BLOM: Bergen Layered Ocean Model

This is the source code of BLOM and includes the ocean biogeochemistry model iHAMOCC. BLOM is the ocean component of the Norwegian Earth System Model (https://github.com/NorESMhub/NorESM).

BLOM documentation

BLOM documetation is integrated in the general NorESM documentation on ReadTheDocs (https://noresm-docs.readthedocs.io/en/noresm2/).

Building the code with meson

When compiling BLOM with NorESM, the NorESM build system should be used. A stand-alone BLOM executable can be built by using the meson build system. To build the code ensure that Meson is available. The following will build the default version of BLOM without MPI.

$ meson setup builddir --buildtype=debugoptimized
$ meson compile -C builddir

The executable blom file will then be stored in the ./builddir directory.

The code has several different configuration options setup in meson_options.txt which can be specified either when setting up or through meson configure.

To change the configuration, after meson setup, use meson configure. E.g. to enable MPI and parallel NetCDF one could reconfigure the build by

$ meson configure builddir -D mpi=true -D parallel_netcdf=true
$ meson compile -C builddir

The same configuration when setting up would be

$ meson setup builddir --buildtype=debugoptimized -D mpi=true -D parallle_netcdf=true
$ meson compile -C builddir

Changing compiler

To change the compiler one must define the FC (Fortran compiler) and CC (C compiler) environment variables. As an example, the following changes the compiler suite to the Intel compilers.

$ CC=icc FC=ifort meson setup builddir --buildtype=debugoptimized
$ meson compiler -C builddir

After the first line all subsequent compiles (and changes with meson configure) will utilize the Intel compiler to build and link BLOM.

Running tests

After successfully building the code it can be a good idea to test that the code behaves as expected and changes to the code does not affect the output.

Tests can be run with the following:

$ meson test -C builddir

The previous command will run all the test suites defined for BLOM. To run tests quicker one can select a few tests to run or just a single test suite. To list the available tests run meson test -C builddir --list. One can then run a single test with:

$ meson test -C builddir "run single_column"

Working with the BLOM git repository

The BLOM wiki includes instructions on how to contribute to the BLOM/iHAMOCC model system, and how to work with the BLOM git repository with your own fork on gitHub.

License

BLOM is licensed under the GNU Lesser General Public License - see the COPYING and COPYING.LESSER files for details.