What is NEMO?

NEMO (Nucleus for European Modelling of the Ocean) is a modelling framework for oceanographic research and operational oceanography. The framework allows several ocean related components e.g. sea-ice, biochemistry, ocean dynamics, tracers etc to work either together or separately. Further information on NEMO and its varied capabilities can be found at, [1].

The NEMO framework currently consists of three components each of which (except for sea-ice) can be run in stand-alone mode. The three components are:

• OPA9 - New version of the OPA ocean model, FORTRAN90
• LIM2 - Louvain-la-Neuve sea-ice model, FORTRAN90
• TOP1 - Transport component based on the OPA9 advection-diffusion equation (TRP) and a biogeochemistry model which includes the two components LOBSTER and PISCES.

This report focuses primarily on the OPA9 component and uses a version of the NEMO code which has been modified by the National Oceanography Centre, Southampton (NOCS) researchers. The NOCS version of NEMO is essentially the release version with NOCS specific enhancements. Two different versions of NEMO are discussed, version 2.3 and version 3.0. The initial work on the project involved version 2.3 and when version 3.0 became available (autumn 2008) work continued using this version.