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101. Monitoring water vapour in the upper troposphere with Raman lidar

Author

Keckhut, Philippe, Hoareau, Christophe, Porteneuve, Jacques, Hauchecorne, Alain, Baray, Jean-Luc, Courcoux, Yann, 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 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), 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 Alarcon, Nicolas

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; Communication about Monitoring water vapour in the upper troposphere with Raman lidar

Published
2010

102. Tropospheric ozone and stratosphere-to-troposphere exchange in the Southern Indian Ocean and South Africa

Author

Baray, Jean-Luc, Clain, Gaëlle, Duflot, Valentin, Posny, Françoise, Bonne, Jean-Louis, Delmas, Robert, 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), 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
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Tropospheric ozone and stratosphere-to-troposphere exchange in the Southern Indian Ocean and South Africa

Published
2010

103. Assessment of biomass burning aerosols absorption properties over the Southern Indian Ocean

Author

Duflot, Valentin, Chazette, Patrick, Royer, P., Courcoux, Yann, Delmas, Robert, Baray, Jean-Luc, 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 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), LEOSPHERE France, LEOSPHERE, 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, and 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)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], fungi, education, respiratory system, complex mixtures, health care economics and organizations
Abstract

International audience; Communication about Assessment of biomass burning aerosols absorption properties over the Southern Indian Ocean

Published
2010

104. Preliminary Statistical Study of subtropical water vapor profiles from Raman LIDAR at La Reunion (21°S, 55°E) over the period 2002-2005

Author

Hoareau, Christophe, Keckhut, Philippe, Baray, Jean-Luc, Goutail, Florence, Porteneuve, Jacques, Courcoux, Yann, 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 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), Alarcon, Nicolas, 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], [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Ground based lidars can provide continuous observations of tropospheric water vapor profiles using the Raman scattering by water vapor and nitrogen molecules. A Raman water vapor lidar was deployed at La Reunion over the period 2002-2005 in aim to perform a preliminary study of water vapor monitoring and evaluate the needs in view of a more specific lidar system to be implemented at the Observatory of Physique de l’Atmosphère de La Reunion (OPAR). A statistical study of the distribution of water vapor profiles is presented, and some investigations concerning the calibration have been evaluated. The data set having several long acquisition measurements during nighttime, an analysis of the diurnal cycle of water vapor has also been investigated. Based on these results, the characteristics and the design of a future lidar system to be implemented at the new observatory (2000 meters) for long-term water vapor monitoring are presented.

Published
2010

105. First observations of low-level dynamics over Reunion Island using UHF wind-profiler data over one year

Author

Lester, Dan, Campistron, Bernard, Baray, Jean-Luc, GHEUSI, François, Delmas, Robert, 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 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), 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]
Abstract

International audience; Communication about First observations of low-level dynamics over Reunion Island using UHF wind-profiler data over one year

Published
2010

106. L'implication de l'OPAR (Observatoire de Physique de l'Atmosphère de la Réunion) dans ROSEA (Réseau d'Observatoires pour la Surveillance de l'Eau Atmosphérique)

Author

Baray, Jean-Luc, Delmas, Robert, Bencherif, Hassan, Plu, Matthieu, Laboratoire de l'Atmosphère et des Cyclones (LACy), 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
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

National audience; Communication about Une infrastructure de recherche sous les tropiques : Le LACy et l'OPAR au sein de l'Observatoire des Sciences de l'Univers de la Réunion

Published
2010

107. Time-series of biomass burning products from ground-based FTIR measurements at Reunion Island (21°S, 55°E) and comparisons with the CTM IMAGES

Author

Vigouroux, Corinne, De Mazière, Martine, Dils, Bart, Müller, Jean-François, Senten, Cindy, Stavrakou, Trissevgeni, Vanhaelewyn, Gauthier, Fally, Sophie, Duflot, Valentin, Baray, Jean-Luc, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Laboratoire de Spectrométrie de Masse et de Chimie Laser (LSMCL), Université Paul Verlaine - Metz (UPVM), 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), 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
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Reunion Island (21°S, 55°E) is part of the Network for the Detection of Atmospheric Composition Change (NDACC), a network dedicated to performing high-quality long-term ground-based observations of atmospheric trace gases at globally distributed sites. Up to now, only a few NDACC stations are located in the Southern Hemisphere, and particularly very few at tropical and subtropical latitudes. Furthermore, Reunion Island is situated in the Indian Ocean, at 2000 km from southeast Africa and at only 700 km from Madagascar. It is therefore a good location to study the transport of biomass burning products from these regions to Reunion Island. Ground-based Fourier transform infrared (FTIR) solar absorption observations are sensitive to a large number of biomass burning products. At present, we have a record of such FTIR observations at Reunion Island from three measurement campaigns, namely in October 2002, from August to October 2004, and from May to October 2007, and from continuous observations that started in May 2009. The measurements in 2007 and 2009-2010 allow the observation of seasonal variability. In this work, we present retrieved time-series of several biomass burning products such as C2H2, C2H6 and HCN. These ground-based data are compared to the CTM IMAGES. The Lagrangian particle dispersion model FLEXPART is used to explain the day-to-day variability of these species by the transport pathways.

