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101. Past changes in the vertical distribution of ozone – Part 3: Analysis and interpretation of trends

Author

Jean-Christopher Lambert, J. D. Wild, M. De Mazière, Birgit Hassler, Adam Bourassa, Wolfgang Steinbrecht, Andy Delcloo, Neil R. P. Harris, Richard Querel, Alan Parrish, Corinne Vigouroux, Irina Petropavlovskikh, Erkki Kyrölä, Amanda C. Maycock, P. K. Bhartia, C. D. Boone, Johannes Staehelin, Nicholas B. Jones, M. J. Kurylo, Sophie Godin-Beekmann, Richard S. Stolarski, Stacey M. Frith, C. E. Sioris, Fiona Tummon, John Anderson, Greg Bodeker, H. J. Wang, B. Liley, D. A. Degenstein, Johanna Tamminen, Lucien Froidevaux, Karen H. Rosenlof, Chris Roth, Emmanuel Mahieu, Kaley A. Walker, Daan Hubert, Marko Laine, René Stübi, S T Leblanc, Joseph M. Zawodny, Sean M. Davis, Department of Chemistry [Cambridge, UK], University of Cambridge [UK] (CAM), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), Institute for Atmospheric and Climate Science [Zürich] (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Bodeker Scientific, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Meteorologisches Observatorium Hohenpeißenberg (MOHp), Deutscher Wetterdienst [Offenbach] (DWD), Hampton University, NASA Goddard Space Flight Center (GSFC), Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), Institut Royal Météorologique de Belgique [Bruxelles] (IRM), Science Systems and Applications, Inc. [Lanham] (SSAI), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), 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), School of Chemistry [Wollongong], University of Wollongong [Australia], Finnish Meteorological Institute (FMI), National Institute of Water and Atmospheric Research [Lauder] (NIWA), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Department of Astronomy [Amherst], University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS)-University of Massachusetts System (UMASS), Johns Hopkins University (JHU), Federal Office of Meteorology and Climatology MeteoSwiss, University of Toronto, Georgia Institute of Technology [Atlanta], NCEP Climate Prediction Center (CPC), NOAA National Weather Service (NWS), NASA Langley Research Center [Hampton] (LaRC), Harris, Neil [0000-0003-1256-3006], Apollo - University of Cambridge Repository, and Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute (IRM)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, Ozone, business.industry, Equivalent effective stratospheric chlorine, Distribution (economics), Pinatubo eruption, Atmospheric sciences, lcsh:QC1-999, lcsh:Chemistry, chemistry.chemical_compound, lcsh:QD1-999, chemistry, 13. Climate action, Climatology, Ozone layer, Environmental science, business, Stratosphere, lcsh:Physics
Abstract

Trends in the vertical distribution of ozone are reported and compared for a number of new and recently revised data sets. The amount of ozone-depleting compounds in the stratosphere (as measured by equivalent effective stratospheric chlorine – EESC) was maximised in the second half of the 1990s. We examine the periods before and after the peak to see if any change in trend is discernible in the ozone record that might be attributable to a change in the EESC trend, though no attribution is attempted. Prior to 1998, trends in the upper stratosphere (~ 45 km, 4 hPa) are found to be −5 to −10 % per decade at mid-latitudes and closer to −5 % per decade in the tropics. No trends are found in the mid-stratosphere (28 km, 30 hPa). Negative trends are seen in the lower stratosphere at mid-latitudes in both hemispheres and in the deep tropics. However, it is hard to be categorical about the trends in the lower stratosphere for three reasons: (i) there are fewer measurements, (ii) the data quality is poorer, and (iii) the measurements in the 1990s are perturbed by aerosols from the Mt Pinatubo eruption in 1991. These findings are similar to those reported previously even though the measurements for the main satellite and ground-based records have been revised. There is no sign of a continued negative trend in the upper stratosphere since 1998: instead there is a hint of an average positive trend of ~ 2 % per decade in mid-latitudes and ~ 3 % per decade in the tropics. The significance of these upward trends is investigated using different assumptions of the independence of the trend estimates found from different data sets. The averaged upward trends are significant if the trends derived from various data sets are assumed to be independent (as in Pawson et al., 2014) but are generally not significant if the trends are not independent. This occurs because many of the underlying measurement records are used in more than one merged data set. At this point it is not possible to say which assumption is best. Including an estimate of the drift of the overall ozone observing system decreases the significance of the trends. The significance will become clearer as (i) more years are added to the observational record, (ii) further improvements are made to the historic ozone record (e.g. through algorithm development), and (iii) the data merging techniques are refined, particularly through a more rigorous treatment of uncertainties.

Published
2015
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102. Multi-model study of chemical and physical controls on transport of anthropogenic and biomass burning pollution to the Arctic

Author

Solène Turquety, Jingqiu Mao, Louisa K. Emmons, Stephen D. Steenrod, Y. Long, Steve R. Arnold, Bryan N. Duncan, Kathy S. Law, Vincent Huijnen, Hans Schlager, S. A. Monks, Gérard Ancellet, Andrew J. Weinheimer, Glenn S. Diskin, Chris Wilson, Jean-Christophe Raut, Simone Tilmes, Martyn P. Chipperfield, Joakim Langner, Johannes Flemming, Jennie L. Thomas, Institute for Climate and Atmospheric Science [Leeds] (ICAS), School of Earth and Environment [Leeds] (SEE), University of Leeds-University of Leeds, National Center for Atmospheric Research [Boulder] (NCAR), 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), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), 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), NASA Goddard Space Flight Center (GSFC), European Centre for Medium-Range Weather Forecasts (ECMWF), Royal Netherlands Meteorological Institute (KNMI), Swedish Meteorological and Hydrological Institute (SMHI), Atmospheric and Oceanic Sciences Program [Princeton] (AOS Program), NOAA Geophysical Fluid Dynamics Laboratory (GFDL), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)-Princeton University, NASA Langley Research Center [Hampton] (LaRC), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
Pollution, Atmospheric Science, Ozone, 010504 meteorology & atmospheric sciences, media_common.quotation_subject, 010501 environmental sciences, Atmospheric sciences, 01 natural sciences, Latitude, lcsh:Chemistry, Troposphere, chemistry.chemical_compound, Arctic, 0105 earth and related environmental sciences, media_common, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], long-range transport, Atmospheric models, Northern Hemisphere, Atmosphärische Spurenstoffe, Miljövetenskap, lcsh:QC1-999, lcsh:QD1-999, Boreal, chemistry, 13. Climate action, Climatology, [SDE]Environmental Sciences, lcsh:Physics, Environmental Sciences, Biomass burning
Abstract

Using observations from aircraft, surface stations and a satellite instrument, we comprehensively evaluate multi-model simulations of carbon monoxide (CO) and ozone (O3) in the Arctic and over lower latitude emission regions, as part of the POLARCAT Model Inter-comparison Project (POLMIP). Evaluation of 11- atmospheric models with chemistry shows that they generally underestimate CO throughout the Arctic troposphere, with the largest biases found during winter and spring. Negative CO biases are also found throughout the Northern Hemisphere, with multi-model mean gross errors (9–12%) suggesting models perform similarly over Asia, North America and Europe. A multi-model annual mean tropospheric OH (10.8 ± 0.6 × 105 molec cm−3) is found to be slightly higher than previous estimates of OH constrained by methyl chloroform, suggesting negative CO biases in models may be improved through better constraints on OH. Models that have lower Arctic OH do not always show a substantial improvement in their negative CO biases, suggesting that Arctic OH is not the dominant factor controlling the Arctic CO burden in these models. In addition to these general biases, models do not capture the magnitude of CO enhancements observed in the Arctic free troposphere in summer, suggesting model errors in the simulation of plumes that are transported from anthropogenic and biomass burning sources at lower latitudes. O3 in the Arctic is also generally underestimated, particularly at the surface and in the upper troposphere. Summer O3 comparisons over lower latitudes show several models overestimate upper tropospheric concentrations. Simulated CO, O3 and OH all demonstrate a substantial degree of inter-model variability. Idealised CO-like tracers are used to quantitatively compare the impact of inter-model differences in transport and OH on CO in the Arctic troposphere. The tracers show that model differences in transport from Europe in winter and from Asia throughout the year are important sources of model variability at Barrow. Unlike transport, inter-model variability in OH similarly affects all regional tracers at Barrow. Comparisons of fixed-lifetime and OH-loss idealised CO-like tracers throughout the Arctic troposphere show that OH differences are a much larger source of inter-model variability than transport differences. Model OH concentrations are correlated with H2O concentrations, suggesting water vapour concentrations are linked to differences in simulated concentrations of CO and OH at high latitudes in these simulations. Despite inter-model differences in transport and OH, the relative contributions from the different source regions (North America, Europe and Asia) and different source types (anthropogenic and biomass burning) are comparable across the models. Fire emissions from the boreal regions in 2008 contribute 33, 43 and 19% to the total Arctic CO-like tracer in spring, summer and autumn, respectively, highlighting the importance of boreal fire emissions in controlling pollutant burdens in the Arctic.

Published
2015
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103. Stratospheric aerosol data records for the climate change initiative : Development, validation and application to chemistry-climate modelling

Author

Thomas Trickl, Julien Jumelet, Nina Mateshvili, Filip Vanhellemont, Michael Höpfner, Kerstin Stebel, Christine Bingen, Jennifer Schallock, Charles Robert, Christoph Brühl, Gerrit de Leeuw, Jean-Paul Vernier, John E. Barnes, Thomas Popp, Simon Pinnock, Department of Physics, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Norwegian Institute for Air Research (NILU), Max-Planck-Institut für Chemie (MPIC), Max-Planck-Gesellschaft, Institut für Meteorologie und Klimaforschung - Atmosphärische Spurengase und Fernerkundung (IMK-ASF), Karlsruher Institut für Technologie (KIT), Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), ESRL Global Monitoring Laboratory [Boulder] (GML), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA), 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), Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Langley Research Center [Hampton] (LaRC), Deutsches Fernerkundungsdatenzentrum / German Remote Sensing Data Center (DFD), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Finnish Meteorological Institute (FMI), Department of Physics [Helsinki], Falculty of Science [Helsinki], University of Helsinki-University of Helsinki, European Centre for Space Applications and Telecommunications (ECSAT), European Space Agency (ESA), Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, and Agence Spatiale Européenne = European Space Agency (ESA)

Subjects
Data records, Climate modelling, 010504 meteorology & atmospheric sciences, Meteorology, GARMISCH-PARTENKIRCHEN, Stratospheric aerosol extinction, Soil Science, Climate change, 010501 environmental sciences, stratosphärisches Aerosol, 01 natural sciences, 114 Physical sciences, SULFUR-DIOXIDE SO2, ddc:550, ENVISAT, Computers in Earth Sciences, GOMOS, Climate data record, Volcanic eruptions, 0105 earth and related environmental sciences, Remote sensing, Aerosol remote sensing, ABSORPTION CROSS-SECTIONS, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Lidar, Vulcanian eruption, Aerosol burden, OZONE, CCI, Geology, Inversion (meteorology), LIDAR MEASUREMENTS, PROFILES, Radiative forcing, EXTINCTION RETRIEVAL, GOMOS OBSERVATIONS, Aerosol, Earth sciences, IMPROVED ALGORITHM, TEMPERATURE-DEPENDENCE, 13. Climate action, Data quality, Atmosphäre
Abstract

This paper presents stratospheric aerosol climate records developed in the framework of the Aerosol_cci project, one of the 14 parallel projects from the ESA Climate Change Initiative. These data records were processed from a stratospheric aerosol dataset derived from the GOMOS experiment, using an inversion algorithm optimized for aerosol retrieval, called AerGOM. They provide a suite of aerosol parameters, such as the aerosol extinction coefficient at different wavelengths in the UV-visible range.The extinction record includes the total extinction as well as separate fields for liquid sulfate aerosols and polar stratospheric clouds (PSCs). Several additional fields (PSC flag, etc.) are also provided. The resulting stratospheric aerosol dataset, which spans the whole duration of the GOMOS mission (2002-2012), was validated using different reference datasets (lidar and balloon profiles). In the present paper, the emphasis is put on the extinction records. After a thorough analysis of the original AerGOM dataset, we describe the methodology used to construct the gridded CCI-GOMOS dataset and the resulting improvements on both the AerGOM algorithm and the binning procedure, in terms of spatio-temporal resolution, coverage and data quality. The extinction datasets were validated using lidar profiles from three ground-based stations (Mauna Loa, Garmisch-Partenkirchen, Dumont d'Urville). The median difference of the CCI-GOMOS (Level 3) extinction and ground-based lidar profiles is between similar to 15% and similar to 45% in the 16-21 km altitude range, depending on the considered site and aerosol type. The CCI-GOMOS dataset was subsequently used, together with a MIPAS SO2 time series, to update a volcanic eruption inventory published previously, thus providing a more comprehensive list of eruptions for the ENVISAT period (2002-2012). The number of quantified eruptions increases from 102 to 230 in the updated inventory. This new inventory was used to simulate the evolution of the global radiative forcing by application of the EMAC chemistry-climate model. Results of this simulation improve the agreement between modelled global radiative forcing of stratospheric aerosols at about 100 hPa compared to values estimated from observations. Medium eruptions like the ones of Soufriere Hills/Rabaul (2006), Sarychev (2009) and Nabro (2011) cause a forcing change from about -0.1 W/m(2) to -0.2 W/m(2). (C) 2017 The Authors. Published by Elsevier Inc.

Published
2017
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104. On the Long-term Stability of Satellite and Ground-based Ozone Profile Records

Author

Hubert, Daan, Lambert, Jean-Christopher, Verhoelst, Tijl, Keppens, Arno, Granville, José, Bhartia, Pawan K., Bourassa, Adam E., Damadeo, Robert, Degenstein, Doug A., Froidevaux, Lucien, Godin-Beekmann, Sophie, Johnson, Bryan J., Kaempfer, Niklaus, Leblanc, Thierry, Lichtenberg, Günter, Murtagh, Donal P., Maillard Barras, Eliane, Nakane, Hideaki, Nedoluha, Gerald, Portafaix, Thierry, Querel, Richard, Raspollini, Piera, Russell, James-M., Salvador, J., Smit, Herman G. J., Sofieva, Viktoria, Stebel, Kerstin, Steinbrecht, Wolfgang, Stübi, René, Swart, Daan P. J., Tarasick, David W., Thompson, Anne M., van Malderen, Roeland, von Clarmann, Thomas, von Der Gathen, Peter, Walker, Kaley A., Weber, Mark, Witte, Jacquelyn C., Elian, Wolfram, Zawodny, Joseph M., Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), NASA Goddard Space Flight Center (GSFC), Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), NASA Langley Research Center [Hampton] (LaRC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), 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), National Oceanic and Atmospheric Administration (NOAA), Oeschger Centre for Climate Change Research (OCCR), University of Bern, DLR Institut für Methodik der Fernerkundung / DLR Remote Sensing Technology Institute (IMF), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Chalmers University of Technology [Göteborg], Federal Office of Meteorology and Climatology MeteoSwiss, National Institute for Environmental Studies (NIES), Naval Research Laboratory (NRL), 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, National Institute of Water and Atmospheric Research [Lauder] (NIWA), Istituto di Fisica Applicata 'Nello Carrara' (IFAC), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Center for Atmospheric Sciences [Hampton] (CAS), Hampton University, 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), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association, Finnish Meteorological Institute (FMI), Norwegian Institute for Air Research (NILU), Meteorologisches Observatorium Hohenpeißenberg (MOHp), Deutscher Wetterdienst [Offenbach] (DWD), Payerne Aerological Station, National Institute for Public Health and the Environment [Bilthoven] (RIVM), Environment and Climate Change Canada, Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute (IRM), Karlsruher Institut für Technologie (KIT), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), University of Toronto, University of Bremen, Science Systems and Applications, Inc. [Lanham] (SSAI), Instituto de Investigaciones Científicas y Técnicas para la Defensa (CITEDEF), California Institute of Technology (CALTECH)-NASA, Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Consiglio Nazionale delle Ricerche [Roma] (CNR), Institut Royal Météorologique de Belgique [Bruxelles] (IRM), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, and Cardon, Catherine

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; In recent years, many analyses of space- and ground-based data records reported signs or evidence of increasing ozone concentrations in the extrapolar upper stratosphere since the late 1990s. However, the magnitude and significance of the trend estimates vary from one study to another, prompting the ozone research community to further investigate the causes of these differences. A broader consensus has emerged in the past year, placing the positive trend in the upper stratosphere on solid ground and heralding the start of an observation-based exploration of the recovery of stratospheric ozone. More accurate trend estimates are needed to identify the geophysical processes contributing to the recovery and their relative importance. Uncovering seasonal and spatial trend patterns will be key in reaching this objective, not just in the extrapolar upper stratosphere but elsewhere as well.However, at the moment, it remains unclear whether current ozone profile observing systems are able to provide this information. We address this question with an exploration of the capabilities and limitations of current data records in space (limb/occultation sounders) and on the ground (NDACC/GAW/SHADOZ-affiliated sonde, stratospheric lidar and microwave radiometer sites) to infer decadal trends and their vertical, latitudinal and seasonal patterns. We focus on long-term stability, one of the key drivers of the ability to detect trends. We present updated results of a comprehensive analysis that allowed us to quantify the drift of satellite data relative to the ground-based networks (Hubert et al., 2016). In a companion analysis we exploited the satellite data to uncover temporal and spatial inhomogeneities in the ground-based time series, some of which were traced to known changes occurring at different moments across the network. These changes add to the challenge to derive unbiased ozone trends from ground-based observations and they impede our ability to constrain satellite drift to the level required for current and future ozone trend assessments. We conclude that ongoing efforts to homogenise the ground-based data records are essential.

