Ice sheets and rising sea level

FOR IMMEDIATE RELEASE December 15, 2008

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The Parallel Ice Sheet Model (PISM) allows scientists to simulate changes in polar ice sheets and how these changes might impact sea levels globally. This animation depicts the last 250,000 years of Greenland ice sheet evolution.Unlike other ice sheet models, PISM is capable of simulating the faster flowing ice streams that can rapidly draw down ice sheets and cause greater sea level rise. The ice sheet visualization was created with Unidata's Integrated Data Viewer (IDV) by ARSC undergraduate research student intern Ben Sperison and modified by ARSC High Performance Computing (HPC)Specialist Patrick Webb using data from PISM.

A critical factor in understanding how ice shed from Greenland and Antarctica contributes to rising sea levels is figuring out how to accurately simulate the movement of ice in an ice sheet.

To do that, scientists have developed a model that realistically simulates the dynamic flow of polar ice sheets and the fast-flowing ice streams that can cause rapid drawdown of inland ice.

Since the turn of the century, satellite measurements indicate that annually the Greenland ice sheet has contributed an average of 80 to 110 cubic kilometers of ice to rising sea level, while the West Antarctic Ice Sheet has contributed 130 to 170 cubic kilometers. That's thought to be a significant increase relative to ice-sheet losses during the previous decade.

Ed Bueler, an associate professor with the University of Alaska Fairbanks mathematics and statistics department; Jed Brown, a former UAF student; and Craig Lingle, geophysics professor emeritus with UAF's Geophysical Institute, are developing the Parallel Ice Sheet Model, or PISM.

Using PISM to simulate the 3D flow of a large ice sheet over significant time periods with adequate resolution requires the massively parallel capabilities of a supercomputing center.UAF is one of the few universities in the U.S. that have a world-class high-performance computing center on its campus, and the only one that directly runs a U.S. Department of Defense HPC facility.

The PISM group is working with computational scientists and HPC specialists at the Arctic Region Supercomputing Center at UAF. Together the team is discovering how to create a more reliable model which simulates, and helps scientists better understand, how ice moves across continents.

As they further develop the model, it will become a much more accurate tool for estimating how changing ice sheets in Alaska and at high latitudes are likely to affect future sea levels.This kind of information is essential for decision-makers around the world for understanding the probable affects of increased coastal erosion on infrastructures and other sea level related economic challenges facing coastal communities.

CONTACT: UAF ARSC Communications Director Debra Damron, 907.450.8662 or damron@arsc.edu .