# OpenIFS AMIP runs ## Background OpenIFS 40r1 is based on IFS from ECMWF. Simply put, it is the atmosphere forecast model in IFS, i.e. without data assimilation, ocean model, parallel I/O server etc. OpenIFS is available to those with a license and GEOMAR has an institute-wide license. OpenIFS is run with ESM-Tools. Therefore, you must first install ESM-Tools before installing OpenIFS. ESM-Tools is a set of scripts that will take care of compiling code, fetching input data, processing output data, and restarting the model. ## How to install First, obtain ESM-Tools ```bash module load git git clone https://<yourdkrzusername>@gitlab.dkrz.de/esm-tools/esm-tools.git cd esm-tools ./install.sh ``` Then you need to switch to the "focioifs" branches ```bash cd esm-master git checkout focioifs cd esm-runscripts git checkout focioifs cd ../esm-environment git checkout focioifs cd .. ``` Now you are ready to compile. ESM Tools may ask you to input your DKRZ username and password. It will also ask you where simulations should be stored. ```bash make get-oifscl make comp-oifscl ``` ## How to run a first test (on HLRN-IV "Emmy") With the model compiled, you should now create a directory where you store your runscripts, and then copy a standard runscript from ESM-Tools which you can modify later. The example is for HLRN-IV Emmy, but you only need to modify the runscript slightly to make it work on DKRZ Mistral or JSC JUWELS. ```bash mkdir my_runscripts cp esm-runscripts/runscripts/oifscl/oifscl_t159_initial_monthly_hlrn4.run my_runscripts/. cd my_runscripts ``` Have a look at the runscript you just copied. It will run a 1 month test on HLRN4 using 7 compute nodes (280 cores) and run a postprocessing job after completion. Make sure the FUNCTION_PATH, MODEL_DIR, BASE_DIR and the NAMELIST_DIR further down all point to the right places. Now you can test the runscript ```bash ./oifscl_t159_initial_monthly_hlrn4.run -e oifs_test_1 -U -c ``` This will set up a run named "oifs_test_1", but will not submit a job (the -c flag). Make sure this runscript completes without errors. You may find that "cf_table" or "t159_red.txt" are missing. This is fine. Then run ```bash ./oifscl_t159_initial_monthly_hlrn4.run -e oifs_test_1 -U ``` If you store stuff in the standard places you will find the output in ```bash /scratch/usr/${USER}/esm-experiment/oifs_test_1/outdata/oifs/ ```