Published
2017

105. Summary Data from the Sixth AIAA CFD Drag Prediction Workshop: CRM Cases

Author

Mitsuhiro Murayama, Mori Mani, Dimitri J. Mavriplis, Richard A. Wahls, Stefan Keye, Edward N. Tinoco, Edward Feltrop, David Hue, Ben Rider, John C. Vassberg, Christopher J. Roy, Joseph H. Morrison, Olaf Brodersen, Kelly R. Laflin, The Boeing Company, retired, Retired, Deutsches Zentrum für Luft- und Raumfahrt [Braunschweig] (DLR), Textron Aviation, The Boeing Company, Huntington Beach, NASA Langley Research Center [Hampton] (LaRC), ONERA - The French Aerospace Lab [Meudon], ONERA-Université Paris Saclay (COmUE), Virginia Tech [Blacksburg], University of Wyoming (UW), and Japan Aerospace Exploration Agency [Tokyo] (JAXA)

Subjects
Lift coefficient, DPW, Direct numerical simulation, Aerospace Engineering, 02 engineering and technology, Computational fluid dynamics, 01 natural sciences, Common Research Model, 010305 fluids & plasmas, Unstructured grid, Computational Fluid Dynamics Drag Prediction Workshop, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Aerodynamics, 0203 mechanical engineering, 0103 physical sciences, TRAINEE, Mathematics, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], 020301 aerospace & aeronautics, business.industry, Mechanics, Finite element method, Moment (mathematics), Drag, Reynolds-averaged Navier–Stokes equations, business, CFD
Abstract

International audience; Results from the Sixth AIAA CFD Drag Prediction Workshop Cases 2 to 5 are presented. These cases focused on force/moment and pressure predictions for the NASA Common Research Model wing–body and wing–body–nacelle–pylon configurations. The Common Research Model geometry differed from previous workshops in that it was deformed to the appropriate static aeroelastic twist and deflection at each specified angle of attack. The grid refinement study and nacelle–pylon drag increment prediction (Case 2) used a common set of overset and unstructured grids, as well as user-created multiblock structured, unstructured, and Cartesian-based grids. Solutions were requested for both the wing–body and wing–body–nacelle–pylon at a fixed Mach number and lift coefficient. The wing–body static aeroelastic/buffet study (Case 3) specified an angle-of-attack sweep at finely spaced intervals through the zone where wing separation was expected to begin. The optional Case 4 requested grid adaption solutions of the wing–body at a specified flight condition. Optional Case 5 requested coupled aerostructural wing–body solutions. Results from this workshop highlight the progress made since the last workshop, and the continuing need for computational fluid dynamics (CFD) improvement, particularly for conditions with significant flow separation. These comparisons also suggest the need for improved experimental diagnostics to guide future CFD development.

Published
2017
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106. A Prototype Method for Diagnosing High Ice Water Content Probability Using Satellite Imager Data

Author

Louis Nguyen, Patrick Minnis, William L. Smith, Konstantin V. Khlopenkov, Douglas A. Spangenberg, J. Walter Strapp, Christopher R. Yost, Rabindra Palikonda, Kristopher M. Bedka, Julien Delanoë, Alain Protat, Science Systems and Applications, Inc. [Hampton] (SSAI), NASA Langley Research Center [Hampton] (LaRC), Met Analytics Inc. [Toronto], Science Systems and Applications, Inc. [Lanham] (SSAI), Australian Bureau of Meteorology [Melbourne] (BoM), Australian Government, SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and 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)

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, 0211 other engineering and technologies, 02 engineering and technology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Collocation (remote sensing), 010502 geochemistry & geophysics, 01 natural sciences, Article, law.invention, law, lcsh:TA170-171, 021101 geological & geomatics engineering, Remote sensing, Icing, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Ice crystals, lcsh:TA715-787, lcsh:Earthwork. Foundations, lcsh:Environmental engineering, 13. Climate action, Brightness temperature, Convective storm detection, Geostationary orbit, Environmental science, Weather radar, Satellite
Abstract

Recent studies have found that flight through deep convective storms and ingestion of high mass concentrations of ice crystals, also known as high ice water content (HIWC), into aircraft engines can adversely impact aircraft engine performance. These aircraft engine icing events caused by HIWC have been documented during flight in weak reflectivity regions near convective updraft regions that do not appear threatening in onboard weather radar data. Three airborne field campaigns were conducted in 2014 and 2015 to better understand how HIWC is distributed in deep convection, both as a function of altitude and proximity to convective updraft regions, and to facilitate development of new methods for detecting HIWC conditions, in addition to many other research and regulatory goals. This paper describes a prototype method for detecting HIWC conditions using geostationary (GEO) satellite imager data coupled with in-situ total water content (TWC) observations collected during the flight campaigns. Three satellite-derived parameters were determined to be most useful for determining HIWC probability: 1) the horizontal proximity of the aircraft to the nearest overshooting convective updraft or textured anvil cloud, 2) tropopause-relative infrared brightness temperature, and 3) daytime-only cloud optical depth. Statistical fits between collocated TWC and GEO satellite parameters were used to determine the membership functions for the fuzzy logic derivation of HIWC probability. The products were demonstrated using data from several campaign flights and validated using a subset of the satellite-aircraft collocation database. The daytime HIWC probability was found to agree quite well with TWC time trends and identified extreme TWC events with high probability. Discrimination of HIWC was more challenging at night with IR-only information. The products show the greatest capability for discriminating TWC ≥ 0.5 g m−3. Product validation remains challenging due to vertical TWC uncertainties and the typically coarse spatio-temporal resolution of the GEO data.

Published
2017
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107. Comet Siding Spring's influence on the Mars' ionosphere

Author

Witasse, Olivier, Sánchez-Cano, B., Molina-Cuberos, Gregorio, Blelly, Pierre-Louis, Lester, M., Leblanc, François, Modolo, Ronan, Chaufray, Jean-Yves, Gronoff, Guillaume, Espley, Jared, Costa, M., Giuranna, M., European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Department of Physics and Astronomy [Leicester], University of Leicester, Department of Electromagnetism and Electronics [Murcia], Universidad de Murcia, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), HELIOS - 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), GSFC Planetary Magnetospheres Laboratory, NASA Goddard Space Flight Center (GSFC), Istituto Nazionale di Astrofisica (INAF), Agence Spatiale Européenne = European Space Agency (ESA), 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), 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
[SDU]Sciences of the Universe [physics]
Abstract

International audience; On October 19th 2014, Mars experienced a close encounter with Comet C/2013 A1 (Siding Spring), at a distance of ~138,000 km. The coma washed over Mars and the planet passed directly through the cometary debris stream, producing significant effects in Mars' upper atmosphere. We present here an overview of ionospheric measurements performed during the comet encounter with Mars Express, MAVEN, and Mars Reconnaissance Orbiter. We discuss the comet's influence on the ionosphere through different processes that work at different altitudes: magnetospheric disturbances, impact of cometary pickup ions, and deposition of cometary dust.

Published
2017

108. On the control of mid-latitude stratospheric aerosol budget from 23-year series of Haute-Provence lidar and global satellite observations

Author

Khaykin, Sergey, Godin-Beekmann, Sophie, Keckhut, Philippe, Hauchecorne, Alain, Vernier, Jean-Paul, Bourassa, Adam, Bingen, Christine, DeLand, Matthew, Bhartia, Pawan, 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, NASA Langley Research Center [Hampton] (LaRC), Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Goddard Space Flight Center (GSFC), and Cardon, Catherine

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.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; The paper presents new high-quality stratospheric aerosol observations spanning 1994-2016 at Haute-Provence observatory (OHP, 44 °N, 6 °E) obtained by two independent lidar systems. Lidar series are analyzed together with global observations by CALIOP and other satellite sounders to characterize the variability and evolution of the mid-latitude stratospheric aerosol over the last two decades. Volcanic contributions and factors controlling the non-volcanic component of aerosol are discussed.

Published
2017

109. 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

110. Antimony oxide based glasses, novel laser materials

Author

Brian M. Walsh, Kheirreddine Lebbou, Yannick Guyot, Marcel Poulain, Karima Ouannes, Guillaume Alombert-Goget, Université Mohamed Khider de Biskra (BISKRA), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), NASA Langley Research Center [Hampton] (LaRC), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)

Subjects
Materials science, Analytical chemistry, Oxide, Mineralogy, 02 engineering and technology, 01 natural sciences, Antimony oxide glasses, Ion, Laser glasses, Inorganic Chemistry, chemistry.chemical_compound, symbols.namesake, Differential scanning calorimetry, Stimulated emission cross-sections, 0103 physical sciences, [CHIM]Chemical Sciences, Thermal stability, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, Spectroscopy, 010302 applied physics, Organic Chemistry, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Judd-Ofelt analysis, Devitrification, chemistry, symbols, Absorption (chemistry), Antimony oxide, 0210 nano-technology, Raman spectroscopy, Erbium ions
Abstract

Glasses based on Sb 2 O 3 make one of the major classes of heavy metal oxide glasses. This paper concerns two antimonite glasses, 88Sb 2 O 3 -10Na 2 O-2Bi 2 O 3 (SNB2) and 60Sb 2 O 3 -20WO 3 -19Na 2 O-1Bi 2 O 3 (SWNB1), doped with 0.25 mol% Er 2 O 3 . Bulk samples have been prepared and their absorption and fluorescence spectra have been recorded. Differential scanning calorimeter (DSC) measurements emphasize a thermal stability range ΔT > 100 °C that expresses a good stability against devitrification. Both FTIR and Raman spectra provide information on the structural organization of the glasses. The maximum phonon energies are 700 cm −1 and 920 cm −1 for SNB2 and SWNB1 glasses, respectively. The spectroscopic analysis of the absorption and emission properties of the Er 3+ ions in the SNB2 and SWNB1 glasses has been performed. The Judd-Ofelt theory has been applied to interpret the local environment of the Er 3+ ion site and covalency of the Er O bond, but also to determine the radiative lifetime (τ r ) for 4 I 13/2 → 4 I 15/2 emission transition. The emission cross-sections for the 4 I 13/2 → 4 I 15/2 transition (1528 nm) were calculated using McCumber and Fuchtbauer-Ladenburg theories. We discuss the potential application of these glasses.

Published
2017
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111. Direct atmosphere opacity observations from CALIPSO provide new constraints on cloud-radiation interactions

Author

Guzman, R., Chepfer, H., Noel, V., Vaillant de Guélis, T., Kay, J. E., Raberanto, P., Cesana, G., Vaughan, M. A., Winker, D. M., Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), 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), 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, University of Colorado [Boulder], California Institute of Technology (CALTECH), NASA Langley Research Center [Hampton] (LaRC), 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), 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
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
Abstract

International audience; The spaceborne lidar CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) directly measures atmospheric opacity. In 8 years of CALIPSO observations, we find that 69% of vertical profiles penetrate through the complete atmosphere. The remaining 31% do not reach the surface, due to opaque clouds. The global mean altitude of full attenuation of the lidar beam (z_opaque) is 3.2 km, but there are large regional variations in this altitude. Of relevance to cloud-climate studies, the annual zonal mean longwave cloud radiative effect and annual zonal mean z_opaque weighted by opaque cloud cover are highly correlated (0.94). The annual zonal mean shortwave cloud radiative effect and annual zonal mean opaque cloud cover are also correlated (À0.95). The new diagnostics introduced here are implemented within a simulator framework to enable scale-aware and definition-aware evaluation of the LMDZ5B global climate model. The evaluation shows that the model overestimates opaque cloud cover (31% obs. versus 38% model) and z_opaque (3.2 km obs. versus 5.1 km model). In contrast, the model underestimates thin cloud cover (35% obs. versus 14% model). Further assessment shows that reasonable agreement between modeled and observed longwave cloud radiative effects results from compensating errors between insufficient warming by thin clouds and excessive warming due to overestimating both z_opaque and opaque cloud cover. This work shows the power of spaceborne lidar observations to directly constrain cloud-radiation interactions in both observations and models.

Published
2017
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112. The link between outgoing longwave radiation and the altitude at which a spaceborne lidar beam is fully attenuated

Author

Vaillant de Guélis, Thibault, Chepfer, Hélène, Noel, Vincent, Guzman, Rodrigo, Dubuisson, Philippe, Winker, David, Kato, Seiji, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), 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), 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), NASA Langley Research Center [Hampton] (LaRC), 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], lcsh:TA715-787, lcsh:Earthwork. Foundations, Astrophysics::Earth and Planetary Astrophysics, lcsh:TA170-171, Astrophysics::Galaxy Astrophysics, Physics::Atmospheric and Oceanic Physics, lcsh:Environmental engineering
Abstract

International audience; According to climate model simulations, the changing altitude of middle and high clouds is the dominant contributor to the positive global mean longwave cloud feedback. Nevertheless, the mechanisms of this longwave cloud altitude feedback and its magnitude have not yet been verified by observations. Accurate, stable, and long-term observations of a metric-characterizing cloud vertical distribution that are related to the longwave cloud radiative effect are needed to achieve a better understanding of the mechanism of longwave cloud altitude feedback. This study shows that the direct measurement of the altitude of atmospheric lidar opacity is a good candidate for the necessary observational metric. The opacity altitude is the level at which a space-borne lidar beam is fully attenuated when probing an opaque cloud. By combining this altitude with the direct lidar measurement of the cloud-top altitude, we derive the effective radiative temperature of opaque clouds which linearly drives (as we will show) the outgoing longwave radiation. We find that, for an opaque cloud, a cloud temperature change of 1 K modifies its cloud radiative effect by 2 W m −2. Similarly, the longwave cloud radiative effect of optically thin clouds can be derived from their top and base altitudes and an estimate of their emissivity. We show with radiative transfer simulations that these relationships hold true at single atmospheric column scale, on the scale of the Clouds and the Earth's Radiant Energy System (CERES) instantaneous footprint, and at monthly mean 2 • × 2 • scale. Opaque clouds cover 35 % of the ice-free ocean and contribute to 73 % of the global mean cloud radiative effect. Thin-cloud coverage is 36 % and contributes 27 % of the global mean cloud radiative effect. The link between outgoing longwave radiation and the altitude at which a spaceborne lidar beam is fully attenuated provides a simple formulation of the cloud radiative effect in the long-wave domain and so helps us to understand the longwave cloud altitude feedback mechanism.

Published
2017
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113. Variability and evolution of the midlatitude stratospheric aerosol budget from 22 years of ground-based lidar and satellite observations

Author

Khaykin, Sergey, Godin-Beekmann, Sophie, Keckhut, Philippe, Hauchecorne, Alain, Jumelet, Julien, Vernier, Jean-Paul, Bourassa, Adam, Degenstein, Doug A., Reiger, Landon A., Bingen, Christine, Vanhellemont, Filip, Robert, Charles, Deland, Matthew, Bhartia, Pawan K., 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), Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Langley Research Center [Hampton] (LaRC), Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), NASA Goddard Space Flight Center (GSFC), Institut National des Sciences de l'Univers (INSU) du Centre National de la Recherche Scientifique (CNRS), Centre National d’Etudes Spatiales (CNES), and European Space Agency (ESA) : AerGom project

Subjects
lcsh:Chemistry, [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:QD1-999, lcsh:Physics, lcsh:QC1-999
Abstract

The article presents new high-quality continuous stratospheric aerosol observations spanning 1994–2015 at the French Observatoire de Haute-Provence (OHP, 44° N, 6° E) obtained by two independent, regularly maintained lidar systems operating within the Network for Detection of Atmospheric Composition Change (NDACC). Lidar series are compared with global-coverage observations by Stratospheric Aerosol and Gas Experiment (SAGE II), Global Ozone Monitoring by Occultation of Stars (GOMOS), Optical Spectrograph and InfraRed Imaging System (OSIRIS), Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and Ozone Mapping Profiling Suite (OMPS) satellite instruments, altogether covering the time span of OHP lidar measurements. Local OHP and zonal-mean satellite series of stratospheric aerosol optical depth are in excellent agreement, allowing for accurate characterization of stratospheric aerosol evolution and variability at northern midlatitudes during the last 2 decades. The combination of local and global observations is used for a careful separation between volcanically perturbed and quiescent periods. While the volcanic signatures dominate the stratospheric aerosol record, the background aerosol abundance is found to be modulated remotely by the poleward transport of convectively cleansed air from the deep tropics and aerosol-laden air from the Asian monsoon region. The annual cycle of background aerosol at midlatitudes, featuring a minimum during late spring and a maximum during late summer, correlates with that of water vapor from the Aura Microwave Limb Sounder (MLS). Observations covering two volcanically quiescent periods over the last 2 decades provide an indication of a growth in the nonvolcanic component of stratospheric aerosol. A statistically significant factor of 2 increase in nonvolcanic aerosol since 1998, seasonally restricted to late summer and fall, is associated with the influence of the Asian monsoon and growing pollution therein.

