A new coupled ice sheet/climate model: description and sensitivity to model physics under Eemian, Last Glacial Maximum, late Holocene and modern climate conditions

Abstract. The need to better understand long-term climate/ice sheet feedback loops is motivating efforts to couple ice sheet models into Earth System models which are capable of long-timescale simulations. In this paper we describe a coupled model that consists of the University of Victoria Earth System Climate Model (UVic ESCM) and the Pennsylvania State University Ice model (PSUI). The climate model generates a surface mass balance (SMB) field via a sub-gridded surface energy/moisture balance model that resolves narrow ice sheet ablation zones. The ice model returns revised elevation, surface albedo and ice area fields, plus coastal fluxes of heat and moisture. An arbitrary number of ice sheets can be simulated, each on their own high-resolution grid and each capable of synchronous or asynchronous coupling with the overlying climate model. The model is designed to conserve global heat and moisture. In the process of improving model performance we developed a procedure to account for modelled surface air temperature (SAT) biases within the energy/moisture balance surface model and improved the UVic ESCM snow surface scheme through addition of variable albedos and refreezing over the ice sheet. A number of simulations for late Holocene, Last Glacial Maximum (LGM), and Eemian climate boundary conditions were carried out to explore the sensitivity of the coupled model and identify model configurations that best represented these climate states. The modelled SAT bias was found to play a significant role in long-term ice sheet evolution, as was the effect of refreezing meltwater and surface albedo. The bias-corrected model was able to reasonably capture important aspects of the Antarctic and Greenland ice sheets, including modern SMB and ice distribution. The simulated northern Greenland ice sheet was found to be prone to ice margin retreat at radiative forcings corresponding closely to those of the Eemian or the present-day.

[1]  Fuyuki Saito,et al.  Initial results of the SeaRISE numerical experiments with the models SICOPOLIS and IcIES for the Greenland ice sheet , 2011, Annals of Glaciology.

[2]  Jason Lowe,et al.  Thresholds for irreversible decline of the Greenland ice sheet , 2010 .

[3]  I. C. Rutt,et al.  Investigating the sensitivity of numerical model simulations of the modern state of the Greenland ice-sheet and its future response to climate change , 2010 .

[4]  Laurence C. Smith,et al.  A spatially calibrated model of annual accumulation rate on the Greenland Ice Sheet (1958-2007) , 2010 .

[5]  David Pollard,et al.  A retrospective look at coupled ice sheet–climate modeling , 2010 .

[6]  G. König‐Langlo,et al.  Modelling snowdrift sublimation on an Antarctic ice shelf , 2010 .

[7]  D. Lunt,et al.  The effect of more realistic forcings and boundary conditions on the modelled geometry and sensitivity of the Greenland ice-sheet , 2010 .

[8]  H. Hellmer,et al.  A box model of circulation and melting in ice shelf caverns , 2010 .

[9]  J. Jungclaus,et al.  Climate modification by future ice sheet changes and consequences for ice sheet mass balance , 2010 .

[10]  Alexander Robinson,et al.  An efficient regional energy-moisture balance model for simulation of the Greenland Ice Sheet response to climate change , 2009 .

[11]  G. Ramstein,et al.  Interactive comment on “Investigating the evolution of major Northern Hemisphere ice sheets during the last glacial-interglacial cycle” by S. Bonelli et al , 2009 .

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

[13]  A. Payne,et al.  The Glimmer community ice sheet model , 2009 .

[14]  Alvaro Montenegro,et al.  Lifetime of Anthropogenic Climate Change: Millennial Time Scales of Potential CO2 and Surface Temperature Perturbations , 2009 .

[15]  R. DeConto,et al.  A coupled ice-sheet/ice-shelf/sediment model applied to a marine-margin flowline: forced and unforced variations , 2009 .

[16]  David Pollard,et al.  Modelling West Antarctic ice sheet growth and collapse through the past five million years , 2009, Nature.

