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 (1690B) --- 1 Ross ice shelf model (prognostic eigencalving mode) 2 ================= 3 4 This example demonstrates prognostic (geometry-evolving) modeling of an 5 ice shelf using the `-calving eigen_calving,thickness_calving` combination. 6 7 The user should probably run the example in `../diagnostic/` before this one, 8 and read the documentation for diagnostic example in section 12.2 of the PISM 9 User's Manual. 10 11 With the applied calving parameterization we reach a (quasi) steady state after 12 runs of a few centuries. Calving parameters, specifically the minimal ice 13 thickness at the front (`-thickness_calving_threshold`) and the eigencalving 14 constant (`-eigen_calving_K`) are among the parameters that can be modified 15 either to get a different steady state or to model changes in the ice shelf. 16 17 As in the diagnostic example, start by running `preprocess.py` in the parent 18 directory. Then do 19 20 $ ./run_prog.sh 4 211 0.6 100 21 22 This 100 model year run on 4 processes and a 5 km grid took about about twenty 23 minutes. It starts with a bootstrapping stage which does a `-y 0` run and then 24 generates `startfile_Mx211.nc`. It then re-initializes to start the prognostic 25 run itself. 26 27 Note `run_prog.sh` accepts four arguments: `run_prog.sh N Mx E Y` does 28 a run with `N` MPI processes, a `Mx`x`Mx` grid, option `-ssa_e E`, and duration 29 `-y Y`. 30 31 To view a "movie" of the resulting thicknesses and surface velocities 32 do 33 34 $ ncview ex-prog_Mx211_yr100.nc 35 36 To see a time-series of ice volume or ice area, among other other quantities, 37 do 38 39 $ ncview ts-prog_Mx211_yr100.nc 40 41 To generate figures comparing the final-time modeled velocity to present-day 42 observed velocity do 43 44 $ ../plot.py prog_Mx211_yr100.nc 45