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Seminar

Title : Mimetic discretization of rotating shallow water equations on arbitrary polygonal grids
Name of the speaker : John THUBURN
Affiliation : Mathematics Research Institute College of Engineering, Mathematics and Physical Sciences University of Exeter
Laboratory organizer : LMD
Date and time : 13-10-2011 14h30
Location : LMD -ENS, 24 rue Lhomond, 75005 Paris, salle E314 du Département des Géosciences
Summary :

For weather and climate models, the traditional latitude-longitude grid is expected to perform poorly on future massively parallel computer architectures. Therefore, model developers are exploring a variety of quasi-uniform alternatives, such as icosahedral and cubed sphere grids. However, accurate simulation of atmospheric dynamics requires the numerical methods to have certain properties, including accurate representation of balance, wave propagation, and conservation. Achieving these properties on exotic grids is especially challenging. Some recent progress has been made towards achieving some of these properties on Voronoi grids, which have an orthogonal dual; the resulting scheme is the basis for a new nonhydrostatic global model (MPAS) being developed at NCAR and LANL. However, there are concerns about computational modes that may be supported on Voronoi grids, and this motivates us to extend these methods to non-orthogonal grids, allowing them to be used, for example, on an equal-angle cubed sphere grid. Some progress in this direction will be presented.