Himalaya experiment
Overview
Teaching: 0 min
Exercises: 0 minQuestions
How to remove Himalaya mountains?
Objectives
Learn to remove the Himalaya mountains in a CESM experiment
Himalaya Mountains: how to update the input dataset?
Copy the original surface geopotential file into your case directory.
On Saga:export EXPNAME=himalaya
cd $HOME/cases/F2000climo-f19_g17.$EXPNAME
cp /cluster/projects/nn1000k/cesm/inputdata/./atm/cam/topo/fv_1.9x2.5_nc3000_Nsw084_Nrs016_Co120_Fi001_ZR_061116.nc .
Use nco utilities to edit the values in the file (http://nco.sourgeforce.net). We will use a function called ncap2 – (netCDF Arithmetic Averager) single line command below.
On Saga:module load NCO/4.7.9-intel-2018b
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))' fv_1.9x2.5_nc3000_Nsw084_Nrs016_Co120_Fi001_ZR_061116.nc fv_1.9x2.5_nc3000_Nsw084_Nrs016_Co120_Fi001_ZR_061116_$EXPNAME.nc
Apply this change.
On Saga:echo "bnd_topo = './fv_1.9x2.5_nc3000_Nsw084_Nrs016_Co120_Fi001_ZR_061116_$EXPNAME.nc'" >> user_nl_cam
./preview_namelists
grep topo /cluster/work/users/$USER/cesm/F2000climo-f19_g17.$EXPNAME/run/atm_in
Copy the modified surface geopotential data file into your run directory.
On Saga:cp fv_1.9x2.5_nc3000_Nsw084_Nrs016_Co120_Fi001_ZR_061116_$EXPNAME.nc /cluster/work/users/$USER/cesm/F2000climo-f19_g17.$EXPNAME/run/.
Key Points
Himalaya