[17]  G. Kuhn,et al.  Obliquity-paced Pliocene West Antarctic ice sheet oscillations , 2009, Nature.

[18]  S. Marshall,et al.  Interannual Atmospheric Variability Affects Continental Ice Sheet Simulations on Millennial Time Scales , 2008 .

[19]  David M. Holland,et al.  Acceleration of Jakobshavn Isbræ triggered by warm subsurface ocean waters , 2008 .

[20]  G. Ramstein,et al.  Amount of CO2 emissions irreversibly leading to the total melting of Greenland , 2008 .

[21]  C. Hillaire‐Marcel,et al.  Natural Variability of Greenland Climate, Vegetation, and Ice Volume During the Past Million Years , 2008, Science.

[22]  David M. Holland,et al.  The Response of Ice Shelf Basal Melting to Variations in Ocean Temperature , 2008 .

[23]  A. Weaver,et al.  The Sensitivity of the Atlantic Meridional Overturning Circulation to Freshwater Forcing at Eddy-Permitting Resolutions , 2008 .

[24]  M. Tedesco.  Updated 2008 Surface Snowmelt Trends in Antarctica , 2008 .

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

[26]  Uwe Mikolajewicz,et al.  Long-term ice sheet–climate interactions under anthropogenic greenhouse forcing simulated with a complex Earth System Model , 2008 .

[27]  S. Marshall,et al.  Neglecting ice‐atmosphere interactions underestimates ice sheet melt in millennial‐scale deglaciation simulations , 2008 .

[28]  Alvaro Montenegro,et al.  Long term fate of anthropogenic carbon , 2007 .

[29]  C. Schoof.  Ice sheet grounding line dynamics: Steady states, stability, and hysteresis , 2007 .

[30]  James Haile,et al.  Ancient Biomolecules from Deep Ice Cores Reveal a Forested Southern Greenland , 2007, Science.

[31]  V. Brovkin,et al.  Modeling the influence of Greenland ice sheet melting on the Atlantic meridional overturning circulation during the next millennia , 2007 .

[32]  Anne W. Nolin,et al.  Classification of glacier zones in western Greenland using albedo and surface roughness from the Multi-angle Imaging SpectroRadiometer (MISR) , 2007 .

[33]  Xavier Fettweis,et al.  The 1979–2005 Greenland ice sheet melt extent from passive microwave data using an improved version of the melt retrieval XPGR algorithm , 2007 .

[34]  Ian Simmonds,et al.  Simulated Antarctic precipitation and surface mass balance at the end of the twentieth and twenty-first centuries , 2006 .

[35]  Paul Steele,et al.  Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP , 2006 .

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

[37]  Sheng-Hung Wang,et al.  Greenland Ice Sheet Surface Mass Balance Variability (1988–2004) from Calibrated Polar MM5 Output* , 2006 .

[38]  J. Overpeck,et al.  Paleoclimatic Evidence for Future Ice-Sheet Instability and Rapid Sea-Level Rise , 2006, Science.

[39]  J. Overpeck,et al.  Simulating Arctic Climate Warmth and Icefield Retreat in the Last Interglaciation , 2006, Science.

[40]  Jonathan L. Bamber,et al.  A surface mass balance model for the Greenland Ice Sheet , 2005 .

[41]  A. Sterl,et al.  The ERA‐40 re‐analysis , 2005 .

[42]  Jonathan M. Gregory,et al.  Elimination of the Greenland ice sheet in a high-CO2 climate , 2005 .

[43]  A. Vieli,et al.  Recent dramatic thinning of largest West Antarctic ice stream triggered by oceans , 2004 .

[44]  C. Ritz,et al.  Quantifying ice‐sheet feedbacks during the last glacial inception , 2004 .

[45]  Jason E. Box,et al.  Greenland ice sheet surface mass balance 1991–2000: Application of Polar MM5 mesoscale model and in situ data , 2004 .

