Workflow of a CCSM4 run

Wed, 20 Apr 2016 00:00:00 +0000

Basic approach, startup run:

Create a new case using the script under ~/CCSM4/scripts, following the template: PATH, compset, resolution and machine file. Compset B is the fully coupled mode.
```
 ./create_newcase -case ~/ccsm4/$casename \
-compset B_2000 \
-res 0.9x1.25_gx1v6 \
-mach bluefire
```
Go to the $CASEROOT directory, `~/ccsm4/$case, modify the processor layout (env_mach_pes.xml) or env_conf.xml` files, then configure and build the model:
```
 ./configure -case
./$casename.$mach.build
```
Create Production test (Optional): This will clone the current case and create a parallel folder ../$casename_ERT.x$mach. Go to the folder, and execute following commands:
```
 ./$casename_ERT.$mach.build
bsub < $casename_ERT.$mach.test
cat TestStatus
```
Once pass the test run, go back to the $CASEROOT, modify the env_run.xml as well as %casename.$mach.run. Using the given xmlchange script is recommended. The %casename.$mach.run is the batch submit script. Depending on the machines, it could be executed through bsub or qsub. In the env_run.xml file, one can edit items such as STOP_N, STOP_OPTION and RESUBMIT, to adjust the simulation length, as well as the resubmit frequencies. This modifications don’t require rebuilding executables.

A branch or hybrid run:

Follow Step 1 in the previous example to create a new case $casename2.

Edit env_conf.xml:

 xmlchange -file env_conf.xml -id RUN_TYPE -val branch
xmlchange -file env_conf.xml -id RUN_REFCASE -val $casename1
xmlchange -file env_conf.xml -id RUN_REFDATE -val 0001-02-01

For a hybrid run, set RUN_TYPE to hybrid instead.

Configure and build the case executable.

 ./configure -case
./$casename.$mach.build

Copy the necessary restart/initial data into $RUNROOT, a path similar to .../exe/$casename2/run
Repeat Step 4 in the previous example.

–

File locking explained:

Locking variables is a feature of CCSM that prevents users from changing variables after they have been resolved (used) in other parts of the scripts system. The variables in env_case are locked when create_newcase is called. The env_conf and env_mach_pes variables are locked when configure is called. The env_build variables are locked when CCSM is built, and the env_run variables are never locked and can be changed anytime. In addition, the Macros file is locked as part of the build step. The $CASEROOT/LockedFiles directory saves copies of the xml files to facilitate the locking feature.

–

More advanced use cases can be found in Chapter 9 of the

CESM |

Workflow of a CCSM4 run

Basic approach, startup run:

A branch or hybrid run:

File locking explained: