Rapid increases in satellite-observed ice sheet surface meltwater production

Abstract

Surface meltwater production influences the contribution of ice sheets to global sea-level change. Ice-sheet-wide meltwater production has thus far primarily been quantified by regional climate models. Here we present a 31-year (1992-2023) time series of daily satellite-observed surface melt flux for the Greenland and Antarctic ice sheets. The annual meltwater volume in Greenland has significantly increased, with intensified melt in the northern basins dominated by a negative North Atlantic Oscillation and elevated melt flux in western basins driven by the decline in Arctic sea-ice. In East Antarctica, high melt rates since 2000 are attributed to warm air incursions from the Southern Ocean due to anomalous atmospheric circulations associated with a negative Southern Annular Mode and the recovery of the Antarctic ozone hole. This region, previously less prone to surface melt, has become a melt hotspot, potentially leading to meltwater ponding and future ice shelf destabilization.