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OSUG - Terre Univers Environnement

Long-term physical and chemical interactions between snow and atmosphere in the Arctic : Impact on the regional climate (ARCSNOW)

Foteini Baladima

11 décembre 2017, par Stéphan Houdier

In the past 30 years, the average temperature in the Arctic has been rising twice as fast as the global mean temperature, which is summarized by the term "Arctic Amplification". Different driving forces causing regional feedbacks have been invoked to explain this difference. Changes in the cryosphere play a major role in such processes and are mainly driven by changes in albedo : for example, the earlier melting of snow exposes the underlying soil surface with a much reduced albedo strongly enhancing the radiative forcing at the surface. While such feedback processes have been reproduced in global models, the exact role of changes in the seasonal snowpack is hardly constrained by observations and detailed snow modeling. It is now well known that snow-albedo feedback processes are related to a complex interplay of physical and chemical processes, for which hitherto neither quality-controlled long-term observations nor adequate modeling tools exist. The project will address these two aspects contributing to a quantification of the role of snow in Arctic Amplification processes. This will be based on existing data concerning the physical and chemical snow properties and the associated meteorological parameters in the area of Ny-Alesund during the period of the most drastic recent change in the Arctic (i.e. last 20 years). Finally, the project includes an important modeling aspect using a recently developed version of the Crocus snow model taking into account chemical species and related processes.
Encadrement : H-W. Jacobi