition of rain, dynamics of a small eutrophic lake under rain forcing, Ecology, Evolution, Behavior and Systematics, Earth-Surface Processes
Abstract: We present an interdisciplinary investigation of the links between the macro and microphysical properties of rain, the biochemical composition of rain, meteorological parameters, and their impacts on the phytoplankton dynamics of a mountain lake. In order to document this interdisciplinary scientific question, Lake Aydat in the French Massif Central mountains was fitted with a set of high-resolution atmospheric radars, a disdrometer, and a precipitation collector in 2020. In parallel, the lake was monitored via sensors and water sampling. To illustrate the potential of this novel experimental setup, we present a case study of a rain event that occurred in September 2020 and during which, three contrasting sub-periods were identified based on the type of rain (convective or stratiform). Using our high-temporal resolution monitoring, we show that the origin of the air mass mainly influences the chemical composition of the rain, which depends on the rain type. In contrast, the photosynthetic cell concentration in the rain is mainly influenced by meteorological variables, predominantly below-cloud scavenging. The very low concentrations of photosynthetic cells found in rain events cannot directly impact the lake's phytoplankton abundance. In contrast, the rain rate directly impacted the lake's thermal stratification during the convective event. The response of the phytoplankton depends on the genus and, interestingly, three cyanobacteria, Microcystis, Coelomoron, and Merismopedia, showed a systematic response to rain events with a sudden decrease in abundance at the lake surface immediately after rain events. In contrast, the abundance of green algae (Elakatothrix), picocyanobacteria (Synechocystis and Synechococcus), and diatoms (Asterionella and Melosira) gradually increased following the rain events, but with a lower intensity compared to the cyanobacteria species. These different phytoplankton responses to the same rainfall event could play a key role in phytoplankton dynamics in the temperate zone. Our results highlight the importance of high-frequency and time resolution monitoring of both atmosphere and lake to better understand the adaptive strategies of cyanobacteria following rain events.
Published: 2022

45. Les verres, quel désordre ?

Author: Cormier, Laurent, Neuville, Daniel, Propriétés des amorphes, liquides et minéraux [IMPMC] (IMPMC_PALM), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: General Medicine, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]
Abstract: L’absence d’ordre à longue distance, par opposition à l’état cristallin, et le phénomène de la transition vitreuse sont les principaux critères qui distinguent le verre des autres états de la matière. Dans cet article, nous revenons sur les notions d’ordre et de désordre, de périodicité, et sur les différentes échelles d’organisation, en comparant les structures les plus ordonnées (les cristaux) avec celles des matériaux amorphes. Nous faisons un état des lieux sur la compréhension actuelle de la structure des verres, en montrant les avancées récentes issues de techniques expérimentales, révélant que cette structure est plus complexe que la vision traditionnelle d’un matériau désordonné homogène.
Published: 2022

46. Empirical H/V spectral ratios at the InSight landing site and implications for the martian subsurface structure

Author: Sebastián Carrasco, Brigitte Knapmeyer-Endrun, Ludovic Margerin, Cédric Schmelzbach, Keisuke Onodera, Lu Pan, Philippe Lognonné, Sabrina Menina, Domenico Giardini, Eléonore Stutzmann, John Clinton, Simon Stähler, Martin Schimmel, Matthew Golombek, Manuel Hobiger, Miroslav Hallo, Sharon Kedar, William Bruce Banerdt, University of Cologne, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Graduate University for Advanced Studies [Hayama] (SOKENDAI), University of Copenhagen = Københavns Universitet (UCPH), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Swiss Seismological Service [ETH Zurich] (SED), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)-Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), and ANR-19-CE31-0008,MAGIS,MArs Geophysical InSight(2019)
Subjects: Geophysics, Seismic noise, Coda waves, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Geochemistry and Petrology, Site effects, Martian seismology, Marsquakes
Abstract: SUMMARY The horizontal-to-vertical (H/V) spectral ratio inversion is a traditional technique for deriving the local subsurface structure on Earth. We calculated the H/V from the ambient vibrations at different wind levels at the InSight landing site, on Mars, and also computed the H/V from the S-wave coda of the martian seismic events (marsquakes). Different H/V curves were obtained for different wind periods and from the marsquakes. From the ambient vibrations, the recordings during low-wind periods are close to the instrument self-noise level. During high-wind periods, the seismic recordings are highly contaminated by the interaction of the lander with the wind and the martian ground. Therefore, these recordings are less favourable for traditional H/V analysis. Instead, the recordings of the S-wave coda of marsquakes were preferred to derive the characteristic H/V curve of this site between 0.4 and 10 Hz. The final H/V curve presents a characteristic trough at 2.4 Hz and a strong peak at 8 Hz. Using a full diffuse wavefield approach as the forward computation and the Neighbourhood Algorithm as the sampling technique, we invert for the 1-D shear wave velocity structure at the InSight landing site. Based on our inversion results, we propose a strong site effect at the InSight site to be due to the presence of a shallow high-velocity layer (SHVL) over low-velocity units. The SHVL is likely placed below a layer of coarse blocky ejecta and can be associated with Early Amazonian basaltic lava flows. The units below the SHVL have lower velocities, possibly related to a Late Hesperian or Early Amazonian epoch with a different magmatic regime and/or a greater impact rate and more extensive weathering. An extremely weak buried low velocity layer (bLVL) between these lava flows explains the data around the 2.4 Hz trough, whereas a more competent bLVL would not generate this latter feature. These subsurface models are in good agreement with results from hammering experiment and compliance measurements at the InSight landing site. Finally, this site effect is revealed only by seismic events data and explains the larger horizontal than vertical ground motion recorded for certain type of marsquakes.
Published: 2022

