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105 results on '"Bouin, Marie-Noelle"'

1. The Role of Dry Layers and Cold Pools in the Activation of Mesoscale Convective Systems: A Characterization Study Based on the Combined Use of Raman Lidar and DIAL Measurements and MESO-NH Model Simulations

Author

Di Girolamo, Paolo, Bouin, Marie-Noelle, Flamant, Cyrille, Summa, Donato, De Rosa, Benedetto, Franco, Noemi, Sullivan, John T., editor, Leblanc, Thierry, editor, Tucker, Sara, editor, Demoz, Belay, editor, Eloranta, Edwin, editor, Hostetler, Chris, editor, Ishii, Shoken, editor, Mona, Lucia, editor, Moshary, Fred, editor, Papayannis, Alexandros, editor, and Rupavatharam, Krishna, editor

Published
2023
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8. HyMeX-SOP2 : The Field Campaign Dedicated to Dense Water Formation in the Northwestern Mediterranean

Author

Estournel, Claude, Testor, Pierre, Taupier-Letage, Isabelle, Bouin, Marie-Noelle, Coppola, Laurent, Durand, Pierre, Conan, Pascal, Bosse, Anthony, Brilouet, Pierre-Etienne, Beguery, Laurent, Belamari, Sophie, Béranger, Karine, Beuvier, Jonathan, Bourras, Denis, Canut, Guylaine, Doerenbecher, Alexis, de Madron, Xavier Durrieu, D'Ortenzio, Fabrizio, Drobinski, Philippe, Ducrocq, Véronique, Fourrié, Nadia, Giordani, Hervé, Houpert, Loïc, Labatut, Laurent, Brossier, Cindy Lebeaupin, Nuret, Mathieu, Prieur, Louis, Roussot, Odile, Seyfried, Leo, and Somot, Samuel

Published
2016

14. HYMEX-SOPI : The Field Campaign Dedicated to Heavy Precipitation and Flash Flooding in the Northwestern Mediterranean

Author

Ducrocq, Véronique, Braud, Isabelle, Davolio, Silvio, Ferretti, Rossella, Flamant, Cyrille, Jansa, Agustin, Kalthoff, Norbert, Richard, Evelyne, Taupier-Letage, Isabelle, Ayral, Pierre-Alain, Belamari, Sophie, Berne, Alexis, Borga, Marco, Boudevillain, Brice, Bock, Olivier, Boichard, Jean-Luc, Bouin, Marie-Noëlle, Bousquet, Olivier, Bouvier, Christophe, Chiggiato, Jacopo, Cimini, Domenico, Corsmeier, Ulrich, Coppola, Laurent, Cocquerez, Philippe, Defer, Eric, Delanoë, Julien, Di Girolamo, Paolo, Doerenbecher, Alexis, Drobinski, Philippe, Dufournet, Yann, Fourrié, Nadia, Gourley, Jonathan J., Labatut, Laurent, Lambert, Dominique, Le Coz, Jérôme, Marzano, Frank S., Molinié, Gilles, Montani, Andrea, Nord, Guillaume, Nuret, Mathieu, Ramage, Karim, Rison, William, Roussot, Odile, Said, Frédérique, Schwarzenboeck, Alfons, Testor, Pierre, Van Baelen, Joël, Vincendon, Béatrice, Aran, Montserrat, and Tamayo, Jorge

Published
2014

15. SUPPLEMENT : HYMEX-SOPI The Field Campaign Dedicated to Heavy Precipitation and Flash Flooding in the Northwestern Mediterranean

Author

Ducrocq, Véronique, Braud, Isabelle, Davolio, Silvio, Ferretti, Rossella, Flamant, Cyrille, Jansa, Agustin, Kalthoff, Norbert, Richard, Evelyne, Taupier-Letage, Isabelle, Ayral, Pierre-Alain, Belamari, Sophie, Berne, Alexis, Borga, Marco, Boudevillain, Brice, Bock, Olivier, Boichard, Jean-Luc, Bouin, Marie-Noëlle, Bousquet, Olivier, Bouvier, Christophe, Chiggiato, Jacopo, Cimini, Domenico, Corsmeier, Ulrich, Coppola, Laurent, Cocquerez, Philippe, Defer, Eric, Delanoë, Julien, Di Girolamo, Paolo, Doerenbecher, Alexis, Drobinski, Philippe, Dufournet, Yann, Fourrié, Nadia, Gourley, Jonathan J., Labatut, Laurent, Lambert, Dominique, Le Coz, Jérôme, Marzano, Frank S., Molinié, Gilles, Montani, Andrea, Nord, Guillaume, Nuret, Mathieu, Ramage, Karim, Rison, William, Roussot, Odile, Said, Frédérique, Schwarzenboeck, Alfons, Testor, Pierre, Van Baelen, Joël, Vincendon, Béatrice, Aran, Montserrat, and Tamayo, Jorge

Published
2014

16. Characterization of Complex Water Vapour Field Structures and their Genesis Based on the Combined use of Raman Lidar Measurements and MESO-NH Model Simulations

