Moist baroclinic wave with Kessler microphysics


The simpler model configurations described in this page are in development and will be considered for integration into the standard CESM Simpler Models after consideration and discussion at upcoming Atmosphere Model Working Group meetings, and in consultation with Lorenzo Polvani ( or Amy Clement (

Note, the following instructions are only valid for CESM2 and subsequent releases

The following describes a moist version of the dry baroclinic wave of Ullrich et al. (2014)  with Kessler microphysics (Kessler, 1969)  that was part of the Dynamical Core Model Intercomparison Project (DCMIP) 2016 test case suite.

Running the FKESSLER test case

After downloading the latest CESM code base, users may perform this test by following the procedures outlined below.  See the CESM user's guide for more infomation on creating and running new cases. 

Step 1: Create the FKESSLER test case

This can be done using the create_newcase script located in the directory $CESM/cime/scripts/ e.g., for the f09_f09_mg17 (~1 deg) resolution

./create_newcase -compset FKESSLER -res f09_f09_mg17 -case $CASEDIR --run-unsupported

 where the case directory is $CASEDIR. -res f09_f09_mg17 sets the dynamical core to the finite-volume dynamical core at 1 degree horizontal resolution. Replace -res f09_f09_mg17  with -res f19_f19_mg17  for the 2 degree horizontal resolution finite-volume dynamical core or -res ne30_ne30_mg17  for the 1 degree horizontal resolution spectral-element dynamical core. Any supported dynamical core and supported resolution for that particular dynamical core in CESM can be used (see source code file components/cam/bld/config_files/horiz_grid.xml).

Step 2: Configure the FKESSLER test case

The FKESSLER compset ensures that most of what is necessary to perform the test case is set up automatically.  The default length of the simulation is set to 5 days, so in order to perform a 12 day test case, the following command must be invoked

./xmlchange STOP_OPTION=ndays,STOP_N=12

For short simulations generating relatively small output files it is sometimes convenient to turn off the automatic archiving functionality in the CESM scripts:

./xmlchange DOUT_S=FALSE

If you want to see what configuration options you are using use

./xmlquery CAM_CONFIG_OPTS

Step 3: Set up and build the FKESSLER test case

From within $CASEDIR run


Step 4: Run the FKESSLER test case


Step 5: Validate the FKESSLER test case output

A number of fields can be used to check that the simulation has produced correct output. Two such fields are shown below.

Figure 1: Large-scale precipitation rate at day 10 using the 1 degree finite-volume dynamical core.


Figure 2: Surface pressure at day 10 using the 1 degree finite-volume dynamical core.


These plots can be reproduced using an ncl script that can be downloaded here