Four decades of Antarctic Ice Sheet mass balance from 1979-2017

Eric Rignot; Jérémie Mouginot; Bernd Scheuchl; Michiel van den Broeke; Melchior J van Wessem; Mathieu Morlighem

doi:10.1073/pnas.1812883116

Four decades of Antarctic Ice Sheet mass balance from 1979-2017

Proc Natl Acad Sci U S A. 2019 Jan 22;116(4):1095-1103. doi: 10.1073/pnas.1812883116. Epub 2019 Jan 14.

Authors

Eric Rignot^{1

2}, Jérémie Mouginot^{3

4}, Bernd Scheuchl³, Michiel van den Broeke⁵, Melchior J van Wessem⁵, Mathieu Morlighem³

Affiliations

¹ Department of Earth System Science, University of California, Irvine, CA 92697; erignot@uci.edu.
² Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109.
³ Department of Earth System Science, University of California, Irvine, CA 92697.
⁴ Institut des Geosciences de l'Environment, Universite Grenoble Alpes, CNRS, 38058 Grenoble, France.
⁵ Institute for Marine and Atmospheric Research Utrecht, Utrecht University, 3508 TA Utrecht, The Netherlands.

Abstract

We use updated drainage inventory, ice thickness, and ice velocity data to calculate the grounding line ice discharge of 176 basins draining the Antarctic Ice Sheet from 1979 to 2017. We compare the results with a surface mass balance model to deduce the ice sheet mass balance. The total mass loss increased from 40 ± 9 Gt/y in 1979-1990 to 50 ± 14 Gt/y in 1989-2000, 166 ± 18 Gt/y in 1999-2009, and 252 ± 26 Gt/y in 2009-2017. In 2009-2017, the mass loss was dominated by the Amundsen/Bellingshausen Sea sectors, in West Antarctica (159 ± 8 Gt/y), Wilkes Land, in East Antarctica (51 ± 13 Gt/y), and West and Northeast Peninsula (42 ± 5 Gt/y). The contribution to sea-level rise from Antarctica averaged 3.6 ± 0.5 mm per decade with a cumulative 14.0 ± 2.0 mm since 1979, including 6.9 ± 0.6 mm from West Antarctica, 4.4 ± 0.9 mm from East Antarctica, and 2.5 ± 0.4 mm from the Peninsula (i.e., East Antarctica is a major participant in the mass loss). During the entire period, the mass loss concentrated in areas closest to warm, salty, subsurface, circumpolar deep water (CDW), that is, consistent with enhanced polar westerlies pushing CDW toward Antarctica to melt its floating ice shelves, destabilize the glaciers, and raise sea level.

Keywords: Antarctica; climate change; glaciology; remote sensing; sea-level rise.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.