Effect of prescribed sea surface conditions on the modern and future Antarctic surface climate simulated by the ARPEGE AGCM

Owing to increase in snowfall, the Antarctic Ice Sheet surface mass balance is expected to increase by the end of current century. Assuming no associated response of ice dynamics, this will be a negative contribution to sea-level rise. However, the assessment of these changes using dynamical downscaling of coupled climate models projections still bears considerable uncertainties due to poorly represented high southern latitudes atmospheric circulation and sea surface conditions (SSC), that is sea surface temperature and sea-ice concentration. 5 This study evaluates the Antarctic surface climate simulated by a global high-resolution atmospheric model, and assesses the effects on the simulated Antarctic surface climate of two different SSC data sets obtained from two coupled climate models projections. The two coupled models from which SSC are taken, MIROC-ESM and NorESM1-M, simulate future Antarctic sea ice trends at the opposite ends of the CMIP5 RCP8.5 projections range. The atmospheric model ARPEGE is used with a stretched grid configuration in order to achieve an average horizontal resolution of 35 kilometers over Antarctica. Over the 1