Published
2017
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114. Overview of the CALIPSO Version 4 Lidar Data Products

Author

Vaughan, Mark A., Garnier, Anne, Tackett, Jason L., Avery, Melody A., Kar, Jayanta, Liu, Zhaoyan, Trepte, Charles, Winker, David, Pelon, Jacques, Omar, Ali, Getzewich, Brian, Lee, Kam‐pui, Cai, Xia, Zeng, Shan, Cardon, Catherine, NASA Langley Research Center [Hampton] (LaRC), Science Systems and Applications, Inc. [Hampton] (SSAI), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and 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)

Subjects
[SDU.STU.ME] Sciences of the Universe [physics]/Earth Sciences/Meteorology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology
Abstract

International audience; NASA’s Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission is scheduled to release version 4 of their level 2 data products in the fall of 2016. This presentation will highlight some of the many significant improvements delivered by the version 4 CALIPSO lidar cloud and aerosol data products, with a particular focus on the retrieval of extinction-to-backscatter ratios for both ice clouds and water clouds.

Published
2017

115. 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
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116. Introducing CALIPSO’s Version 4 Level 2 Lidar Data Products

Author

Vaughan, Mark, Garnier, Anne, Tackett, Jason L., Avery, Melody A., Young, Stuart, Kar, Jay, Getzewich, Brian, Omar, Ali, Liu, Zhaoyan, Lee, Kam‐pui, Cai, Xia, Zeng, Shan, Hu, Yongxiang, Lambeth, Jim, Ryan, Rob, Magill, Brian, Rodier, Sharon, Murray, Tim, Beaumont, Ken, Detweiler, Paula, Lucker, Pat, Pelon, Jacques, Winker, David, Trepte, Chip, Cardon, Catherine, NASA Langley Research Center [Hampton] (LaRC), Science Systems and Applications, Inc. [Hampton] (SSAI), CISRO Oceans and Atmosphere, TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and 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)

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 NASA-CNES CALIPSO mission released Version 4.1 (V4.1) of their lidar level 2 (LL2) data products in November 2016. This new release from uses significantly improved retrieval algorithms to provide increased accuracy and substantially reduced uncertainties in the derived parameters. Here we present a comprehensive overview of the V4.1 LL2 data products, and show examples illustrating the improvements made in retrieving the spatial distributions and optical properties of clouds and aerosols.

Published
2017

117. Observations of Arctic snow and sea ice cover from CALIOP lidar measurements

Author

Sharon Rodier, Yongxiang Hu, Zhaoyan Liu, Jacques Pelon, Charles R. Trepte, Patricia L. Lucker, Xiaomei Lu, Mark A. Vaughan, Science Systems and Applications, Inc. [Hampton] (SSAI), NASA Langley Research Center [Hampton] (LaRC), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and 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)

Subjects
010504 meteorology & atmospheric sciences, 0208 environmental biotechnology, Sea ice, Soil Science, 02 engineering and technology, Snow field, Atmospheric sciences, 01 natural sciences, Snow, Cryosphere, Computers in Earth Sciences, Sea ice concentration, 0105 earth and related environmental sciences, Remote sensing, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], geography, geography.geographical_feature_category, CALIOP, Geology, Arctic ice pack, 020801 environmental engineering, Arctic, 13. Climate action, Sea ice thickness, Environmental science, Surface type identification
Abstract

International audience; This paper describes the development and validation of a method to accurately identify snow/ice cover, surface melting, land surface and open water in polar regions using polar-orbiting Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) lidar measurements from the Cloud and Aerosol Lidar and Infrared Pathfinder Observation (CALIPSO) mission. The technique is based on the relationship between integrated attenuated backscatter color ratio and integrated depolarization ratio, and is proven to efficiently separate snow/ice cover and surface melting from open water and land surfaces. The method has been applied to 10 years (2006–2016) of CALIOP data to study the seasonal and inter-annual variability of Arctic sea ice cover and its declining trend. Results show that the area fraction of snow cover over land at latitudes > 60°N varied between 0.9 during winter and 0.1 in summer. The CALIOP observations of Arctic sea ice cover exhibit a strong seasonal cycle and significant inter-annual variability, which are consistent with the passive microwave-based sea ice results. The > 10 years of CALIOP continuous observations of the snow/ice cover will benefit the communities modeling snow/ice melting and climate change.

Published
2017
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118. Using Space Lidar Observations to Decompose Longwave Cloud Radiative Effect Variations Over the Last Decade

Author

Vaillant de Guélis, Thibault, Chepfer, Hélène, Noel, Vincent, Guzman, Rodrigo, Winker, David, Plougonven, Riwal, 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), 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, NASA Langley Research Center [Hampton] (LaRC), 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 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], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract

International audience; Measurements of the longwave cloud radiative effect (LWCRE) at the top of the atmosphere assess the contribution of clouds to the Earth warming but do not quantify the cloud property variations that are responsible for the LWCRE variations. The CALIPSO space lidar observes directly the detailed profile of cloud, cloud opacity, and cloud cover. Here we use these observations to quantify the influence of cloud properties on the variations of the LWCRE observed between 2008 and 2015 in the tropics and at global scale. At global scale, the method proposed here gives good results except over the Southern Ocean. We find that the global LWCRE variations observed over ocean are mostly due to variations in the opaque cloud properties (82%); transparent cloud columns contributed 18%. Variation of opaque cloud cover is the first contributor to the LWCRE evolution (58%); opaque cloud temperature is the second contributor (28%).

Published
2017
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119. Virtual Prototyping of Position Synchronized Electro-mechanical Actuators Driving Independent Loads for More Electric Aircraft Flight Control Actuation System Application

Author

Fu, J., Maré, Jean-Charles, Fu, Y., Institut Clément Ader (ICA), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), NASA Langley Research Center [Hampton] (LaRC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)

Subjects
[PHYS]Physics [physics], [PHYS.MECA]Physics [physics]/Mechanics [physics]
Abstract

International audience; In the field of more electric aircraft, electromechanical actuators (EMAs) are becoming more and more attractive because of their outstanding benefits of aircraft fuel reduction, maintenance costs saving, and system flexibility improvement. For aerospace electromechanical actuator applications, the proposed communication addresses the combination of extensive use of EMAs and electrical synchronization. Two EMAs drive two independent loads which positions are to be synchronized at any time. Due to the different natural dynamics and external loads, the two independent driven loads tend to get a different position, which is not acceptable. Even in case one actuator failure, priority is given to synchronization instead of following the position setpoint. Therefore, virtual prototype of the EMAs actuation system is proposed to assess and pre-validate the synchronization concepts with resort to a model-based approach. Firstly, a linear virtual prototype is proposed to preliminary study the position synchronization strategy. Then a full model is proposed with the consideration of more cross-linked physical effects and it can be adapted to the different engineering needs to make simulation as realistic as possible.

Published
2017

120. An update on ozone profile trends for the period 2000 to 2016

Author

W. Steinbrecht, L. Froidevaux, R. Fuller, R. Wang, J. Anderson, C. Roth, A. Bourassa, D. Degenstein, R. Damadeo, J. Zawodny, S. Frith, R. McPeters, P. Bhartia, J. Wild, C. Long, S. Davis, K. Rosenlof, V. Sofieva, K. Walker, N. Rahpoe, A. Rozanov, M. Weber, A. Laeng, T. von Clarmann, G. Stiller, N. Kramarova, S. Godin-Beekmann, T. Leblanc, R. Querel, D. Swart, I. Boyd, K. Hocke, N. Kämpfer, E. Maillard Barras, L. Moreira, G. Nedoluha, C. Vigouroux, T. Blumenstock, M. Schneider, O. García, N. Jones, E. Mahieu, D. Smale, M. Kotkamp, J. Robinson, I. Petropavlovskikh, N. Harris, B. Hassler, D. Hubert, F. Tummon, Meteorologisches Observatorium Hohenpeißenberg (MOHp), Deutscher Wetterdienst [Offenbach] (DWD), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), School of Earth and Atmospheric Sciences [Atlanta], Georgia Institute of Technology [Atlanta], Department of Atmospheric and Planetary Sciences [Hampton] (APS), Hampton University, Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), NASA Langley Research Center [Hampton] (LaRC), Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Goddard Space Flight Center (GSFC), NCEP Climate Prediction Center (CPC), NOAA National Weather Service (NWS), Innovim LLC, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), ESRL Chemical Sciences Division [Boulder] (CSD), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA), Finnish Meteorological Institute (FMI), Department of Physics [Toronto], University of Toronto, Institute of Environmental Physics [Bremen] (IUP), University of Bremen, Institute for Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology (KIT), 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), Lauder Atmospheric Research Station, National Institute of Water and Atmospheric Research [Auckland] (NIWA), National Institute for Public Health and the Environment [Bilthoven] (RIVM), Bc Scientific Consulting LLC, Oeschger Centre for Climate Change Research (OCCR), University of Bern, Institut für angewandte Physik [Bern] (IAP), Universität Bern [Bern], Federal Office of Meteorology and Climatology MeteoSwiss, Naval Research Laboratory (NRL), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), Karlsruher Institut für Technologie (KIT), Izaña Atmospheric Research Center (IARC), Agencia Estatal de Meteorología (AEMet), School of Chemistry [Wollongong], University of Wollongong [Australia], Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, ESRL Global Monitoring Laboratory [Boulder] (GML), Centre for Atmospheric Informatics and Emissions Technology, Cranfield University, Bodeker Scientific, Institute for Atmospheric and Climate Science [Zürich] (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), and Universität Bern [Bern] (UNIBE)

Subjects
Atmospheric Science, Ozone, 010504 meteorology & atmospheric sciences, Atmospheric sciences, 010502 geochemistry & geophysics, 01 natural sciences, Latitude, lcsh:Chemistry, chemistry.chemical_compound, Altitude, Ozone layer, Montreal Protocol, ddc:550, Ozone profile trends, Stratosphere, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 620 Engineering, lcsh:QC1-999, Earth sciences, chemistry, lcsh:QD1-999, 13. Climate action, Climatology, Satellite data, Period (geology), Environmental science, Upper stratosphere, Satellite, Ozone depleting chlorine, lcsh:Physics
Abstract

Ozone profile trends over the period 2000 to 2016 from several merged satellite ozone data sets and from ground-based data measured by four techniques at stations of the Network for the Detection of Atmospheric Composition Change indicate significant ozone increases in the upper stratosphere, between 35 and 48 km altitude (5 and 1 hPa). Near 2 hPa (42 km), ozone has been increasing by about 1.5 % per decade in the tropics (20° S to 20° N), and by 2 to 2.5 % per decade in the 35 to 60° latitude bands of both hemispheres. At levels below 35 km (5 hPa), 2000 to 2016 ozone trends are smaller and not statistically significant. The observed trend profiles are consistent with expectations from chemistry climate model simulations. This study confirms positive trends of upper stratospheric ozone already reported, e.g., in the WMO/UNEP Ozone Assessment 2014 or by Harris et al. (2015). Compared to those studies, three to four additional years of observations, updated and improved data sets with reduced drift, and the fact that nearly all individual data sets indicate ozone increase in the upper stratosphere, all give enhanced confidence. Uncertainties have been reduced, for example for the trend near 2 hPa in the 35 to 60° latitude bands from about ±5 % (2σ) in Harris et al. (2015) to less than ±2 % (2σ). Nevertheless, a thorough analysis of possible drifts and differences between various data sources is still required, as is a detailed attribution of the observed increases to declining ozone-depleting substances and to stratospheric cooling. Ongoing quality observations from multiple independent platforms are key for verifying that recovery of the ozone layer continues as expected. Fiona Tummon was supported by Swiss National Science Foundation grant num-5 ber 20FI21_138017.

Published
2017
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121. Where and when will we observe cloud changes due to climate warming?

Author

Hélène Chepfer, Marjolaine Chiriaco, Vincent Noel, Dave Winker, 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), NASA Langley Research Center [Hampton] (LaRC), SPACE - 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), 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), and 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)

Subjects
Cloud forcing, Coupled model intercomparison project, 010504 meteorology & atmospheric sciences, Climate, Space borne lidar, Cloud cover, Cloud top, Global warming, Atmospheric Model Intercomparison Project, Remote sensing, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Physics::Geophysics, Geophysics, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, 13. Climate action, Clouds, International Satellite Cloud Climatology Project, General Earth and Planetary Sciences, Environmental science, Climate model, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences
Abstract

Climate models predict that the geographic distribution of clouds will change in response to anthropogenic warming, though uncertainties in the existing satellite record are larger than the magnitude of the predicted effects. Here we argue that cloud vertical distribution, observable by active spaceborne sensors, is a more robust signature of climate change. Comparison of Atmospheric Model Intercomparison Project present day and +4 K runs from Coupled Model Intercomparison Project Phase 5 shows that cloud radiative effect and total cloud cover do not represent robust signatures of climate change, as predicted changes fall within the range of variability in the current observational record. However, the predicted forced changes in cloud vertical distribution (directly measurable by spaceborne active sensors) are much larger than the currently observed variability and are expected to first appear at a statistically significant level in the upper troposphere, at all latitudes.

Published
2014
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122. Validation of MIPAS IMK/IAA V5R_O3_224 ozone profiles

Author

A. Laeng, U. Grabowski, T. von Clarmann, G. Stiller, N. Glatthor, M. Höpfner, S. Kellmann, M. Kiefer, A. Linden, S. Lossow, V. Sofieva, I. Petropavlovskikh, D. Hubert, T. Bathgate, P. Bernath, C. D. Boone, C. Clerbaux, P. Coheur, R. Damadeo, D. Degenstein, S. Frith, L. Froidevaux, J. Gille, K. Hoppel, M. McHugh, Y. Kasai, J. Lumpe, N. Rahpoe, G. Toon, T. Sano, M. Suzuki, J. Tamminen, J. Urban, K. Walker, M. Weber, J. Zawodny, Institute for Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology (KIT), Finnish Meteorological Institute (FMI), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), University of Saskatchewan [Saskatoon] (U of S), Old Dominion University [Norfolk] (ODU), University of Toronto, 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), NASA Langley Research Center [Hampton] (LaRC), Science Systems and Applications, Inc. [Lanham] (SSAI), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), National Center for Atmospheric Research [Boulder] (NCAR), Naval Research Laboratory (NRL), National Institute of Information and Communications Technology [Tokyo, Japan] (NICT), Computational Physics, Inc., Institut für Umweltphysik [Bremen] (IUP), Universität Bremen, Japan Aerospace Exploration Agency [Tokyo] (JAXA), and Chalmers University of Technology [Göteborg]

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Atmospheric sciences, 01 natural sciences, Occultation, 010309 optics, Troposphere, Physico-chimie générale, 0103 physical sciences, Ozone layer, ddc:550, Nadir, lcsh:TA170-171, Stratosphere, 0105 earth and related environmental sciences, Remote sensing, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric sounding, lcsh:TA715-787, lcsh:Earthwork. Foundations, SCIAMACHY, lcsh:Environmental engineering, Earth sciences, 13. Climate action, Environmental science, Satellite
Abstract

We present the results of an extensive validation program of the most recent version of ozone vertical profiles retrieved with the IMK/IAA (Institute for Meteorology and Climate Research/Instituto de Astrofísica de Andalucía) MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) research level 2 processor from version 5 spectral level 1 data. The time period covered corresponds to the reduced spectral resolution period of the MIPAS instrument, i.e. January 2005-April 2012. The comparison with satellite instruments includes all post-2005 satellite limb and occultation sensors that have measured the vertical profiles of tropospheric and stratospheric ozone: ACE-FTS, GOMOS, HALOE, HIRDLS, MLS, OSIRIS, POAM, SAGE II, SCIAMACHY, SMILES, and SMR. In addition, balloon-borne MkIV solar occultation measurements and ground-based Umkehr measurements have been included, as well as two nadir sensors: IASI and SBUV. For each reference data set, bias determination and precision assessment are performed. Better agreement with reference instruments than for the previous data version, V5R-O3-220 (Laeng et al. 2014), is found: the known high bias around the ozone vmr (volume mixing ratio) peak is significantly reduced and the vertical resolution at 35 km has been improved. The agreement with limb and solar occultation reference instruments that have a known small bias vs. ozonesondes is within 7% in the lower and middle stratosphere and 5% in the upper troposphere. Around the ozone vmr peak, the agreement with most of the satellite reference instruments is within 5%; this bias is as low as 3% for ACE-FTS, MLS, OSIRIS, POAM and SBUV., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2014
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123. Microphysical properties and high ice water content in continental and oceanic mesoscale convective systems and potential implications for commercial aircraft at flight altitude

