5: Control case using MOM6

5: Control case using MOM6#

We will use a different CESM tag (cesm2_3_beta17) for this exercise.

Download CESM (tag cesm2_3_beta17)#

If needed, revisit the Download CESM section before executing the following steps.

Git Clone#

Change the current directory to the code workspace directory: 
cd /glade/u/home/$USER/code

Download the cesm code to your code workspace directory as cesm2_3_beta17: 

git clone https://github.com/ESCOMP/CESM.git cesm2_3_beta17
cd cesm2_3_beta17
git checkout cesm2_3_beta17

Download the Component Models with checkout_externals#

MOM6 is still an optional component in this version of CESM. Therefore, we need to run the checkout_externals command with the -o (optional) argument to download the required and optional component models:

cd /glade/u/home/$USER/code/cesm2_3_beta17
./manage_externals/checkout_externals -o

*Note: If you get a message about accepting a certificate permanently or temporarily, accept the certificate permanently. If you do not get this message, do not worry, you are still on track!

Congratulations, you have now downloaded the cesm2_3_beta17 tag on your workspace!!

Exercise#

Run a JRA-forced MOM6 control case

Create a case called gmom_jra.run_length using the compset GMOM_JRA at TL319_t232 resolution.

Set the run length to 5 year.

Build and run the model. Since this is a control case, we want to build it “out of the box” without any modifications.

Click here for hints

How do I check the composets with MOM6?

Go to CESM2.2.0 Component Sets Definitions and look for “MOM” using the “Search” box.

How do I compile?

You can compile with the command:

qcmd -- ./case.build

How do I check my solution?

When your run is completed, go to the archive directory.

(1) Check that your archive directory contains files mom6.h.z, mom6.h.sfc, etc

(2) Compare the contents of the h.z and h.sfc files using ncdump.

ncdump -h gmom_jra.run_length.mom6.h.z.0005-12.nc
ncdump -h gmom_jra.run_length.mom6.h.sfc.0005-12.nc

(3) Look at the sizes of the files.

Click here for the solution

Create a new case gmom_jra.run_length with the command:

cd /glade/u/home/$USER/code/cesm2_3_beta17/cime/scripts/
./create_newcase --case /glade/u/home/$USER/cases/gmom_jra.run_length --compset GMOM_JRA --res TL319_t232

Case setup:

cd ~/cases/gmom_jra.run_length 
./case.setup

Change the run length:

./xmlchange STOP_N=5,STOP_OPTION=nyears

If needed, change job queue and account number. For instance:

./xmlchange JOB_QUEUE=tutorial,PROJECT=UESM0013 --force

Build and submit:

qcmd -- ./case.build
./case.submit

When the run is completed, look into the archive directory for: gmom_jra.run_length.

(1) Check that your archive directory on derecho (The path will be different on other machines):

cd /glade/derecho/scratch/$USER/archive/gmom_jra.run_length/ocn/hist

ls
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