setup-mom6-nci

This is a fork of Angus' mom6-ninja-nci repo, with updates to work with the latest codebase available for running MOM6 and SIS2. Unlike the original repository, there's a src folder here which contains submodules corresponding to versions of each respective piece of source code that works with the compile scripts. Previously, one needed to clone the https://github.com/NOAA-GFDL/MOM6-examples repo, but as the code here was updated parts of the compile script would break. This repo serves to keep both pieces of the puzzle (compile scripts and coressponding source code) together.

The rest of the readme is an updated version of Angus' original.

Painless shell scripts to set up a ninja build of MOM6 on NCI with Intel compilers. As prerequisites, I recommend you have the latest intel-compiler module loaded, netcdf, and a modern version of OpenMPI (4.0.x).

Setup

1. Clone this repository. Keep in mind that this directory will fill up fith objects, files and executables so putting it in scratch might be a good idea
2. Inside the setup-mom6-nci repository run git submodule update --init --recursive to pull down all of the source code
3. Run ./gen_build.sh to generate the overall config file for compiler flags (you may edit the config.ninja file afterwards to change these)
4. Make sure you have the ninja executable somewhere in your PATH

If modifying the source code

In this case you'll not want the source code on Scratch! Instead, it's easiest to move the src directory somewhere safe and replace it with a symlink ln -s path_to_src setup-mom6/src

Building FMS

The shared subdirectory is to build the FMS library against which MOM6 is linked.

1. In shared, run ./gen_build.sh to generate the build script
2. (Optional) Check build.ninja seems sensibly populated
3. Build it! Run ninja

Building MOM6

The ocean_only_symmetric subdirectory contains configuration for the ocean only (i.e. no sea ice or other coupling), symmetric C-grid, dynamic memory version of the model. Build steps are identical to FMS:

1. In ocean_only_symmetric, run ./gen_build.sh to generate the build script
2. (Optional) Check build.ninja seems sensibly populated
3. Build it! Run ninja

You now have a MOM6 executable.

Updating the source

Most of the time, you will only be tweaking MOM6 source, so only MOM6 itself needs to be rebuilt. In many cases, changes to the source won't change the dependency order, so you can just re-run ninja, which will recompile only what is necessary, as any build system would. If the dependency order is changed (usually from added use statements here and there), re-run ./gen_build.sh.

Symmetric?

This refers to the memory configuration. Symmetric means that, say, the eastward and westwards boundaries both end with a cell edge. In a nonsymmetric case, one would end with a cell edge, and the other with a cell centre. For regional configurations you need symmetric memory. If you want to change this, then simply replace symmetric with nonsymmetric where in the gen_build.sh files.