Documentation for PISM, a parallel Ice Sheet Model

NEWS: PISM at AGU 2014

The Parallel Ice Sheet Model pism0.6 is an open source, parallel, high-resolution ice sheet model. Features:

  • hierarchy of available stress balances
  • marine ice sheet physics, dynamic calving fronts
  • polythermal, enthalpy-based conservation of energy scheme
  • subglacial hydrology and till model
  • extensible coupling to atmospheric and ocean models
  • inversion toolbox in Python
  • verification and validation tools
  • complete documentation for users and developers
  • uses MPI and PETSc for parallel simulations
  • reads and writes CF-compliant NetCDF

PISM Application of the Month

December 2014

Surface velocity, calculated fracture density, and modeled flow results for Filchner Ice Shelf. Click the image to go to The Cryosphere article page.

Fracture-induced softening for large-scale ice dynamics
investigators: T. Albrecht and A. Levermann
journal: The Cryosphere

Fracture processes within ice shelfs have been observed to reduce the retentive forces of the shelves on the Antarctic ice sheet. This paper adds a continuum representation of fractures, and their evolution, to PISM, and applies it to several major ice shelves in Antarctica. A key addition is the introduction of a higher-order scheme for advecting the two-dimensional fracture density field. Fractures and ice flow are coupled through a reduction of modeled ice viscosity proportional to the fracture density, so fracture-induced softening can feed back to cause added shear and self-amplified fracturing. The results of the simulations are compared to observations. Observed sharp across-flow velocity gradients in fracture-weakened regions are reproduced. This fracture-softening model is a basis for a future model of enhanced fracture-based calving.

2014/12/04 07:47 · Ed Bueler

Latest News

PISM v0.6.2 is out

This minor release fixes several bugs and adds PETSc 3.5.x support.

Full list of changes since v0.6.1

If you have questions about installing or using PISM, you can reach UAF developers by sending an e-mail to

2014/11/06 15:22 · Constantine Khroulev

PISM models the Antarctic contribution to meltwater pulse 1A

In a new Nature Communications paper, researchers at Victoria University and the University of New South Wales describe a model study of Antarctic ice sheet evolution over the last 25 kyr using PISM with ocean-forcing inputs from the Earth system model LOVECLIM. They show that when the ocean around Antarctica becomes more stratified, warm water at depth melts the ice sheet faster than when the ocean is less stratified.

The study used a large ensemble of 15 km PISM simulations in a data-constrained mode. In the simulations that best fit a variety of temporal and spatial observations, several episodes of accelerated ice-sheet recession occurred, with the timing of the largest being coincident with meltwater pulse 1A. This episode saw an abrupt rise in global sea level, with an Antarctic contribution of nearly three meters over just a few centuries.

Both this blog entry and this Science Daily news item summarize the work and relate the modeled melt from 14,000 years ago to present-day Antarctic conditions.

2014/10/08 18:16 · Ed Bueler

PISM team

PISM is jointly developed at the University of Alaska, Fairbanks (UAF) and the Potsdam Institute for Climate Impact Research (PIK). 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, NNX13AK27G) and by the Arctic Region Supercomputing Center.

home.txt · Last modified: 2014/12/23 08:53 by Ed Bueler
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