Time-evolving mass loss of the Greenland Ice Sheet from satellite altimetry

Mass changes of the Greenland Ice Sheet may be estimated by the input–output method (IOM), satellite gravimetry, or via surface elevation change rates (d H /d t ). Whereas the first two have been shown to agree well in reconstructing ice-sheet wide mass changes over the last decade, there are few decadal estimates from satellite altimetry and none that provide a time-evolving trend that can be readily compared with the other methods. Here, we interpolate radar and laser altimetry data between 1995 and 2009 in both space and time to reconstruct the evolving volume changes. A firn densification model forced by the output of a regional climate model is used to convert volume to mass. We consider and investigate the potential sources of error in our reconstruction of mass trends, including geophysical biases in the altimetry, and the resulting mass change rates are compared to other published estimates. We find that mass changes are dominated by surface mass balance (SMB) until about 2001, when mass loss rapidly accelerates. The onset of this acceleration is somewhat later, and less gradual, compared to the IOM. Our time-averaged mass changes agree well with recently published estimates based on gravimetry, IOM, laser altimetry, and with radar altimetry when merged with airborne data over outlet glaciers. We demonstrate that, with appropriate treatment, satellite radar altimetry can provide reliable estimates of mass trends for the Greenland Ice Sheet. With the inclusion of data from CryoSat-2, this provides the possibility of producing a continuous time series of regional mass trends from 1992 onward.

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

[2]  Adrian A. Borsa,et al.  A range correction for ICESat and its potential impact on ice-sheet mass balance studies , 2013 .

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

[4]  I. Joughin,et al.  Spatiotemporal Interpolation of Elevation Changes Derived from Satellite Altimetry for Jakobshavn Isbrae, Greenland , 2012 .

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

[6]  Eric Rignot,et al.  Timing and origin of recent regional ice-mass loss in Greenland , 2012 .

[7]  J. Bamber,et al.  Brief communication 'Importance of slope-induced error correction in volume change estimates from radar altimetry' , 2012 .

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

[9]  Kirill S. Khvorostovsky,et al.  Merging and Analysis of Elevation Time Series Over Greenland Ice Sheet From Satellite Radar Altimetry , 2012, IEEE Transactions on Geoscience and Remote Sensing.

[10]  I. Joughin,et al.  Spatio-temporal interpolation of elevation changes derived from satellite altimetry for Jakobshavn , 2012 .

[11]  Byron D. Tapley,et al.  Interannual variability of Greenland ice losses from satellite gravimetry , 2011 .

[12]  Ian M. Howat,et al.  Mass balance of Greenland's three largest outlet glaciers, 2000–2010 , 2011 .

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

[14]  Sebastian B. Simonsen,et al.  Mass balance of the Greenland ice sheet (2003–2008) from ICESat data – the impact of interpolation, sampling and firn density , 2011 .

[15]  E. Schrama,et al.  Revisiting Greenland ice sheet mass loss observed by GRACE , 2011 .

[16]  Jack L. Saba,et al.  Greenland ice sheet mass balance: distribution of increased mass loss with climate warming; 2003–07 versus 1992–2002 , 2011, Journal of Glaciology.

[17]  K. Steffen,et al.  Climate of the Greenland ice sheet using a high-resolution climate model – Part 1: Evaluation , 2010 .

[18]  Christopher Nuth,et al.  Recent elevation changes of Svalbard glaciers derived from ICESat laser altimetry , 2010 .

[19]  M. Bevis,et al.  Spread of ice mass loss into northwest Greenland observed by GRACE and GPS , 2010 .

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

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

[22]  Jonathan L. Bamber,et al.  A new 1 km Digital Elevation Model of the Antarctic Derived From Combined Satellite Radar and Laser Data , 2008 .

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

[24]  D. Chambers,et al.  GRACE observes small‐scale mass loss in Greenland , 2008 .

[25]  B. Smith,et al.  Rates of southeast Greenland ice volume loss from combined ICESat and ASTER observations , 2008 .

[26]  Niels Reeh,et al.  A nonsteady‐state firn‐densification model for the percolation zone of a glacier , 2008 .

[27]  Yonghong Li,et al.  Decadal Mass Balance of the Greenland and Antarctic Ice Sheets from High Resolution Elevation Change Analysis of ERS-2 and Envisat Radar Altimetry Measurements , 2008, IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium.

[28]  M. R. van den Broeke,et al.  Elevation Changes in Antarctica Mainly Determined by Accumulation Variability , 2008, Science.

[29]  W. V. D. Berg.  Present-day climate of Antarctica : A study with a regional atmospheric climate model , 2008 .

[30]  Eric Rignot,et al.  Recent Antarctic ice mass loss from radar interferometry and regional climate modelling , 2008 .

[31]  W. Krabill,et al.  A comparison of Greenland ice-sheet volume changes derived from altimetry measurements , 2008, Journal of Glaciology.

[32]  Benoit Rivard,et al.  Melt season duration and ice layer formation on the Greenland ice sheet, 2000–2004 , 2007 .

[33]  R. Nerem,et al.  Recent Greenland Ice Mass Loss by Drainage System from Satellite Gravity Observations , 2006, Science.

[34]  Yonghong Li,et al.  Improved Methods for Analysis of Decadal Elevation-Change Time Series Over Antarctica , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[35]  E. Rignot,et al.  Changes in the Velocity Structure of the Greenland Ice Sheet , 2006, Science.

[36]  J. Abshire,et al.  Geoscience Laser Altimeter System (GLAS) on the ICESat Mission: On‐orbit measurement performance , 2005 .

[37]  Jack L. Saba,et al.  Mass changes of the Greenland and Antarctic ice sheets and shelves and contributions to sea-level rise: 1992-2002 , 2005 .

[38]  David A. Fisher,et al.  An empirical firn-densification model comprising ice lenses , 2005, Annals of Glaciology.

[39]  Robert N. Swift,et al.  Greenland Ice Sheet: Increased coastal thinning , 2004 .

[40]  Li Jun,et al.  Seasonal and interannual variations of firn densification and ice-sheet surface elevation at the Greenland summit , 2002, Journal of Glaciology.

[41]  Ian Joughin,et al.  Ice-sheet velocity mapping: a combined interferometric and speckle-tracking approach , 2002, Annals of Glaciology.

[42]  Jonathan L. Bamber,et al.  A new, high‐resolution digital elevation model of Greenland fully validated with airborne laser altimeter data , 2001 .

[43]  D. Myers,et al.  Estimating and modeling space–time correlation structures , 2001 .

[44]  W. Krabill,et al.  Greenland Ice Sheet: High-Elevation Balance and Peripheral Thinning. , 2000, Science.

[45]  Johan J. Mohr,et al.  Three-dimensional glacial flow and surface elevation measured with radar interferometry , 1998, Nature.

[46]  Curt H. Davis,et al.  A robust threshold retracking algorithm for measuring ice-sheet surface elevation change from satellite radar altimeters , 1997, IEEE Trans. Geosci. Remote. Sens..

[47]  Jonathan L. Bamber,et al.  Ice sheet altimeter processing scheme , 1994 .

[48]  Clayton V. Deutsch,et al.  GSLIB: Geostatistical Software Library and User's Guide , 1993 .

[49]  N. Reeh,et al.  Parameterization of melt rate and surface temperature on the Greenland ice sheet , 1989 .

[50]  Michael M. Herron,et al.  Firn Densification: An Empirical Model , 1980, Journal of Glaciology.