tREADME.md - pism - [fork] customized build of PISM, the parallel ice sheet model (tillflux branch) (HTM) git clone git://src.adamsgaard.dk/pism (DIR) Log (DIR) Files (DIR) Refs (DIR) LICENSE --- tREADME.md (1152B) --- 1 ### A simplified setup showing that `-kill_icebergs` should always be "on". 2 3 We start with three blobs of ice on a flat bed. As the run goes on, 4 the sea level rises, and blobs start floating, starting with the 5 smallest one. 6 7 Once the whole blob is afloat the SSA solver will fail because of a 8 zero pivot. The option `-kill_icebergs` removes such disconnected floating ice. 9 10 To run this example, first put `util/PISMNC.py` on your `PYTHONPATH`, or do 11 12 $ ln -s ../../../util/PISMNC.py 13 14 Now run all examples 15 16 $ make 17 18 First look at variable `thk` in `flood.nc` to see initial geometry. 19 See evolving `mask` and `thk` variables in output files `ex_*.nc` to see 20 the effect of various options including `[none]`, `-cfbc`, 21 `-cfbc -kill_icebergs`. 22 23 Note that without the calving front boundary condition (`make no_cfbc` 24 which uses `[none]`), the strength extension "ties" floating blobs to the 25 biggest blob, which remains grounded. In this (not-recommended) case the 26 SSA solver does not see a zero pivot. 27 28 As a result of this example and others, the option combination 29 `-cfbc -kill_icebergs` is generally recommended for marine ice sheet 30 simulations.