Published
2010

108. Introduction to the Maïdo Lidar Calibration Campaign dedicated to the validation of upper air meteorological parameters

Author

Keckhut, Philippe, primary, Courcoux, Yann, additional, Baray, Jean-Luc, additional, Porteneuve, Jacques, additional, Vérèmes, Hélène, additional, Hauchecorne, Alain, additional, Dionisi, Davide, additional, Posny, Françoise, additional, Cammas, Jean-Pierre, additional, Payen, Guillaume, additional, Gabarrot, Franck, additional, Evan, Stephanie, additional, Khaykin, Sergey, additional, Rüfenacht, Rolf, additional, Tschanz, Brigitte, additional, Kämpfer, Niklaus, additional, Ricaud, Philippe, additional, Abchiche, Abdel, additional, Leclair-de-Bellevue, Jimmy, additional, and Duflot, Valentin, additional

Published
2015
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109. The Atmospheric Observatory of Reunion Island

Author

Delmas, Robert, Baray, Jean-Luc, Courcoux, Yann, Alarcon, Nicolas, 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), 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), 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], [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about The Atmospheric Observatory of Reunion Island

Published
2010

110. Biomass burning aerosols in the southern Indian Ocean: Retrieval of optical properties

Author

Duflot, Valentin, Royer, P., Chazette, Patrick, Courcoux, Yann, Delmas, Robert, Baray, Jean-Luc, Alarcon, Nicolas, 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 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), LEOSPHERE France, LEOSPHERE, 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), 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, and 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)

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; Communication about Analysis of the origin of the distribution of CO in the subtropical Southern Indian Ocean in 2007

Published
2010

111. Satellite validation with lidar

Author

van Gijsel, J. A. E., Swart, D. P. J., Baray, Jean-Luc, Bencherif, Hassan, Claude, Hans, Fehr, T., Godin-Beekmann, Sophie, Hansen, G. H., Keckhut, Philippe, Leblanc, Thierry, Mcdermid, I. Stuart, Nakane, H., Quel, E. J., Stebel, K., Steinbrecht, Wolfgang, Strawbridge, K. B., Tatarov, B. I., National Institute for Public Health and the Environment [Bilthoven] (RIVM), 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), Meteorologisches Observatorium Hohenpeißenberg (MOHp), Deutscher Wetterdienst [Offenbach] (DWD), 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), Norwegian Institute for Air Research (NILU), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), National Institute for Environmental Studies (NIES), Centro de Investigaciones en Láseres y Aplicaciones [Buenos Aires] (CEILAP), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Instituto de Investigaciones Científicas y Técnicas para la Defensa (CITEDEF), Science and Technology Branch, Alarcon, Nicolas, 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], [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; The "Satellite validation with lidar" (VALID) project supports the long-term multi-mission validation of atmospheric chemistry and physics instruments with ground-based lidars. VALID involves lidar stations around the world measuring stratospheric ozone and temperature profiles, and tropospheric aerosol and cloud properties. Currently over 8000 lidar profiles have been made available for validation purposes in VALID and its predecessor EQUAL (ENVISAT quality assessment with lidar). The satellite data under investigation here are the ozone and temperature profiles delivered by the GOMOS (Global ozone monitoring by occultation of stars), MIPAS (Michelson interferometer for passive atmospheric sounding) and SCIAMACHY (Scanning imaging absorption spectrometer for atmospheric chartography) instruments. We have collocated these profiles with the lidar measurements and analysed the comparison results for dependence on several geophysical and instrument observational parameters, keeping a close look at the instruments’ performances during the seven years of data acquisition. Validation results will be presented for the operational ESA products and various scientific products.

Published
2009

112. Contribution au développement d'une station d'observation de l'Atmosphère à la Réunion et à l'étude de l'ozone troposphérique en région tropicale

Author

Baray, Jean-Luc, 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), Université de la Réunion, and Jean Leveau

Subjects
biomass burning, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Station d'observation atmospherique, trends and climatology, feux de biomasse, radiometer, stratosphere-troposphere exchange, radiomère, échanges stratosphère-troposphère, ozone, radiosonde, tendances et climatologie, Station of atmospheric observation, lidar, radiosondages
Abstract

This document is a synthesis of about ten years of scientific activity at Reunion Island in the Southern Tropics, as “physicien adjoint” affected to IPSL and detached to Reunion university, in the laboratory LPA which became LACY while joining Meteo-France. This document thus contains a presentation of instrumental development of the station OPAR and its place in the international networks of research, which corresponds to my mission of participation in the observation services. A synthesis of the main results obtained within the tropical tropospheric ozone problematic is then presented. Indeed, this ten years of tropospheric ozone measurements by lidar and radiosonde has allowed us to look further into detail cases studies of mechanisms source of tropospheric ozone at Reunion Island, to establish the climatology of ozone and of the tropopause and to release the first estimates of trends of tropospheric ozone.; Ce document constitue une synthèse de ma dizaine d'années d'activité scientifique passées sous les tropiques, en tant que physicien adjoint affecté à l'IPSL et détaché à la Réunion, au LPA qui devint LACY en s'associant à Météo-France. Ce document contient donc une présentation de l'essor instrumental de la station de l'OPAR et sa place dans les réseaux de recherche internationaux, qui reflète mon activité dans le cadre de ma mission de participation aux services d'observation. Une synthèse des principaux résultats obtenus par rapport au bilan de l'ozone troposphérique tropical est ensuite présentée. En effet, cette dizaine d'années d'observation de l'ozone troposphérique par lidar et radiosondages nous a permis d'approfondir des cas d'études pour détailler les mécanismes source de l'ozone troposphérique à la Réunion, d'établir la climatologie de l'ozone et de la tropopause et de dégager les premières estimations de tendances de l'ozone troposphérique.