Author

Di Girolamo Paolo and Bouin Marie-Noelle

Subjects
Physics, QC1-999
Abstract

As part of the Cevennes-Vivarais site, the University of Basilicata Raman lidar system (BASIL) was deployed in Candillargues throughout the duration of HyMeX-SOP 1 (September-November 2012), providing high-resolution and accurate measurements, both in daytime and night-time, of atmospheric temperature, water vapour mixing ratio and particle backscattering and extinction coefficient at three wavelengths. Measurements carried out by BASIL on 28 September 2012 reveal a quite complex vertical structure of the water vapor field. Reported Raman lidar measurements were run in the time interval between two consecutive heavy precipitation events, from 15:30 UTC on 28 September to 03:30 UTC on 29 September 2012. Throughout most of this observation period, lidar measurements reveal the presence of four distinct humidity layers. The present research effort aims at assessing the origin of the different humidity filaments observed by BASIL on this day. The analysis relies on the comparisons between Raman lidar MESO-NH model simulations. Back-trajectory analyses from the model reveal that air masses ending in Candillargues at different altitudes levels are coming from different geographical regions. Specifically, the analysis reveals that air masses within the surface humidity layer were originated over the Atlantic Ocean, while air masses within the elevated filamentary humidity layer, also coming from the Atlantic Ocean, overpassed the sea stretch North of Spain and Southern France at an altitude of ~1 km. In addition, air masses within the lower of the two upper layers are found to overpass Southern Spain and Marocco, descending from an elevation of 2-3.5 km, while air masses within the uppermost layer are found to overpass Algeria, descending from an elevation of 3.5-5 km.

Published
2020
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24. Two‐sided turbulent surface layer parameterizations for computing air‐sea fluxes

Author

Pelletier, Charles, Lemarie, Florian, Blayo, Eric, Bouin, Marie-noelle, Redelsperger, Jean-luc, Pelletier, Charles, Lemarie, Florian, Blayo, Eric, Bouin, Marie-noelle, and Redelsperger, Jean-luc

Abstract

Standard methods for determining air ‐ sea fluxes typically rely on bulk algorithms set in the frame of Monin‐Obukhov stability theory (MOST), using ocean surface fields and atmosphere near‐surface fields. In the context of coupled ocean ‐ atmosphere simulations, the shallowest ocean vertical level is usually used as bulk input and by default, the turbulent closure is one‐sided: it extrapolates atmosphere near‐surface solution profiles (for wind speed, temperature and humidity) to the prescribed ocean surface values. Using near‐surface ocean fields as surface ones is equivalent to considering that in the ocean surface layer, solution profiles are constant instead of also being determined by a turbulent closure. Here we introduce a method for extending existing turbulent parameterizations to a two‐sided framework by explicitely including the ocean surface layer within the aforementioned parameterizations. The formalism we use for this method is derived from that of classical turbulent closures, so that our novelties can easily be implemented within existing formulations. Special care is taken to ensure the smoothness of resulting solution profiles. Other physical phenomena, such as the penetration of radiative fluxes in the ocean and the formation of waves, are then included within our formalism, and their effects are assessed. We also investigate the impact of such two‐sided bulk formulations on air ‐ sea fluxes evaluated from a setting similar to those of coupled ocean ‐ atmosphere simulations.

Published
2021
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30. Impacts of surface gravity waves on a tidal front: A coupled model perspective

Author

Brumer, Sophia, Garnier, Valerie, Redelsperger, Jean-luc, Bouin, Marie-noelle, Ardhuin, Fabrice, Accensi, Mickael, Brumer, Sophia, Garnier, Valerie, Redelsperger, Jean-luc, Bouin, Marie-noelle, Ardhuin, Fabrice, and Accensi, Mickael

Abstract

A set of realistic coastal coupled ocean-wave numerical simulations is used to study the impact of surface gravity waves on a tidal temperature front and surface currents. The processes at play are elucidated through analyses of the budgets of the horizontal momentum, the temperature, and the turbulence closure equations. The numerical system consists of a 3D coastal hydrodynamic circulation model (Model for Applications at Regional Scale, MARS3D) and the third generation wave model WAVEWATCH III (WW3) coupled with OASIS-MCT at horizontal resolutions of 500 and 1500 m, respectively. The models were run for a period of low to moderate southwesterly winds as observed during the Front de Marée Variable (FroMVar) field campaign in the Iroise Sea where a seasonal small-scale tidal sea surface temperature front is present. Over the 2 day period considered, long fetch waves grow gradually propagating north east and east. Contrasting a stand-alone ocean run with a coupled ocean-wave run shows that waves move the Ushant front offshore by up to 4 kilometres and cool the offshore stratified side of the front by up to 1.5°C. The analysis of the temperature budget shows that the change in advection is the dominant factor contributing to the frontal shift while the contribution of wave enhanced vertical temperature diffusion is secondary. Temperature, considered to be a tracer, is advected in the coupled run by the Lagrangian current resulting from the quasi-Eulerian and Stokes drift. Although the Stokes drift is directed shorewards, changes in the quasi-Eulerian current lead to a more offshore advection in the coupled than the stand-alone run. The quasi-Eulerian current is reduced (enhanced) during the ebb (flood) flow which correspond to periods of wave-following (-opposing) currents. This is due to wave breaking enhanced vertical mixing acting on the positive vertical gradient present in the quasi-Eulerian current during both ebb and flood tides. Partially coupled runs reveal

Published
2020
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34. Characterization of Complex Water Vapour Field Structures and their Genesis Based on the Combined use of Raman Lidar Measurements and MESO-NH Model Simulations.

