Himalaya Mountains: how to update input dataset?


Copy surface geopotential file to your case directory:
On Abel:
export EXPNAME=himalaya
cd ~/cesm_case/f2000.T31T31.$EXPNAME

cp /work/users/$USER/inputdata/atm/cam/topo/USGS-gtopo30_48x96_c050520.nc .



Use nco utilities to edit values on the file (http://nco.sourgeforce.net) We will use a function called ncap2 – (netCDF Arithmetic Averager) single line command below

On Abel:
module load nco



ncap2 -O -s 'lat2d[lat,lon]=lat ; lon2d[lat,lon]=lon' -s 'omask=(lat2d >= 30.0 && lat2d <= 50.0) && (lon2d >=70.0 && lon2d <= 100.0)' -s 'PHIS=(PHIS*(1-omask))' USGS-gtopo30_48x96_c050520.nc  USGS-gtopo30_48x96_c050520_$EXPNAME.nc


Apply this change
echo "bnd_topo = './USGS-gtopo30_48x96_c050520_$EXPNAME.nc'" >> user_nl_cam 	

./preview_namelists

grep topo /work/users/$USER/f2000.T31T31.$EXPNAME/run/atm_in


Copy changed surface geopotential data file to run directory
cp USGS-gtopo30_48x96_c050520_$EXPNAME.nc /work/users/$USER/f2000.T31T31.$EXPNAME/run/.

Before submitting your experiment, make sure you adjust the wall clock time! Now you are ready to submit your simulation:
On Abel:
cd ~/cesm_case/f2000.T31T31.$EXPNAME

./f2000.T31T31.$EXPNAME.submit

Once your short simulation is done, check the outputs: were your changes taken into account? Do you get significant results?
If you are happy with your short run, you can setup your long run (14 months) experiment.