Basin-scale partitioning of Greenland ice sheet mass balance components (2007-2011)

M.L. Andersen, Lars Stenseng, Henriette Skourup, W. Colgan, Shfaqat Abbas Khan, Steen Savstrup Kristensen, S. B. Andersen, J.E. Box, A. P. Ahlstrøm, X. Fettweis, René Forsberg

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The current deficit in Greenland ice sheet mass balance is due to both a decrease in surface mass balance (SMB) input and an increase in ice discharge (D) output. While SMB processes are beginning to be well captured by observationally-constrained climate modeling, insight into D is relatively limited. We use InSAR-derived velocities, in combination with ice thickness observations, to quantify the mass flux (F) across a flux perimeter around the ice sheet at ~1700 m elevation. To quantify D, we correct F for SMB, as well as changes in volume due to ice dynamics, in the area downstream of the gate. Using a 1961-1990 reference climatology SMB field from the MAR regional climate model, we quantify ice sheet mass balance within eighteen basins. We find a 2007-2011 mean D of 515±57 Gtyr-1. We find a 2007-2011 mean total mass balance of -262±21 Gtyr-1, which is equal to a 0.73 mm yr-1 global sea level rise contribution. This mass loss is dominated by SMB, which accounts for 61% of mass loss in the basins where partitioning is possible.
Original languageEnglish
JournalEarth and Planetary Science Letters
Volume409
Pages (from-to)89-95
Number of pages7
ISSN0012-821X
DOIs
Publication statusPublished - 2015

Keywords

  • Airborne survey
  • Flux gate
  • Greenland ice sheet
  • Ice discharge
  • Mass loss partition
  • Surface mass balance
  • Climate models
  • Glacial geology
  • Glaciers
  • Sea level
  • Surveys
  • Airborne surveys
  • Greenland Ice Sheet
  • Ice discharges
  • Mass loss
  • Ice

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