47. First results of the Piton de la Fournaise STRAP 2015 experiment: multidisciplinary tracking of a volcanic gas and aerosol plume

Author: Pierre Tulet, Andréa Di Muro, Aurélie Colomb, Cyrielle Denjean, Valentin Duflot, Santiago Arellano, Brice Foucart, Jérome Brioude, Karine Sellegri, Aline Peltier, Alessandro Aiuppa, Christelle Barthe, Chatrapatty Bhugwant, Soline Bielli, Patrice Boissier, Guillaume Boudoire, Thierry Bourrianne, Christophe Brunet, Fréderic Burnet, Jean-Pierre Cammas, Franck Gabarrot, Bo Galle, Gaetano Giudice, Christian Guadagno, Fréderic Jeamblu, Philippe Kowalski, Jimmy Leclair de Bellevue, Nicolas Marquestaut, Dominique Mékies, Jean-Marc Metzger, Joris Pianezze, Thierry Portafaix, Jean Sciare, Arnaud Tournigand, Nicolas Villeneuve, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Observatoire Volcanologique du Piton de la Fournaise (OVPF), Institut de Physique du Globe de Paris (IPG Paris), Laboratoire de météorologie physique (LaMP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Department of Earth and Space Sciences [Göteborg], Chalmers University of Technology [Göteborg], Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Observatoire réunionnais de l'Air (ORA), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Cyprus Institute (CyI), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Palermo (INGV), Dipartimento DiSTeM, Università di Palermo, Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Tulet, P., Di Muro, A., Colomb, A., Denjean, C., Duflot, V., Arellano, S., Foucart, B., Brioude, J., Sellegri, K., Peltier, A., Aiuppa, A., Barthe, C., Bhugwant, C., Bielli, S., Boissier, P., Boudoire, G., Bourrianne, T., Brunet, C., Burnet, F., Cammas, J., Gabarrot, F., Galle, B., Giudice, G., Guadagno, C., Jeamblu, F., Kowalski, P., Leclair De Bellevue, J., Marquestaut, N., Mã©kies, D., Metzger, J., Pianezze, J., Portafaix, T., Sciare, J., Tournigand, A., Villeneuve, N., Università degli studi di Palermo - University of Palermo, and Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], STRAP 2015 experiment, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Atmospheric Science, Piton de La Fournaise, Gaz volcaniques, lcsh:QC1-999, La Réunion, lcsh:Chemistry, Reunion Island, volcano, Volcanic gas, lcsh:QD1-999, 13. Climate action, aerosol plume, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, lcsh:Physics
Abstract: The STRAP (Synergie Transdisciplinaire pour Répondre aux Aléas liés aux Panaches volcaniques) campaign was conducted in 2015 to investigate the volcanic plumes of Piton de La Fournaise (La Réunion, France). For the first time, measurements at the local (near the vent) and at the regional scales around the island were conducted. The STRAP 2015 campaign has become possible thanks to a strong cross-disciplinary collaboration between volcanologists and meteorologists. The main observations during four eruptive periods (85 days) are summarized. They include the estimates of SO2, CO2 and H2O emissions, the altitude of the plume at the vent and over different areas of La Réunion Island, the evolution of the SO2 concentration, the aerosol size distribution, and the aerosol extinction profile. A climatology of the volcanic plume dispersion is also reported. Simulations and measurements showed that the plume formed by weak eruption has a stronger interaction with the surface of the island. Strong SO2 and particles concentrations above 1000 ppb and 50 000 cm−3, respectively, are frequently measured over 20 km of distance from the Piton de la Fournaise. The measured aerosol size distribution shows the predominance of small particles in the volcanic plume. A particular emphasis is placed on the gas-particle conversion with several cases of strong nucleation of sulfuric acid observed within the plume and at the distal site of the Maïdo observatory. The STRAP 2015 campaign gave a unique set of multi-disciplinary data that can now be used by modellers to improve the numerical paramameterizations of the physical and chemical evolution of the volcanic plumes.
Published: 2016