Author

Liu, D., Wang, Y., Wu, Y., Gross, B., Moshary, F., Di Girolamo, Paolo, and Bouin, Marie-Noelle

Subjects
WATER vapor, LIDAR, BACKSCATTERING, HUMIDITY
Abstract

As part of the Cevennes-Vivarais site, the University of Basilicata Raman lidar system (BASIL) was deployed in Candillargues throughout the duration of HyMeX-SOP 1 (September-November 2012), providing high-resolution and accurate measurements, both in daytime and night-time, of atmospheric temperature, water vapour mixing ratio and particle backscattering and extinction coefficient at three wavelengths. Measurements carried out by BASIL on 28 September 2012 reveal a quite complex vertical structure of the water vapor field. Reported Raman lidar measurements were run in the time interval between two consecutive heavy precipitation events, from 15:30 UTC on 28 September to 03:30 UTC on 29 September 2012. Throughout most of this observation period, lidar measurements reveal the presence of four distinct humidity layers. The present research effort aims at assessing the origin of the different humidity filaments observed by BASIL on this day. The analysis relies on the comparisons between Raman lidar MESO-NH model simulations. Back-trajectory analyses from the model reveal that air masses ending in Candillargues at different altitudes levels are coming from different geographical regions. Specifically, the analysis reveals that air masses within the surface humidity layer were originated over the Atlantic Ocean, while air masses within the elevated filamentary humidity layer, also coming from the Atlantic Ocean, overpassed the sea stretch North of Spain and Southern France at an altitude of ~1 km. In addition, air masses within the lower of the two upper layers are found to overpass Southern Spain and Marocco, descending from an elevation of 2-3.5 km, while air masses within the uppermost layer are found to overpass Algeria, descending from an elevation of 3.5-5 km. [ABSTRACT FROM AUTHOR]

Published
2020
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35. Multi-scale observations of deep convection in the northwestern Mediterranean Sea during winter 2012-2013 using multiple platforms

Author

Testor, Pierre, Bosse, Anthony, Houpert, Loïc, Margirier, Félix, Mortier, Laurent, Legoff, Hervé, Dausse, Denis, Labaste, Matthieu, Karstensen, Johannes, Hayes, Daniel, Olita, Antonio, Ribotti, Alberto, Schroeder, Katrin, Chiggiato, Jacopo, Onken, Reiner, Heslop, Emma, Mourre, Baptiste, D'ortenzio, Fabrizio, Mayot, Nicolas, Lavigne, Héloise, de Fommervault, Orens, Coppola, Laurent, Prieur, Louis, Taillandier, Vincent, Durrieu de Madron, Xavier, Bourrin, Francois, Many, Gael, Damien, Pierre, Estournel, Claude, Marsaleix, Patrick, Taupier-Letage, Isabelle, Raimbault, Patrick, Waldman, Robin, Bouin, Marie Noelle, Giordani, Hervé, Caniaux, Guy, Somot, Samuel, Ducrocq, Véronique, Conan, Pascal, Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), 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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-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)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences [Bergen] (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), Scottish Association for Marine Science (SAMS), Développement Instrumental et Techniques Marines (DITM), Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Cyprus Oceanography Center, University of Cyprus (UCY), CNR Institute for Coastal Marine Environment (IAMC), Consiglio Nazionale delle Ricerche (CNR), Istituto di Science Marine (ISMAR ), Helmholtz-Zentrum Geesthacht (GKSS), SOCIB Balearic Islands Coastal Ocean Observing and Forecasting System, Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LAERO), 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), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Bio-Argo project (CNES-TOSCA), COST Action ES0904 ‘‘EGO’’ (Everyone’s Gliding Observatories), MISTRALS, ANR-12-BS06-0003,ASICS-MED,Couplage Océan-Atmosphère en présence de structures de Submésoéchelle(2012), ANR-10-EQPX-0040,NAOS,Observations de l'océan global pour l'étude et la prévision de l'océan et du climat: préparation de la nouvelle décennie d'Argo(2010), European Project: 284321,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2011-1,GROOM(2011), European Project: 287600,EC:FP7:ENV,FP7-OCEAN-2011,PERSEUS(2012), European Project: 262584,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2010-1,JERICO(2011), 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, Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Cyprus [Nicosia] (UCY), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB)

Subjects
0106 biological sciences, Ocean observations, 010504 meteorology & atmospheric sciences, oceanic deep convection, ocean observation, Oceanography, 01 natural sciences, Symmetric instability, Deep convection, Mediterranean sea, symmetric instability, Geochemistry and Petrology, plumes, Mediterranean Sea, Earth and Planetary Sciences (miscellaneous), 14. Life underwater, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, Argo, 0105 earth and related environmental sciences, energy and buoyancy fluxes, 010604 marine biology & hydrobiology, Plumes, Ocean observation, Mooring, Energy and buoyancy fluxes, Geophysics, Oceanic deep convection, Eddy, 13. Climate action, Space and Planetary Science, Climatology, Thermohaline circulation, eddies, Bloom, Eddies, Geology
Abstract

