Spatial and temporal Antarctic Ice Sheet mass trends, glacio‐isostatic adjustment, and surface processes from a joint inversion of satellite altimeter, gravity, and GPS data

We present spatiotemporal mass balance trends for the Antarctic Ice Sheet from a statistical inversion of satellite altimetry, gravimetry, and elastic‐corrected GPS data for the period 2003–2013. Our method simultaneously determines annual trends in ice dynamics, surface mass balance anomalies, and a time‐invariant solution for glacio‐isostatic adjustment while remaining largely independent of forward models. We establish that over the period 2003–2013, Antarctica has been losing mass at a rate of −84 ± 22 Gt yr−1, with a sustained negative mean trend of dynamic imbalance of −111 ± 13 Gt yr−1. West Antarctica is the largest contributor with −112 ± 10 Gt yr−1, mainly triggered by high thinning rates of glaciers draining into the Amundsen Sea Embayment. The Antarctic Peninsula has experienced a dramatic increase in mass loss in the last decade, with a mean rate of −28 ± 7 Gt yr−1 and significantly higher values for the most recent years following the destabilization of the Southern Antarctic Peninsula around 2010. The total mass loss is partly compensated by a significant mass gain of 56 ± 18 Gt yr−1 in East Antarctica due to a positive trend of surface mass balance anomalies.

[1]  N. Glasser,et al.  Speedup and fracturing of George VI Ice Shelf, Antarctic Peninsula , 2013 .

[2]  Peter J. Clarke,et al.  Widespread low rates of Antarctic glacial isostatic adjustment revealed by GPS observations , 2011 .

[3]  A. Raftery,et al.  Strictly Proper Scoring Rules, Prediction, and Estimation , 2007 .

[4]  Chris Rizos,et al.  The International GNSS Service in a changing landscape of Global Navigation Satellite Systems , 2009 .

[5]  B. Scheuchl,et al.  Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith, and Kohler glaciers, West Antarctica, from 1992 to 2011 , 2014 .

[6]  D. Bolin,et al.  Geostatistical Modelling Using Non‐Gaussian Matérn Fields , 2015 .

[7]  Matt A. King,et al.  A new glacial isostatic adjustment model for Antarctica: calibrated and tested using observations of relative sea‐level change and present‐day uplift rates , 2012 .

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

[9]  B. Legrésy,et al.  Ocean access to a cavity beneath Totten Glacier in East Antarctica , 2015 .

[10]  G. Marshall,et al.  Mass balance of the Antarctic ice sheet , 2006, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[11]  E. Rignot,et al.  Mass loss of the Amundsen Sea Embayment of West Antarctica from four independent techniques , 2014 .

[12]  Olga Didova,et al.  Empirical estimation of present-day Antarctic glacial isostatic adjustment and ice mass change , 2013, The Cryosphere.

[13]  Matt A. King,et al.  Increased ice loading in the Antarctic Peninsula since the 1850s and its effect on glacial isostatic adjustment , 2012 .

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

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

[16]  Oliver Baur,et al.  GRACE‐derived ice‐mass variations over Greenland by accounting for leakage effects , 2009 .

[17]  Matt A. King,et al.  On the Rebound: Modeling Earth's Ever-Changing Shape , 2015, Eos.

[18]  C. Rizos,et al.  The International GNSS Service in a changing landscape of Global Navigation Satellite Systems , 2009 .

[19]  Scott B. Luthcke,et al.  Estimation of ICESat intercampaign elevation biases from comparison of lidar data in East Antarctica , 2013 .

[20]  B. Scheuchl,et al.  Ice Flow of the Antarctic Ice Sheet , 2011, Science.

[21]  A. Zammit‐Mangion,et al.  Resolving the Antarctic contribution to sea-level rise: a hierarchical modelling framework† , 2013, Environmetrics.

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

[23]  Helmut Rott,et al.  Mass changes of outlet glaciers along the Nordensjköld Coast, northern Antarctic Peninsula, based on TanDEM‐X satellite measurements , 2014 .

[24]  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 .

[25]  J. Camp,et al.  Antarctica, Greenland and Gulf of Alaska land-ice evolution from an iterated GRACE global mascon solution , 2013, Journal of Glaciology.

[26]  Eric Rignot,et al.  Improved representation of East Antarctic surface mass balance in a regional atmospheric climate model , 2014 .