Published
2009

113. Contribution to the development of a station of atmospheric observation at Reunion Island and to the study of tropospheric ozone in tropical region

Author

Baray, Jean-Luc, 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), Université de la Réunion, and Jean Leveau

Subjects
biomass burning, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Station d'observation atmospherique, trends and climatology, feux de biomasse, radiometer, stratosphere-troposphere exchange, radiomère, échanges stratosphère-troposphère, ozone, radiosonde, tendances et climatologie, Station of atmospheric observation, lidar, radiosondages
Abstract

This document is a synthesis of about ten years of scientific activity at Reunion Island in the Southern Tropics, as “physicien adjoint” affected to IPSL and detached to Reunion university, in the laboratory LPA which became LACY while joining Meteo-France. This document thus contains a presentation of instrumental development of the station OPAR and its place in the international networks of research, which corresponds to my mission of participation in the observation services. A synthesis of the main results obtained within the tropical tropospheric ozone problematic is then presented. Indeed, this ten years of tropospheric ozone measurements by lidar and radiosonde has allowed us to look further into detail cases studies of mechanisms source of tropospheric ozone at Reunion Island, to establish the climatology of ozone and of the tropopause and to release the first estimates of trends of tropospheric ozone.; Ce document constitue une synthèse de ma dizaine d'années d'activité scientifique passées sous les tropiques, en tant que physicien adjoint affecté à l'IPSL et détaché à la Réunion, au LPA qui devint LACY en s'associant à Météo-France. Ce document contient donc une présentation de l'essor instrumental de la station de l'OPAR et sa place dans les réseaux de recherche internationaux, qui reflète mon activité dans le cadre de ma mission de participation aux services d'observation. Une synthèse des principaux résultats obtenus par rapport au bilan de l'ozone troposphérique tropical est ensuite présentée. En effet, cette dizaine d'années d'observation de l'ozone troposphérique par lidar et radiosondages nous a permis d'approfondir des cas d'études pour détailler les mécanismes source de l'ozone troposphérique à la Réunion, d'établir la climatologie de l'ozone et de la tropopause et de dégager les premières estimations de tendances de l'ozone troposphérique.

Published
2009

114. Tropospheric ozone trends in the southern subtropics (Reunion Island and South Africa) based on radiosondes linear regression analysis

Author

Baray, Jean-Luc, Delmas, Robert, Clain, Gaëlle, Leclair de Bellevue, Jimmy, Posny, Françoise, Metzger, Jean-Marc, Keckhut, Philippe, Diab, Roseanne, 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, Service d'aéronomie (SA), 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), School of Environmental Sciences [Durban], University of KwaZulu-Natal (UKZN), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, and University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Tropospheric ozone trends in the southern subtropics (Reunion Island and South Africa) based on radiosondes linear regression analysis

Published
2008

115. Detection of stratospheric intrusions in the troposphere with a lagrangian approach at Reunion Island (Southern Subtropics, Indian Ocean)

Author

Clain, Gaëlle, Baray, Jean-Luc, Delmas, Robert, 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), 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
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Detection of stratospheric intrusions in the troposphere with a lagrangian approach at Reunion Island (Southern Subtropics, Indian Ocean)

Published
2008

116. Télédétection Appliquée à l'Observation de l'Atmosphère : région tropicale de l'hémisphère sud

Author

Bencherif, Hassan, Baray, Jean-Luc, Courcoux, Yann, Laboratoire de l'Atmosphère et des Cyclones (LACy), 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
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Télédétection Appliquée à l'Observation de l'Atmosphère : région tropicale de l'hémisphère sud

Published
2008

117. Ozone climatology in the southern subtropics

Author

Clain, Gaëlle, Baray, Jean-Luc, Delmas, Robert, Diab, R., Leclair De Bellevue, Jimmy, Posny, Françoise, 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, School of Environmental Sciences [Durban], University of KwaZulu-Natal (UKZN), 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), and Université Fédérale Toulouse Midi-Pyrénées

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Ozone climatology in the southern subtropics

Published
2008

118. Stratosphere-troposphere exchange study in the Southern subtropics using experimental data, trajectory and Reverse Domain Filling calculations

Author

Baray, Jean-Luc, Delmas, Robert, Clain, Gaëlle, Gabarrot, Franck, Cammas, Jean-Pierre, Keckhut, Philippe, 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), 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, Service d'aéronomie (SA), 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), 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), 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.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Stratosphere-troposphere exchange study in the Southern subtropics using experimental data, trajectory and Reverse Domain Filling calculations

Published
2008

119. L'OPAR (Observatoire de Physique de l'Atmosphère de la Réunion), un site privilégié pour l'étude de l'atmosphère tropicale : parc instrumental, résultats scientifiques et projets

Author

Baray, Jean-Luc, Delmas, Robert, Courcoux, Yann, Metzger, Jean-Marc, Ferré, H., Gabarrot, Franck, Keckhut, Philippe, Porteneuve, Jacques, 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, Service d'aéronomie (SA), 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), 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]
Abstract

National audience; Communication about L'OPAR (Observatoire de Physique de l'Atmosphère de la Réunion), un site privilégié pour l'étude de l'atmosphère tropicale : parc instrumental, résultats scientifiques et projets

Published
2008

120. Observations of halogens, CO, CH4, and H2CO at Ile de La Réunion from ground-based FTIR and MAXDOAS campaign measurements

Author

De Mazière, Martine, Vigouroux, Corinne, Hendrick, François, Vanhaelewyn, Gauthier, De Smedt, Isabelle, Van Roozendael, Michel, Dils, Bart, Hermans, Christian, Kruglanski, Michel, Merlaud, Alexis, Scolas, Francis, Senten, Cindy, Carleer, Michel, Fally, Sophie, Duflot, Valentin, Metzger, Jean-Marc, Baray, Jean-Luc, Delmas, Robert, Duchatelet, Pierre, 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)-Météo France-Université de La Réunion (UR)-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
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

Poster; International audience; Ile de La Réunion is a complementary site in the Network for the Detection of Atmospheric Composition Change (NDACC), situated in the southern tropics, at 21°S, 55°E. In support of a better understanding of atmospheric chemistry and physics above tropical regions, we have implemented new ground-based MAX-DOAS (multi-axis DOAS) and FTIR (Fourier transform infrared) observations at this site, on a campaign basis since 2002. At present, we have data from 2002 (month of October), 2004 (August to October) and 2007 (end of May until the end of October). Additional campaigns are planned until the availability of a new infrastructure for permanent observations at the Maido (~ 2000 masl), around 2010. Here, we report on the available time series for a number of tropospheric species (CO, H2CO and CH4,) and stratospheric halogen species, comparisons between MAX-DOAS and FTIR data of H2CO, and comparisons of ground-based and satellite data.