48. Maïdo observatory: a new high-altitude station facility at Reunion Island (21° S, 55° E) for long-term atmospheric remote sensing and in situ measurements

Author: Françoise Posny, Yann Courcoux, F. Desmet, Karine Sellegri, Robert Delmas, M. De Mazière, Thierry Portafaix, Alain Hauchecorne, Jean Sciare, J. Leclair de Bellevue, Franck Gabarrot, S. Godin Beekmann, Guillaume Payen, Jean-Luc Baray, Aurélie Colomb, C. Vuillemin, Davide Dionisi, Valentin Duflot, Jacques Porteneuve, Jean-Pierre Cammas, T. Gaudo, Christelle Barthe, Philippe Ricaud, Pierre Tulet, Jean-Marc Metzger, Hélène Vérèmes, Abdel Abchiche, Michel Ramonet, Christian Hermans, Philippe Keckhut, Christophe Hoareau, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), Laboratoire de météorologie physique (LaMP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), ICOS-RAMCES (ICOS-RAMCES), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Chimie Atmosphérique Expérimentale (CAE), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, lcsh:TA715-787, lcsh:Earthwork. Foundations, Climate change, Subtropics, 01 natural sciences, lcsh:Environmental engineering, 010309 optics, Troposphere, Lidar, Observatory, 0103 physical sciences, Environmental science, 14. Life underwater, lcsh:TA170-171, Sociologie politique, Southern Hemisphere, Stratosphere, Sea level, 0105 earth and related environmental sciences, Remote sensing
Abstract: Since the nineties, atmospheric measurement systems have been deployed at Reunion Island, mainly for monitoring the atmospheric composition in the framework of NDSC/NDACC (Network for the Detection of Stratospheric< /i> Change/Network for the Detection of Atmospheric Composition Change). The location of Reunion Island presents a great interest because there are very few multi-instrumented stations in the tropics and particularly in the southern hemisphere. In 2012, a new observatory was commissioned in Maïdo at 2200 m above sea level: it hosts various instruments for atmospheric measurements, including lidar systems, spectro-radiometers and in situ gas and aerosol measurements. This new high-altitude Maïdo station provides an opportunity: 1. to improve the performance of the optical instruments above the marine boundary layer, and to open new perspectives on upper troposphere and lower stratosphere studies; 2. to develop in situ measurements of the atmospheric composition for climate change surveys, in a reference site in the tropical/subtropical region of the southern hemisphere; 3. to offer trans-national access to host experiments or measurement campaigns for focused process studies. © 2013 Author(s)., SCOPUS: ar.j, info:eu-repo/semantics/published
Published: 2013

49. Reorganization of Asian climate in relation to Tibetan Plateau uplift

Author: Fuli Wu, Xiaomin Fang, Yibo Yang, Guillaume Dupont-Nivet, Junsheng Nie, Frédéric Fluteau, Tao Zhang, Wenxia Han, Chinese Academy of Sciences [Beijing] (CAS), Lanzhou University, Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Linyi University, Second Tibetan Plateau Scientific Expedition and Research (2019QZKK0707), National Natural Science Foundation of China BSCTPES project (41988101-01), and Strategic Priority Research Program of Chinese Academy of Sciences (XDA20070201).
Subjects: [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, Atmospheric Science, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Pollution, Nature and Landscape Conservation, Earth-Surface Processes
Abstract: International audience; Reorganization of the Asian climate from one dominated by global planetary wind systems to a regional monsoon climate is closely related to the surface uplift of the Tibetan Plateau (TP). However, evaluating this climatic reorganization is limited by difficulty in constraining the complex, multistaged uplift of the TP and contradictory evidence regarding Asian Monsoon onset. In this Review, we summarize proxy and model evidence for Asian Monsoon initiation at different latitudes to identify the main controls on monsoon evolution. Stratigraphy and palaeoclimate proxy records indicate that the Asian climate was reorganized in a two-stage northward expansion process. At ~41 million years ago (Ma), the monsoon advanced northwards from the tropic to the southern subtropical regions (~26° N, approximately present-day Yunnan), probably driven by central TP uplift, global cooling and rapid regression of the proto-Paratethys Sea. At ~26 Ma, the monsoon expanded northwards into temperate regions (~30–36° N, equivalent to the present-day Asian Monsoon boundary), likely driven by TP growth and global warming. Additional proxy records are needed to fill regional gaps, establishing more solid boundary conditions and improving parameter constraints for climate models.
Published: 2022

