SST experiment

Overview

Teaching: 0 min
Exercises: 0 min

Questions

• How to modify Sea Surface Temperature (SST)?

Objectives

• Learn to modify SST in a CESM experiment

SST: how to update the input dataset?

Copy the original SST file into your case directory.

export EXPNAME=SST
cd ~/cases/F2000climo-f19_g17.$EXPNAME

cp /cluster/projects/nn1000k/cesm/inputdata/./atm/cam/sst/sst_HadOIBl_bc_1x1_2000climo_c180511.nc .

To change SST (+6K), use nco utilities to edit values from the original file.

We will use a function called ncap2 – (netCDF Arithmetic Averager) single line command below.

module load NCO/4.7.9-intel-2018b

ncap2 -O -s 'lat2d[lat,lon]=lat ; lon2d[lat,lon]=lon' -s 'omask=(lat2d >= -5.0 && lat2d <= 5.0) && (lon2d >=180.0 && lon2d <= 275.0)' -s 'SST_cpl=(SST_cpl + 6.0*omask)' sst_HadOIBl_bc_1x1_2000climo_c180511.nc sst_HadOIBl_bc_1x1_2000climo_c180511_$EXPNAME.nc

• Figure out which namelist variable to change

grep sst_ *.xml

• Change it in env_run.xml

./xmlchange SSTICE_DATA_FILENAME=./sst_HadOIBl_bc_1x1_2000climo_c180511_$EXPNAME.nc

Process env_run.xml to make namelist changes effective (create namelist files).

./preview_namelists

Copy the modified SST data file into the run directory.

cp sst_HadOIBl_bc_1x1_2000climo_c180511_$EXPNAME.nc /cluster/work/users/$USER/F2000climo-f19_g17.$EXPNAME/run/.

Key Points

• SST