Published
2008

121. A Raman lidar at Maïdo Observatory (Reunion Island) to measure water vapor in the troposphere and lower stratosphere: calibration and validation.

Author

Vérèmes, Hélène, Payen, Guillaume, Keckhut, Philippe, Duflot, Valentin, Baray, Jean-Luc, Cammas, Jean-Pierre, De Bellevue, Jimmy Leclair, Evan, Stéphanie, Posny, Françoise, Gabarrot, Franck, Metzger, Jean-Marc, Marquestaut, Nicolas, Meier, Susanne, Vömel, Holger, and Dirksen, Ruud

Subjects
ATMOSPHERIC water vapor measurement, LIDAR, FOURIER transform infrared spectroscopy
Abstract

The Maïdo high-altitude observatory located in Reunion Island (21°?S, 55.5°?E) is equipped with Lidar1200, an innovative Raman lidar designed to measure the water vapor mixing ratio in the troposphere and the lower stratosphere. The calibration methodology is based on a GNSS (Global Navigation Satellite System) IWV (Integrated Water Vapor) dataset and lamp measurements. The mean relative standard error on the calibration coefficient is around 2.7?%. Two years of lidar water vapor measurements from November 2013 to October 2015 are now processed. By comparing CFH (Cryogenic Frost point Hygrometer) radiosonde profiles with the Raman lidar profiles, the ability of the lidar to provide accurate measurements is possible up to 22?km. The ability of measuring water vapor mixing ratios of a few ppmv in the lower stratosphere is demonstrated with a 48-hours integration time period, an absolute error lower than 0.8?ppmv and a relative error less than 20?%. This Raman lidar is dedicated to provide regular profiles of water vapor measurements with a high vertical resolution and low uncertainties to international networks; in the wider interest of research on stratosphere-troposphere exchange processes and on the long-term survey of water vapor in the upper troposphere and lower stratosphere in the Southern Hemisphere. A strategy of data sampling and filtering is proposed to meet these objectives with regard to the altitude range requested. 10-min time integration and 65-90?m vertical resolution ensure a vertical profile reaching 10?km, but more than 2800 minutes and a vertical resolution of 150-1300?m are necessary to reach the lower stratosphere with an uncertainty less than 20?%. [ABSTRACT FROM AUTHOR]

Published
2017
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122. Ozone profiles by DIAL at Maïdo Observatory (Reunion Island) Part 1. Tropospheric ozone lidar: system description, performances evaluation and comparison with ancillary data.

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, and Cammas, Jean-Pierre

Subjects
*OZONE, *LIDAR, *TROPOSPHERE
Abstract

Recognizing the importance of ozone in the troposphere and lower stratosphere in the tropics, a DIAL tropospheric ozone lidar system (LIO3TUR) was developped and installed at the Université de la Réunion campus site (close to the sea) in Reunion Island (southern tropics) in 1998. From 1998 to 2010, it acquired 427 ozone 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 m above mean sea level - amsl) where it started operation in February 2013. The current system (LIO3T) configuration generates a 266 nm 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 nm beams enabling the use of the DIAL method for ozone profile measurements. Optimal range for the actual system is 6-19 km amsl, depending on the instrumental and atmospheric conditions; for a 1-hour integration time, vertical resolution varies from 0.7 km at 6 km amsl to 1.3 km at 19 km amsl, and mean uncertainty within the 6-19 km range is between 6 and 13 %. Comparisons with 8 electrochemical concentration cell (ECC) sondes simultaneously launched from the Maïdo Observatory show a good agreement between datasets with a 7.7 % mean absolute value of the relative differences with respect to the mean (D) between 6 and 17 km amsl (LIO3T low); comparisons with 37 ECC sondes launched from the nearby Gillot site during day time in a ±24-hour window around lidar shooting result in a 10.3 % D between 6 and 19 km amsl (LIO3T low); comparisons with 11 ground-based Network for Detection of Atmosphere Composition Change (NDACC) Fourier Transform Infrared (FTIR) spectrometer measurements acquired during day time in a ±24-hour window around lidar shooting show a good agreement between datasets with a D of 11.8 % for the 8.5-16 km partial column (LIO3T high); and comparisons with 39 simultaneous Infrared Atmospheric Sounding Interferometer (IASI) observations over Reunion Island show a good agreement between datasets with a D of 11.3 % for the 6-16 km partial column (LIO3T high). 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, the ozonopause altitude decrease in late austral winter-spring, as well as the signature of deep convection bringing boundary layer-ozone poor air masses up to the mid-upper troposphere in late austral summer, are clearly visible on all datasets. [ABSTRACT FROM AUTHOR]

Published
2017
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123. 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