International audience; During winter 2012–2013, open‐ocean deep convection which is a major driver for the thermohaline circulation and ventilation of the ocean, occurred in the Gulf of Lions (Northwestern Mediterranean Sea) and has been thoroughly documented thanks in particular to the deployment of several gliders, Argo profiling floats, several dedicated ship cruises, and a mooring array during a period of about a year. Thanks to these intense observational efforts, we show that deep convection reached the bottom in winter early in February 2013 in a area of maximum 28 ± 3 109 m2. We present new quantitative results with estimates of heat and salt content at the subbasin scale at different time scales (on the seasonal scale to a 10 days basis) through optimal interpolation techniques, and robust estimates of the deep water formation rate of 2.0 ± 0.2 Sv. We provide an overview of the spatiotemporal coverage that has been reached throughout the seasons this year and we highlight some results based on data analysis and numerical modeling that are presented in this special issue. They concern key circulation features for the deep convection and the subsequent bloom such as Submesoscale Coherent Vortices (SCVs), the plumes, and symmetric instability at the edge of the deep convection area.

Published
2018
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36. Strong winds in a coupled wave-atmosphere model during a North Atlantic storm event: evaluation against observations

Author

Pineau-guillou, Lucia, Ardhuin, Fabrice, Bouin, Marie-noelle, Redelsperger, Jean-luc, Chapron, Bertrand, Bidlot, Jean-raymond, Quilfen, Yves, Pineau-guillou, Lucia, Ardhuin, Fabrice, Bouin, Marie-noelle, Redelsperger, Jean-luc, Chapron, Bertrand, Bidlot, Jean-raymond, and Quilfen, Yves

Abstract

Strong winds may be biased in atmospheric models. Here the ECMWF coupled wave-atmosphere model is used (1) to evaluate strong winds against observations, (2) to test how alternative wind stress parameterizations could lead to a more accurate model. For the period of storms Kaat and Lilli (23 to 27 January 2014), we compared simulated winds with in-situ – moored buoys and platforms - and satellite observations available from the North Atlantic. Five wind stress parameterizations were evaluated. The first result is that moderate simulated winds (5-20 m s-1) match with all observations. However, for strong winds (above 20 m s-1), mean differences appear, as much as -7 m s-1 at 30 m s-1. Significant differences also exist between observations, with buoys and ASCAT-KNMI generally showing lower wind speeds than the platforms and other remote sensing data used in this study (AMSR2, ASCAT-RSS, WindSat, SMOS and JASON-2). It is difficult to conclude which dataset should be used as a reference. Even so, buoy and ASCAT-KNMI winds are likely to underestimate the real wind speed. The second result is that common wave-age dependent parameterizations produce unrealistic drags and are not appropriate for coupling, whereas a newly empirically-adjusted Charnock parameterization leads to higher winds compared to the default ECMWF parameterization. This proposed new parameterization may lead to more accurate results in an operational context.

Published
2018
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37. Multiscale observations of deep convection in the northwestern mediterranean sea during winter 2012-2013 using multiple platforms

Author

Testor, Pierre, Bosse, Anthony, Houpert, Loïc, Margirier, Félix, Mortier, Laurent, Legoff, Hervé, Dausse, Denis, Labaste, Matthieu, Karstensen, Johannes, Hayes, Daniel, Olita, Antonio, Ribotti, Alberto, Schroeder, Katrin, Chiggiato, Jacopo, Onken, Reiner, Heslop, Emma, Mourre, Baptiste, D'ortenzio, Fabrizio, Mayot, Nicolas, Lavigne, Héloise, de Fommervault, Orens, Coppola, Laurent, Prieur, Louis, Taillandier, Vincent, Durrieu de Madron, Xavier, Bourrin, Francois, Many, Gael, Damien, Pierre, Estournel, Claude, Marsaleix, Patrick, Taupier-Letage, Isabelle, Raimbault, Patrick, Waldman, Robin, Bouin, Marie-Noelle, Giordani, Hervé, Caniaux, Guy, Somot, Samuel, Ducrocq, Véronique, Conan, Pascal, Testor, Pierre, Bosse, Anthony, Houpert, Loïc, Margirier, Félix, Mortier, Laurent, Legoff, Hervé, Dausse, Denis, Labaste, Matthieu, Karstensen, Johannes, Hayes, Daniel, Olita, Antonio, Ribotti, Alberto, Schroeder, Katrin, Chiggiato, Jacopo, Onken, Reiner, Heslop, Emma, Mourre, Baptiste, D'ortenzio, Fabrizio, Mayot, Nicolas, Lavigne, Héloise, de Fommervault, Orens, Coppola, Laurent, Prieur, Louis, Taillandier, Vincent, Durrieu de Madron, Xavier, Bourrin, Francois, Many, Gael, Damien, Pierre, Estournel, Claude, Marsaleix, Patrick, Taupier-Letage, Isabelle, Raimbault, Patrick, Waldman, Robin, Bouin, Marie-Noelle, Giordani, Hervé, Caniaux, Guy, Somot, Samuel, Ducrocq, Véronique, and Conan, Pascal

