Towards the inversion of GRACE gravity fields for present-day ice-mass changes and glacial-isostatic adjustment in North America and Greenland

We perform an inversion of gravity fields from the Gravity Recovery and Climate Experiment (GRACE) (August 2002 to August 2009) of four processing centres for glacial-isostatic adjustment (GIA) over North America and present-day ice-mass change in Alaska and Greenland. We apply a statistical filtering approach to reduce noise in the GRACE data by confining our investigations to GRACE coefficients containing a statistically significant linear trend. Selecting the subset of reliable coefficients in all GRACE time series (GFZ RL04, ITG 2010, JPL RL04 and CSR RL04) results in a non-isotropic smoothing of the GRACE gravity fields, which is effective in reducing the north-south oriented striping associated with correlated errors in GRACE coefficients. In a next step, forward models of GIA induced by the glacial history NAWI (Zweck and Huybrechts, 2005), as well as present-day ice mass changes in Greenland from ICESat (Sorensen et al., 2011) and Alaska from airborne laser altimetry (Arendt et al., 2002) are simultaneously adjusted in scale to minimize the misfit to the filtered GRACE trends. From the adjusted models, we derive the recent sea-level contributions for Greenland and Alaska (August 2002 to August 2009), and, interpret the residual misfit over the GIA-dominated region around the Hudson Bay, Canada, in terms of mantle viscosities beneath North America.

[1]  Isabella Velicogna,et al.  Greenland mass balance from GRACE , 2005 .

[2]  C. Shum,et al.  Non-isotropic filtering of GRACE temporal gravity for geophysical signal enhancement , 2005 .

[3]  Michael G. Sideris,et al.  Analysis of Gravity Recovery and Climate Experiment time‐variable mass redistribution signals over North America by means of principal component analysis , 2007 .

[4]  On Postglacial Sea Level , 2007 .

[5]  Bob E. Schutz,et al.  Glacial Isostatic Adjustment over Antarctica from combined ICESat and GRACE satellite data , 2009 .

[6]  M. Cheng,et al.  Variations in the Earth's oblateness during the past 28 years , 2004 .

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

[8]  David A. Yuen,et al.  Normal modes of the viscoelastic earth , 1982 .

[9]  M. Tamisiea,et al.  GRACE Gravity Data Constrain Ancient Ice Geometries and Continental Dynamics over Laurentia , 2007, Science.

[10]  Tidal Models in a New Era of Satellite Gravimetry , 2003 .

[11]  D. Wolf.  An upper bound on lithosphere thickness from glacio-isostatic adjustment in Fennoscandia , 1987 .

[12]  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 .

[13]  Chung-Yen Kuo,et al.  Laurentia crustal motion observed using TOPEX/POSEIDON radar altimetry over land , 2008 .

[14]  W. R. Peltier,et al.  Constraints on mantle viscosity from relative sea level variations in Hudson Bay , 1992 .

[15]  Jürgen Müller,et al.  Glacial isostatic adjustment in Fennoscandia from GRACE data and comparison with geodynamical models , 2008 .

[16]  Peter J. Clarke,et al.  Validation of ocean tide models around Antarctica using onshore GPS and gravity data , 2005 .

[17]  W. Peltier,et al.  Viscous gravitational relaxation , 1982 .

[18]  K. Lambeck,et al.  Refining the eustatic sea-level curve since the Last Glacial Maximum using far- and intermediate-field sites , 1998 .

[19]  James L. Davis,et al.  Constraining hydrological and cryospheric mass flux in southeastern Alaska using space‐based gravity measurements , 2005 .

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

[21]  P. Gasperini,et al.  Lateral heterogeneities in mantle viscosity and post‐glacial rebound , 1989 .

[22]  Ingo Sasgen,et al.  Wiener optimal filtering of GRACE data , 2006 .

[23]  W. Peltier.  The impulse response of a Maxwell Earth , 1974 .

[24]  Archie Paulson,et al.  FAST TRACK PAPER: Inference of mantle viscosity from GRACE and relative sea level data , 2007 .

[25]  C. Shum,et al.  Non-isotropic Gaussian smoothing and leakage reduction for determining mass changes over land and ocean using GRACE data , 2010 .