Author

Alain Protat, Anne Garnier, Jacques Pelon, Luca Bugliaro, Jean-François Gayet, Julien Delanoë, Valery Shcherbakov, 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), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Centre for Australian Weather and Climate Research (CAWCR), SPACE - 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), TROPO - LATMOS, Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Langley Research Center [Hampton] (LaRC), and Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, Meteosat-9/SEVIRI, microphysical properties, CALIPSO, Mesoscale meteorology, Atmospheric sciences, 01 natural sciences, Latitude, airtraffic threat, CloudSat, lcsh:Chemistry, high ice water content, convective mesoscale systems, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Effective radius, Ice crystals, 010505 oceanography, Fernerkundung der Atmosphäre, Cloud top, lcsh:QC1-999, Aerosol, Lidar, lcsh:QD1-999, 13. Climate action, Brightness temperature, in-situ microphysical measurements, Environmental science, lcsh:Physics
Abstract

Two complementary case studies are conducted to analyse convective system properties in the region where strong cloud-top lidar backscatter anomalies are observed as reported by Platt et al. (2011). These anomalies were reported for the first time using in situ microphysical measurements in an isolated continental convective cloud over Germany during the CIRCLE2 experiment (Gayet et al., 2012). In this case, in situ observations quasi-collocated with CALIPSO (Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation), CloudSat and Meteosat-9/SEVIRI observations confirm that regions of backscatter anomalies represent the most active and dense convective cloud parts with likely the strongest core updrafts and unusually high values of the particle concentration, extinction and ice water content (IWC), with the occurrence of small ice crystal sizes. Similar spaceborne observations of a maritime mesoscale cloud system (MCS) located off the Brazilian coast between 0° and 3° N latitude on 20 June 2008 are then analysed. Near cloud-top backscatter anomalies are evidenced in a region which corresponds to the coldest temperatures with maximum cloud top altitudes derived from collocated CALIPSO/IIR and Meteosat-9/SEVIRI infrared brightness temperatures. The interpretation of CALIOP (Cloud Aerosol Lidar with Orthogonal Polarization) data highlights significant differences in microphysical properties from those observed in the continental isolated convective cloud. Indeed, SEVIRI (Spinning Enhanced Visible and InfraRed Imager) retrievals in the visible spectrum confirm much smaller ice particles near the top of the isolated continental convective cloud, i.e. effective radius (Reff) ~ 15 μm as opposed to 22–27 μm in the whole MCS area. Cloud profiling observations at 94 GHz from CloudSat are then used to describe the properties of the most active cloud regions at and below cloud top. The cloud ice-water content and effective radius retrieved with the CloudSat 2B-IWC and DARDAR (raDAR/liDAR) inversion techniques, show that at usual cruise altitudes of commercial aircraft (FL 350 or ~ 10 700 m level), high IWC (i.e. up to 2 to 4 g m−3) could be identified according to specific IWC–Z (Z being the reflectivity factor) relationships. These values correspond to a maximum reflectivity factor of +18 dBZ (at 94 GHz). Near-top cloud properties also indicate signatures of microphysical characteristics according to the cloud-stage evolution as revealed by SEVIRI images to identify the development of new cells within the MCS cluster. It is argued that the availability of real-time information (on the kilometre-scale) about cloud top IR brightness temperature decreases with respect to the cloud environment would help identify MCS cloud areas with potentially high ice water content and small particle sizes against which onboard meteorological radars may not be able to provide timely warning.

Published
2014
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124. Intrinsic brittleness origination of micro-scale phase-separating metallic glasses: Based on mechanical relaxations and theoretical analysis

Author

Kai Zhao, Q.S. Xue, Y. Hu, Liyuan Wang, Hongshan Zhang, J.C. Qiao, D.L. Yan, S. Wu, Kaikai Song, Jean-Marc Pelletier, Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and NASA Langley Research Center [Hampton] (LaRC)

Subjects
Materials science, Plasticity, Cobalt alloys, Relaxation peak, Phase separation, Dynamic mechanical analysis (DMA), Mechanical performance, 02 engineering and technology, 01 natural sciences, Compositional difference, [SPI.MAT]Engineering Sciences [physics]/Materials, Lanthanum alloys, Brittleness, Phase (matter), 0103 physical sciences, Activation energy, Fracture mechanics, Anelastic relaxation, General Materials Science, Relaxation behaviors, Composite material, 010306 general physics, Ductility, Amorphous metal, Ductile phase, Mechanical Engineering, Dynamic mechanical analysis, Macroscopic plasticity, Zircaloy, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Aluminum alloys, Metallic glass, Mechanics of Materials, Glass, 0210 nano-technology, Structural unit
Abstract

cited By 0; Pronounced slow β-relaxation in metallic glasses (MGs) has been proven to be closely related to macroscopic plasticity especially around 0.6–0.8Tg. However, the micro-scale phase-separating (ZrxLa1-x)57Co27Al16 (x = 0.2, 0.3, and 0.4) MGs obviously display brittleness around 0.7Tg even though an obvious slow β-relaxation peak is observed based on the dynamic mechanical analysis (DMA). In order to probe their intrinsic brittleness, the slow β-relaxation processes of the (ZrxLa1-x)57Co27Al16 (x = 0, 0.2, 0.3, 0.4, and 1) MGs were observed together with their mechanical performances. The results demonstrated that the La57Co27Al16 and Zr57Co27Al16 MGs show obvious ductility around 0.7Tg. Based on DMA results, the La57Co27Al16 MG displays an evident slow β-relaxation peak while the Zr57Co27Al16 MG presents an excess wing. When the phase-separating Zr–La–Co–Al MGs consisting of La-rich and Zr-rich components were heated up to 0.7Tg, only the β-relaxation behavior originating from La-rich components rather than from Zr-rich components is preferentially thermal-activated. In addition, the slow β-relaxation is well described by the Cole-Cole (CC) model, which becomes more obvious with increasing phase-separating degree. Then only partial but not all of potential structural units in whole samples can be activated, leading to the whole intrinsic brittleness of the micro-scale phase-separating MGs. These findings suggests that the large compositional difference between components is harmful to design ductile phase-separating MGs. © 2019 Elsevier B.V.

Published
2019
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125. Analysis of Water Vapor Correction for CloudSat W-Band Radar

Author

Peng-Wang Zhai, Yongxiang Hu, Jacques Pelon, Simone Tanelli, Damien Josset, Science Systems and Applications, Inc. [Lanham] (SSAI), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), NASA Langley Research Center [Hampton] (LaRC), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and 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)

Subjects
010504 meteorology & atmospheric sciences, 0211 other engineering and technologies, 02 engineering and technology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, 01 natural sciences, law.invention, W band, law, Electrical and Electronic Engineering, Radar, Physics::Atmospheric and Oceanic Physics, Water vapor, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Remote sensing, Radiometer, Attenuation, Laser radar, Lidar, 13. Climate action, Brightness temperature, General Earth and Planetary Sciences, Environmental science, Microwave
Abstract

International audience; We analyzed different models to estimate absorption at W-band by gaseous species by taking advantage of the collocated CloudSat-Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) measurements. We used the power backscattered by the surface in the green visible wavelength of the lidar of CALIPSO as a reference to infer CloudSat's 94-GHz ocean surface backscatter in clear air and infer the attenuation introduced by gaseous absorption. Different millimeter-wave propagation models (MPMs) and different sources to determine the profile of atmospheric thermodynamic state are used to estimate CloudSat attenuation. These estimates are compared to the observations to calculate the residual dispersion. We show here that we need to adjust the empirical constants of preexisting water vapor absorption models to minimize the dispersion. Our results indicate an overestimation of absorption by the water vapor continuum at 94 GHz in Liebe-based MPM. We also propose a new empirical model to better represent the absorption of the water vapor continuum near 94 GHz. When this model is used in combination with the Advanced Microwave Scanning Radiometer for the Earth Observing System water vapor path and the Global Modeling and Assimilation Office water vapor vertical profile distribution, it leads to the lowest dispersion of the data on a statistical basis (global data over one month). The improved model is expected to optimize water vapor correction applied to CloudSat data and, potentially, also to improve interpretation of brightness temperature measurements in the W-band (e.g., 85- and 98-GHz radiometric channels).

Published
2013
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126. CGILS: Results from the first phase of an international project to understand the physical mechanisms of low cloud feedbacks in single column models

Author

Zhang, Minghua, Blossey, Peter N., Khairoutdinov, Marat F., Austin, Phillip H., Bacmeister, Julio T., Bony, Sandrine, Brient, Florent, Cheedela, Suvarchal K., Del Genio, Anthony D., De Roode, Stephan R., Endo, Satoshi, Golaz, Jean-Christophe, Stevens, Bjorn, Isotta, Francesco Alessandro, Franklin, Charmaine N., Cheng, Anning, Kang, In-Sik, Kawai, Hideaki, Liu, Yangang, Xu, Kuan-Man, Koehler, Martin, Lock, Adrian P., Molod, Andrea M., Hannay, Cecile, Zhao, Ming, Lohmann, Ulrike, Neggers, Roel A. J., Rasch, Philip, Sandu, Irina, Siegenthaler-Le Drian, Colombe, Senkbeil, Ryan, Heus, Thijs, Bretherton, Christopher S., Suarez, Max J., Wolf, Audrey, Siebesma, A. Pier, von Salzen, Knut, Webb, Mark J., Larson, Vincent E., Dufresne, Jean-Louis, Institute for Terrestrial and Planetary Atmospheres [Stony Brook] (ITPA), School of Marine and Atmospheric Sciences [Stony Brook] (SoMAS), Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA, Univ British Columbia, Dept Earth & Ocean Sci, Vancouver, BC V5Z 1M9, Canada, NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), 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), Max-Planck-Institut für Meteorologie (MPI-M), Max-Planck-Gesellschaft, NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Department of Geoscience and Remote Sensing [Delft], Delft University of Technology (TU Delft), Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA, NOAA Geophysical Fluid Dynamics Laboratory (GFDL), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), CSIRO, Ctr Australian Weather & Climate Res, Aspendale, Vic, Australia, NASA Langley Research Center [Hampton] (LaRC), Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea, Meteorol Res Inst, Tsukuba, Ibaraki 305, Japan, European Centre for Medium-Range Weather Forecasts (ECMWF), Met Off Hadley Ctr, Exeter, Devon, England, Global Modeling and Assimilation Office (GMAO), Royal Netherlands Meteorological Institute (KNMI), Pacific NW Natl Lab, Richland, WA 99352 USA, Univ Wisconsin, Dept Math Sci, Milwaukee, WI 53201 USA, Canadian Ctr Climate Modelling & Anal, Victoria, BC, Canada, Department of Atmospheric Sciences [Seattle], University of Washington [Seattle], 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, large eddy models, low cloud feedbacks, single column models, CGILS
Abstract

International audience; CGILS-the CFMIP-GASS Intercomparison of Large Eddy Models (LESs) and single column models (SCMs)-investigates the mechanisms of cloud feedback in SCMs and LESs under idealized climate change perturbation. This paper describes the CGILS results from 15 SCMs and 8 LES models. Three cloud regimes over the subtropical oceans are studied: shallow cumulus, cumulus under stratocumulus, and well-mixed coastal stratus/stratocumulus. In the stratocumulus and coastal stratus regimes, SCMs without activated shallow convection generally simulated negative cloud feedbacks, while models with active shallow convection generally simulated positive cloud feedbacks. In the shallow cumulus alone regime, this relationship is less clear, likely due to the changes in cloud depth, lateral mixing, and precipitation or a combination of them. The majority of LES models simulated negative cloud feedback in the well-mixed coastal stratus/stratocumulus regime, and positive feedback in the shallow cumulus and stratocumulus regime. A general framework is provided to interpret SCM results: in a warmer climate, the moistening rate of the cloudy layer associated with the surface-based turbulence parameterization is enhanced; together with weaker large-scale subsidence, it causes negative cloud feedback. In contrast, in the warmer climate, the drying rate associated with the shallow convection scheme is enhanced. This causes positive cloud feedback. These mechanisms are summarized as the "NESTS" negative cloud feedback and the "SCOPE" positive cloud feedback (Negative feedback from Surface Turbulence under weaker Subsidence-Shallow Convection PositivE feedback) with the net cloud feedback depending on how the two opposing effects counteract each other. The LES results are consistent with these interpretations.

Published
2013
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127. Retrieval of ocean subsurface particulate backscattering coefficient from space-borne CALIOP lidar measurements

Author

Claude Audouy, Sharon Rodier, S. Zeng, Said Haouchine, Katie Liu, Brian Getzewich, Jacques Pelon, Charles R. Trepte, Jamie Wilson, Yongxiang Hu, Xiaomei Lu, Christophe Ferrier, Bill Hunt, Ron Verhappen, Patricia L. Lucker, Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Langley Research Center [Hampton] (LaRC), 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), and Centre National d’Études Spatiales [Paris] (CNES)

Subjects
010504 meteorology & atmospheric sciences, Backscatter, Climate, Cloud-Aerosol Lidar, Backscattering, 01 natural sciences, Physics::Geophysics, 010309 optics, 0103 physical sciences, 14. Life underwater, Volume scattering, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Remote sensing, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], CALIOP Lidar, Scattering, Instrument, Particulates, Polarization (waves), CALIPSO Satellite, Atomic and Molecular Physics, and Optics, Earth Radiation, Lidar, Ocean color, Ocean Subsurface Backscatter, Attenuation coefficient, Global Ocean Carbon, Environmental science
Abstract

International audience; A new approach has been proposed to determine ocean subsurface particulate backscattering coefficient b from CALIOP 30° off-nadir lidar measurements. The new method also provides estimates of the particle volume scattering function at the 180° scattering angle. The CALIOP based layer-integrated lidar backscatter and particulate backscattering coefficients are compared with the results obtained from MODIS ocean color measurements. The comparison analysis shows that ocean subsurface lidar backscatter and particulate backscattering coefficient bbp can be accurately obtained from CALIOP lidar measurements, thereby supporting the use of space-borne lidar measurements for ocean subsurface studies.

Published
2016
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128. Modeling Transport and Processing of Light Absorbing Aerosols Deposited on the Greenland Ice Sheet in 2013

Author

Thomas, Jennie L., Polashenski, Chris, Soja, Amber Jeanine, Dibb, Jack, Choi, Hyun-Deok, Flanner, Mark, Bergin, Michael H., Casey, Kimberly, Chen, Justin, Courville, Zoe, Raut, Jean-Christophe, Shafer, Martin M., Ward, Jamie Lynn, Wiedinmyer, Christine, 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), US Army Corps of Engineers (USACE), NASA Langley Research Center [Hampton] (LaRC), University of New Hampshire (UNH), National Institute of Aerospace [Hampton] (NIA), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Department of Civil and Environmental Engineering [Durham] (CEE), Duke University [Durham], Earth Science System Interdisciplinary Center [College Park] (ESSIC), College of Computer, Mathematical, and Natural Sciences [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System-University of Maryland [College Park], University of Maryland System-University of Maryland System, NASA Goddard Space Flight Center (GSFC), Massachusetts Institute of Technology (MIT), ERDC Cold Regions Research and Engineering Laboratory (CRREL), USACE Engineer Research and Development Center (ERDC), Environmental Chemistry and Technology Program, University of Wisconsin-Madison, University of Michigan System, National Center for Atmospheric Research [Boulder] (NCAR), and Cardon, Catherine

Subjects
[SDE] 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, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDE]Environmental Sciences, [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; The processes that result in aerosol deposition within the Arctic are important for understanding how mid-latitude pollution impacts and modifies the natural Arctic environment. Aerosol deposition is a dominant source of light-absorbing impurities, including black carbon, found in Arctic ice and snow. Trace amounts of light absorbing impurities in snow are important because they are used to interpret past pollution trends (e.g. fire frequency) using ice cores and because they have important climate impacts (warming) due to their modification of snow and ice albedo. Here, we focus on the role of biomass burning in controlling the amount of black carbon deposited on the Greenland ice sheet. Biomass burning is known to modify the Arctic aerosol burden, but large uncertainties remain with respect to the specific processes and impacts.In this presentation, a specific case of light absorbing aerosol deposition to the Greenland ice sheet is studied by combining extensive snow pit measurements with simulations using the regional model WRF-Chem. Light absorbing impurities were measured in snow pits (in 2014) and snow accumulation rates (2013-2014) were monitored at several remote sites on the Greenland ice sheet as part of the SAGE project. The largest black carbon deposition quantity measured was traced to a snow accumulation event that occurred in early August 2013, which included snow deposition having 2-4 cm water equivalent with BC concentrations of up to 40ng/g . In order to understand the origin and identify the processes controlling the observed deposition event, the regional model WRF-Chem is used (run from 17 July – 5 August 2013). The model simulation includes anthropogenic and fire emissions in North America as well as transport and chemical/physical transport processes for both trace gases and aerosols. Model results show that the observed deposition event can be traced to fires burning in northern Canada in late July 2013. The processes controlling aerosol deposition will be discussed including the critical role of transport pathways and storm systems, which are essential in controlling the fate of emissions within the Arctic region.