Abstract

During winter 2012–2013, open‐ocean deep convection which is a major driver for the thermohaline circulation and ventilation of the ocean, occurred in the Gulf of Lions (Northwestern Mediterranean Sea) and has been thoroughly documented thanks in particular to the deployment of several gliders, Argo profiling floats, several dedicated ship cruises, and a mooring array during a period of about a year. Thanks to these intense observational efforts, we show that deep convection reached the bottom in winter early in February 2013 in a area of maximum 28 ± 3 . We present new quantitative results with estimates of heat and salt content at the subbasin scale at different time scales (on the seasonal scale to a 10 days basis) through optimal interpolation techniques, and robust estimates of the deep water formation rate of 2.0 . We provide an overview of the spatiotemporal coverage that has been reached throughout the seasons this year and we highlight some results based on data analysis and numerical modeling that are presented in this special issue. They concern key circulation features for the deep convection and the subsequent bloom such as Submesoscale Coherent Vortices (SCVs), the plumes, and symmetric instability at the edge of the deep convection area.

Published
2018

38. Multiscale Observations of Deep Convection in the Northwestern Mediterranean Sea During Winter 2012-2013 Using Multiple Platforms

Author

Testor, Pierre, primary, Bosse, Anthony, additional, Houpert, Loïc, additional, Margirier, Félix, additional, Mortier, Laurent, additional, Legoff, Hervé, additional, Dausse, Denis, additional, Labaste, Matthieu, additional, Karstensen, Johannes, additional, Hayes, Daniel, additional, Olita, Antonio, additional, Ribotti, Alberto, additional, Schroeder, Katrin, additional, Chiggiato, Jacopo, additional, Onken, Reiner, additional, Heslop, Emma, additional, Mourre, Baptiste, additional, D'ortenzio, Fabrizio, additional, Mayot, Nicolas, additional, Lavigne, Héloise, additional, de Fommervault, Orens, additional, Coppola, Laurent, additional, Prieur, Louis, additional, Taillandier, Vincent, additional, Durrieu de Madron, Xavier, additional, Bourrin, Francois, additional, Many, Gael, additional, Damien, Pierre, additional, Estournel, Claude, additional, Marsaleix, Patrick, additional, Taupier-Letage, Isabelle, additional, Raimbault, Patrick, additional, Waldman, Robin, additional, Bouin, Marie-Noelle, additional, Giordani, Hervé, additional, Caniaux, Guy, additional, Somot, Samuel, additional, Ducrocq, Véronique, additional, and Conan, Pascal, additional

Published
2018
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39. SURFEX v8.0 interface with OASIS3-MCT to couple atmosphere with hydrology, ocean, waves and sea-ice models, from coastal to global scales

Author

Voldoire, Aurore, Decharme, Bertrand, Pianezze, Joris, Brossier, Cindy Lebeaupin, Sevault, Florence, Seyfried, Leo, Garnier, Valerie, Bielli, Soline, Valcke, Sophie, Alias, Antoinette, Accensi, Mickael, Ardhuin, Fabrice, Bouin, Marie-noelle, Ducrocq, Veronique, Faroux, Stephanie, Giordani, Herve, Leger, Fabien, Marsaleix, Patrick, Rainaud, Romain, Redelsperger, Jean-luc, Richard, Evelyne, Riette, Sebastien, Voldoire, Aurore, Decharme, Bertrand, Pianezze, Joris, Brossier, Cindy Lebeaupin, Sevault, Florence, Seyfried, Leo, Garnier, Valerie, Bielli, Soline, Valcke, Sophie, Alias, Antoinette, Accensi, Mickael, Ardhuin, Fabrice, Bouin, Marie-noelle, Ducrocq, Veronique, Faroux, Stephanie, Giordani, Herve, Leger, Fabien, Marsaleix, Patrick, Rainaud, Romain, Redelsperger, Jean-luc, Richard, Evelyne, and Riette, Sebastien

Abstract

This study presents the principles of the new coupling interface based on the SURFEX multi-surface model and the OASIS3-MCT coupler. As SURFEX can be plugged into several atmospheric models, it can be used in a wide range of applications, from global and regional coupled climate systems to high-resolution numerical weather prediction systems or very fine-scale models dedicated to process studies. The objective of this development is to build and share a common structure for the atmosphere-surface coupling of all these applications, involving on the one hand atmospheric models and on the other hand ocean, ice, hydrology, and wave models. The numerical and physical principles of SURFEX interface between the different component models are described, and the different coupled systems in which the SURFEX OASIS3-MCT-based coupling interface is already implemented are presented.