[26]  Michael G. Sideris,et al.  Sea levels and uplift rate from composite rheology in glacial isostatic adjustment modeling , 2010 .

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

[28]  L. Vermeersen,et al.  A new class of stratified viscoelastic models by analytical techniques , 1997 .

[29]  D. L. Anderson,et al.  Preliminary reference earth model , 1981 .

[30]  Archie Paulson,et al.  Limitations on the inversion for mantle viscosity from postglacial rebound , 2007 .

[31]  Z. Martinec.  The Density Contrast At the Mohorovičic̀ Discontinuity , 1994 .

[32]  W. Fjeldskaar.  Viscosity and thickness of the asthenosphere detected from the Fennoscandian uplift , 1994 .

[33]  Carsten Braun,et al.  Sharply increased mass loss from glaciers and ice caps in the Canadian Arctic Archipelago , 2011, Nature.

[34]  Michael G. Sideris,et al.  Use of GRACE determined secular gravity rates for glacial isostatic adjustment studies in North-America , 2008 .

[35]  Patrick Wu,et al.  Some analytical solutions for the viscoelastic gravitational relaxation of a two-layer non-self-gravitating incompressible spherical earth , 1996 .

[36]  J. Mitrovica,et al.  Glacial isostatic adjustment and the anomalous tide gauge record of eastern North America , 1996, Nature.

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

[38]  K. Lambeck,et al.  Holocene glacial rebound and sea-level change in NW Europe , 1990 .

[39]  Guillaume Ramillien,et al.  Glacial isostatic adjustment and nonstationary signals observed by GRACE , 2009 .

[40]  Z. Martinec,et al.  Models of Active Glacial Isostasy Roofing Warm Subduction: Case of the South Patagonian Ice Field , 2007 .

[41]  J. Kusche.  Approximate decorrelation and non-isotropic smoothing of time-variable GRACE-type gravity field models , 2007 .

[42]  A. Arendt,et al.  Rapid Wastage of Alaska Glaciers and Their Contribution to Rising Sea Level , 2002, Science.

[43]  L. Cathles,et al.  The Viscosity of the Earth's Mantle , 1975 .

[44]  J. Tromp,et al.  Surface loading of a viscoelastic earth—II. Spherical models , 1999 .

[45]  M. Sideris,et al.  Contributions of terrestrial and GRACE data to the study of the secular geoid changes in North America , 2008 .

[46]  Z. Martinec.  Spectral–finite element approach to three‐dimensional viscoelastic relaxation in a spherical earth , 2000 .

[47]  A. Paulson,et al.  The rotational stability of an ice-age earth , 2005 .

[48]  E. Schrama,et al.  Improved accuracy of GRACE gravity solutions through empirical orthogonal function filtering of spherical harmonics , 2007 .

[49]  Byron D. Tapley,et al.  Correction to “Variations in the Earth's oblateness during the past 28 years” , 2005 .

[50]  S. Swenson,et al.  Post‐processing removal of correlated errors in GRACE data , 2006 .

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

[52]  Kurt Lambeck,et al.  Tests of glacial rebound models for Fennoscandinavia based on instrumented sea‐ and lake‐level records , 1998 .

[53]  M. Fang,et al.  The singularity mystery associated with a radially continuous Maxwell viscoelastic structure , 1995 .

[54]  Z. Martinec,et al.  Time-domain approach to linearized rotational response of a three-dimensional viscoelastic earth model induced by glacial-isostatic adjustment: I. Inertia-tensor perturbations , 2005 .

[55]  K. Lambeck,et al.  Constraints on the Greenland Ice Sheet since the Last Glacial Maximum from sea-level observations and glacial-rebound models , 2004 .

[56]  P. Döll,et al.  A global hydrological model for deriving water availability indicators: model tuning and validation , 2003 .

[57]  I. Sasgen,et al.  Regional ice-mass changes and glacial-isostatic adjustment in Antarctica from GRACE , 2007 .

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

[59]  Heiner Denker,et al.  Analysis of Mass Variations in Northern Glacial Rebound Areas from GRACE Data , 2009 .