Published
2016

129. Modeled Response of Greenland Climate to the Presence of Biomass Burning-Based Absorbing Aerosols in the Atmosphere and Snow

Author

Ward, Jamie Lynn, Flanner, Mark, Bergin, Michael Howard, Courville, Zoe, Dibb, Jack E., Polashenski, Chris, Soja, Amber Jeanine, Strellis, Brandon M., Thomas, Jennie L., University of Michigan [Ann Arbor], University of Michigan System, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan System-University of Michigan System, Georgia Institute of Technology [Atlanta], ERDC Cold Regions Research and Engineering Laboratory (CRREL), USACE Engineer Research and Development Center (ERDC), Institute for the Study of Earth, Oceans, and Space [Durham] (EOS), University of New Hampshire (UNH), Dartmouth College [Hanover], NASA Langley Research Center [Hampton] (LaRC), 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), and Cardon, Catherine

Subjects
[SDE] Environmental Sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDE]Environmental Sciences
Abstract

International audience; Combustion of biomass material results in the emission of microscopic particles, some of which absorb incoming solar radiation. Including black carbon (BC), these absorbing species can affect regional climate through changes in the local column energy budgets, cloud direct and indirect effects, and atmospheric dynamical processes. The cryosphere, which consists of both snow and ice, is unusually susceptible to changes in radiation due to its characteristically high albedo. As the largest element of the cryosphere in the Northern Hemisphere, the Greenland Ice Sheet (GrIS) covers most of Greenland’s terrestrial surface and, if subjected to the increased presence of light-absorbing impurities, could experience enhanced melt. A particularly enhanced melt episode of the GrIS occurred during July 2012; at the same time, large-scale biomass burning events were observed in Eurasia and North America. Observations showed that, at the same time, single-scattering albedo (SSA) was lower than average while aerosol optical depth (AOD) was high for the Greenland region.In this study, we apply idealized climate simulations to analyze how various aspects of Greenland’s climate are affected by the enhanced presence of particulate matter in the atmospheric and on the surface of the GrIS. We employ the Community Earth System Model (CESM) with prescribed sea surface temperatures and active land and atmospheric components. Using four sets of modeling experiments, we perturb 1) only AOD, 2) only SSA, 3) mass mixing ratios of BC and dust in snow, and 4) both AOD and in-snow impurity concentrations. The chosen values for each of these modeling experiments are based on field measurements taken in 2011 (AOD, SSA) and the summers of 2012-2014 (mass mixing ratios of BC and dust). Comparing the results of these experiments provides information on how the overall climate of Greenland could be affected by large biomass burning events.

Published
2016

130. Sunlight Absorption on the Greenland Ice Sheet Experiment (SAGE) – Tracing black carbon from emissions to deposition

Author

Polashenski, Chris, Soja, Amber Jeanine, Thomas, Jennie L., Dibb, Jack E., Choi, Hyun-Deok, Flanner, Mark, Bergin, Michael H., Casey, Kimberly, Chen, Justin, Courville, Zoe, Lai, Alexandra, Schauer, James J., Shafer, Martin M., Ward, Jamie Lynn, Dartmouth College [Hanover], NASA Langley Research Center [Hampton] (LaRC), 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), Institute for the Study of Earth, Oceans, and Space [Durham] (EOS), University of New Hampshire (UNH), National Institute of Aerospace [Hampton] (NIA), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Department of Civil and Environmental Engineering [Durham] (CEE), Duke University [Durham], Earth Science System Interdisciplinary Center [College Park] (ESSIC), College of Computer, Mathematical, and Natural Sciences [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System-University of Maryland [College Park], University of Maryland System-University of Maryland System, NASA Goddard Space Flight Center (GSFC), Massachusetts Institute of Technology (MIT), ERDC Cold Regions Research and Engineering Laboratory (CRREL), USACE Engineer Research and Development Center (ERDC), University of Wisconsin-Madison, Environmental Chemistry and Technology Program, and University of Michigan System

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

International audience; The SAGE project seeks to understand the impact of light absorbing impurities on the Greenland Ice Sheet (GrIS). In general, the project has found that black carbon and dust concentrations in snow were low in the dry snow zones of the GrIS during 2012-2014 and that their concentrations do not appear to be trending relative to observations of these concentrations in snow over recent decades. We provide a revised analysis of MODIS albedo trends on the GrIS using new collection 6 data. These indicate that observed albedo of dry snow is not substantially trending. Sensor drift which had been present in collection 5 data has been substantially removed and the observed albedo of dry snow on the GrIS is now showing near zero trend.Episodic enhancements in BC deposition are, however, found in specific layers in our extensive snow pit observations. These peak enhancements include concentrations of up to ~40 ng/g BC and would have reduced the albedo of the snow by 0.01-0.02. If timed correctly, the deposition of such a layer could be an important factor in initiating a melt-albedo feedback. Here we present an overview of synthesis work seeking to trace the formation of such a layer back to emission sources and call attention to multiple presentations making up the project. Collectively, the work traces a specific enhanced deposition event occurring on the northwest region of the ice sheet in early August 2013 to source fires in Canada. We summarize the multi-modal approach including remote sensing of aerosols, atmospheric trajectory modeling, chemical transport modeling, and coupled Earth system modeling. The emission, transport, and deposition of the enhanced event is observed and predicted by these tools and we find general agreement between these several modes of sensing and predicting. Further investigations explore other events where BC was emitted and even transported over the ice sheet but did not cause deposition events, resulting in no BC signature in the snow. We also show the spatial distribution of enhanced BC deposition from the event we studied, and highlight its limited nature. The results have significance for understanding the role episodic BC deposition might play in interannual variability of ice sheet surface melt and for interpreting the relationship between fire-frequency and fire signatures in ice cores.

Published
2016

131. Global Carbon Budget 2016

Author

Ian Harris, Richard A. Houghton, Josep G. Canadell, Pieter P. Tans, Abdirahman M Omar, Thomas A. Boden, Leticia Barbero, Arne Körtzinger, Adrienne J. Sutton, Guido R. van der Werf, Frank J. Millero, Benjamin D. Stocker, Julia E. M. S. Nabel, Louise Chini, Denis Pierrot, Scott C. Doney, Shin-Ichiro Nakaoka, Andrew Lenton, Kim I. Currie, Nicolas Viovy, Pedro M. S. Monteiro, Sönke Zaehle, Oliver Andrews, Philippe Ciais, Peter Landschützer, Ute Schuster, Stephen Sitch, Pierre Friedlingstein, Vanessa Haverd, Simone R. Alin, Judith Hauck, Christian Rödenbeck, Atul K. Jain, Nathalie Lefèvre, Ingrid T. van der Laan-Luijkx, Joe R. Melton, Mario Hoppema, Benjamin Poulter, Frédéric Chevallier, Taro Takahashi, Hanqin Tian, Thanos Gkritzalis, Tsuneo Ono, Etsushi Kato, Andrew C. Manning, Roland Séférian, Danica Lombardozzi, Jörg Schwinger, Jan Ivar Korsbakken, David R. Munro, Corinne Le Quéré, Anthony P. Walker, Laurent Bopp, Peter Anthoni, Bronte Tilbrook, Glen P. Peters, Andy Wiltshire, Sebastian Lienert, Are Olsen, Ralph F. Keeling, Nicolas Metzl, Robbie M. Andrew, Christine Delire, Joe Salisbury, Kees Klein Goldewijk, K. O'Brien, Ingunn Skjelvan, Tyndall Centre for Climate Change Research, University of East Anglia [Norwich] (UEA), Center for International Climate and Environmental Research [Oslo] (CICERO), University of Oslo (UiO), Global Carbon Project (GCP), CSIRO Marine and Atmospheric Research (CSIRO-MAR), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO)-Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), College of Life and Environmental Sciences, University of Exeter, Centre for Ocean and Atmospheric Sciences [Norwich] (COAS), School of Environmental Sciences [Norwich], University of East Anglia [Norwich] (UEA)-University of East Anglia [Norwich] (UEA), Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC, NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Woods Hole Oceanographic Institution (WHOI), University of California [San Diego] (UC San Diego), University of California, NOAA Pacific Marine Environmental Laboratory [Seattle] (PMEL), Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology (KIT), NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML), Cooperative Institute for Marine and Atmospheric Studies (CIMAS), Rosenstiel School of Marine and Atmospheric Science (RSMAS), University of Miami [Coral Gables]-University of Miami [Coral Gables], 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), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), 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), Department of Geographical Sciences, University of Maryland [College Park], University of Maryland System-University of Maryland System, ICOS-ATC (ICOS-ATC), National Institute of Water and Atmospheric Research [Wellington] (NIWA), 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), College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Flanders Marine Institute, VLIZ, Climatic Research Unit, University of East Anglia, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Commonwealth Scientific and Industrial Research Organisation (CSIRO), Oceans and Atmosphere Flagship, PBL Netherlands Environmental Assessment Agency, STMicroelectronics [Crolles] (ST-CROLLES), The Institute of Applied Energy (IAE), Christian-Albrechts-Universität zu Kiel (CAU), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Max-Planck-Institut für Meteorologie (MPI-M), Max-Planck-Gesellschaft, Austral, Boréal et Carbone (ABC), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Oceans and Atmosphere Flagship (CSIRO), CSIRO Oceans and Atmosphere Flagship, Équipe CO2 (E-CO2), Department of Ocean Sciences, University of Miami [Coral Gables], Department of Civil and Environmental Engineering [Berkeley] (CEE), University of California [Berkeley], University of California-University of California, University of Wisconsin Whitewater, Max Planck Institute for Meteorology (MPI-M), National Institute for Environmental Studies (NIES), NASA Langley Research Center [Hampton] (LaRC), National Institute of Advanced Industrial Science and Technology (AIST), Entrepôts, Représentation et Ingénierie des Connaissances (ERIC), Université Lumière - Lyon 2 (UL2)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Max-Planck-Institut, Ocean Process Analysis Laboratory (OPAL), University of New Hampshire (UNH), Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences [Bergen] (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), Imperial College London, Scripps Institution of Oceanography (SIO), Joint Institute for the Study of the Atmosphere and Ocean (JISAO), University of Washington [Seattle], Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Shandong Agricultural University (SDAU), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Wageningen University and Research [Wageningen] (WUR), Faculty of Earth and Life Sciences [Amsterdam] (FALW), Vrije Universiteit Amsterdam [Amsterdam] (VU), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), School of Earth and Environment [Leeds] (SEE), University of Leeds, Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], Biogeochemical Systems Department [Jena], Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Environmental Sciences, Faculty of Earth and Life Sciences, Earth and Climate, University of California (UC), 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), 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), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-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 Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-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)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-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 Pierre-Simon-Laplace (IPSL (FR_636)), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), and Scripps Institution of Oceanography (SIO - UC San Diego)

Subjects
Meteorologie en Luchtkwaliteit, 010504 meteorology & atmospheric sciences, Meteorology and Air Quality, 530 Physics, Climate change, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 02 engineering and technology, 010501 environmental sciences, Atmospheric sciences, 01 natural sciences, 7. Clean energy, Carbon cycle, Latitude, SDG 17 - Partnerships for the Goals, Deforestation, ddc:550, SDG 13 - Climate Action, Life Science, lcsh:Environmental sciences, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, lcsh:GE1-350, WIMEK, business.industry, Fossil fuel, lcsh:QE1-996.5, Biosphere, Vegetation, 15. Life on land, 021001 nanoscience & nanotechnology, lcsh:Geology, Earth sciences, 13. Climate action, General Earth and Planetary Sciences, Environmental science, Sink (computing), 0210 nano-technology, business
Abstract

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates and consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models. We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2006–2015), EFF was 9.3 ± 0.5 GtC yr−1, ELUC 1.0 ± 0.5 GtC yr−1, GATM 4.5 ± 0.1 GtC yr−1, SOCEAN 2.6 ± 0.5 GtC yr−1, and SLAND 3.1 ± 0.9 GtC yr−1. For year 2015 alone, the growth in EFF was approximately zero and emissions remained at 9.9 ± 0.5 GtC yr−1, showing a slowdown in growth of these emissions compared to the average growth of 1.8 % yr−1 that took place during 2006–2015. Also, for 2015, ELUC was 1.3 ± 0.5 GtC yr−1, GATM was 6.3 ± 0.2 GtC yr−1, SOCEAN was 3.0 ± 0.5 GtC yr−1, and SLAND was 1.9 ± 0.9 GtC yr−1. GATM was higher in 2015 compared to the past decade (2006–2015), reflecting a smaller SLAND for that year. The global atmospheric CO2 concentration reached 399.4 ± 0.1 ppm averaged over 2015. For 2016, preliminary data indicate the continuation of low growth in EFF with +0.2 % (range of −1.0 to +1.8 %) based on national emissions projections for China and USA, and projections of gross domestic product corrected for recent changes in the carbon intensity of the economy for the rest of the world. In spite of the low growth of EFF in 2016, the growth rate in atmospheric CO2 concentration is expected to be relatively high because of the persistence of the smaller residual terrestrial sink (SLAND) in response to El Niño conditions of 2015–2016. From this projection of EFF and assumed constant ELUC for 2016, cumulative emissions of CO2 will reach 565 ± 55 GtC (2075 ± 205 GtCO2) for 1870–2016, about 75 % from EFF and 25 % from ELUC. This living data update documents changes in the methods and data sets used in this new carbon budget compared with previous publications of this data set (Le Quéré et al., 2015b, a, 2014, 2013). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2016).

Published
2016
Full Text
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132. Variations of Ice Microphysical Properties in Tropical MCS Using Cloud In-Situ Data and Corresponding Radar Reflectivity Profiles

Author

Fontaine, Emmanuel, Leroy, Delphine, Schwarzenboeck, Alfons, Coutris, Pierre, Delanoë, Julien, Protat, Alain, Dezitter, Fabien, Calmels, Alice, Strapp, John Walter, Lilie, Lyle, Minnis, Patrick, Yost, Christopher R., 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), SPACE - 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), Australian Bureau of Meteorology [Melbourne] (BoM), Australian Government, Airbus [France], Met Analytics Inc. [Toronto], Science Engineering Associates Inc., NASA Langley Research Center [Hampton] (LaRC), Science Systems and Applications, Inc. [Lanham] (SSAI), Cardon, Catherine, 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
[SDU.STU.ME] Sciences of the Universe [physics]/Earth Sciences/Meteorology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology
Abstract

International audience; Mesoscale convective systems (MCS) can last several hours or more and affect human societies in different ways. In order to predict and identify hazardous weather (e. g. in view of aviation safety) linked to MCS, numerical weather forecast and active/passive remote sensing products are currently the most useful tools. A major obstacle to increasing the accuracy of those tools is the fact that cumulonimbus clouds in MCS are composed of liquid droplets and ice hydrometeors (ice crystals); the latter have complex shapes based on diffusional growth, aggregation, and riming, which complicates the interpretation of remote sensing products and increases the uncertainties in numerical weather forecast. In this context, the study presented here investigates the properties of ice hydrometeors in MCS as a function of temperature and horizontal distance from the convective core. For this purpose, ice hydrometeor images, bulk TWC, and simultaneously measured radar reflectivity factors from three airborne campaigns in tropical MCS have been used. The underlying scope of producing these results is to improve the retrieval of MCS microphysical properties from satellite products and also improve cloud parameterizations in numerical weather prediction models.

Published
2016

133. Hyperbolic Method for Dispersive PDEs: Same High-Order of Accuracy for Solution, Gradient, and Hessian

Author

Hiroaki Nishikawa, Alireza Mazaheri, Mario Ricchiuto, NASA Langley Research Center [Hampton] (LaRC), Certified Adaptive discRete moDels for robust simulAtions of CoMplex flOws with Moving fronts (CARDAMOM), Institut de Mathématiques de Bordeaux (IMB), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Inria Bordeaux - Sud-Ouest, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), National Institute of Aerospace [Hampton] (NIA), and Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Inria Bordeaux - Sud-Ouest

Subjects
Hessian matrix, FTCS scheme, Hessian equation, Mathematical analysis, First-order partial differential equation, Order of accuracy, 010103 numerical & computational mathematics, 01 natural sciences, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, 010305 fluids & plasmas, symbols.namesake, Elliptic partial differential equation, Method of characteristics, 0103 physical sciences, symbols, 0101 mathematics, Hyperbolic partial differential equation, ComputingMilieux_MISCELLANEOUS, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], Mathematics
Abstract

In this paper, we introduce a new hyperbolic first-order system for general dispersive partial differential equations (PDEs). We then extend the proposed system to general advection-diffusion-dispersion PDEs. We apply the fourth-order RD scheme of Ref. 1 to the proposed hyperbolic system, and solve time-dependent dispersive equations, including the classical two-soliton KdV and a dispersive shock case. We demonstrate that the predicted results, including the gradient and Hessian (second derivative), are in a very good agreement with the exact solutions. We then show that the RD scheme applied to the proposed system accurately captures dispersive shocks without numerical oscillations. We also verify that the solution, gradient and Hessian are predicted with equal order of accuracy.

