Regional Climate simulations in Antarctica : atmosphere - ocean - sea ice coupling.

• Main Author: Jourdain, Nicolas
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Joseph-Fourier - Grenoble I, Hubert Gallée([e-mail])
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2007
• Subjects: antarctica; coupling; climate; polynya; katabatic; sea ice; modelling; TANGO; antarctique; couplage; climat; polynies; catabatique; glace de mer; atmosphère; océan; modélisation; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Antarc*; Antarctic; Antarctica; Antarctique*; Ice Sheet; Sea ice
• Online Access: https://theses.hal.science/tel-00266564; https://theses.hal.science/tel-00266564/document; https://theses.hal.science/tel-00266564/file/these.pdf

In th econtext of global warming, predicting sea level remains chalanging. The surface mass balance of Antarctica may be the only negative contribution. On the other hand, the ice sheet dynamics could exhibit a non-linear behaviour and it could therefore accelerate and thin some glaciers (Meehl et al. 2007). For these 2 reasons, climate of Antarctica needs a lot of onvestigations. Global climate models badly reproduce some important features of antarctic climate : precipitations are over-estimated because of the too smooth topography the surface energy balance is badly simulated because physical parametrizations are too poor. That is why the regional modelling is used in this work. It allows a better resolution and more detailed parametrizations. Sea ice has a key role in the antarctic climate for exemple because its extension modfies available humidity for the atmosphere. The whole ocean also play an important role since the coastal deep water formation increases exchanges netween surface and deep ocean. That is why the aim of the present work is to create and to evaluate a new ocean - sea ice - atmosphere coupled model. Regarding the atmospheric part, the model MAR (Modèle Atmosphérique Régional, Gallée et al. 2005) is used here. This model has been especially developped for polar regions. It differs from other polar regional models by its ellaborated snow representation, and an interactive representation of blowing snow. Ocean and sea-ice are simulated with NEMO (Nucleus for European Modeling of the Ocean), made of OPA-9 (Océan PArallélisé, Madec 2007) and of LIM-2 (Louvain Ice Model, Fichefet 1997). The ocean model uses an ellaborated representation of turbulent diffusion along isopycnes and of vertical diffusion. The sea ice model uses a 3 layers thermodynamical model, and a viscous-plastic rheology. MAR and NEMO are coupled via OASIS-3 (Valcke et al. 2003). The resulting model is called TANGO, it stands for Triade Atmosphere-Neige, Glace de mer, Océan. Before analysing TANGO simulations, one has to know ...