NEWS: Summer time!
The Parallel Ice Sheet Model pism0.7 is an open source, parallel, high-resolution ice sheet model. Features:
|Mass-conserving subglacial hydrology in the Parallel Ice Sheet Model v0.6|
|investigator:||E. Bueler and W. van Pelt|
|journal:||Geoscientific Model Development|
This paper describes and tests a major extension of PISM, introduced in v0.6 and fully-supported in v0.7, a two-horizontal-dimension subglacial hydrology model which combines till with a distributed system of water-filled, linked cavities. This sub-model accomplishes three specific goals: (1) conservation of the mass of water, (2) simulation of spatially- and temporally-variable basal shear stress from physical mechanisms based on a minimal number of free parameters, and (3) convergence under grid refinement. Besides a broad approach to the source of the model equations and detailed attention to the implementation and testing of the numerics, this paper demonstrates the model at scale by modeling the whole Greenland ice sheet at 2 km horizontal resolution, with one million nodes in the hydrology grid. But the model is far from complete. It both takes a very conservative approach to coupling hydrology to a model for basal shear, and it does not include the physics which determines the location and evolution of subglacial conduits.
PISM v0.7.1 was released today. In addition to bug fixes this version adds support for PETSc 3.6.1 (which is not released yet). PETSc 3.6.0 is not supported due to a bug in PETSc.
Please go to PETSc's web page to check if version 3.6.1 is available. In the meantime we recommend building PISM with PETSc 3.5.4. Alternatively, you can get PETSc 3.6.0 with the relevant bug fix by running the command below.
git clone -b maint https://bitbucket.org/petsc/petsc petsc
It's summer time; UAF PISM developers are currently writing proposals, work on their own projects, and enjoy the summer. Please give us some slack responding to questions, bug reports, etc. We will try fix serious bugs as quickly as possible though. We'll be back in Fall.
PETSc 3.6 was released on June 9, 2016. We are currently working on making PISM compatible with PETSc 3.6 and will announce it here as soon as possible.
In the meantime, please install petsc 3.5.4 from here. PISM version 0.7 (
stable0.7 branch) works with any PETSc 3.5.X.
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.