Baray, Jean Luc, Portafaix, Thierry, Tulet, Pierre, Cammas, Jean Pierre, Duflot, Valentin, Vérèmes, H., Leclair De Bellevue, J., Barthe, Christelle, Posny, Françoise, Delmas, Robert, Gabarrot, Franck, Gaudo, T., Metzger, J.M., Payen, G., Sellegri, Karine, Colomb, Aurélie, Courcoux, Yann, Keckhut, Philippe, Hauchecorne, Alain, Godin Beekmann, Sophie, Dionisi, D., Porteneuve, Jacques, De Mazière, Martine, Desmet, F., Ramonet, Michel, Sciare, Jean, Vuillemin, C., Hoareau, Christophe, Ricaud, Philippe, Abchiche, A., Baray, Jean Luc, Portafaix, Thierry, Tulet, Pierre, Cammas, Jean Pierre, Duflot, Valentin, Vérèmes, H., Leclair De Bellevue, J., Barthe, Christelle, Posny, Françoise, Delmas, Robert, Gabarrot, Franck, Gaudo, T., Metzger, J.M., Payen, G., Sellegri, Karine, Colomb, Aurélie, Courcoux, Yann, Keckhut, Philippe, Hauchecorne, Alain, Godin Beekmann, Sophie, Dionisi, D., Porteneuve, Jacques, De Mazière, Martine, Desmet, F., Ramonet, Michel, Sciare, Jean, Vuillemin, C., Hoareau, Christophe, Ricaud, Philippe, and Abchiche, A.

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

124. Étude des transferts stratosphère-troposphère en bordure sud de la zone tropicale et impact sur le bilan d'ozone troposphérique

Author

Baray, Jean-Luc, 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 Pierre et Marie Curie - Paris VI, and Serge Baldy

Subjects
courant-jet subtropical, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, subtropical jet-stream, ozone, cyclone tropical, subtropical tropopause fold, tropical cyclone, foliation subtropicale, échange stratosphère-troposphère, lidar ozone troposphérique, tropospheric ozone lidar, stratosphere-troposphere exchange
Abstract

The stratosphere-troposphere exchanges induced by the polar jet-stream of the northern hemisphere are well documented. In the subtropics, since few data are available, studies of stratosphere-troposphere exchanges are limited. These exchange result from jet-stream instabilities, and also from the detrainment of stratospheric air induced by deep convection in cyclones and in the inter-tropical convergence zone. Using the Reunion station data base of radiosoundings performed at a semi-monthly frequency, and also various other experimental data, (satellite and ECMWF global model data), a first qualitative approach based on cases study is presented. The concepts of ageostrophism, jet-streak and upper level frontogenesis, allowed to characterise and analyse the formation of several subtropical tropopause folds and cut-off lows. A strong subsiding transfer on April 6, 1995 (300 ppbv at altitude 10 km), following from the cyclone Marlene activity, is suggested in the peripheral part of the cyclone, at approximately 1000 km of the centre of the cyclone. The dynamic analysis seems to indicate a limited horizontal extension transfer, which would involve typically dynamic meso-scale mechanisms. To allow a better tropospheric ozone monitoring, an ozone lidar, range toping near the high tropical tropopause, has been developed and installed at Reunion university. The results, obtained within the framework of the TRACAS campaign in July 1998, evidenced very regular stratospheric ozone in the free troposphere, during the whole month of measurement. ECMWF and Meteosat analyses led evidence of a planetary-scale tropopause fold. These mechanisms are necessarily different from midlatitude folds, and could be controlled by the return flow of the Indian monsoon, and by the downward branch of the southern Hadley cell.; Les échanges entre la stratosphère et la troposphère induits par le courant-jet de l'hémisphère Nord sont bien documentés. Cependant, peu de données sont disponibles dans les régions subtropicales, ce qui a longtemps limité les études des échanges stratosphère-troposphère dans ces régions, en relation d'une part à la barrière dynamique et au courant-jet subtropical de l'hémisphère sud, et, d'autre part, à la convection tropicale, nuages convectifs tropicaux, cyclones et zone de convergence intertropicale. Se basant principalement sur l'analyse des radiosondages effectués à un rythme bimensuel par le laboratoire depuis 1992, complétés par diverses autres données expérimentales, satellitales, et des sorties du modèle dynamique global du centre européen ECMWF, une première approche qualitative a débouché sur l'identification et l'analyse de plusieurs cas d'étude. Les concepts d'agéostrophisme, de jet-streak et de frontogénèse d'altitude ont permis de caractériser et d'analyser la formation de plusieurs foliations subtropicales et gouttes froides d'altitude. Les échanges entre la stratosphère et la troposphère en relation avec la convection tropicale, ont été ensuite abordés, dans un cas de transfert subsident intense le 6 avril 1995 (300 ppbv à l'altitude 10 km), alors que la Réunion était dans la partie périphérique du cyclone Marlène, à environ 1000 km du centre du cyclone. Après vérification de la bonne prise en compte du cyclone par les données des modèles utilisés (NMC et ECMWF), l'analyse dynamique semble indiquer une extension horizontale assez limitée du transfert, qui serait constitué typiquement par des mécanismes dynamiques à méso-echelle. Pour permettre un meilleur suivi temporel de la concentration d'ozone troposphérique, un lidar ozone a été installé à la Réunion. Les résultats obtenus dans le cadre de la campagne TRACAS en juillet 1998 ont montré des apports d'ozone ayant une origine stratosphérique dans la troposphère, d'une manière extrêmement régulière pendant le mois de campagne de mesure. L'analyse dynamique au moyen des données du modèle européen et des données Météosat a permis la mise en évidence d'un pli de la tropopause d'échelle planétaire. Ces mécanismes sont nécessairement différents de ceux mis en jeu dans les latitudes moyennes et pourraient être contrôlés par le flux de retour de mousson et la branche descendante de la cellule de Hadley.

