1. Newbies guide

This guide provides basic instructions on how set up and run a standard NorESM case by excecuting 4 steps:

  • create a new case (the create_newcase script)

  • configure case (the case_setup script)

  • build case (the case_build script)

  • submit case (the case_submit script).

It is assumed that you have sucsessfully downloaded the model (see Downloading the model code), which means you have a copy of the model on your computer in a folder with a name of your choice. For simplicity we call this folder <noresm-base> in this guide.

1.1. Create a new case

The create_newcase script is an excecutable python script located in:

<noresm-base>/cime/scripts/

The script for creating a new case takes several command line arguments as input to know how to configure your case. Some of the most important arguments are as follows:

  • -case defines a casename of your choice and created a folder by that name in <noresm-base>/cases/.

  • -mach defines the machine you will run the model on. The model NorESM2 has been configured to be run on a set of different machines (see list at Running on different platforms). If you are running the model on a machine not listed you will need to configure the model beyond this newbie guide.

  • -res defines the resolution of your run. See Experiments for more details.

  • -compset defines what compset you will be using. A list of compsets for fully-coupled configurations can be found in the file <noresm_base>/cime_config/config_compsets.xml (see Atmosphere for compsets for AMIP-type simulations)

To investigate the full list of arguments, enter the <noresm_base>/cmie/scripts folder and run create_newcase with the –help argument:

  cd <noresm_base>/cime/scripts/
./create_newcase --help

To create a new case, enter the scripts directory and run the create_newcase scripts:

cd <noresm_base>/cime/scripts/
./create_newcase --case ../../cases/$CASENAME --mach $MACHINE --res f19_g16 --compset $COMPSET

You have now created the case folder <noresm_base>/cases/$CASENAME! Go to the case folder to start configuring your experiment.

1.1.1. More advanced examples

The following example creates a case (test1910_1) on the machine Fram:

./create_newcase --case ../../cases/test1910_1 --compset N1850 --res f19_tn14 --machine fram --project snic2019-1-2 --user-mods-dir cmip6_noresm_DECK

Here we use the N1850 compset, which configures the case as a 1850 pre-industrial control simulation. Note that we use the argument –run-unsupported, which required if the grid resolution is not supported in the compset (see Experiments), –project to set the id of the project used in the batch system accounting on Fram, –user-mods-dir to set the path to a folder containing files that will further configure your case (like user namelists, shell scripts with xmlchange commands or SourceMods).

The following example creates a case (also called test1910_1), but on the machine Tetralith::

./create_newcase --case ../../cases/test1910_1 --walltime 24:00:00 --compset N1850 --res f19_tn14 --machine tetralith --project snic2019-1-2 --output-root /proj/bolinc/users/${USER}/NorESM2/noresm2_out

Note that here we use the argument –output-root, which is only required if the noresm_run_dir (the running directory of the mode) differs from default running directory <path_to_run_dir>/noresm/

1.2. Configure the case

The case folder <noresm_base>/cases/$CASENAME/` is where you configure your case by changing enviroment files (such as the <noresm_base>/cases/$CASENAME/env_run.xml file;see experiment_environments), changing the user namelists for the different model components (files named user_nl_$COMP where $COMP is a model component such as cam), or even add your own code changes to SourceMods/src.$COMP/. But for now we stick to the standard out-of-the-box set up and configure the case as follows:

cd <noresm_base>/cases/$CASENAME
./case.setup

1.3. Build the case

After your configuration is finished you can start bulding your case by invoking the case.build script from your case folder:

./case.build

Which may take a while.

1.4. Submit your case

When your case has finished building you are ready to submit and run your case. This is done by invoking the case.submit script from your case folder:

./case.submit

If your model simulation was successful, you should find the following line in slurm.out (or similar) in your cse folder

Tue Feb 9 21:41:33 CET 2016 -- CSM EXECUTION BEGINS HERE Wed Feb 10 13:37:56 CET 2016 -- CSM EXECUTION HAS FINISHED
(seq_mct_drv): =============== SUCCESSFUL TERMINATION OF CPL7-CCSM ===============

And you are finished!