Different transformations and 2D interpolations are available in OASIS3 to adapt the coupling fields from a source model grid to a target model grid. They are divided into five general classes that have precedence one over the other in the following order: time transformation (with CLIM/MPI1-MPI2 communication technique only), pre-processing, interpolation, ``cooking'', and post-processing. This order of precedence is conceptually logical, but is also constrained by the OASIS3 software internal structure.
In the following paragraphs, it is first described how to use OASIS3 in an interpolator-only mode. Then a description of each transformation with its corresponding configuring lines is given.