Published
2017
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40. Dense Water Formation in the North-Western Mediterranean area during HyMeX-SOP2 in 1/36° ocean simulations: Ocean-atmosphere coupling impact

Author

Lebeaupin Brossier, Cindy, Leger, Fabien, Giordani, Herve, Beuvier, Jonathan, Bouin, Marie-noelle, Ducrocq, Veronique, Fourrie, Nadia, Lebeaupin Brossier, Cindy, Leger, Fabien, Giordani, Herve, Beuvier, Jonathan, Bouin, Marie-noelle, Ducrocq, Veronique, and Fourrie, Nadia

Abstract

The north-western Mediterranean Sea is a key location for the thermohaline circulation of the basin. The area is characterized by intense air-sea exchanges favoured by the succession of strong northerly and north-westerly wind situations (mistral and tramontane) in autumn and winter. Such meteorological conditions lead to significant evaporation and ocean heat loss that are well known as the main triggering factor for the Dense Water Formation (DWF) and winter deep convection episodes. During the HyMeX second field campaign (SOP2, 1 February to 15 March 2013), several platforms were deployed in the area in order to document the DWF and the ocean deep convection, as the air-sea interface conditions. This study investigates the role of the ocean-atmosphere coupling on DWF during winter 2012-2013. The coupled system, based on the NEMO-WMED36 ocean model (1/36° resolution) and the AROME-WMED atmospheric model (2.5 km-resolution), was run during two months covering the SOP2 and is compared to an ocean-only simulation forced by AROME-WMED real-time forecasts and to observations collected in the north-western Mediterranean area during the HyMeX SOP2. The comparison shows small differences in terms of net heat, water and momentum fluxes. On average, DWF is slightly sensitive to air-sea coupling. However fine-scale ocean processes, such as shelf DWF and export or eddies and fronts at the rim of the convective patch are significantly modified. The wind-current interactions constitute an efficient coupled process at fine scale, acting as a turbulence propagating vectors, producing large mixing and convection at the rim of the convective patch.

Published
2017
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42. Dense water formation in the north-western Mediterranean area during HyMeX-SOP2 in 1/36° ocean simulations: Sensitivity to initial conditions

Author

Leger, Fabien, Brossier, Cindy Lebeaupin, Giordani, Herve, Arsouze, Thomas, Beuvier, Jonathan, Bouin, Marie-noelle, Bresson, Emilie, Ducrocq, Veronique, Fourrie, Nadia, Nuret, Mathieu, Leger, Fabien, Brossier, Cindy Lebeaupin, Giordani, Herve, Arsouze, Thomas, Beuvier, Jonathan, Bouin, Marie-noelle, Bresson, Emilie, Ducrocq, Veronique, Fourrie, Nadia, and Nuret, Mathieu

Abstract

The north-western Mediterranean Sea is a key location where intense air-sea exchanges occur in autumn and winter. The succession of strong mistral and tramontane situations, leading to significant evaporation and ocean heat loss, is well known as the controlling factor in the dense water formation (DWF) with deep convection episodes. During HyMeX-SOP2 (1 February to 15 March 2013), several platforms sampled the area in order to document DWF and air-sea exchanges. This study investigates the ability of the NEMO-WMED36 ocean model (1/36°-resolution), driven in surface by the hourly air-sea fluxes from the AROME-WMED forecasts (2.5 km resolution), to represent DWF during HyMeX-SOP2 and focuses on the sensitivity to initial conditions. After a short evaluation of the atmospheric forcing, the high-resolution oceanic simulations using three different data sets as initial and boundary conditions are compared to observations collected during the field campaign. It evidences that using regional model outputs may lead to unrealistic thermohaline characteristics for the intermediate and deep waters, which degrade the simulated new dense water formed. Using ocean analyses built from observations, permits to obtain more realistic characteristics of the Western Mediterranean dense water. However, a low stratification favors an overestimation of the convective area and of the DWF rate. The DWF chronology is also impacted. Nevertheless, in every run, SOP2 is characterized by the production of water denser than 29.11 kg m−3 with a peak during the strong mistral event of 23–25 February followed by a period of restratification, before a last event of bottom convection on 13–15 March.

Published
2016
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43. Characterizing, modelling and understanding the climate variability of the deep water formation in the North-Western Mediterranean Sea

Author

Somot, Samuel, primary, Houpert, Loic, additional, Sevault, Florence, additional, Testor, Pierre, additional, Bosse, Anthony, additional, Taupier-Letage, Isabelle, additional, Bouin, Marie-Noelle, additional, Waldman, Robin, additional, Cassou, Christophe, additional, Sanchez-Gomez, Emilia, additional, Durrieu de Madron, Xavier, additional, Adloff, Fanny, additional, Nabat, Pierre, additional, and Herrmann, Marine, additional

Published
2016
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44. High resolution modeling of dense water formation in the north‐western Mediterranean during winter 2012–2013: Processes and budget

Author

Estournel, Claude, primary, Testor, Pierre, additional, Damien, Pierre, additional, D'Ortenzio, Fabrizio, additional, Marsaleix, Patrick, additional, Conan, Pascal, additional, Kessouri, Faycal, additional, Durrieu de Madron, Xavier, additional, Coppola, Laurent, additional, Lellouche, Jean‐Michel, additional, Belamari, Sophie, additional, Mortier, Laurent, additional, Ulses, Caroline, additional, Bouin, Marie‐Noelle, additional, and Prieur, Louis, additional

Published
2016
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45. Interseismic velocity field in the central Vanuatu locked subduction zone context from GPS measurements: Evidence for a central Vanuatu locked zone

