We have developed a numerical model of ice
sheets called PISM (a Parallel Ice Sheet Model). The thickness,
temperature, velocity and age of the ice
are all simulated, as is the deformation of the earth underneath the
ice. New techniques for fast ice dynamics, earth deformation, and
verification have been included into this comprehensive model. Ice sheet
simulations have run on parallel computers using from one to 500
processors. PISM has been developed on machines at the
Arctic Region
Supercomputing
Center
on the UAF campus among others.
The
major purpose
is to simulate the evolution of the Antarctic and Greenland ice sheets
over
time scales of a complete ice-age cycle and longer (100,000+
years).
A closely-related purpose will be to simulate the evolution of the ice
sheets over the next 100+ years from the present as the ice sheet
responds
to climatic changes anticipated due to increasing CO2 in the
atmosphere. This work will simulate
the global relative sea-level changes likely to be caused by the
evolution
of the ice sheets in response to changing climate.
Students involved in this effort
will work with a broad range of geophysical problems associated with
the flow of the polar ice sheets and their interactions with the
oceans,
the climate, and the solid earth. Students will apply modern high performance
computing techniques and recent
mathematical advances to the simulation of ice flow.
Figures at right, clockwise from upper left:
- comparison of observed Jakoshavn isbrae, Greenland flow
speeds in 1992
(left) and 2000 (right), from (Joughin et al 2004)
- ice stream in Palmer Land, Antartica; from (Post and
LaChappelle, 2000)
- PISM modeled vertically-integrated ice speed for Ross Ice
Shelf, Antarctica, based on RIGGS and EISMINT-Ross data
- PISM modeled vertically-integrated ice speed for the
Greenland ice sheet
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