skip to main content

DOE PAGESDOE PAGES

Title: Adaptive mesh refinement versus subgrid friction interpolation in simulations of Antarctic ice dynamics

At least in conventional hydrostatic ice-sheet models, the numerical error associated with grounding line dynamics can be reduced by modifications to the discretization scheme. These involve altering the integration formulae for the basal traction and/or driving stress close to the grounding line and exhibit lower – if still first-order – error in the MISMIP3d experiments. MISMIP3d may not represent the variety of real ice streams, in that it lacks strong lateral stresses, and imposes a large basal traction at the grounding line. We study resolution sensitivity in the context of extreme forcing simulations of the entire Antarctic ice sheet, using the BISICLES adaptive mesh ice-sheet model with two schemes: the original treatment, and a scheme, which modifies the discretization of the basal traction. The second scheme does indeed improve accuracy – by around a factor of two – for a given mesh spacing, but $$\lesssim 1$$ km resolution is still necessary. For example, in coarser resolution simulations Thwaites Glacier retreats so slowly that other ice streams divert its trunk. In contrast, with $$\lesssim 1$$ km meshes, the same glacier retreats far more quickly and triggers the final phase of West Antarctic collapse a century before any such diversion can take place.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [2]
  1. Univ. of Bristol, Bristol (United Kingdom)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Annals of Glaciology
Additional Journal Information:
Journal Volume: 57; Journal Issue: 73; Journal ID: ISSN 0260-3055
Publisher:
International Glaciological Society
Research Org:
Lawrence Berkeley National Laboratory, E-Scholarship Repository, Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ice dynamics; ice streams; ice-sheet modelling
OSTI Identifier:
1378355

Cornford, S. L., Martin, D. F., Lee, V., Payne, A. J., and Ng, E. G.. Adaptive mesh refinement versus subgrid friction interpolation in simulations of Antarctic ice dynamics. United States: N. p., Web. doi:10.1017/aog.2016.13.
Cornford, S. L., Martin, D. F., Lee, V., Payne, A. J., & Ng, E. G.. Adaptive mesh refinement versus subgrid friction interpolation in simulations of Antarctic ice dynamics. United States. doi:10.1017/aog.2016.13.
Cornford, S. L., Martin, D. F., Lee, V., Payne, A. J., and Ng, E. G.. 2016. "Adaptive mesh refinement versus subgrid friction interpolation in simulations of Antarctic ice dynamics". United States. doi:10.1017/aog.2016.13. https://www.osti.gov/servlets/purl/1378355.
@article{osti_1378355,
title = {Adaptive mesh refinement versus subgrid friction interpolation in simulations of Antarctic ice dynamics},
author = {Cornford, S. L. and Martin, D. F. and Lee, V. and Payne, A. J. and Ng, E. G.},
abstractNote = {At least in conventional hydrostatic ice-sheet models, the numerical error associated with grounding line dynamics can be reduced by modifications to the discretization scheme. These involve altering the integration formulae for the basal traction and/or driving stress close to the grounding line and exhibit lower – if still first-order – error in the MISMIP3d experiments. MISMIP3d may not represent the variety of real ice streams, in that it lacks strong lateral stresses, and imposes a large basal traction at the grounding line. We study resolution sensitivity in the context of extreme forcing simulations of the entire Antarctic ice sheet, using the BISICLES adaptive mesh ice-sheet model with two schemes: the original treatment, and a scheme, which modifies the discretization of the basal traction. The second scheme does indeed improve accuracy – by around a factor of two – for a given mesh spacing, but $\lesssim 1$ km resolution is still necessary. For example, in coarser resolution simulations Thwaites Glacier retreats so slowly that other ice streams divert its trunk. In contrast, with $\lesssim 1$ km meshes, the same glacier retreats far more quickly and triggers the final phase of West Antarctic collapse a century before any such diversion can take place.},
doi = {10.1017/aog.2016.13},
journal = {Annals of Glaciology},
number = 73,
volume = 57,
place = {United States},
year = {2016},
month = {5}
}