...
| Code Block |
|---|
./xmlchange ATM_NCPL=288
./xmlchange DEBUG=TRUE #debug rather than optimized build.
./xmlchange JOB_QUEUE=pdebug #debug if on cori or perlmutter
./xmlchange JOB_WALLCLOCK_TIME=0:30:00
./xmlchange STOP_OPTION=ndays #how long to run for
./xmlchange STOP_N=1
./xmlchange HIST_OPTION=ndays #how often to write cpl.hi files
./xmlchange HIST_N=1
./xmlchange NTASKS=675 #change how many MPI tasks to use
./xmlchange PIO_NETCDF_FORMAT="64bit_data"
./xmlchange SCREAM_CMAKE_OPTIONS=SCREAM_NP 4 SCREAM_NUM_VERTICAL_LEV 128 SCREAM_NUM_TRACERS 10 |
The point of these changes are (respectively):
change the atm timestep to 288 steps per day (300 sec). This needs to be done via ATM_NCPL or else the land model will get confused about how frequently it is coupling with land
compile in debug mode. Will run 10x slower but will provide better error messages. And doesn’t run in any other mode on some machines.
change the default queue and wallclock from the standard queue with 1 hr walltime to debug queue and its max of 30 min walltime to get through the queue faster. Note that the format for summit wallclock limits is hh:mm instead of hh:mm:ss on other machines.
change the default length of the run from just a few steps to 1 day (or whatever you choose). This change is made in both env_run.xml and env_test.xml because case.submit seems to grab for one or the other file according to confusing rules - easier to just change both.
HIST_OPTION and HIST_N set the frequency of coupler snapshots (cpl.hi) files, which are useful for figuring out whether SCREAM is getting or giving bad data from/to the surface models
NTASKS is the number of MPI tasks to use (which sets the number of nodes submit asks for). You can also set this via --pecount setting in create_newcase.
Changing the PIO_NETCDF_FORMAT to 64bit_data is needed at very high resolutions to avoid exceeding max variables size limits.
Low-resolutions uses 72 layers by default. If you want to use 128 vertical layers (or 72), you need to change the number of levels. Note that this line completely replaces SCREAM_CMAKE_OPTIONS, so you also need to tell it some other stuff. SCREAM_NP is the number of GLL points per side of an element, which is always set to 4. The atm initial condition file keys off the compset AND the vertical grid, so you don’t need to worry about changing that.
Step 5: Configure the case
...