[27]  Duncan J. Wingham,et al.  Increased ice losses from Antarctica detected by CryoSat‐2 , 2014 .

[28]  Peter J. Clarke,et al.  Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading , 2014 .

[29]  Finn Lindgren,et al.  Multivariate spatio-temporal modelling for assessing Antarctica's present-day contribution to sea-level rise , 2015, Environmetrics.

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

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

[32]  Jun Li,et al.  Mass gains of the Antarctic ice sheet exceed losses , 2015 .

[33]  Simon D. P. Williams,et al.  CATS: GPS coordinate time series analysis software , 2008 .

[34]  A data-driven approach for assessing ice-sheet mass balance in space and time , 2015, Annals of Glaciology.

[35]  H. Schuh,et al.  Elastic and Viscoelastic Response of the Lithosphere to Surface Loading , 2015 .

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

[37]  Axel Rülke,et al.  On-land ice loss and glacial isostatic adjustment at the drake passage: 2003-2009 , 2011 .

[38]  Thomas A. Herring,et al.  MATLAB Tools for viewing GPS velocities and time series , 2003 .

[39]  Angelika Humbert,et al.  Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2 , 2014 .

[40]  Theodore A. Scambos,et al.  Mass loss of Larsen B tributary glaciers (Antarctic Peninsula) unabated since 2002 , 2012 .

[41]  Philippe Huybrechts,et al.  Sea-level changes at the LGM from ice-dynamic reconstructions of the Greenland and Antarctic ice sheets during the glacial cycles , 2002 .

[42]  F. Rémy,et al.  Simultaneous solution for mass trends on the West Antarctic Ice Sheet , 2014 .

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

[44]  M. R. van den Broeke,et al.  An improved semi-empirical model for the densification of Antarctic firn , 2011 .

[45]  Sivaprasad Gogineni,et al.  Airborne‐radar and ice‐core observations of annual snow accumulation over Thwaites Glacier, West Antarctica confirm the spatiotemporal variability of global and regional atmospheric models , 2013 .

[46]  Martin Horwath,et al.  Recent snowfall anomalies in Dronning Maud Land, East Antarctica, in a historical and future climate perspective , 2013 .

[47]  Axel Rülke,et al.  An investigation of Glacial Isostatic Adjustment over the Amundsen Sea sector, West Antarctica , 2012 .

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

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

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

[51]  D. Vaughan,et al.  Antarctic ice-sheet loss driven by basal melting of ice shelves , 2012, Nature.

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

[53]  A. Dziewoński,et al.  Nonlinear Crustal Corrections for Normal-Mode Seismograms , 2007 .

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

[55]  Graeme L. Stephens,et al.  Snowfall‐driven mass change on the East Antarctic ice sheet , 2012 .

[56]  Isabella Velicogna,et al.  Regional acceleration in ice mass loss from Greenland and Antarctica using GRACE time‐variable gravity data , 2014 .

[57]  Frederik J. Simons,et al.  Accelerated West Antarctic ice mass loss continues to outpace East Antarctic gains , 2015 .

[58]  Bryant D. Loomis,et al.  Optimized signal Denoising and Adaptive estimation of seasonal Timing and Mass Balance from Simulated GRACE-like Regional Mass variations , 2014, Adv. Data Sci. Adapt. Anal..

[59]  Bamber,et al.  Widespread complex flow in the interior of the antarctic ice sheet , 2000, Science.

[60]  Charles R. Bentley,et al.  Timing of stagnation of Ice Stream C, West Antarctica, from short-pulse radar studies of buried surface crevasses , 1993, Journal of Glaciology.

[61]  Eric Rignot,et al.  Changes in ice dynamics and mass balance of the Antarctic ice sheet , 2006, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[62]  Leonhard Held,et al.  Gaussian Markov Random Fields: Theory and Applications , 2005 .

[63]  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 .

[64]  M. R. van den Broeke,et al.  Dynamic thinning of glaciers on the Southern Antarctic Peninsula , 2015, Science.

[65]  Alvaro Santamaría-Gómez,et al.  Geodetic secular velocity errors due to interannual surface loading deformation , 2015 .

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

[67]  M. R. van den Broeke,et al.  Ice Sheets and Sea Level: Thinking Outside the Box , 2011 .