Documentation for PISM, a parallel Ice Sheet Model

NEWS: New PISM user help email: uaf-pism@alaska.edu

The Parallel Ice Sheet Model pism0.7 is open source and capable of high resolution. It is widely adopted as a tool for doing science. Features include:

PISM Application of the Month

April 2017

The temperature of an ice sheet is an important control on the deformation of ice, but it also controls basal melt. The geothermal flux (GHF) is a significant thermal boundary condition, and there is large uncertainty in its magnitude and local variation. On the other hand, a balance of heat conduction and advection—the latter dominates in the large—determines the 3D temperature field within the ice. Thus a thermomechanically-important input—it is a velocity boundary condition—is the rate of surface accumulation. The 3D conduction/advection balance determines sliding because the base is weak where it is well-lubricated; this is dominated by basal melt in a cold ice sheet like the Antarctic.

All of this is modeled by PISM—not perfectly but it is all there. However, understanding the sensitivity of this thermomechanical system to it inputs, in a particular glacier, is not easy. This paper studies the Lambert-Amery ice stream/shelf system in East Antarctica by using observed surface velocities and ice thicknesses as the major constraints. The authors conclude that the ice flow is most sensitive to spatial variation in GHF near the ice divides and under the edges of the ice streams. Their control simulation has temperate ice up to 150 m thick, an average basal melt of 1.3 mm per year, and maximum basal melting of about 0.5 m per year.

2017/04/12 13:28 · Ed Bueler

Latest News

New PISM user help email: uaf-pism@alaska.edu

The core team at UAF continues to support PISM users. The new email for help is uaf-pism@alaska.edu; it replaces help@pism-docs.org. As before, email to this address will be distributed to all the UAF developers, and so it will get the most prompt response year-round.

2017/02/21 20:47 · Ed Bueler

Study of Juneau Ice Field in Cambridge Core news

A recent PISM application Ziemen et al (2016) is covered by a news item in Cambridge Core news.

The 4000 square km ice field in Southeast Alaska is well-known and accessible since its outlets are in the suburbs of the Alaska state capital, Juneau. But climate data for the area are sparse.

Those model runs that agreed well with observations for 1971 to 2010 generated volume and area losses of more than half by 2099. While co-author Regine Hock (UAF) is quoted as saying “The massive icefield that feeds Alaska’s Mendenhall Glacier may be gone by 2200 if warming trend predictions hold true,”, the authors emphasize that spatially-distributed mass balance measurements and improved climate projections that resolve the local temperature and precipitation patterns are essential to solidifying these predictions.

2016/10/06 14:26 · Ed Bueler

Reminder for authors of PISM-using papers

Please acknowledge the funding that makes PISM possible, and which supports its continued maintenance and technical support. Include the sentence “Development of PISM is supported by NASA grants NNX13AM16G and NNX13AK27G.” in the Acknowledgments part of your paper.

If authors do this consistently then it will help to ensure continued funding of PISM!

For specific suggestions on how to cite the design or justification of PISM see this page.

2016/08/18 11:44 · Ed Bueler

PISM team

PISM is jointly developed at the University of Alaska, Fairbanks (UAF) and the Potsdam Institute for Climate Impact Research (PIK). For more about the team see the UAF Developers and PIK Developers pages.

UAF developers, who are in the Glaciers Group at the GI, are supported by NASA's Modeling, Analysis, and Prediction and Cryospheric Sciences Programs (grants NAG5-11371, NNX09AJ38C, NNX13AM16G, NNX16AQ40G, NNX17AG65G) and by NSF grants PLR-1603799 and PLR-1644277.

home.txt · Last modified: 2017/04/06 13:10 by Andy Aschwanden
© 2016 by PISM | webmaster