A new, high‐resolution surface mass balance map of Antarctica (1979–2010) based on regional atmospheric climate modeling

Abstract

A new, high resolution (27 km) surface mass balance (SMB) map of the Antarctic ice sheet is presented, based on output of a regional atmospheric climate model that includes snowdrift physics and is forced by the most recent reanalysis data from the European Centre for Medium‐Range Weather Forecasts (ECMWF), ERA‐Interim (1979–2010). The SMB map confirms high accumulation zones in the western Antarctic Peninsula (>1500 mm y−1) and coastal West Antarctica (>1000 mm y−1), and shows low SMB values in large parts of the interior ice sheet (<25 mm y−1). The location and extent of ablation areas are modeled realistically. The modeled SMB is in good agreement with ±750 in‐situ SMB measurements (R = 0.88), without a need for post‐calibration. The average ice sheet‐integrated SMB (including ice shelves) is estimated at 2418 ± 181 Gt y−1. Snowfall shows modest interannual variability (σ = 114 Gt y−1), but a pronounced seasonal cycle (σ = 30 Gt mo−1), with a winter maximum. The main ablation process is drifting snow sublimation, which also peaks in winter but with little interannual variability (σ = 9 Gt y−1).