Published
2016
Full Text
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134. On the stratospheric aerosol budget at Northern mid-latitudesfrom 21 years of ground-based lidar and satellite observations

Author

Khaykin, Sergey, Godin-Beekmann, Sophie, Hauchecorne, Alain, Vernier, Jean-Paul, Jumelet, Julien, Keckhut, Philippe, 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), Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Langley Research Center [Hampton] (LaRC), and Cardon, Catherine

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 paper presents a new high-quality 21-year series of continuous stratospheric aerosol observations at Observa- toire de Haute-Provence (OHP, 44 ̊N, 6 ̊E) in Southern France using two powerful and well-maintained lidar sys- tems. In contrast to previous studies making use of the observations by aerosol-dedicated lidars operating within the Network for Detection of Atmospheric Composition Change (NDACC), we exploit the backscatter measure- ments from the off-line 355 nm channel of stratospheric ozone lidar (LiO3S) and low-gain 532 nm channel of stratospheric temperature lidar (LTA). The presented series of stratospheric aerosol backscatter and extinction at 532 nm, spanning from January 1994 through 2016, include on average 10-11 lidar acquisitions per month after careful quality screening.The OHP lidar observations are compared with global space-borne measurements of zonal-mean stratospheric extinction by SAGE II, GOMOS, OSIRIS and CALIOP instruments, altogether covering the time span of OHP lidar data sets. Both ground-based and satellite monthly-mean stratospheric Aerosol Optical Depth between 17 and 30 km altitude (sAOD1730km) series are in good cross-agreement with discrepancies well below the measurement errors, thereby ensuring the quality and coherency of all data sets exploited for our study. The global satellite observations are then used to identify the drivers of stratospheric aerosol variability observed locally by the OHP lidars.The 21-year aerosol series reflect two essential periods in the global volcanic activity over the past two decades. The first one, a long volcanically-quiescent period of low aerosol burden (0.002

Published
2016

135. 1D-coupled photochemical model of neutrals, cations and anions in the atmosphere of Titan

Author

Guillaume Gronoff, Jean-Christophe Loison, Kevin M. Hickson, Michel Dobrijevic, Institut des Sciences Moléculaires (ISM), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC), ASP 2016, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and NASA Langley Research Center [Hampton] (LaRC)

Subjects
Atmospheres, 010504 meteorology & atmospheric sciences, Photochemistry, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry, Atmospheric sciences, 01 natural sciences, Ion, Atmosphere, symbols.namesake, 0103 physical sciences, Atmosphere of Titan, 010303 astronomy & astrophysics, Stratosphere, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Astronomy and Astrophysics, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Ionospheres, composition, 13. Climate action, Space and Planetary Science, Chemical physics, Atmospheric chemistry, symbols, Mass spectrum, Astrophysics::Earth and Planetary Astrophysics, Ionosphere, Titan, Titan (rocket family)
Abstract

Many models with different characteristics have been published so far to study the chemical processes at work in Titan’s atmosphere. Some models focus on neutral species in the stratosphere or ionic species in the ionosphere, but few of them couple all the species throughout the whole atmosphere. Very few of these emphasize the importance of uncertainties in the chemical scheme and study their propagation in the model. We have developed a new 1D-photochemical model of Titan’s atmosphere coupling neutral species with positive and negative ions from the lower atmosphere up to the ionosphere and have compared our results with observations to have a comprehensive view of the chemical processes driving the composition of the stratosphere and ionosphere of Titan. We have updated the neutral, positive ion and negative ion chemistry and have improved the description of N 2 photodissociation by introducing high resolution N 2 absorption cross sections. We performed for the first time an uncertainty propagation study in a fully coupled ion-neutral model. We determine how uncertainties on rate constants on both neutral and ionic reactions influence the model results and pinpoint the key reactions responsible for this behavior. We find very good agreement between our model results and observations in both the stratosphere and in the ionosphere for most neutral compounds. Our results are also in good agreement with an average INMS mass spectrum and specific flybys in the dayside suggesting that our chemical model (for both neutral and ions) provides a good approximation of Titan’s atmospheric chemistry as a whole. Our uncertainty propagation study highlights the difficulty to interpret the INMS mass spectra for masses 14, 31, 41 and we identified the key reactions responsible for these ambiguities. Despite an overall improvement in the chemical model, disagreement for some specific compounds (HC 3 N, C 2 H 5 CN, C 2 H 4 ) highlights the role that certain physical processes could play (meridional dynamics or sticking on aerosols). We find that some critical key reactions are important for many compounds including both neutrals and ions and should be studied in priority to lower the remaining model uncertainties. Extensive studies for some specific processes (including photolyses) are required.

Published
2016
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136. Biomass Burning Emissions and Transport of Black Carbon (BC) to the Greenland Ice Sheet (GrIS) in 2013

Author

Choi, Hyun-Deok, Soja, Amber Jeanine, Polashenski, Chris, Thomas, Jennie L., Dibb, Jack E., Fairlie, Thomas Duncan, Winker, David M., Flanner, Mark, Bergin, Michael H., Casey, Kimberly, Courville, Zoe, Trepte, Charles R., Lai, Alexandra, Schauer, James J., Shafer, Martin M., Cardon, Catherine, National Institute of Aerospace [Hampton] (NIA), NASA Langley Research Center [Hampton] (LaRC), Dartmouth College [Hanover], 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), Institute for the Study of Earth, Oceans, and Space [Durham] (EOS), University of New Hampshire (UNH), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Department of Civil and Environmental Engineering [Durham] (CEE), Duke University [Durham], Earth Science System Interdisciplinary Center [College Park] (ESSIC), College of Computer, Mathematical, and Natural Sciences [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System-University of Maryland [College Park], University of Maryland System-University of Maryland System, NASA Goddard Space Flight Center (GSFC), ERDC Cold Regions Research and Engineering Laboratory (CRREL), USACE Engineer Research and Development Center (ERDC), University of Wisconsin-Madison, and Environmental Chemistry and Technology Program

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDE] Environmental Sciences, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDE]Environmental Sciences
Abstract

International audience; This study is the part of the SAGE project investigating the impact of light absorbing impurities (e.g., aerosols) on the Greenland Ice Sheet (GrIS). Previously ice-core snow samples collected on the GrIS indicated that black carbon (BC) concentrations were significantly enhanced, which could contribute to a decrease in albedo. Along with high levels of BC, the samples also showed significant amounts of ammonia, indicating the BC was sourced from biomass burning – likely from active forest fires in Eurasia and North America in July and August of 2013.In this study, we simulate the transport of potential smoke-filled air parcels using the NASA Langley Trajectory Model (LaTM), running in a backwards mode from selected ice-core sample sites on the GrIS from June 1st to August 31st 2013. The trajectory model is initialized for 24-hour sustained injection from each site, and air parcels are released from the surface to 2 km at 200m intervals. With the trajectory model outputs, we are able to identify trajectories that have coincidences with fires. As a case study, we focus on an event in early August 2013 when episodic enhancements in black carbon deposition are found in snow pit observations. We also utilize Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data to verify smoke-aerosol signatures in boreal regions based on the NASA LaTM results from late July to early August. We ran backward and forward trajectories from the CALIOP aerosol signatures to verify coincidence with fire events and transport to the GrIS. We found large fires burning west side of the Hudson Bay in late July. CALIOP data captured thick smoke plumes on July 28th over that region and backward/forward trajectories and MODIS Terra/Aqua images support the transport of smoke from these fires to the GrIS.

Published
2016

137. Ground-based assessment of the bias and long-term stability of 14 limb and occultation ozone profile data records

Author

Bryan J. Johnson, Ghassan Taha, David W. Tarasick, Sophie Godin-Beekmann, Marion Marchand, J. C. Lambert, Kerstin Stebel, Elian Wolfram, Adam Bourassa, Herman G. J. Smit, Arno Keppens, Daan Hubert, Hideaki Nakane, C. Thomas McElroy, Daan Swart, Ugo Cortesi, Karl W. Hoppel, Joanna A. E. van Gijsel, Donal P. Murtagh, James M. Russell, Tijl Verhoelst, Anne M. Thompson, Peter von der Gathen, Erkki Kyrölä, Günter Lichtenberg, Richard Querel, Kevin Strawbridge, Doug Degenstein, Wolfgang Steinbrecht, Kaley A. Walker, Joachim Urban, Roeland Van Malderen, Thierry Portafaix, José Granville, Jean-Luc Baray, Thierry Leblanc, Lucien Froidevaux, Jacobo Salvador, René Stübi, Joseph M. Zawodny, 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, 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), Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), Istituto di Fisica Applicata 'Nello Carrara' (IFAC), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), 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), Naval Research Laboratory (NRL), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Finnish Meteorological Institute (FMI), DLR Institut für Methodik der Fernerkundung / DLR Remote Sensing Technology Institute (IMF), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), University of York [York, UK], Department of Earth and Space Sciences [Göteborg], Chalmers University of Technology [Göteborg], Kochi University of Technology (KUT), National Institute for Environmental Studies (NIES), National Institute of Water and Atmospheric Research [Lauder] (NIWA), Department of Atmospheric and Planetary Sciences [Hampton] (APS), Hampton University, 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), Institut für Energie- und Klimaforschung - Troposphäre (IEK-8), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Norwegian Institute for Air Research (NILU), Meteorologisches Observatorium Hohenpeißenberg (MOHp), Deutscher Wetterdienst [Offenbach] (DWD), Environment and Climate Change Canada, Payerne Aerological Station, Federal Office of Meteorology and Climatology MeteoSwiss, National Institute for Public Health and the Environment [Bilthoven] (RIVM), NASA Goddard Space Flight Center (GSFC), Universities Space Research Association (USRA), Royal Netherlands Meteorological Institute (KNMI), Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute (IRM), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Department of Physics [Toronto], University of Toronto, NASA Langley Research Center [Hampton] (LaRC), 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), Consiglio Nazionale delle Ricerche [Roma] (CNR), and Institut Royal Météorologique de Belgique [Bruxelles] (IRM)

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, 010502 geochemistry & geophysics, 01 natural sciences, Occultation, Ozone depletion, SCIAMACHY, lcsh:Environmental engineering, Troposphere, Zeppelinobservatoriet, 13. Climate action, Stratopause, Ozone layer, ddc:550, Environmental science, Tropopause, lcsh:TA170-171, Stratosphere, 0105 earth and related environmental sciences
Abstract

The ozone profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of these data sets, especially of their long-term stability and their mutual consistency. To this end, we made a systematic assessment of 14 limb and occultation sounders that, together, provide more than three decades of global ozone profile measurements. In particular, we considered the latest operational Level-2 records by SAGE II, SAGE III, HALOE, UARS MLS, Aura MLS, POAM II, POAM III, OSIRIS, SMR, GOMOS, MIPAS, SCIAMACHY, ACE-FTS and MAESTRO. Central to our work is a consistent and robust analysis of the comparisons against the ground-based ozonesonde and stratospheric ozone lidar networks. It allowed us to investigate, from the troposphere up to the stratopause, the following main aspects of satellite data quality: long-term stability, overall bias and short-term variability, together with their dependence on geophysical parameters and profile representation. In addition, it permitted us to quantify the overall consistency between the ozone profilers. Generally, we found that between 20 and 40 km the satellite ozone measurement biases are smaller than ±5 %, the short-term variabilities are less than 5–12 % and the drifts are at most ±5 % decade−1 (or even ±3 % decade−1 for a few records). The agreement with ground-based data degrades somewhat towards the stratopause and especially towards the tropopause where natural variability and low ozone abundances impede a more precise analysis. In part of the stratosphere a few records deviate from the preceding general conclusions; we identified biases of 10 % and more (POAM II and SCIAMACHY), markedly higher single-profile variability (SMR and SCIAMACHY) and significant long-term drifts (SCIAMACHY, OSIRIS, HALOE and possibly GOMOS and SMR as well). Furthermore, we reflected on the repercussions of our findings for the construction, analysis and interpretation of merged data records. Most notably, the discrepancies between several recent ozone profile trend assessments can be mostly explained by instrumental drift. This clearly demonstrates the need for systematic comprehensive multi-instrument comparison analyses.

Published
2016
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138. Absorption cross-sections of ozone in the ultraviolet and visible spectral regions: Status report 2015

Author

Viktor Gorshelev, Stanley P. Sander, Dimitris Balis, Michael C. Pitts, Georg Wagner, Michel Van Roozendael, Anna Serdyuchenko, Thierry Leblanc, Michael Petersen, Christophe Lerot, Philippe Moussay, Jean-Marie Flaud, Mark Weber, Bénédicte Picquet-Varrault, Alberto Redondas, Christof Janssen, Doug Degenstein, Alkiviadis F. Bais, Marie-Renée De Backer, Pepijn Veefkind, Aline Gratien, Edward Hare, Robert Wielgosz, Erkki Kyrölä, Alain Barbe, Pawan K. Bhartia, Gordon Labow, Tom McElroy, Claus Zehner, David Flittner, Geir O. Braathen, Xiong Liu, Matthias Schneider, Irina Petropavlovskikh, R. Evans, Sophie Godin-Beekmann, Johannes Staehelin, Joële Viallon, Maud Rotger-Languereau, Kelly Chance, Johannes Orphal, Maud Pastel, Camille Viatte, Anthony Cox, Johanna Tamminen, Richard D. McPeters, Manfred Birk, Thomas von Clarmann, James W. Burkholder, Institute for Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology (KIT), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Finnish Meteorological Institute (FMI), World Meteorological Organization (WMO), Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Laboratory of Atmospheric Physics [Thessaloniki], Aristotle University of Thessaloniki, NASA Goddard Space Flight Center (GSFC), German Aerospace Center (DLR), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, University of Cambridge [UK] (CAM), Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), 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), NASA Langley Research Center [Hampton] (LaRC), 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), University of Bremen, Environment and Climate Change Canada, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Bureau International des Poids et Mesures (BIPM), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Agencia Estatal de Meteorología (AEMet), Royal Netherlands Meteorological Institute (KNMI), California Institute of Technology (CALTECH), Institute of Environmental Physics [Bremen] (IUP), European Space Research Institute (ESRIN), European Space Agency (ESA), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), 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), Environment Canada (Toronto), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), NASA-California Institute of Technology (CALTECH), Spanish State Meteorological Agency (AEMET), Jacquinet, Nicole, Flaud, Jean-Marie, Gamache, Robert R., Predoi-Cross, Adriana, Vander Auwera, Jean, Harvard University-Smithsonian Institution, École normale supérieure - Paris (ENS-PSL), and Agence Spatiale Européenne = European Space Agency (ESA)

Subjects
Ozone, 010504 meteorology & atmospheric sciences, 010501 environmental sciences, Atmospheric sciences, medicine.disease_cause, 01 natural sciences, Absorption, Atmosphere, chemistry.chemical_compound, Reference data, medicine, Physical and Theoretical Chemistry, Experimentelle Verfahren, Absorption (electromagnetic radiation), Spectroscopy, 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, Remote sensing, Status report, Atomic and Molecular Physics, and Optics, Lidar, Cross sections, chemistry, 13. Climate action, Atmospheric chemistry, Environmental science, Ultraviolet, Atmospheric ozone
Abstract

The activity “Absorption Cross-Sections of Ozone” (ACSO) started in 2008 as a joint initiative of the International Ozone Commission (IO3C), the World Meteorological Organization (WMO) and the IGACO (“Integrated Global Atmospheric Chemistry Observations”) O3/UV subgroup to study, evaluate, and recommend the most suitable ozone absorption cross-section laboratory data to be used in atmospheric ozone measurements. The evaluation was basically restricted to ozone absorption cross-sections in the UV range with particular focus on the Huggins band. Up until now, the data of Bass and Paur published in 1985 (BP, 1985) are still officially recommended for such measurements. During the last decade it became obvious that BP (1985) cross-section data have deficits for use in advanced space-borne ozone measurements. At the same time, it was recognized that the origin of systematic differences in ground-based measurements of ozone required further investigation, in particular whether the BP (1985) cross-section data might contribute to these differences. In ACSO, different sets of laboratory ozone absorption cross-section data (including their dependence on temperature) of the group of Reims (France) (Brion et al., 1993, 1998, 1992, 1995, abbreviated as BDM, 1995) and those of Serdyuchenko et al. (2014), and Gorshelev et al. (2014), (abbreviated as SER, 2014) were examined for use in atmospheric ozone measurements in the Huggins band. In conclusion, ACSO recommends: (a) The spectroscopic data of BP (1985) should no longer be used for retrieval of atmospheric ozone measurements. (b) For retrieval of ground-based instruments of total ozone and ozone profile measurements by the Umkehr method performed by Brewer and Dobson instruments data of SER (2014) are recommended to be used. When SER (2014) is used, the difference between total ozone measurements of Brewer and Dobson instruments are very small and the difference between Dobson measurements at AD and CD wavelength pairs are diminished. (c) For ground-based Light Detection and Ranging (LIDAR) measurements the use of BDM (1995) or SER (2014) is recommended. (d) For satellite retrieval the presently widely used data of BDM (1995) should be used because SER (2014) seems less suitable for retrievals that use wavelengths close to 300 nm due to a deficiency in the signal-to-noise ratio in the SER (2014) dataset. The work of ACSO also showed: • The need to continue laboratory cross-section measurements of ozone of highest quality. The importance of careful characterization of the uncertainties of the laboratory measurements. • The need to extend the scope of such studies to other wavelength ranges (particularly to cover not only the Huggins band but also the comparison with the mid-infrared region). • The need for regular cooperation of experts in spectral laboratory measurements and specialists in atmospheric (ozone) measurements.

