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

• Published in: The Cryosphere
• Main Authors: N. Hansen, S. B. Simonsen, F. Boberg, C. Kittel, A. Orr, N. Souverijns, J. M. van Wessem, R. Mottram
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2022
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Antarctic; The Antarctic; Antarc*; Ice Sheet; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-16-711-2022; https://doaj.org/article/0b686305f47d4a7880a74b52d4cfca86

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