[46]  Katrin J. Meissner,et al.  The role of land surface dynamics in glacial inception: a study with the UVic Earth System Model , 2003 .

[47]  A. Ohmura,et al.  Effects of polar ice sheets on global sea level in high‐resolution greenhouse scenarios , 2003 .

[48]  Andreas Schmittner,et al.  Instability of Glacial Climate in a Model of the Ocean- Atmosphere-Cryosphere System , 2002, Science.

[49]  Sivaprasad Gogineni,et al.  A new ice thickness and bed data set for the Greenland ice sheet: 1. Measurement, data reduction, and errors , 2001 .

[50]  David G. Vaughan,et al.  BEDMAP: a new ice thickness and subglacial topographic model of Antarctica , 2001 .

[51]  S. Marshall,et al.  Glacial termination: sensitivity to orbital and CO2 forcing in a coupled climate system model , 2001 .

[52]  S. Marshall,et al.  Substantial contribution to sea-level rise during the last interglacial from the Greenland ice sheet , 2000, Nature.

[53]  T. Stocker,et al.  Atmospheric CO2 concentration from 60 to 20 kyr BP from the Taylor Dome Ice Core, Antarctica , 2000 .

[54]  D. Pollard.  Comparisons of ice-sheet surface mass budgets from Paleoclimate Modeling Intercomparison Project (PMIP) simulations , 2000 .

[55]  Michael Metcalf,et al.  Fortran 90/95/HPF , 1999, SIGP.

[56]  Michael Metcalf,et al.  Fortran 90/95 explained (2nd ed.) , 1999 .

[57]  J. Jouzel,et al.  Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica , 1999, Nature.

[58]  A. Weaver,et al.  Simulated influence of carbon dioxide, orbital forcing and ice sheets on the climate of the Last Glacial Maximum , 1998, Nature.

[59]  S. Marshall,et al.  A continuum mixture model of ice stream thermomechanics in the Laurentide Ice Sheet 1. Theory , 1997 .

[60]  S. Marshall,et al.  A continuum mixture model of ice stream thermomechanics in the Laurentide Ice Sheet 2. Application to the Hudson Strait Ice Stream , 1997 .

[61]  Mark F. Meier,et al.  Retention of Greenland runoff by refreezing: Implications for projected future sea level change , 1991 .

[62]  Carl E. Bøggild,et al.  A new present-day temperature parameterization for Greenland , 2009, Journal of Glaciology.

[63]  S. Tulaczyk,et al.  Sensitivity of ocean circulation and sea-ice conditions to loss of West Antarctic ice shelves and ice sheet , 2007 .

[64]  Sridhar Anandakrishnan,et al.  Ice-sheet mass balance: assessment, attribution and prognosis , 2007, Annals of Glaciology.

[65]  L. Hinzman,et al.  Observations: Changes in Snow, Ice and Frozen Ground , 2007 .

[66]  H. L. Miller,et al.  Climate Change 2007: The Physical Science Basis , 2007 .

[67]  D. Etheridge,et al.  Law Dome CO 2 , CH 4 and N 2 O ice core records extended to 2000 years , 2006 .

[68]  D. Bromwich,et al.  Greenland Ice Sheet Surface Mass Balance Variability ( 1988 – 2004 ) from Calibrated Polar MM 5 Output , 2006 .

[69]  D. Bromwich,et al.  Greenland ice sheet surface mass balance 1991 – 2000 : Application of Polar MM 5 mesoscale model and in situ data , 2004 .

[70]  G. Denton,et al.  Reconstructing the Antarctic Ice Sheet at the Last Glacial Maximum. , 2002 .

[71]  Michael Metcalf,et al.  Fortran 90/95 explained , 1996 .

[72]  R. S. W. van de Wal,et al.  An energy balance model for the Greenland ice sheet , 1994 .