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Sunday, June 19, 2011

I.M. Howat et al., GRL 38, Mass balance of Greenland's three largest outlet glaciers, 2000–2010

Geophysical Research Letters, 38 (2011) L12501; doi: 10.1029/2011GL047565.


Mass balance of Greenland's three largest outlet glaciers, 2000–2010


Ian M. Howat (School of Earth Sciences, and the Byrd Polar Research Center, Ohio State University, Columbus, OH, USA), Yushin Ahn (Byrd Polar Research Center, Ohio State University, Columbus, OH, USA), Ian Joughin (Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA), Michiel R. van den Broeke (Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands), Jan T. M. Lenaerts (Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands) and Ben Smith (Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA)


Abstract


Acceleration of Greenland's three largest outlet glaciers, Helheim, Kangerdlugssuaq and Jakobshavn Isbræ, accounted for a substantial portion of the ice sheet's mass loss over the past decade. Rapid changes in their discharge, however, make their cumulative mass-change uncertain. We derive monthly mass balance rates and cumulative balance from discharge and surface mass balance (SMB) rates for these glaciers from 2000 through 2010. Despite the dramatic changes observed at Helheim, the glacier gained mass over the period, due primarily to the short-duration of acceleration and a likely longer-term positive balance. In contrast, Jakobshavn Isbræ lost an equivalent of over 11 times the average annual SMB and loss continues to accelerate. Kangerdlugssuaq lost over 7 times its annual average SMB, but loss has returned to the 2000 rate. These differences point to contrasts in the long-term evolution of these glaciers and the danger in basing predictions on extrapolations of recent changes.


Received 24 March 2011; accepted 7 May 2011; published 18 June 2011


Howat, I. M., Y. Ahn, I. Joughin, M. R. van den Broeke, J. T. M. Lenaerts, and B. Smith. 2011. Mass balance of Greenland's three largest outlet glaciers, 2000–2010. Geophys. Res. Lett. 38, L12501, doi: 10.1029/2011GL047565.


http://www.agu.org/pubs/crossref/2011/2011GL047565.shtml

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