Published
1999

125. Technical Note: New ground-based FTIR measurements at Ile de la Réunion: Observations, error analysis, and comparisons with independent data

Author

Senten, C., De Mazière, Martine, Dils, Bart, Hermans, Christian, Kruglanski, Michel, Neefs, E., Scolas, F., Vandaele, Ann Carine, Vanhaelewyn, G., Vigouroux, Corinne, Carleer, Michel, Coheur, Pierre, Fally, Sophie, Barret, Brice, Baray, Jean Luc, Delmas, Robert, Leveau, J., Metzger, J.M., Mahieu, Emmanuel, Boone, Chris, Walker, Kaley, Bernath, Peter, Strong, Kimberly, Senten, C., De Mazière, Martine, Dils, Bart, Hermans, Christian, Kruglanski, Michel, Neefs, E., Scolas, F., Vandaele, Ann Carine, Vanhaelewyn, G., Vigouroux, Corinne, Carleer, Michel, Coheur, Pierre, Fally, Sophie, Barret, Brice, Baray, Jean Luc, Delmas, Robert, Leveau, J., Metzger, J.M., Mahieu, Emmanuel, Boone, Chris, Walker, Kaley, Bernath, Peter, and Strong, Kimberly

Abstract

info:eu-repo/semantics/published

Published
2008

126. An instrumented station for the survey of ozone and climate change in the southern tropics

Author

Baray, Jean Luc, Baldy, S., Jouzel, Jean, Keckhut, Philippe, Bergametti, G., Ancellet, G., Bencherif, H., Cadet, B., Carleer, Michel, David, Christiane, De Mazière, Martine, Faduilhe, D., Beekmann, S.G., Goloub, P., Goutail, Florence, Metzger, J.M., Morel, B., Pommereau, Jean Pierre, Porteneuve, Jacques, Portafaix, Thierry, Posny, Françoise, Robert, L., Van Roozendael, Michel, Baray, Jean Luc, Baldy, S., Jouzel, Jean, Keckhut, Philippe, Bergametti, G., Ancellet, G., Bencherif, H., Cadet, B., Carleer, Michel, David, Christiane, De Mazière, Martine, Faduilhe, D., Beekmann, S.G., Goloub, P., Goutail, Florence, Metzger, J.M., Morel, B., Pommereau, Jean Pierre, Porteneuve, Jacques, Portafaix, Thierry, Posny, Françoise, Robert, L., and Van Roozendael, Michel

Abstract

info:eu-repo/semantics/published

Published
2006

128. Review of ozone and temperature lidar validations performed within the framework of the Network for the Detection of Stratospheric Change

Author

Keckhut, Philippe, McDermid, Stuart, Swart, Daan, McGee, Thomas, Godin-Beekmann, Sophie, Adriani, Alberto, Barnes, John, Baray, Jean-Luc, Bencherif, Hassan, Claude, Hans, di Sarra, Aleide G., Fiocco, Georgio, Hansen, Georg, Hauchecorne, Alain, Leblanc, Thierry, Lee, Choo Hie, Pal, Shiv, Megie, Gerard, Nakane, Hideaki, Neuber, Roland, Steinbrecht, Wolfgang, Thayer, Jeffrey, Keckhut, Philippe, McDermid, Stuart, Swart, Daan, McGee, Thomas, Godin-Beekmann, Sophie, Adriani, Alberto, Barnes, John, Baray, Jean-Luc, Bencherif, Hassan, Claude, Hans, di Sarra, Aleide G., Fiocco, Georgio, Hansen, Georg, Hauchecorne, Alain, Leblanc, Thierry, Lee, Choo Hie, Pal, Shiv, Megie, Gerard, Nakane, Hideaki, Neuber, Roland, Steinbrecht, Wolfgang, and Thayer, Jeffrey

Abstract

The use of assimilation tools for satellite validation requires true estimates of the accuracy of the reference data. Since its inception, the Network for Detection of Stratospheric Change (NDSC) has provided systematic lidar measurements of ozone and temperature at several places around the world that are well adapted for satellite validations. Regular exercises have been organised to ensure the data quality at each individual site. These exercises can be separated into three categories: large scale intercomparisons using multiple instruments, including a mobile lidar; using satellite observations as a geographic transfer standards to compare measurements at different sites; and comparative investigations of the analysis software. NDSC is a research network, so each system has its own history, design, and analysis, and has participated differently in validation campaigns. There are still some technological differences that may explain different accuracies. However, the comparison campaigns performed over the last decade have always proved to be very helpful in improving the measurements. To date, more efforts have been devoted to characterising ozone measurements than to temperature observations. The synthesis of the published works shows that the network can potentially be considered as homogeneous within +/-2% between 20-35 km for ozone and +/-1 K between 35-60 km for temperature. Outside this altitude range, larger biases are reported and more efforts are required. In the lower stratosphere, Raman channels seem to improve comparisons but such capabilities were not systematically compared. At the top of the profiles, more investigations on analysis methodologies are still probably needed. SAGE II and GOMOS appear to be excellent tools for future ozone lidar validations but need to be better coordinated and take more advantage of assimilation tools. Also, temperature validations face major difficulties caused by atmospheric tides and therefore require intercompari

Published
2004

131. Review of ozone and temperature lidar validations performed within the framework of the Network for the Detection of Stratospheric Change

