Coupling atmospheres and oceans with OASIS3
Climate modelling has advanced greatly over the past few decades as computing power has grown rapidly. Yet modelling the Earth's climatic system remains a complicated affair. Interactions between several different systems, namely the atmosphere and oceans but also the biosphere, must be taken into account. The climate modelling community addresses this complexity by coupling together separate atmospheric, ocean and chemical models. Proper management of the fluxes of energy, heat, water vapour and chemical species between the various realms is critical. Interpolating between the various time and space scales of the component models is another challenge. The European Centre for Research and Advanced Training in Scientific Computation (CERFACS) developed the OASIS3 coupler and tested it in the framework of the PRISM project. OASIS3 was put to the test with a toy-coupled model, TOYCLIM, stripped of all physics but producing realistic results nonetheless. OASIS3 was designed to take advantage of the PRISM System Model Interface Library (PSMILe), helping streamline communication with TOYCLIM. CERFACS was able to compile and run the OASIS3/TOYCLIM combination on a wide variety of machine configurations, demonstrating its platform-independence. As the spirit of PRISM was to share expertise among the modelling community, CERFACS composed and published a guide for the OASIS3 coupler. The PRISM TOYCLIM Coupled Model Adaptation Guide contains valuable information that will support climate modellers looking to couple their own component models with OASIS3.
