Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes

Ben Smith; Helen A Fricker; Alex S Gardner; Brooke Medley; Johan Nilsson; Fernando S Paolo; Nicholas Holschuh; Susheel Adusumilli; Kelly Brunt; Bea Csatho; Kaitlin Harbeck; Thorsten Markus; Thomas Neumann; Matthew R Siegfried; H Jay Zwally

doi:10.1126/science.aaz5845

Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes

Science. 2020 Jun 12;368(6496):1239-1242. doi: 10.1126/science.aaz5845. Epub 2020 Apr 30.

Authors

Ben Smith¹, Helen A Fricker², Alex S Gardner³, Brooke Medley⁴, Johan Nilsson³, Fernando S Paolo³, Nicholas Holschuh^{5

6}, Susheel Adusumilli², Kelly Brunt⁷, Bea Csatho⁸, Kaitlin Harbeck⁹, Thorsten Markus⁴, Thomas Neumann⁴, Matthew R Siegfried¹⁰, H Jay Zwally^{4

7}

Affiliations

¹ Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA. besmith@uw.edu.
² Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA.
³ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
⁴ Cryospheric Science Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA.
⁵ Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA.
⁶ Department of Geology, Amherst College, Amherst, MA, USA.
⁷ Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA.
⁸ Department of Geological Sciences, University at Buffalo, Buffalo, NY, USA.
⁹ KBR, Greenbelt, MD, USA.
¹⁰ Department of Geophysics, Colorado School of Mines, Golden, CO, USA.

PMID: 32354841
DOI: 10.1126/science.aaz5845

Abstract

Quantifying changes in Earth's ice sheets and identifying the climate drivers are central to improving sea level projections. We provide unified estimates of grounded and floating ice mass change from 2003 to 2019 using NASA's Ice, Cloud and land Elevation Satellite (ICESat) and ICESat-2 satellite laser altimetry. Our data reveal patterns likely linked to competing climate processes: Ice loss from coastal Greenland (increased surface melt), Antarctic ice shelves (increased ocean melting), and Greenland and Antarctic outlet glaciers (dynamic response to ocean melting) was partially compensated by mass gains over ice sheet interiors (increased snow accumulation). Losses outpaced gains, with grounded-ice loss from Greenland (200 billion tonnes per year) and Antarctica (118 billion tonnes per year) contributing 14 millimeters to sea level. Mass lost from West Antarctica's ice shelves accounted for more than 30% of that region's total.

Publication types

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