Regional acceleration in ice mass loss from Greenland and Antarctica using GRACE time‐variable gravity data

We use Gravity Recovery and Climate Experiment (GRACE) monthly gravity fields to determine the regional acceleration in ice mass loss in Greenland and Antarctica for 2003-2013. We find that the total mass loss is controlled by only a few regions. In Greenland, the southeast and northwest generate 70% of the loss (280 ± 58 Gt/yr) mostly from ice dynamics, the southwest accounts for 54% of the total acceleration in loss (25.4 ± 1.2 Gt/yr 2 ) from a decrease in surface mass balance (SMB), followed by the northwest (34%), and we find no significant acceleration in the northeast. In Antarctica, the Amundsen Sea (AS) sector and the Antarctic Peninsula account for 64% and 17%, respectively, of the total loss (180 ± 10 Gt/yr) mainly from ice dynamics. The AS sector contributes most of the acceleration in loss (11 ± 4 Gt/yr 2 ), and Queen Maud Land, East Antarctica, is the only sector with a significant mass gain due to a local increase in SMB (63 ± 5 Gt/yr).

[1]  Byron D. Tapley,et al.  Accelerated Antarctic ice loss from satellite gravity measurements , 2009 .

[2]  D. Vaughan,et al.  Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets , 2009, Nature.

[3]  D. Chambers,et al.  Estimating Geocenter Variations from a Combination of GRACE and Ocean Model Output , 2008 .

[4]  Thomas Flament,et al.  Dynamic thinning of Antarctic glaciers from along-track repeat radar altimetry , 2012, Journal of Glaciology.

[5]  S. Bettadpur,et al.  Assessment of GRACE mission performance and the RL05 gravity fields , 2012 .

[6]  I. Velicogna.  Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE , 2009 .

[7]  Matt A. King,et al.  Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation , 2014 .

[8]  E. Meijgaard,et al.  Snowfall in coastal West Antarctica much greater than previously assumed , 2006 .

[9]  M. Cheng,et al.  Deceleration in the Earth's oblateness , 2013 .

[10]  Allan Aasbjerg Nielsen,et al.  Acceleration of the Greenland ice sheet mass loss as observed by GRACE: Confidence and sensitivity , 2013 .

[11]  Eric Rignot,et al.  Mass balance of the Greenland ice sheet from 1958 to 2007 , 2008 .

[12]  E. van Meijgaard,et al.  Reassessment of the Antarctic surface mass balance using calibrated output of a regional atmospheric climate model , 2006 .

[13]  M. R. van den Broeke,et al.  Partitioning Recent Greenland Mass Loss , 2009, Science.

[14]  M. R. van den Broeke,et al.  Higher surface mass balance of the Greenland ice sheet revealed by high‐resolution climate modeling , 2009 .

[15]  I. Joughin,et al.  21st-Century Evolution of Greenland Outlet Glacier Velocities , 2011, Science.

[16]  W. Farrell.  Deformation of the Earth by surface loads , 1972 .

[17]  E. Ivins,et al.  Antarctic contribution to sea level rise observed by GRACE with improved GIA correction , 2013 .

[18]  M. R. van den Broeke,et al.  Evaluating Greenland glacial isostatic adjustment corrections using GRACE, altimetry and surface mass balance data , 2014 .

[19]  Eric Rignot,et al.  A Reconciled Estimate of Ice-Sheet Mass Balance , 2012, Science.

[20]  Isabella Velicogna,et al.  Time‐variable gravity observations of ice sheet mass balance: Precision and limitations of the GRACE satellite data , 2013 .

[21]  Eric Rignot,et al.  Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise , 2011 .

[22]  I. Sasgen,et al.  Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates , 2013 .

[23]  F. Bryan,et al.  Time variability of the Earth's gravity field: Hydrological and oceanic effects and their possible detection using GRACE , 1998 .

[24]  M. Bevis,et al.  Sustained mass loss of the northeast Greenland ice sheet triggered by regional warming , 2014 .

[25]  Eric Rignot,et al.  Sustained increase in ice discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to 2013 , 2014, Geophysical Research Letters.

[26]  M. R. van den Broeke,et al.  A Reconciled Estimate of Glacier Contributions to Sea Level Rise: 2003 to 2009 , 2013, Science.

[27]  E. van Meijgaard,et al.  A new, high‐resolution surface mass balance map of Antarctica (1979–2010) based on regional atmospheric climate modeling , 2012 .

[28]  Bert Wouters,et al.  Irreversible mass loss of Canadian Arctic Archipelago glaciers , 2013 .

[29]  S. Swenson,et al.  Accuracy of GRACE mass estimates , 2006 .

[30]  G. Milne,et al.  Calibrating a glaciological model of the Greenland ice sheet from the Last Glacial Maximum to present-day using field observations of relative sea level and ice extent , 2009 .

[31]  Niels Reeh,et al.  Mass Balance of the Greenland Ice Sheet at Dye 3 , 1985, Journal of Glaciology.

[32]  N. Reeh.  Mass Balance of the Greenland Ice Sheet: Can Modern Observation Methods Reduce the Uncertainty? , 1999 .

[33]  M P Schodlok,et al.  Observed thinning of Totten Glacier is linked to coastal polynya variability , 2013, Nature Communications.

[34]  David R. Anderson,et al.  Model Selection and Multimodel Inference , 2003 .

[35]  T. Scambos,et al.  Rapid Changes in Ice Discharge from Greenland Outlet Glaciers , 2007, Science.

[36]  Ingo Sasgen,et al.  Limits in detecting acceleration of ice sheet mass loss due to climate variability , 2013 .