Acceleration of Dynamic Ice Loss in Antarctica From Satellite Gravimetry

The dynamic stability of the Antarctic Ice Sheet is one largest uncertainties in projections future global sea-level rise. Essential for improving ice sheet evolution understanding ongoing trends and accelerations mass loss context dynamics. Here, we examine change from 2002 to 2020 using data GRACE (Gravity Recovery Climate Experiment; 2002–2017) its follow-on GRACE-FO (2018-present) satellite missions. By subtracting estimates net snow accumulation provided by re-analysis regional climate models GRACE/GRACE-FO changes, isolate variations ice-dynamic discharge compare them direct measurements based on remote sensing surface-ice velocity (2002–2017). We show that time series are modulated caused large-scale atmospheric circulation. first that, after removal these surface effects, agree well with those independently derived velocities. For 2002–2020, recover a acceleration -5.3 ± 2.2 Gt yr −2 entire sheet; increasing losses originate mainly Amundsen Bellingshausen Sea Embayment regions (68%), additional significant contributions Dronning Maud Land (18%) Filchner-Ronne Shelf region (13%). Under assumption recovered rates persisted independent any external forcing, Antarctica would contribute 7.6 2.9 cm mean rise year 2100, more than two times amount 0.6 obtained linear extrapolation current trends.