Author

Keckhut, Philippe, primary, McDermid, Stuart, additional, Swart, Daan, additional, McGee, Thomas, additional, Godin-Beekmann, Sophie, additional, Adriani, Alberto, additional, Barnes, John, additional, Baray, Jean-Luc, additional, Bencherif, Hassan, additional, Claude, Hans, additional, di Sarra, Aleide G., additional, Fiocco, Georgio, additional, Hansen, Georg, additional, Hauchecorne, Alain, additional, Leblanc, Thierry, additional, Lee, Choo Hie, additional, Pal, Shiv, additional, Megie, Gerard, additional, Nakane, Hideaki, additional, Neuber, Roland, additional, Steinbrecht, Wolfgang, additional, and Thayer, Jeffrey, additional

Published
2004
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132. Climatology of the upper troposphere with lidar

Author

Keckhut, Philippe, primary, Ancellet, Gerard, additional, Goldfarb, Leah, additional, Hauchecorne, Alain, additional, Riedinger, Emmanuel, additional, Baray, Jean-Luc, additional, Cadet, Bertrand, additional, Leveau, Jean, additional, Randriambelo, Tantely, additional, Rechou, Anne, additional, and Robert, Laurent, additional

Published
2003
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136. Temporal variations of antimicrobial resistance genes in aerosols: A one-year monitoring at the puy de Dôme summit (Central France).

Author

Rossi F, Duchaine C, Tignat-Perrier R, Joly M, Larose C, Dommergue A, Turgeon N, Veillette M, Sellegri K, Baray JL, and Amato P

Subjects
Humans, Macrolides, Genes, Bacterial, France, Aerosols, Anti-Bacterial Agents pharmacology, Drug Resistance, Bacterial genetics
Abstract

The recent characterization of antibiotic resistance genes (ARGs) in clouds evidenced that the atmosphere actively partakes in the global spreading of antibiotic resistance worldwide. Indeed, the outdoor atmosphere continuously receives large quantities of particles of biological origins, emitted from both anthropogenic or natural sources at the near Earth's surface. Nonetheless, our understanding of the composition of the atmospheric resistome, especially at mid-altitude (i.e. above 1000 m a.s.l.), remains largely limited. The atmosphere is vast and highly dynamic, so that the diversity and abundance of ARGs are expected to fluctuate both spatially and temporally. In this work, the abundance and diversity of ARGs were assessed in atmospheric aerosol samples collected weekly between July 2016 and August 2017 at the mountain site of puy de Dôme (1465 m a.s.l., central France). Our results evidence the presence of 33 different subtypes of ARGs in atmospheric aerosols, out of 34 assessed, whose total concentration fluctuated seasonally from 59 to 1.1 × 10 5 copies m -3 of air. These were heavily dominated by genes from the quinolone resistance family, notably the qepA gene encoding efflux pump mechanisms, which represented >95 % of total ARGs concentration. Its abundance positively correlated with that of bacteria affiliated with the genera Kineococcus, Neorhizobium, Devosia or Massilia, ubiquitous in soils. This, along with the high abundance of Sphingomonas species, points toward a large contribution of natural sources to the airborne ARGs. Nonetheless, the increased contribution of macrolide resistance (notably the erm35 gene) during winter suggests a sporadic diffusion of ARGs from human activities. Our observations depict the atmosphere as an important vector of ARGs from terrestrial sources. Therefore, monitoring ARGs in airborne microorganisms appears necessary to fully understand the dynamics of antimicrobial resistances in the environment and mitigate the threats they may represent., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

Published
2024
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137. Exploring the size-dependent dynamics of photosynthetic cells in rainwater: The influence of atmospheric variables and rain characteristics.

Author

Noirmain F, Baray JL, Deguillaume L, Van Baelen J, and Latour D

Subjects
Ecosystem, Environmental Monitoring methods, Rain, Atmosphere analysis, Air Pollutants analysis, Inorganic Chemicals
Abstract

The presence of microalgae in the atmosphere raises health and environmental concerns. Despite recent scientific advances, our knowledge of the origins and dynamics of photosynthetic cells in relation to atmospheric processes is limited due to a lack of empirical data. To address this gap, we conducted a one-year survey, collecting and analyzing rainwater samples. This study proposes to investigate the temporal dynamics of photosynthetic cells based on their size in combination with a unique dataset of variables of interest: type of rain and its characteristics, local meteorology, concentrations of inorganic chemical species, and long-range air mass transport. The analysis of the biochemical composition of rainwater, along with its correlation with the origin of air masses using ions as tracers, provides evidence of the long-range transport of photosynthetic cells. Additionally, our study reveals distinct removal mechanisms from the atmosphere for photosynthetic cells depending on their size. Our results suggest that convective events with high-intensity rainfall led to the efficient removal of medium-sized photosynthetic cells (4-15 μm) from the atmosphere. However, removal mechanisms for small (<4 μm) and large-sized cells (>15 μm) are not influenced by microphysical rainfall characteristics and seem to be governed by different atmospheric processes: dry deposition is proposed to be a significant mechanism for the removal of large-sized photosynthetic cells, while small-sized cells detected in rain are correlated with the horizontal wind speed and duration of rainfall, particularly during stratiform events. This implies that the removal of photosynthetic cells from the atmosphere is strongly influenced by environmental variables, which are expected to vary in response to global change. Therefore, it is crucial to enhance the monitoring of photosynthetic cells in relation to atmospheric processes and investigate the potential impact of the dissemination of genetic material from distant sources on recipient ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Published
2024
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138. Modeling long-distance seed dispersal of the invasive tree Spathodea campanulata in the Society Islands.

