{ "id": "2106.07154", "version": "v1", "published": "2021-06-14T04:20:57.000Z", "updated": "2021-06-14T04:20:57.000Z", "title": "Local time stepping for the shallow water equations in MPAS-Ocean", "authors": [ "Giacomo Capodaglio", "Mark Petersen" ], "categories": [ "math.NA", "cs.NA" ], "abstract": "We assess the performance of a set of local time-stepping schemes for the shallow water equations implemented in the global ocean model MPAS-Ocean. The availability of local time-stepping tools is of major relevance for ocean codes such as MPAS-Ocean, which rely on a multi-resolution approach to perform regional grid refinement, for instance in proximity of the coast. In presence of variable resolution, the size of the time-step of explicit numerical integrators is bounded above by the size of the smallest cell on the grid, according to the Courant-Friedrichs-Lewy (CFL) condition. This constraint means that the time-step size used in low resolution regions must be the same as the one used in high resolution regions, resulting in an unnecessary computational effort. Local time-stepping, on the other hand, allows one to select different time-step sizes according to local, rather than global, CFL conditions, resulting in a more tailored integration process and reduced computational times. The present work is a preliminary but necessary effort aimed at paving the way for a more comprehensive work on local time-stepping for the primitive equation set with realistic geography.", "revisions": [ { "version": "v1", "updated": "2021-06-14T04:20:57.000Z" } ], "analyses": { "keywords": [ "shallow water equations", "local time stepping", "local time-stepping", "perform regional grid refinement", "global ocean model mpas-ocean" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }