How to modify the case.run script to make ensemble runs?

[jizh]

Hi all,
I try to use CAM6 to examine the atmospheric response to some SST anomalies during JJA. First, I ran a 50-yr control run with compset F2000climo. Then I plan to add the SST anomalies to the SST forcing file, restart the simulation from June 1st of each year, and run three months for each member. At last, I will compare the ensemble mean of the anomalous SST run with the climatological SST run.

For cesm1, the case.run file is shell script. The commands of copying the restart files, changing XML variables could be added to the case.run (or submit) script. I only need to submit the batch job once and then the model could complete many JJA-run members (using loops in the script). But for cesm2, the run and submit scripts are python files with many python functions. If there is no modification, the model will only finish one JJA-run once, and I need to submit it again and again. It would cost a lot of waiting time. I am not familiar with python. Does anyone know how to modify the cesm2 script to perform such a simulation similar to cesm1? Thanks for any sharing.

Jian

 

[peverley]

Hi Jian,

Our recommendation is to:
1. Start with your 50 year control case as normal
2. Create a shell script that will create X new cases based on that control case and include the necessary XML variable changes. The shell script should set up the cases, change the necessary variables, set up the namelist, build, and submit the cases.
3. Run the shell script (submit it to the batch system)

This way, you are not at risk of overwriting previous run configurations or output with your XML variable changes.

Let me know if you have any further questions!
Courtney