Brief communication: Impact of common ice mask in surface mass balance estimates over the Antarctic ice sheet

Abstract. Regional climate models compute ice sheet surface mass balance (SMB) over a mask that defines the area covered by glacier ice, but masks have not been harmonised between models. Intercomparison studies of modelled SMB therefore use common mask. The in areas outside mask, which are typically coastal and high-precipitation regions, is discarded. Ice differences change integrated 40.5 140.6 Gt yr−1 (1.8 % to 6.0 ensemble mean SMB), equivalent entire Antarctic imbalance. We conclude there pressing need for protocol.