[60]  B. Tapley,et al.  Alaskan mountain glacial melting observed by satellite gravimetry , 2006 .

[61]  G. Spada,et al.  Analytical visco-elastic relaxation models , 1996 .

[62]  Matt A. King,et al.  Antarctic ice mass balance estimates from GRACE: Tidal aliasing effects , 2008 .

[63]  Z. Martinec,et al.  Spectral-finite element approach to viscoelastic relaxation in a spherical compressible Earth: application to GIA modelling , 2011 .

[64]  K. Fleming,et al.  Geoid displacement about Greenland resulting from past and present‐day mass changes in the Greenland Ice Sheet , 2004 .

[65]  J. Wünsch,et al.  A Reanalysis and Reinterpretation of Geodetic and Geological Evidence of Glacial-Isostatic Adjustment in the Churchill Region, Hudson Bay , 2006 .

[66]  G. Spada,et al.  Postglacial rebound in a non‐Newtonian spherical Earth , 2000 .

[67]  M. J. Bentley.  Volume of Antarctic Ice at the Last Glacial Maximum, and its impact on global sea level change , 1999 .

[68]  J. Mitrovica,et al.  Postglacial sea-level change on a rotating Earth , 1998 .

[69]  W. R. Peltier,et al.  Validation of the ICE‐3G Model of Würm‐Wisconsin Deglaciation using a global data base of relative sea level histories , 1992 .

[70]  J. Tromp,et al.  Surface loading of a viscoelastic earth—I. General theory , 1999 .

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

[72]  Patrick Wu,et al.  Glacial isostatic adjustment in Fennoscandia-A review of data and modeling , 2011 .

[73]  Z. Martinec,et al.  An Estimate of Global Mean Sea-level Rise Inferred from Tide-gauge Measurements Using Glacial-isostatic Models Consistent with the Relative Sea-level Record , 2007 .

[74]  M. Nakada.  Implications of a non-adiabatic density gradient for the Earth's viscoelastic response to surface loading , 1999 .

[75]  P. Gasperini,et al.  Finite element modeling of lateral viscosity heterogeneities and post-glacial rebound , 1990 .

[76]  W. Peltier.  GLOBAL GLACIAL ISOSTASY AND THE SURFACE OF THE ICE-AGE EARTH: The ICE-5G (VM2) Model and GRACE , 2004 .

[77]  W. Peltier,et al.  ICE-3G: A new global model of late Pleistocene deglaciation based upon geophysical predictions of po , 1991 .

[78]  S. Seneviratne,et al.  Basin scale estimates of evapotranspiration using GRACE and other observations , 2004 .

[79]  J. Kusche,et al.  Significance of secular trends of mass variations determined from GRACE solutions , 2009 .

[80]  R. Hock,et al.  Regionally differentiated contribution of mountain glaciers and ice caps to future sea-level rise , 2011 .

[81]  J. Freymueller,et al.  Tide gauge records of uplift along the northern Pacific-North American plate boundary, 1937 to 2001 , 2003 .

[82]  D. Wolf,et al.  Deglacial land emergence and lateral upper-mantle heterogeneity in the Svalbard Archipelago—II. Extended results for high-resolution load models , 1996 .

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

[84]  C. Shum,et al.  Glacial isostatic adjustment at the Laurentide ice sheet margin: Models and observations in the Great Lakes region , 2008 .

[85]  J. Wahr,et al.  The viscoelastic relaxation of a realistically stratified earth, and a further analysis of postglacial rebound , 1995 .

[86]  D. Wolf,et al.  Effects of lateral viscosity variations on postglacial rebound: an analytical approach , 2002 .

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

[88]  A. Paulson,et al.  Three-dimensional finite-element modelling of Earth's viscoelastic deformation: effects of lateral variations in lithospheric thickness , 2003 .

[89]  C. Zweck,et al.  Modeling of the northern hemisphere ice sheets during the last glacial cycle and glaciological sensitivity , 2005 .

[90]  J. Wahr,et al.  Measurements of Time-Variable Gravity Show Mass Loss in Antarctica , 2006, Science.