50. TESS and CHEOPS Discover Two Warm Sub-Neptunes Transiting the Bright K-dwarf HD 15906

Author: Tuson, A., Queloz, D., Osborn, H. P., Wilson, T. G., Hooton, M. J., Beck, M., Lendl, M., Olofsson, G., Fortier, A., Bonfanti, A., Brandeker, A., Buchhave, L. A., Collier Cameron, A., Ciardi, D. R., Collins, K. A., Gandolfi, D., Garai, Z., Giacalone, S., Gomes da Silva, J., Howell, S. B., Patel, J. A., Persson, C. M., Serrano, L. M., Sousa, S. G., Ulmer-Moll, S., Vanderburg, A., Ziegler, C., Alibert, Y., Alonso, R., Anglada, G., Bàrczy, T., Barrado Navascues, D., Barros, S. C. C., Baumjohann, W., Beck, T., Benz, W., Billot, N., Bonfils, X., Borsato, L., Broeg, C., Cabrera, J., Charnoz, S., Conti, D. M., Csizmadia, Szilard, Cubillos, P. E., Davies, M. B., Deleuil, M., Delrez, L., Demangeon, O. D. S., Demory, B. -O., Dragomir, D., Dressing, C. D., Ehrenreich, D., Erikson, A., Essack, Z., Farinato, J., Fossati, L., Fridlund, M., Furlan, E., Gill, H., Gillon, M., Gnilka, C. L., Gonzales, E.J., Güdel, M., Günther, M. N., Hoyer, S., Isaak, K. G., Jenkins, J. M., Kiss, L. L., Laskar, J., Latham, D. W., Law, N., Lecavelier des Etangs, A., Curto, G. Lo, Lovis, C., Luque, R., Magrin, D., Mann, A. W., Maxted, P. F. L., Mayor, M., McDermott, S., Mecina, M., Mordasini, C., Mortier, A., Nascimbeni, V., Ottensamer, R., Pagano, I., Palle, E., Peter, G., Piotto, G., Pollacco, D., Pritchard, T., Ragazzoni, R., Rando, N., Ratti, F., Rauer, H, Ribas, I., Ricker, G. R., Rieder, M., Santos, N. C., Savel, A. B., Scandariato, G., Schwarz, R. P., Seager, S., Ségransan, D., Shporer, A., Simon, A. E., Smith, A. M. S., Steller, M., Stockdale, C., Szabó, Gy. M., Thomas, N., Torres, G., Tronsgaard, R., Udry, S., Ulmer, B., Van Grootel, V., Vanderspek, R., Venturini, J., Walton, N. A., Winn, J. N., Wohler, B., Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), and Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), planets and satellites: detection, fundamental parameters [Planets and satellites], photometric [Techniques], TIC 4646810), individual: HD 15906 (TOI 461, TIC 4646810) [Stars], FOS: Physical sciences, fundamental parameters [Stars], detection [Planets and satellites], techniques: photometric, [SDU]Sciences of the Universe [physics], stars: fundamental parameters, stars: individual: HD 15906 (TOI 461, planets and satellites: fundamental parameters, Astrophysics - Earth and Planetary Astrophysics
Abstract: We report the discovery of two warm sub-Neptunes transiting the bright (G = 9.5 mag) K-dwarf HD 15906 (TOI 461, TIC 4646810). This star was observed by the Transiting Exoplanet Survey Satellite (TESS) in sectors 4 and 31, revealing two small transiting planets. The inner planet, HD 15906 b, was detected with an unambiguous period but the outer planet, HD 15906 c, showed only two transits separated by $\sim$ 734 days, leading to 36 possible values of its period. We performed follow-up observations with the CHaracterising ExOPlanet Satellite (CHEOPS) to confirm the true period of HD 15906 c and improve the radius precision of the two planets. From TESS, CHEOPS and additional ground-based photometry, we find that HD 15906 b has a radius of 2.24 $\pm$ 0.08 R$_\oplus$ and a period of 10.924709 $\pm$ 0.000032 days, whilst HD 15906 c has a radius of 2.93$^{+0.07}_{-0.06}$ R$_\oplus$ and a period of 21.583298$^{+0.000052}_{-0.000055}$ days. Assuming zero bond albedo and full day-night heat redistribution, the inner and outer planet have equilibrium temperatures of 668 $\pm$ 13 K and 532 $\pm$ 10 K, respectively. The HD 15906 system has become one of only six multiplanet systems with two warm ($\lesssim$ 700 K) sub-Neptune sized planets transiting a bright star (G $\leq$ 10 mag). It is an excellent target for detailed characterisation studies to constrain the composition of sub-Neptune planets and test theories of planet formation and evolution., 30 pages, 20 figures, 11 tables (including appendix). Published in MNRAS
Published: 2023

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