Exercise 1: Modify run length

Exercise 1: Modify run length#

Exercise: Modify the env_run.xml file

Part I:
Create a new fully coupled startup case named “b1850.run_length” from the 1850 climate conditions with a resolution of f19_g17. Increase the amount of standard output produced by the model for debugging. Run for 1 month.

Hint!

  1. Which variable controls the amount of standard output for debugging? We can use partial query to find out:

    ./xmlquery -p DBUG

  1. Use xmlchange to modify env_run.xml

  2. Make sure to update the walltime to match the run length.

Click here for the solution to Part I

From the SRCROOT (/glade/u/home/$USER/code/my_cesm_code) directory, create your case:

    cd /glade/u/home/$USER/code/my_cesm_code/cime/scripts
    ./create_newcase --case /glade/u/home/$USER/cases/b1850.run_length --res f19_g17 --compset B1850

In your case directory, change debugging levels and set runtime variables:

    cd /glade/u/home/$USER/cases/b1850.run_length
    ./xmlchange INFO_DBUG=2,STOP_N=1,STOP_OPTION=nmonths
    ./xmlchange --subgroup case.run JOB_WALLCLOCK_TIME=2:00:00

Remember to manually update your README.case file to document your changes.

Carry on to setup, build and submit the run:

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

Remember that qcmd is used on derecho only.

Exercise: Modify the env_run.xml file

Part II: Do part II only after Part I has finished running.
Change the debug level back to 1. Expand Part I to produce a total of 38 months of model run. Remember that you have already run for 1 month.

  • You can only do part II after Part I has finished running

  • You should submit this at the end of the day so that it will (hopefully) run overnight and be available the following day. You can continue with Exercise 2-3 and submit the run later.

  • VERY, VERY IMPORTANT: Don’t use the tutorial for this run as it is an overnight run. You should submit that run in the main queue

To submit in the main queue, you need to add:

  ./xmlchange JOB_QUEUE=main
Hint!

  1. Which variable controls the amount of standard output for debugging? We can use partial query to find out:

    ./xmlquery -p DBUG

  1. Use xmlchange to modify env_run.xml

  2. Make sure to update the walltime to match the run length.

  3. For Part II, how to tell the model that this run continues from the previously finished run of 1 month?

Click here for the solution to Part II
1. To continue the run, set `CONTINUE_RUN` to `TRUE` 
    cd /glade/u/home/$USER/cases/b1850.run_length
    ./xmlchange CONTINUE_RUN=TRUE

2. Keep `STOP_OPTION` as "nmonths”
3. Set `STOP_N` to “37” 
    ./xmlchange STOP_N=37

4. Set INFO_DBUG to 1 
    ./xmlchange INFO_DBUG=1

5. Change queue 
    ./xmlchange JOB_QUEUE=main

6. Change wallclock time to use the maximum of the allowed wallclock on derecho: 
    ./xmlchange --subgroup case.run JOB_WALLCLOCK_TIME=12:00:00
    ./xmlchange --subgroup case.st_archive JOB_WALLCLOCK_TIME=6:00:00

7. Submit (./case.submit) from your b1850.run_length case directory: 
    ./case.submit