Knowledge Base

openIFS@Reading

Introduction

The ECMWF OpenIFS programme provides an easy-to-use, exportable version of the IFS in use at ECMWF for operational weather forecasting. For more information about the model itself, please visit the ECMWF OpenIFS website.

If you want to start using the OpenIFS on the Reading Academic Computing Cluster (RACC), please follow the instructions below. You don’t need to install it from source code from ECMWF, there is a pre-configured version available on the RACC already.

Join our OpenIFS mailing list to receive updates on OpenIFS@Reading progress and to post to the OpenIFS users group.

 

Obtaining and compiling the OpenIFS on the Reading Academic Computing Cluster (RACC)

Once you’re logged in to the RACC  (see here how to do this), you’ll need to download a few scripts to acquire, compile and run OpenIFS. You can copy those from the following location:

The 3 scripts in the above directory are:

get_oifs.sh – This downloads the OpenIFS model code and a sample experiment setup.

setup_oifs – This sets up your OpenIFS model environment.

compile_oifs.sh – This compiles your model code.

These scripts need to be run in succession. Make sure you are not in your home directory when you run these. An OpenIFS model run needs quite a bit of space and the storage platforms for the home directories are not designed to store the input to or output from jobs running on the cluster as this type of usage can cause problems when you fill your home directory up.

First, execute get_oifs.sh:

This will download the model code along with an example configuration which you can use to check if your setup is working. Next, the shell environment needs to be set up. To do this, type:

You should see a screen message displaying the currently loaded modulefiles, as well as some important OpenIFS directory paths that are set up with the above command.

Now you can compile the model by executing the compile_oifs.sh script. You should only need to do this once if you’re not making changes to the source code.

You will see a long sequence of messages as each piece of code is compiled in turn. This may take a little while and as long as messages keep scrolling though then all is fine. At the end you should see a few summary lines telling you how successful the compilation was. If you see failed=0 in there for all occasions then the compilation worked.

 

Running the test example

First, navigate to the experiment directory. It was created where you ran the get_oifs.sh script.

In there, you’ll see 2 scripts which you need to run the model:

ifs_job.sh – This contains all the options necessary to run the model.

submit_job.sh – This submits your model to the job queue to run on the cluster.

You will need to edit ifs_job.sh and change the variable OIFS_EXPDIR to the path of the directory you’re currently in (the experiment directory). No other settings need to be changed to run this test example. The default setup is the ‘giq5’ experiment with a 255 resolution number. It runs the model executable ‘master.exe’ (compiled with compile_oifs.sh in oifs_model/make/gnu-opt/oifs/bin/) with a timestep of 3600s on 12 processors for a forecast length of 2 days. It will save the results in a directory called output_1 for the first run. For subsequent runs you should change the OIFS_RUN number so that the results don’t get overwritten.

You’re now ready to run the model! Simply execute the submission script:

This submits your model to the batch queue on the cluster. You can track the progress of the job via the logfile (myout.txt in this example) that is created in the directory you’re in. You can check the status of the job on the cluster with the ‘queue’ command (see the RACC User Guide for further info.)