Published
2016
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139. Combining In-situ Measurements, Passive Satellite Imagery, and Active Radar Retrievals for the Detection of High Ice Water Content

Author

Yost, Christopher R., Minnis, Patrick, Bedka, Kristopher M., Nguyen, Louis, Palikonda, Rabindra, Spangenberg, Douglas, Strapp, John Walter, Delanoë, Julien, Protat, Alain, Cardon, Catherine, Science Systems and Applications, Inc. [Lanham] (SSAI), NASA Langley Research Center [Hampton] (LaRC), NASA, Met Analytics Inc. [Toronto], SPACE - 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), Australian Bureau of Meteorology [Melbourne] (BoM), and Australian Government

Subjects
[SDU.STU.ME] Sciences of the Universe [physics]/Earth Sciences/Meteorology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology
Abstract

International audience; At least one hundred jet engine power loss events since the 1990s have been attributed to the phenomenon known as ice crystal icing (ICI). Ingestion of high concentrations of ice particles into aircraft engines is thought to cause these events, but it is clear that the use of current on-board weather radar systems alone is insufficient for detecting conditions that might cause ICI. Passive radiometers in geostationary orbit are valuable for monitoring systems that produce high ice water content (HIWC) and will play an important role in nowcasting, but are incapable of making vertically resolved measurements of ice particle concentration, i.e., ice water content (IWC). Combined radar, lidar, and in-situ measurements are essential for developing a skilled satellite-based HIWC nowcasting technique. The High Altitude Ice Crystals – High Ice Water Content (HAIC-HIWC) field campaigns in Darwin, Australia, and Cayenne, French Guiana, have produced a valuable dataset of in-situ total water content (TWC) measurements with which to study conditions that produce HIWC. The NASA Langley Satellite ClOud and Radiative Property retrieval System (SatCORPS) was used to derive cloud physical and optical properties such cloud top height, temperature, optical depth, and ice water path from multi-spectral satellite imagery acquired throughout the HAIC-HIWC campaigns. These cloud properties were collocated with the in-situ TWC measurements in order to characterize cloud properties in the vicinity of HIWC. Additionally, a database of satellite-derived overshooting cloud top (OT) detections was used to identify TWC measurements in close proximity to convective cores likely producing large concentrations of ice crystals. Certain cloud properties show some sensitivity to increasing TWC and a multivariate probabilistic indicator of HIWC was developed from these datasets. This paper describes the algorithm development and demonstrates the HIWC indicator with imagery from the HAIC-HIWC campaigns. Vertically resolved IWC retrievals from active sensors such as the Cloud Profiling Radar (CPR) on CloudSat and the Doppler Radar System Airborne (RASTA) provide IWC profiles with which to validate and potentially enhance the satellite-based HIWC indicator.

Published
2016

140. Using in-situ airborne measurements to evaluate three cloud phase products derived from CALIPSO

Author

Cesana, Gregory, Chepfer, H., Winker, D., Getzewich, B., Cai, X., Jourdan, O., Mioche, G., Okamoto, H., Hagihara, Y., Noel, V., Reverdy, M., Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), 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), NASA Langley Research Center [Hampton] (LaRC), Science Systems and Applications, Inc. [Lanham] (SSAI), 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), Research Institute for Applied Mechanics [Fukuoka] (RIAM), Kyushu University, 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), 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), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Kyushu University [Fukuoka], 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, 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, Science Systems and Applications, Inc. [Hampton] (SSAI), 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), Laboratoire d'aérologie (LA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-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], validation, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, in situ, CALIPSO, cloud, cloud phase, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology
Abstract

International audience; We compare the cloud detection and cloud phase determination of three independent climatologies based on Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) to airborne in situ measurements. Our analysis of the cloud detection shows that the differences between the satellite and in situ measurements mainly arise from three factors. First, averaging CALIPSO Level l data along track before cloud detection increases the estimate of high-and low-level cloud fractions. Second, the vertical averaging of Level 1 data before cloud detection tends to artificially increase the cloud vertical extent. Third, the differences in classification of fully attenuated pixels among the CALIPSO climatologies lead to differences in the low-level Arctic cloud fractions. In another section, we compare the cloudy pixels detected by colocated in situ and satellite observations to study the cloud phase determination. At midlatitudes, retrievals of homogeneous high ice clouds by CALIPSO data sets are very robust (more than 94.6% of agreement with in situ). In the Arctic, where the cloud phase vertical variability is larger within a 480 m pixel, all climatologies show disagreements with the in situ measurements and CALIPSO-General Circulation Models-Oriented Cloud Product (GOCCP) report significant undefined-phase clouds, which likely correspond to mixed-phase clouds. In all CALIPSO products, the phase determination is dominated by the cloud top phase. Finally, we use global statistics to demonstrate that main differences between the CALIPSO cloud phase products stem from the cloud detection (horizontal averaging, fully attenuated pixels) rather than the cloud phase determination procedures.

Published
2016
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141. Evaluation of the aerosol vertical distribution in global aerosol models through comparison against CALIOP measurements: AeroCom phase II results

Author

Koffi, Brigitte, Schulz, Michael, Breon, Francois-Marie, Dentener, Frank, Steensen, Birthe Marie, Griesfeller, Jan, Winker, David, Balkanski, Yves, Bauer, Susanne E., Bellouin, Nicolas, Berntsen, Terje, Bian, Huisheng, Chin, Mian, Diehl, Thomas, Easter, Richard, Ghan, Steven, Hauglustaine, Didier A., Iversen, Trond, Kirkevag, Alf, Liu, Xiaohong, Lohmann, Ulrike, Myhre, Gunnar, Rasch, Phil, Seland, Oyvind, Skeie, Ragnhild B., Steenrod, Stephen D., Stier, Philip, Tackett, Jason, Takemura, Toshihiko, Tsigaridis, Kostas, Vuolo, Maria Raffaella, Yoon, Jinho, Zhang, Kai, JRC Institute for Environment and Sustainability (IES), European Commission - Joint Research Centre [Ispra] (JRC), Norwegian Meteorological Institute [Oslo] (MET), 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), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), 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), NASA Langley Research Center [Hampton] (LaRC), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Center for Climate Systems Research [New York] (CCSR), Columbia University [New York], Department of Meteorology [Reading], University of Reading (UOR), Department of Geosciences [Tucson], University of Arizona, Center for International Climate and Environmental Research [Oslo] (CICERO), University of Oslo (UiO), Joint Center for Earth Systems Technology [Baltimore] (JCET), University of Maryland [Baltimore County] (UMBC), University of Maryland System-University of Maryland System-NASA Goddard Space Flight Center (GSFC), Pacific Northwest National Laboratory (PNNL), University of Wyoming (UW), Swiss Federal Institute of Technology, Department of Physics [Oxford], University of Oxford [Oxford], Science Systems and Applications Inc (SSAI), Research Institute for Applied Mechanics [Fukuoka] (RIAM), Kyushu University [Fukuoka], Gwangju Institute of Science and Technology (GIST), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, European Commission [070307/ENV/2012/636596/C3], Research Council of Norway [207711/E10, 229771], CRAICC, EU, Norwegian Space Center, US Department of Energy, Office of Science, DOE [DE-AC06-76RLO 1830], NASA MAP program Modeling, Analysis, and Prediction Climate Variability and Change [NNH08ZDA001N-MAP], Research Council of Norway, 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), Department of Geosciences [University of Arizona], NASA Goddard Space Flight Center (GSFC)-University of Maryland [Baltimore County] (UMBC), University of Maryland System-University of Maryland System, University of Oxford, and Kyushu University

Subjects
[SDV]Life Sciences [q-bio], Article
Abstract

The ability of 11 models in simulating the aerosol vertical distribution from regional to global scales, as part of the second phase of the AeroCom model intercomparison initiative (AeroCom II), is assessed and compared to results of the first phase. The evaluation is performed using a global monthly gridded data set of aerosol extinction profiles built for this purpose from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) Layer Product 3.01. Results over 12 subcontinental regions show that five models improved, whereas three degraded in reproducing the interregional variability in Zα0–6 km, the mean extinction height diagnostic, as computed from the CALIOP aerosol profiles over the 0–6 km altitude range for each studied region and season. While the models' performance remains highly variable, the simulation of the timing of the Zα0–6 km peak season has also improved for all but two models from AeroCom Phase I to Phase II. The biases in Zα0–6 km are smaller in all regions except Central Atlantic, East Asia, and North and South Africa. Most of the models now underestimate Zα0–6 km over land, notably in the dust and biomass burning regions in Asia and Africa. At global scale, the AeroCom II models better reproduce the Zα0–6 km latitudinal variability over ocean than over land. Hypotheses for the performance and evolution of the individual models and for the intermodel diversity are discussed. We also provide an analysis of the CALIOP limitations and uncertainties contributing to the differences between the simulations and observations. ©2016. American Geophysical Union. All Rights Reserved.

Published
2016
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142. The second Sandia Fracture Challenge: predictions of ductile failure under quasi-static and moderate-rate dynamic loading

Author

Victoria Brinnel, Sheng Wei Chi, Scott Edward Sanborn, Benedikt Döbereiner, Tiantian Zhang, P. D Mattie, Junhe Lian, X. J. Fang, Matthieu Mazière, Ashkan Mahdavi, Thomas Bosiljevac, Napat Vajragupta, Michael Veilleux, Sylvia Feld-Payet, Tomasz Wierzbicki, James E. Warner, John A. Moore, Bruce W. Williams, Keunhwan Pack, Khalil I. Elkhodary, James W. Foulk, Jim Lua, Denis Novokshanov, Arthur A. Brown, Brad L. Boyce, Sharlotte Kramer, Vladislav A. Yastrebov, Krishnaswamy Ravi-Chandar, Yidu Di, Bo Wu, John L. Bignell, A. R. Cerrone, Anthony R. Ingraffea, Aida Nonn, Jožef Predan, G.F. Bomarito, Kyle N. Karlson, B.J. Carter, Pawel Kucharczyk, Edmundo Corona, Sebastian Münstermann, Jacob D. Hochhalter, Shih-Po Lin, M. K. Neilsen, Derek H. Warner, Kristin Dion, J. Zadravec, Jacques Besson, C. H M Simha, Christopher Andrew Jones, Vincent Chiaruttini, Jean-Louis Chaboche, Liang Xue, Andrew J. Gross, Sandia National Laboratories [Albuquerque] (SNL), Sandia National Laboratories - Corporation, Northwestern University [Evanston], American University in Cairo, CANMET, GE Global Research Center, Ostbayerische Technische Hochschule, NASA Langley Research Center [Hampton] (LaRC), Cornell University [New York], Global engineering and materials iNC, ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), Centre des Matériaux (MAT), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Rheinisch-Westfälische Technische Hochschule Aachen (RWTH), Sandia National Laboratories [Livermore], Massachusetts Institute of Technology (MIT), University of Illinois [Chicago] (UIC), University of Illinois System, University of Maribor, University of Texas at Austin [Austin], Thinkviewer LLC, Massachusetts Institute of Technology. Department of Mechanical Engineering, Wierzbicki, Tomasz, and Pack, Keun Hwan

Subjects
Engineering, metal, Computational Mechanics, 02 engineering and technology, 0203 mechanical engineering, Consistency (statistics), Modelling and Simulation, alloy, Tearing, Computational mechanics, ddc:530, tearing, business.industry, Work (physics), deformation, modeling, Structural engineering, prediction, 021001 nanoscience & nanotechnology, simulation, 020303 mechanical engineering & transports, Mechanics of Materials, Dynamic loading, fracture, Modeling and Simulation, Heat generation, plasticity, Fracture (geology), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], rupture, Deformation (engineering), 0210 nano-technology, business
Abstract

Ductile failure of structural metals is relevant to a wide range of engineering scenarios. Computational methods are employed to anticipate the critical conditions of failure, yet they sometimes provide inaccurate and misleading predictions. Challenge scenarios, such as the one presented in the current work, provide an opportunity to assess the blind, quantitative predictive ability of simulation methods against a previously unseen failure problem. Rather than evaluate the predictions of a single simulation approach, the Sandia Fracture Challenge relies on numerous volunteer teams with expertise in computational mechanics to apply a broad range of computational methods, numerical algorithms, and constitutive models to the challenge. This exercise is intended to evaluate the state of health of technologies available for failure prediction. In the first Sandia Fracture Challenge, a wide range of issues were raised in ductile failure modeling, including a lack of consistency in failure models, the importance of shear calibration data, and difficulties in quantifying the uncertainty of prediction [see Boyce et al. (Int J Fract 186:5–68, 2014) for details of these observations]. This second Sandia Fracture Challenge investigated the ductile rupture of a Ti–6Al–4V sheet under both quasi-static and modest-rate dynamic loading (failure in ∼∼ 0.1 s). Like the previous challenge, the sheet had an unusual arrangement of notches and holes that added geometric complexity and fostered a competition between tensile- and shear-dominated failure modes. The teams were asked to predict the fracture path and quantitative far-field failure metrics such as the peak force and displacement to cause crack initiation. Fourteen teams contributed blind predictions, and the experimental outcomes were quantified in three independent test labs. Additional shortcomings were revealed in this second challenge such as inconsistency in the application of appropriate boundary conditions, need for a thermomechanical treatment of the heat generation in the dynamic loading condition, and further difficulties in model calibration based on limited real-world engineering data. As with the prior challenge, this work not only documents the ‘state-of-the-art’ in computational failure prediction of ductile tearing scenarios, but also provides a detailed dataset for non-blind assessment of alternative methods., National Science Foundation (U.S.)

Published
2016
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143. Ocean lidar measurements of beam attenuation and a roadmap to accurate phytoplankton biomass estimates

Author

Mark A. Vaughan, Carolus C. Verhappen, Ray D. Rhew, Damien Josset, Carolyn F. Butler, Ali Omar, Sharon Rodier, Peng-Wang Zhai, Chris A. Hostetler, David G. MacDonnell, Bill Hunt, Michael J. Behrenfeld, Jacques Pelon, Anne Lifermann, Ivona Cetinić, Charles R. Trepte, Wayne H. Slade, Johnathan W. Hair, Xiaomei Lu, Weilin Hou, Carl Weimer, David M. Winker, Yongxiang Hu, Zhaoyan Liu, NASA Langley Research Center [Hampton] (LaRC), Oregon State University (OSU), 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), Sequoia Scientific Inc., University of Maine, University of Maryland [Baltimore County] (UMBC), University of Maryland System, Ball Aerospace and Technologies Corp., National Institute of Aerospace [Hampton] (NIA), Naval Research Laboratory (NRL), and Centre National d'Etudes Spatiales (CNES)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 010504 meteorology & atmospheric sciences, Backscatter, Scattering, Attenuation, Physics, QC1-999, 01 natural sciences, 010309 optics, Lidar, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, 13. Climate action, Brillouin scattering, Ocean color, 0103 physical sciences, Depolarization ratio, Satellite, 14. Life underwater, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Remote sensing
Abstract

International audience; Beam attenuation coefficient, c, provides an important optical index of plankton standing stocks, such as phytoplankton biomass and total particulate carbon concentration. Unfortunately, c has proven difficult to quantify through remote sensing. Here, we introduce an innovative approach for estimating c using lidar depolarization measurements and diffuse attenuation coefficients from ocean color products or lidar measurements of Brillouin scattering. The new approach is based on a theoretical formula established from Monte Carlo simulations that links the depolarization ratio of sea water to the ratio of diffuse attenuation Kd and beam attenuation C (i.e., a multiple scattering factor).On July 17, 2014, the CALIPSO satellite was tilted 30° off-nadir for one nighttime orbit in order to minimize ocean surface backscatter and demonstrate the lidar ocean subsurface measurement concept from space. Depolarization ratios of ocean subsurface backscatter are measured accurately. Beam attenuation coefficients computed from the depolarization ratio measurements compare well with empirical estimates from ocean color measurements. We further verify the beam attenuation coefficient retrievals using aircraft-based high spectral resolution lidar (HSRL) data that are collocated with in-water optical measurements.

Published
2016
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144. Unstructured Grid Adaptation: Status, Potential Impacts, and Recommended Investments Towards CFD 2030

Author

Michael A. Park, Juan J. Alonso, Todd Michal, Joshua A. Krakos, Adrien Loseille, NASA Langley Research Center [Hampton] (LaRC), The Boeing Company, Automatic mesh generation and advanced methods (Gamma3), Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut Charles Delaunay (ICD), Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS), Stanford University, Institut Charles Delaunay (ICD), Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)

Subjects
020301 aerospace & aeronautics, Process (engineering), Computer science, Context (language use), 02 engineering and technology, Supercomputer, Grid, 01 natural sciences, 7. Clean energy, Industrial engineering, 010305 fluids & plasmas, Unstructured grid, Workflow, 0203 mechanical engineering, Mesh generation, 0103 physical sciences, Adaptation (computer science), [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract

International audience; Unstructured grid adaptation is a powerful tool to control Computational Fluid Dynamics (CFD) discretization error. It has enabled key increases in the accuracy, automation, and capacity of some fluid simulation applications. Slotnick et al. provide a number of case studies in the CFD Vision 2030 Study: A Path to Revolutionary Computational Aerosciences to illustrate the current state of CFD capability and capacity. The study authors forecast the potential impact of emerging High Performance Computing (HPC) environments forecast in the year 2030 and identify that mesh generation and adaptivity will continue to be significant bottlenecks in the CFD workflow. These bottlenecks may persist because very little government investment has been targeted in these areas. To motivate investment, the impacts of improved grid adaptation technologies are identified. The CFD Vision 2030 Study roadmap and anticipated capabilities in complementary disciplines are quoted to provide context for the progress made in grid adaptation in the past fifteen years, current status, and a forecast for the next fifteen years with recommended investments. These investments are specific to mesh adaptation and impact other aspects of the CFD process. Finally, a strategy is identified to di↵use grid adaptation technology into production CFD work flows.

