We evaluate modelled Antarctic ice sheet (AIS) near-surface climate, surface mass balance (SMB) and surface energy balance (SEB) from the updated polar version of the regional atmospheric climate model, RACMO2 (1979-2016). The updated model, referred to as RACMO2.3p2, incorporates upper-air relaxation, a revised topography, tuned parameters in the cloud scheme to generate more precipitation towards the AIS interior and modified snow properties reducing drifting snow sublimation and increasing surface snowmelt.
Comparisons of RACMO2 model output with several independent observational data show that the existing biases in AIS temperature, radiative fluxes and SMB components are further reduced with respect to the previous model version. The model-integrated annual average SMB for the ice sheet including ice shelves (minus the Antarctic Peninsula, AP) now amounts to 2229ĝ€Gtĝ€yĝ'1, with an interannual variability of 109ĝ€Gtĝ€yĝ'1. The largest improvement is found in modelled surface snowmelt, which now compares well with satellite and weather station observations. For the high-resolution ( ĝ1/4 ĝ€5.5ĝ€km) AP simulation, results remain comparable to earlier studies.
Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, Netherlands; Royal Netherlands Meteorological Institute, De Bilt, Netherlands; Department of Geography, University of Liege, Liege, Belgium; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, CO, United States; Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, Netherlands; Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, United States; KU Leuven, Department of Earth and Environmental Sciences, Leuven, Belgium; Department of Geology, Rowan University, Glassboro, NJ, United States; ENVEO IT GmbH, Innsbruck, Austria
Recommended Citation:
Melchior Van Wessem J,, Jan Van De Berg W,, Noël B,et al. Modelling the climate and surface mass balance of polar ice sheets using RACMO2 - Part 2: Antarctica (1979-2016)[J]. Cryosphere,2018-01-01,12(4)