Affiliations:
1School of Geography, Planning, and Spatial Science, University of Tasmania; Hobart 7001, Tasmania, Australia2The Australian Centre for Excellence in Antarctic Science, University of Tasmania; Hobart 7001, Tasmania, Australia.3State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China4Centre for Southern Hemisphere Oceans Research, CSIRO Oceans and Atmosphere; Hobart, Tasmania, Australia. *Corresponding author. Email: Matt.King@utas.edu.au
Abstract: Antarctica has been losing ice mass for decades, but its link to large-scale climate forcing is not clear. Shorter-period variability has been partly associated with El Niño Southern Oscillation (ENSO), but a clear connection with the dominant climate mode, the Southern Annular Mode (SAM), is yet to be found. We show that space gravimetric estimates of ice-mass variability over 2002-2021 may be substantially explained by a simple linear relation with detrended, time-integrated SAM and ENSO indices, from the whole ice sheet down to individual drainage basins. Approximately 40% of the ice-mass trend can be ascribed to increasingly persistent positive SAM forcing which, since the 1940s, is likely due to anthropogenic activity. Similar attribution over 2002-2021 could connect recent ice-sheet change to human activity.
One-Sentence Summary: Observed decadal variability and change of Antarctic ice-sheet mass is substantially explained by large-scale climate modes.