skip to main content


Title: An ice sheet model validation framework for the Greenland ice sheet

We propose a new ice sheet model validation framework the Cryospheric Model Comparison Tool (CMCT) that takes advantage of ice sheet altimetry and gravimetry observations collected over the past several decades and is applied here to modeling of the Greenland ice sheet. We use realistic simulations performed with the Community Ice Sheet Model (CISM) along with two idealized, non-dynamic models to demonstrate the framework and its use. Dynamic simulations with CISM are forced from 1991 to 2013 using combinations of reanalysis-based surface mass balance and observations of outlet glacier flux change. We propose and demonstrate qualitative and quanti- tative metrics for use in evaluating the different model simulations against the observations. We find 10 that the altimetry observations used here are largely ambiguous in terms of their ability to distinguish one simulation from another. Based on basin- and whole-ice-sheet scale metrics, the model initial condition as well as output from idealized and dynamic models all provide an equally reasonable representation of the ice sheet surface (mean elevation differences of <1 m). This is likely due to their short period of record, biases inherent to digital elevation models used for model initial conditions, and biases resulting from firn dynamics, which aremore » not explicitly accounted for in the models or observations. On the other hand, we find that the gravimetry observations used here are able to unambiguously distinguish between simulations of varying complexity, and along with the CMCT, can provide a quantitative score for assessing a particular model and/or simulation. The new framework demonstrates that our proposed metrics can distinguish relatively better from relatively worse simulations and that dynamic ice sheet models, when appropriately initialized and forced with the right boundary conditions, demonstrate predictive skill with respect to observed dynamic changes occurring on Greenland over the past few decades. An extensible design will allow for continued use of the CMCT as future altimetry, gravimetry, and other remotely sensed data become available for use in ice sheet model validation.« less
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [2] ;  [8] ;  [8] ;  [9] ;  [1] ;  [10] ;  [10] ;  [10] ;  [9] ;  [4]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Univ. of South Florida, Tampa, FL (United States)
  3. The Ohio State Univ., Columbus, OH (United States)
  4. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
  5. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Science, Systems, and Applications, Inc., Lanham, MD (United States)
  6. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  7. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Sigma Space Corp., Lanham, MD (United States)
  8. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  9. Univ. of Utrecht (Netherlands)
  10. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1991-959X; KP1703020; ERKP814
Grant/Contract Number:
AC05-00OR22725; AC52-06NA25396; NNX11AR47G; ANT-0424589; AC02-05CH11231
Accepted Manuscript
Journal Name:
Geoscientific Model Development
Additional Journal Information:
Journal Volume: 10; Journal ID: ISSN 1991-959X
European Geosciences Union
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Aeronautics and Space Administration (NASA)
Country of Publication:
United States
58 GEOSCIENCES; ice sheet models; validation; Greenland ice sheet; Computer Science; Earth Sciences
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1345150