Pism Versions Save

• Use time.time() instead of time.clock() in examples/python/ssa_forward.py (contributed by Moritz Kreuzer).
• von Mises calving is applied at both floating and grounded ice fronts.
• Update the list of Debian (Ubuntu) packages in the installation manual.
• Use python3 instead of python in all Python scripts. This is needed to support Ubuntu 20.04, for example.
• Support Clang 10.0 and GCC 9.3.
• Formally require PROJ 6.0 or newer. PISM v1.2 required PROJ 5.0 or later, but it turns out that there are significant differences between PROJ 5.x and 6.x that make supporting both version too complicated.
• Fix #462 (asymmetric gl_mask even though ice geometry is symmetric).
• Update the minimal NetCDF version required by PISM (4.4 instead of 4.1).

• Use better notation for different lapse rates in the manual.
• Fix bugs in the fracture density code and a related scrips.
• Fix the orographic precipitation model.
• Continue after warning about missing "units" in an input file.
• Stop if -ocean_kill_file is set.
• Update all scripts that used -ocean_kill_file and use -front_retreat_file instead.
• Improve regression tests.
• Remove some old or unused code.
• Fix #454 (PICO initialization fails with dummy values).
• Use high yield stress in all ice-free areas (see #456).
• Set stress_balance.ssa.fd.max_speed to about the speed of light. See #455. The default value of this parameter should be high enough to disable this mechanism.

Compared to v1.1, the new version includes

• modifications required by ISMIP6 experiments,
• the frontal melt parameterization by Rignot et al,
• the orographic precipitation model following Smith and Barstad, A linear theory of orographic precipitation (2004),
• the ability to use NCAR ParallelIO for better I/O performance,
• numerous bug fixes and minor improvements.

Please see the change log for more details.

This is the version of PISM used in "Contribution of the Greenland Ice Sheet to sea-level over the next millennium" by Andy Aschwanden, Mark A. Fahnestock, Martin Truffer, Douglas J. Brinkerhoff, Regine Hock, Constantine Khroulev, Ruth Mottram, and S. Abbas Khan.

This code is based on v1.0 but contains many of the improvements included in v1.1.

This is a PISM code release for paleo simulations of the Antarctic Ice Sheet as discussed in Kingslake, Scherer, Albrecht et al., "Extensive retreat and re-advance of the West Antarctic Ice Sheet during the Holocene." Nature 558, no. 7710 (2018): 430. For input data and plotting scripts please contact the author ([email protected]).

Torsten Albrecht