Author

Bergeot, Nicolas, Bouin, Marie-Noelle, Diament, Michel, Pelletier, Bernard, Régnier, Marc, Calmant, Stéphane, Ballu, Valérie, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), LAboratoire de Recherche en Géodésie (LAREG), Ecole nationale des sciences géographiques (ENSG), Institut géographique national [IGN] (IGN)-Institut géographique national [IGN] (IGN), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie]), Géosciences Azur, Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - 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)-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 Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), 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; We analyzed interseismic velocity fields along the Vanuatu arc subduction zone from more than 45 GPS station measurements spanning 15 years. Convergence with respect to the Australian plate (AP) is normal to the trench, with amplitudes that vary greatly from a maximum of 170 mm a−1 at Vanikoro to 27 mm a−1 facing the D'Entrecasteaux Ridge (DER). Motions expressed relative to the Pacific plate (PP) highlight arc segmentation. Both the northern and southern segments undergo back‐arc spreading in a roughly NE‐SW direction, rotating anticlockwise and clockwise, respectively, while the central block moves eastward at a faster rate with respect to the PP than to the AP. More convergence is therefore accommodated at the eastern bound of the arc than at the Vanuatu trench. A right lateral strike‐slip movement (26 ± 1 mm a−1) along a zone normal to the trench (direction N70°) is necessary to accommodate the rate variation between the central and southern parts of the arc. Horizontal and vertical rates indicate partitioning between Malekula–southernmost Santo and central‐northern Santo blocks. Simple elastic modeling of the interseismic stage deformation gives locked zone characteristics (25° dip and 50 km width) and a 54 mm a−1 long‐term convergence rate between the AP and the central part of the Vanuatu arc from GPS horizontal and vertical velocities estimated south of the DER. The modeling does not fit the observed velocities facing the DER, probably because it does not account for the inelastic deformation associated with buoyant ridge subduction and back‐arc thrusting.

Published
2009
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46. Evidence for a differential sea level rise between hemispheres over the twentieth century

Author

Woeppelmann, Guy, Marcos, Marta, Santamaria-gomez, Alvaro, Martin-miguez, Belen, Bouin, Marie-noelle, Gravelle, Mederic, Woeppelmann, Guy, Marcos, Marta, Santamaria-gomez, Alvaro, Martin-miguez, Belen, Bouin, Marie-noelle, and Gravelle, Mederic

Abstract

Tide gauge records are the primary source of sea level information over multidecadal to century timescales. A critical issue in using this type of data to determine global climate-related contributions to sea level change concerns the vertical motion of the land upon which the gauges are grounded. Here we use observations from the Global Positioning System for the correction of this vertical land motion. As a result, the spatial coherence in the rates of sea level change during the twentieth century is highlighted at the local and the regional scales, ultimately revealing a clearly distinct behavior between the Northern and the Southern Hemispheres with values of 2.0mm/yr and 1.1mm/yr, respectively. Our findings challenge the widely accepted value of global sea level rise for the twentieth century.

Published
2014
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48. Using Scintillometry to Estimate Sensible Heat Fluxes over Water: First Insights

Author

Bouin, Marie-noelle, Legain, D., Traulle, O., Belamari, S., Caniaux, G., Fiandrino, Annie, Lagarde, Franck, Barrie, J., Moulin, E., Bouhours, G., Bouin, Marie-noelle, Legain, D., Traulle, O., Belamari, S., Caniaux, G., Fiandrino, Annie, Lagarde, Franck, Barrie, J., Moulin, E., and Bouhours, G.

Abstract

An extra large aperture scintillometer (XLAS) was used over several months across the Thau Lagoon (South of France) to retrieve one-wavelength scintillation and, thence, sensible heat flux. We present the experiment with the XLAS, an eddy-covariance station and meteorological stations measuring on or near the Thau Lagoon. Changes implemented to adapt the scintillometry processing schemes to the above water conditions are presented together with a full error budget, including sensitivity tests to the relevant parameters of the scintillometer processing scheme. The XLAS error budget amounts to 16% (systematic part) +/- 50% (random part). Sensible heat fluxes obtained using the XLAS under unstable atmospheric conditions are then compared to eddy-covariance estimates used as a reference. The scintillometry technique proved to perform satisfactorily in such a watery environment. Some discrepancies observed between the XLAS and eddy-covariance measurements were investigated according to the lagoon fraction of the source area, to discriminate whether they were related to deviations from the Monin-Obukhov similarity theory or to different atmospheric conditions at the respective instrument locations. Local atmospheric conditions agreed well with the Monin-Obukhov similarity theory, especially measurements with source areas largely composed of the lagoon surface. Retaining only the measurements with almost only the lagoon surface in the source area improved the agreement between the XLAS and eddy-covariance measurements. The remaining discrepancies are interpreted as being due to significant location differences between the two instruments, resulting in different atmospheric conditions, and to size differences in the source areas.