Published
2016
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145. Longpath DOAS observations of surface BrO at Summit, Greenland

Author

Luke D. Ziemba, R. von Glasow, S. C. Hurlock, K. A. Gorham, Jack E. Dibb, M. Piot, Jennie L. Thomas, Jochen Stutz, Barry Lefer, Max Schneider, John F. Burkhart, Department of Atmospheric and Oceanic Sciences [Los Angeles] (AOS), University of California [Los Angeles] (UCLA), University of California-University of California, School of Environmental Sciences [Norwich], University of East Anglia [Norwich] (UEA), EnBW Trading GmbH, School of Physical Sciences [Irvine], University of California [Irvine] (UCI), Norwegian Institute for Air Research (NILU), NASA Langley Research Center [Hampton] (LaRC), Institute for the Study of Earth, Oceans, and Space [Durham] (EOS), University of New Hampshire (UNH), Department of Earth and Atmospheric Sciences [Houston], and University of Houston

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, air, Greenland ice sheet, snow, 010501 environmental sciences, chemistry, Atmospheric sciences, 01 natural sciences, lcsh:Chemistry, Diurnal cycle, tropospheric bro, Physical Sciences and Mathematics, peroxy-radicals, ozone destruction, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], geography, region, geography.geographical_feature_category, Diurnal temperature variation, temperature, boundary-layer, absorption cross-sections, Snowpack, Snow, Ozone depletion, lcsh:QC1-999, lcsh:QD1-999, Arctic, 13. Climate action, Climatology, Ice sheet, lcsh:Physics
Abstract

Reactive halogens, and in particular bromine oxide (BrO), have frequently been observed in regions with large halide reservoirs, for example during bromine catalyzed coastal polar ozone depletion events. Much less is known about the presence and impact of reactive halogens in areas without obvious halide reservoirs, such as the polar ice sheets or continental snow. We report the first LP-DOAS measurements of BrO at Summit research station in the center of the Greenland ice sheet at an altitude of 3200 m. BrO mixing ratios in May 2007 and June 2008 were typically between 1–3 pmol mol−1, with maxima of up to 5 pmol mol−1. These measurements unequivocally show that halogen chemistry is occurring in the remote Arctic, far from known bromine reservoirs, such as the ocean. During periods when FLEXPART retroplumes show that airmasses resided on the Greenland ice sheet for 3 or more days, BrO exhibits a clear diurnal variation, with peak mixing ratios of up to 3 pmol mol−1 in the morning and at night. The diurnal cycle of BrO can be explained by a changing boundary layer height combined with photochemical formation of reactive bromine driven by solar radiation at the snow surface. The shallow stable boundary layer in the morning and night leads to an accumulation of BrO at the surface, leading to elevated BrO despite the expected smaller release from the snowpack during these times of low solar radiation. During the day when photolytic formation of reactive bromine is expected to be highest, efficient mixing into a deeper neutral boundary layer leads to lower BrO mixing ratios than during mornings and nights. The extended period of contact with the Greenland snowpack combined with the diurnal profile of BrO, modulated by boundary layer height, suggests that photochemistry in the snow is a significant source of BrO measured at Summit during the 2008 experiment. In addition, a rapid transport event on 4 July 2008, during which marine air from the Greenland east coast was rapidly transported to Summit, led to enhanced mixing ratios of BrO and a number of marine tracers. However, rapid transport of marine air from the Greenland east coast is rare and most likely not the main source of bromide in surface snow at Summit. The observed levels of BrO are predicted to influence NOx chemistry as well as impact HOx partitioning. However, impact of local snow photochemistry on HOx is smaller than previously suggested for Summit.

Published
2011
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146. Overshooting of clean tropospheric air in the tropical lower stratosphere as seen by the CALIPSO lidar

Author

Julien Jumelet, Jean-Paul Vernier, Anne Garnier, Larry W. Thomason, Jacques Pelon, Terry Deshler, Johannes K. Nielsen, Jean-Pierre Pommereau, NASA Langley Research Center [Hampton] (LaRC), 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), SPACE - LATMOS, Department of Atmospheric Science [Laramie], University of Wyoming (UW), and Danish Meteorological Institute (DMI)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, 010504 meteorology & atmospheric sciences, Atmospheric circulation, Northern Hemisphere, Atmospheric sciences, 010502 geochemistry & geophysics, 01 natural sciences, lcsh:QC1-999, Aerosol, Troposphere, lcsh:Chemistry, lcsh:QD1-999, Atmospheric convection, 13. Climate action, Climatology, Tropical cyclone, Tropopause, Stratosphere, Geology, lcsh:Physics, 0105 earth and related environmental sciences
Abstract

The evolution of aerosols in the tropical upper troposphere/lower stratosphere between June 2006 and October 2009 is examined using the observations of the space borne CALIOP lidar aboard the CALIPSO satellite. Superimposed on several volcanic plumes and soot from an extreme biomass-burning event in 2009, the measurements reveal the existence of fast-cleansing episodes in the lower stratosphere to altitudes as high as 20 km. The cleansing of the layer, which extends from 14 to 20 km, takes place within 1 to 4 months during the southern tropics convective season that transports aerosol-poor tropospheric air into the lower stratosphere. In contrast, the convective season of the Northern Hemisphere summer shows an increase in the particle load at the tropopause consistent with a lofting of air rich with aerosols. These aerosols can consist of surface-derived material such as mineral dust and soot as well as liquid sulfate and organic particles. The flux of tropospheric air during the Southern Hemisphere convective season derived from CALIOP observations is shown to be 5 times at 16 km and 20 times at 19 km larger, respectively, than that associated with flux caused by slow ascent through radiative heating. These results suggest that convective overshooting is a major contributor to troposphere-to-stratosphere transport with concomitant implications for the Tropical Tropopause Layer top height, the humidity, the photochemistry and the thermal structure of the layer.

Published
2011
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147. Can CO2 Turbulent Flux Be Measured by Lidar? A Preliminary Study

Author

Upendra N. Singh, Jeffrey Y. Beyon, Arlyn E. Andrews, Grady J. Koch, Kenneth J. Davis, Pierre H. Flamant, Fabien Gibert, Timothy W. Hilton, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), 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), Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA, NASA Langley Research Center [Hampton] (LaRC), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Physics, Atmospheric Science, 010504 meteorology & atmospheric sciences, Planetary boundary layer, Turbulence, Eddy covariance, Ocean Engineering, Covariance, Atmospheric sciences, 01 natural sciences, 010309 optics, Dial, Boundary layer, Lidar, 13. Climate action, 0103 physical sciences, Mixing ratio, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Remote sensing
Abstract

The vertical profiling of CO2 turbulent fluxes in the atmospheric boundary layer (ABL) is investigated using a coherent differential absorption lidar (CDIAL) operated nearby a tall tower in Wisconsin during June 2007. A CDIAL can perform simultaneous range-resolved CO2 DIAL and velocity measurements. The lidar eddy covariance technique is presented. The aims of the study are (i) an assessment of performance and current limitation of available CDIAL for CO2 turbulent fluxes and (ii) the derivation of instrument specifications to build a future CDIAL to perform accurate range-resolved CO2 fluxes. Experimental lidar CO2 mixing ratio and vertical velocity profiles are successfully compared with in situ sensors measurements. Time and space integral scales of turbulence in the ABL are addressed that result in limitation for time averaging and range accumulation. A first attempt to infer CO2 fluxes using an eddy covariance technique with currently available 2-μm CDIAL dataset is reported.

Published
2011
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148. Carbon monoxide distributions from the IASI/METOP mission: evaluation with other space-borne remote sensors

Author

Maya George, David P. Edwards, Matthieu Pommier, Solène Turquety, Daniel Hurtmans, Pierre-François Coheur, W. McMillan, Juliette Hadji-Lazaro, Helen M. Worden, Cathy Clerbaux, Curtis P. Rinsland, M. Luo, 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), National Center for Atmospheric Research [Boulder] (NCAR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), NASA Langley Research Center [Hampton] (LaRC), NOAA Center for Satellite Applications and Research (STAR), NOAA National Environmental Satellite, Data, and Information Service (NESDIS), and National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, 0211 other engineering and technologies, 02 engineering and technology, Infrared atmospheric sounding interferometer, 01 natural sciences, MOPITT, lcsh:QC1-999, Troposphere, lcsh:Chemistry, Tropospheric Emission Spectrometer, lcsh:QD1-999, 13. Climate action, Atmospheric Infrared Sounder, Radiance, Nadir, Environmental science, Satellite, lcsh:Physics, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Remote sensing
Abstract

The Infrared Atmospheric Sounding Interferometer (IASI) onboard the MetOp satellite measures carbon monoxide (CO) on a global scale, twice a day. CO total columns and vertical profiles are retrieved in near real time from the nadir radiance spectra measured by the instrument in the thermal infrared (TIR) spectral range. This paper describes the measurement vertical sensitivity and provides a first assessment of the capabilities of IASI to measure CO distributions. On the global scale, 0.8 to 2.4 independent pieces of information are available for the retrieval. At mid latitudes, the information ranges between 1.5 and 2, which enables the lower and upper troposphere to be distinguished, especially when thermal contrast is significant. Global distributions of column CO are evaluated with correlative observations available from other nadir looking TIR missions currently in operation: the Measurements of Pollution in the Troposphere (MOPITT) onboard TERRA, the Atmospheric Infrared Sounder (AIRS) onboard AQUA and the Tropospheric Emission Spectrometer (TES) onboard AURA. The IASI CO columns are compared with MOPITT, AIRS and TES CO columns, adjusted with the a priori, for three different months: August 2008, November 2008 and February 2009. On average, total column discrepancies of about 7% are found between IASI and the three other sounders in the Northern Hemisphere and in the equatorial region. However when strong CO concentrations are present, such as during fire events, these discrepancies can climb as high as 17%. Instrument specifications of IASI versus other missions are also discussed.

Published
2009
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149. Ozone and temperature trends in the upper stratosphere at five stations of the Network for the Detection of Atmospheric Composition Change

Author

Alan Parrish, Greg Bodeker, F. Schönenborn, Alain Hauchecorne, Klemens Hocke, Stacey M. Frith, John P. Burrows, Niklaus Kämpfer, D. P. J. Swart, Philippe Keckhut, Richard S. Stolarski, I. S. Boyd, Thierry Leblanc, A. Rozanov, Hans Claude, C. von Savigny, Sophie Godin-Beekmann, Larry W. Thomason, Ellis E. Remsberg, J. A. E. van Gijsel, I. S. McDermid, Wolfgang Steinbrecht, Meteorologisches Observatorium Hohenpeißenberg (MOHp), Deutscher Wetterdienst [Offenbach] (DWD), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), 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), National Institute for Public Health and the Environment [Bilthoven] (RIVM), National Institute of Water and Atmospheric Research [Lauder] (NIWA), Department of Astronomy [Amherst], University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS)-University of Massachusetts System (UMASS), Institut für angewandte Physik [Bern] (IAP), Universität Bern [Bern], NASA Goddard Space Flight Center (GSFC), NASA Langley Research Center [Hampton] (LaRC), Institut für Umweltphysik [Bremen] (IUP), Universität Bremen, and Universität Bern [Bern] (UNIBE)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Ozone, Stratospheric Aerosol and Gas Experiment, 010504 meteorology & atmospheric sciences, Microwave radiometer, Global Ozone Monitoring by Occultation of Stars, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, SCIAMACHY, chemistry.chemical_compound, chemistry, 13. Climate action, Ozone layer, Montreal Protocol, General Earth and Planetary Sciences, Environmental science, Stratosphere, 0105 earth and related environmental sciences
Abstract

International audience; Upper stratospheric ozone anomalies from the satellite-borne Solar Backscatter Ultra-Violet (SBUV), Stratospheric Aerosol and Gas Experiment II (SAGE II), Halogen Occultation Experiment (HALOE), Global Ozone Monitoring by Occultation of Stars (GOMOS), and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instruments agree within 5% or better with ground-based data from lidars and microwave radiometers at five stations of the Network for the Detection of Atmospheric Composition Change (NDACC), from 45°S to 48°N. From 1979 until the late 1990s, all available data show a clear decline of ozone near 40 km, by 10%–15%. This decline has not continued in the last 10 years. At some sites, ozone at 40 km appears to have increased since 2000, consistent with the beginning decline of stratospheric chlorine. The phaseout of chlorofluorocarbons after the International Montreal Protocol in 1987 has been successful, and is now showing positive effects on ozone in the upper stratosphere. Temperature anomalies near 40 km altitude from European Centre for Medium Range Weather Forecast reanalyses (ERA-40), from National Centers for Environmental Prediction (NCEP) operational analyses, and from HALOE and lidar measurements show good consistency at the five stations, within about 3 K. Since about 1985, upper stratospheric temperatures have been fluctuating around a constant level at all five NDACC stations. This non-decline of upper stratospheric temperatures is a significant change from the more or less linear cooling of the upper stratosphere up until the mid-1990s, reported in previous trend assessments. It is also at odds with the almost linear 1 K per decade cooling simulated over the entire 1979–2010 period by chemistry–climate models (CCMs). The same CCM simulations, however, track the historical ozone anomalies quite well, including the change of ozone tendency in the late 1990s.

Published
2009
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150. Transpacific transport of ozone pollution and the effect of recent Asian emission increases on air quality in North America: an integrated analysis using satellite, aircraft, ozonesonde, and surface observations

Author

L. Zhang, D. J. Jacob, K. F. Boersma, D. A. Jaffe, J. R. Olson, K. W. Bowman, J. R. Worden, A. M. Thompson, M. A. Avery, R. C. Cohen, J. E. Dibb, F. M. Flocke, H. E. Fuelberg, L. G. Huey, W. W. McMillan, H. B. Singh, A. J. Weinheimer, Department of Earth and Planetary Sciences [Cambridge, USA] (EPS), Harvard University [Cambridge], Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), University of Washington [Seattle], Atmospheric Sciences Division [Hampton], NASA Langley Research Center [Hampton] (LaRC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), PennState Meteorology Department, Pennsylvania State University (Penn State), Penn State System-Penn State System, Department of Chemistry, University of California, Climate Change Research Center [Durham], University of New Hampshire (UNH), Earth Observing Laboratory [Boulder] (EOL), National Center for Atmospheric Research [Boulder] (NCAR)-University Corporation for Atmospheric Research (UCAR), Department of Earth, Ocean and Atmospheric Science [Tallahassee] (FSU | EOAS), Florida State University [Tallahassee] (FSU), School of Earth and Atmospheric Sciences [Atlanta], Georgia Institute of Technology [Atlanta], Department of Physics [Baltimore], University of Maryland [Baltimore County] (UMBC), University of Maryland System-University of Maryland System, NASA Ames Research Center (ARC), and National Center for Atmospheric Research [Boulder] (NCAR)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:Chemistry, 010504 meteorology & atmospheric sciences, lcsh:QD1-999, 13. Climate action, 0211 other engineering and technologies, 02 engineering and technology, 01 natural sciences, lcsh:Physics, lcsh:QC1-999, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences
Abstract

We use an ensemble of aircraft, satellite, sonde, and surface observations for April–May 2006 (NASA/INTEX-B aircraft campaign) to better understand the mechanisms for transpacific ozone pollution and its implications for North American air quality. The observations are interpreted with a global 3-D chemical transport model (GEOS-Chem). OMI NO2 satellite observations constrain Asian anthropogenic NOx emissions and indicate a factor of 2 increase from 2000 to 2006 in China. Satellite observations of CO from AIRS and TES indicate two major events of Asian transpacific pollution during INTEX-B. Correlation between TES CO and ozone observations shows evidence for transpacific ozone pollution. The semi-permanent Pacific High and Aleutian Low cause splitting of transpacific pollution plumes over the Northeast Pacific. The northern branch circulates around the Aleutian Low and has little impact on North America. The southern branch circulates around the Pacific High and some of that air impacts western North America. Both aircraft measurements and model results show sustained ozone production driven by peroxyacetylnitrate (PAN) decomposition in the southern branch, roughly doubling the transpacific influence from ozone produced in the Asian boundary layer. Model simulation of ozone observations at Mt. Bachelor Observatory in Oregon (2.7 km altitude) indicates a mean Asian ozone pollution contribution of 9±3 ppbv to the mean observed concentration of 54 ppbv, reflecting mostly an enhancement in background ozone rather than episodic Asian plumes. Asian pollution enhanced surface ozone concentrations by 5–7 ppbv over western North America in spring 2006. The 2000–2006 rise in Asian anthropogenic emissions increased this influence by 1–2 ppbv.

Published
2008

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