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Thursday, October 15, 2009

I. Velicogna, GRL 36, Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE

Geophysical Research Letters, 36 (2009) L19503; doi: 10.1029/2009GL040222. 

Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE

I. Velicogna (Department of Earth System Science, University of California, Irvine, CA; and Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, U.S.A.)

Received 28 July 2009; accepted 3 September 2009; published 13 October 2009.

Abstract

We use monthly measurements of time-variable gravity from the GRACE (Gravity Recovery and Climate Experiment) satellite gravity mission to determine the ice mass-loss for the Greenland and Antarctic Ice Sheets during the period between April 2002 and February 2009. We find that during this time period the mass loss of the ice sheets is not a constant, but accelerating with time, i.e., that the GRACE observations are better represented by a quadratic trend than by a linear one, implying that the ice sheets contribution to sea level becomes larger with time. In Greenland, the mass loss increased from 137 Gt/yr in 2002–2003 to 286 Gt/yr in 2007–2009, i.e., an acceleration of −30 ± 11 Gt/yr2 in 2002–2009. In Antarctica, the mass loss increased from 104 Gt/yr in 2002–2006 to 246 Gt/yr in 2006–2009, i.e., an acceleration of −26 ± 14 Gt/yr2 in 2002–2009. The observed acceleration in ice sheet mass loss helps reconcile GRACE ice mass estimates obtained for different time periods.

Velicogna, I. (2009). Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE, Geophysical Research Letters, 36, L19503; doi: 10.1029/2009GL040222.

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