Published
2012
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49. Moose: An integrated multi-sites observatory system in the NW Mediterranean sea

Author

Mantoura, F, Coppola, Laurent, Cousin, M., Antoine, David, Beguery, Laurent, Blain, Stephane, Bouin, Marie-noelle, Cadiou, Jean-francois, Durrieu De Madron, Xavier, Forget, Philippe, Fraunie, Philippe, Gojak, Carl, Gorsky, Gaby, Goyet, Catherine, Lebaron, Philippe, Lellouche, Jean-michel, Ludwig, Hubert, Molcard, Anne, Mortier, Laurent, Petit De La Villeon, Loic, Petrenko, Anne, Piazzola, J., Queguiner, B., Raimbault, Patrick, Rigaud, Vincent, Sempere, Richard, Tamburini, Jean-simon, Testor, Pierre, Vuillemin, Renaud, Zakardjian, B., Mantoura, F, Coppola, Laurent, Cousin, M., Antoine, David, Beguery, Laurent, Blain, Stephane, Bouin, Marie-noelle, Cadiou, Jean-francois, Durrieu De Madron, Xavier, Forget, Philippe, Fraunie, Philippe, Gojak, Carl, Gorsky, Gaby, Goyet, Catherine, Lebaron, Philippe, Lellouche, Jean-michel, Ludwig, Hubert, Molcard, Anne, Mortier, Laurent, Petit De La Villeon, Loic, Petrenko, Anne, Piazzola, J., Queguiner, B., Raimbault, Patrick, Rigaud, Vincent, Sempere, Richard, Tamburini, Jean-simon, Testor, Pierre, Vuillemin, Renaud, and Zakardjian, B.

Published
2009

50. GPS data processing in the Antarctic: crustal movements, postglacial rebound and reference systems

Author

Bouin, Marie-Noelle, Barbet, Virginie, Observatoire de Paris, Université Paris sciences et lettres (PSL), LAboratoire de Recherche en Géodésie (LAREG), Ecole nationale des sciences géographiques (ENSG), Institut géographique national [IGN] (IGN)-Institut géographique national [IGN] (IGN), Claude Boucher, and C. Vigny (co-directeur)

Subjects
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, astronomy, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Isostasie, GPS, Tectonique des plaques, Astronomie géodésique, [SDU.STU.TE] Sciences of the Universe [physics]/Earth Sciences/Tectonics, [SDU.STU.GP] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
Abstract

The subject of this thesis is the processing of GPS data from the permanent stations in Antarctica, for the assessment of vertical and horizontal motions induced by glacial rebound. An accurate knowledge of the current deformations provides information about the validity of the late Pleistocene deglaciation models and the present-day Antarctic ice-sheet behavior. This could largely affect global sea level change. We have analysed 4 years of continuous IGS data from the stations in and around Antarctica. We have improved the processing method in order to take into account the specifities of GPS data analysis in Antarctica, and obtained station position time series, from which we derive significant horizontal and vertical velocities. The horizontal velocities show a very good agreement with a rigide plate motion, which is slightly different from the Nuvell predicted motion, but very coherent with the recent results obtained by Heflin (1999) for the Australian plate motion. The particular case of the Dumont station was good agreement with the recent results obtained investigated to estimate the influence of the March 1998 Balleny Islands earthquake, in relatively good agreement with the dislocation models. From the vertical trends, we detect a global uplift of the whole Antarctic continent, at about 1 cm/yr, consistent with the upper limit of the vicous model predictions. Based upon O’Higgins observations, we see that the Peninsula is affected by a higher rate of 2.5 cm/yr, including a purely elastic part, which reflects the present-day increase of the melting rate over the West Antarctica, confirmed by the glaciological and geodetic observations. The seasonal variations detected for this station on the vertical component haven’t found their explanation yet., Le sujet de cette thèse est l'utilisation des données GPS des stations permanentes antarctiques pour la mesure de mouvements verticaux et horizontaux liés au rebond glaciaire. Les constantes de temps de l'isostasie terrestre sont telles que la croute terrestre subit encore les effets de la dernière déglaciation, par le biais de remontée visqueuse. La mesure de rebond élastique améliore de manière indirecte notre connaissance du comportement actuel de la calotte Antarctique, avec des conséquences importantes sur l'évolution à court terme du niveau des mers. Nous avons traité 4 ans de mesures continues sur les stations IGS situées sur le continent antarctique et autour. L’optimisation de la méthode de traitement en fonction du but de l'étude et de spécificités géographiques a permis d'extraire des séries temporelles des vitesses horizontales et verticales exploitables pour la géophysique. Les vitesses horizontales sur les stations de la plaque tectonique antarctique sont très compatibles avec une rotation de plaque rigide et donnent lieu à une réévaluation du pôle et de la vitesse de rotation de Nuvell, en très bon accord avec les résultats récents de Heflin (1999) sur la plaque Australie. Sur la station de Dumont, on mesure un déplacement cosismique provoqué par le séisme des îles Balleny en mars 1998, proche des prédictions de modèles de dislocation. Les vitesses verticales sur l'ensemble du continent antarctique indiquent une surrection d'ensemble d'environ 1 cm/an, soit légèrement supérieure aux modèles de rebond visqueux, compatible compte tenu des barres d'erreur. La péninsule est affectée par une vitesse de remontée plus importante de 2,5 cm/an, dans laquelle on détecte une composante élastique correspondant à une accélération actuelle de la fonte, en accord avec d'autres observations récentes de glaciologie ou de géodésie. Les variations saisonnières de la composante verticale sur cette station n'ont pas encore trouve d'explication définitive.

Published
1999

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