Optimal numerical solvers for transient simulations of ice flow using the Ice Sheet System Model (ISSM versions 4.2.5 and 4.11)
Identifying fast and robust numerical solvers is a critical issue that needs to be addressed in order to improve projections of polar ice sheets evolving in a changing climate. This work evaluates the impact of using advanced numerical solvers for transient ice-flow simulations conducted with the JP...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2017-01-01
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Series: | Geoscientific Model Development |
Online Access: | http://www.geosci-model-dev.net/10/155/2017/gmd-10-155-2017.pdf |
Summary: | Identifying fast and robust numerical solvers is a critical issue that needs to
be addressed in order to improve projections of polar ice sheets evolving in a
changing climate. This work evaluates the impact of using advanced numerical
solvers for transient ice-flow simulations conducted with the JPL–UCI Ice Sheet
System Model (ISSM). We identify optimal numerical solvers by testing a broad
suite of readily available solvers, ranging from direct sparse solvers to
preconditioned iterative methods, on the commonly used Ice Sheet Model
Intercomparison Project for Higher-Order ice sheet Models benchmark tests.
Three types of analyses are considered: mass transport, horizontal stress
balance, and incompressibility. The results of the fastest solvers for
each analysis type are ranked based on their scalability across mesh size and
basal boundary conditions. We find that the fastest iterative solvers are
∼ 1.5–100 times faster than the default direct solver used in ISSM, with
speed-ups improving rapidly with increased mesh resolution. We provide a set of
recommendations for users in search of efficient solvers to use for transient
ice-flow simulations, enabling higher-resolution meshes and faster turnaround
time. The end result will be improved transient simulations for short-term,
highly resolved forward projections (10–100 year time scale) and also improved
long-term paleo-reconstructions using higher-order representations of stresses
in the ice. This analysis will also enable a new generation of comprehensive
uncertainty quantification assessments of forward sea-level rise projections,
which rely heavily on ensemble or sampling approaches that are inherently
expensive. |
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ISSN: | 1991-959X 1991-9603 |