OASIS coupler is a software allowing synchronized exchanges of coupling information between numerical codes representing different components of the climate system. Current OASIS developers are CERFACS (Toulouse, France) and Centre National de la Recherche Scientifique (Paris, France).

OASIS3-MCT, the version of the OASIS coupler interfaced with the Model Coupling Toolkit (MCT) from the Argonne National Laboratory, offers today a fully parallel implementation of coupling field regridding and exchange. Low-intrusiveness, portability and flexibility are OASIS3-MCT key design concepts as for all previous OASIS versions. OASIS3-MCT is a coupling library that needs to be linked to the component models, with the main function of interpolating and exchanging the coupling fields between these components.

OASIS3-MCT supports coupling of general two-dimensional fields. Unstructured grids and 3D grids are also supported using a one dimension representation of the two or three dimensional structures.