Author

Larrue S, Baray JL, Chadeyron J, Meyer JY, Mazal L, Daehler CC, and Fumanal B

Subjects
Seeds, Introduced Species, Oceans and Seas, Islands, Trees, Seed Dispersal
Abstract

Long-distance dispersal is a key factor explaining the success of invasive alien species, particularly across oceanic islands. However, it is often not feasible to reliably measure long-distance seed dispersal (LDD) over many kilometers in the field. Here, we used a three-dimensional kinematic trajectory model (Computing Atmospheric Trajectory tool [CAT]) initiated on the basis of regional wind field data to assess the potential for LDD of a wind-dispersed invasive tree, Spathodea campanulata (African tulip tree), across the Society Islands (French Polynesia, South Pacific Ocean) following its initial planting and spread on the island of Tahiti. The main objective of our study was to determine whether S. campanulata could be expected to spread naturally among islands. Atmospheric dynamics, seed terminal velocity, precipitation, and temperature of air masses were considered to assess the potential for LDD between oceanic islands, with the island of Tahiti serving as the island source for multiple, geographically distant invasions. Aerial trajectories of modeled S. campanulata seeds indicated that wind-dispersed seeds originating from trees on the island of Tahiti could reach most of the Society Islands and disperse as far as 1364 km. This result suggests that Spathodea can be expected to spread naturally among the Society Islands. When rainfall events were modeled as causal agents of seed settlement, fewer seeds reached distant islands, but more seeds settled on the closest island (20 km away). Including effects of island topography ("barrier effects") also resulted in more seeds settling on the closest island and fewer seeds reaching the most distant islands. Overall, our findings suggest that recent atmospheric models can provide valuable insights into LDD and invasion patterns of wind-dispersed invasive species., (© 2023 The Ecological Society of America.)

Published
2023
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139. Quantification of antibiotic resistance genes (ARGs) in clouds at a mountain site (puy de Dôme, central France).

Author

Rossi F, Péguilhan R, Turgeon N, Veillette M, Baray JL, Deguillaume L, Amato P, and Duchaine C

Subjects
Humans, Genes, Bacterial, Tetracycline analysis, Bacteria genetics, Sulfanilamide, Drug Resistance, Microbial genetics, beta-Lactamases genetics, France, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents analysis, Quinolones
Abstract

Antibiotic resistance in bacteria is becoming a major sanitary concern worldwide. The extensive use of large quantities of antibiotics to sustain human activity has led to the rapid acquisition and maintenance of antibiotic resistant genes (ARGs) in bacteria and to their spread into the environment. Eventually, these can be disseminated over long distances by atmospheric transport. Here, we assessed the presence of ARGs in clouds as an indicator of long-distance travel potential of antibiotic resistance in the atmosphere. We hypothesized that a variety of ARGs can reach the altitude of clouds mainly located within the free troposphere. Once incorporated in the atmosphere, they are efficiently transported and their respective concentrations should differ depending on the sources and the geographical origin of the air masses. We deployed high-flow rate impingers and collected twelve clouds between September 2019 and October 2021 at the meteorological station of the puy de Dôme summit (1465 m a.s.l., France). Total airborne bacteria concentration was assessed by flow cytometry, and ARGs subtypes of the main families of antibiotic resistance (quinolone, sulfonamide, tetracycline; glycopeptide, aminoglycoside, β-lactamase, macrolide) including one mobile genetic element (transposase) were quantified by qPCR. Our results indicate the presence of 29 different ARGs' subtypes at concentrations ranging from 1.01 × 10 3 to 1.61 × 10 4 copies m -3 of air. Clear distinctions could be observed between clouds in air masses transported over marine areas (Atlantic Ocean) and clouds influenced by continental surfaces. Specifically, quinolones (mostly qepA) resistance genes were prevalent in marine clouds (54 % of the total ARGs on average), whereas higher contributions of sulfonamide, tetracycline; glycopeptide, β-lactamase and macrolide were found in continental clouds. This study constitutes the first evidence for the presence of microbial ARGs in clouds at concentrations comparable to other natural environments. This highlights the atmosphere as routes for the dissemination of ARGs at large scale., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Published
2023
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140. Original and Low-Cost ADS-B System to Fulfill Air Traffic Safety Obligations during High Power LIDAR Operation.

Author

Peyrin F, Fréville P, Montoux N, and Baray JL

Abstract

LIDAR is an atmospheric sounding instrument based on the use of high-power lasers. The use of these lasers involves fulfilling obligations with respect to air safety. In this article, we present a low-cost air traffic surveillance solution integrated into an automated operating system for the Rayleigh-Mie-Raman LIDAR of Clermont Ferrand and the statistical elements of its application over more than two years of operation from September 2019 to March 2022. Air traffic surveillance that includes the possibility of shutting off lasers is required by international regulations because LIDAR is equipped with a class four laser that presents potential dangers to aircraft flying overhead. The original system presented in this article is based on software-defined radio. ADS-B transponder frames are analyzed in real-time, and laser emission is stopped during LIDAR operation when an aircraft is detected within a 2 km radius around the LIDAR. The system was accredited in 2019 by the French air traffic authorities. Laser shutdowns due to the detection of aircraft near the Clermont Ferrand LIDAR caused a data loss rate of less than 2% during the period of application.

Published
2023
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141. Evaluation of the Sources, Precursors, and Processing of Aerosols at a High-Altitude Tropical Site.

Author

Dominutti PA, Chevassus E, Baray JL, Jaffrezo JL, Borbon A, Colomb A, Deguillaume L, El Gdachi S, Houdier S, Leriche M, Metzger JM, Rocco M, Tulet P, Sellegri K, and Freney E

Abstract

This work presents the results from a set of aerosol- and gas-phase measurements collected during the BIO-MAÏDO field campaign in Réunion between March 8 and April 5, 2019. Several offline and online sampling devices were installed at the Maïdo 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 PM 10 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 Réunion. 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., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Published
2022
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