A GLOBAL OCEAN MESH TO OVERCOME THE NORTH-POLE SINGULARITY

A semi-analytical method is presented for constructing a global orthog onal curvilinear ocean mesh which has no singularity point inside the computational domain since the mesh poles are moved to land points. Th e method involves defining an analytical set of mesh parallels in the stereographic polar plan, computing the associated set of mesh meridia ns, and projecting the resulting mesh onto the sphere. The set of mesh parallels proposed here is defined as a series of embedded circles. T he resulting mesh presents no loss of continuity in either the mesh li nes or the scale factors over the whole ocean domain, as the mesh is n ot a composite mesh. Thus, the Bering Strait can be opened without spe cific treatment. The equator is a mesh line, which provides a better n umerical solution for equatorial dynamics. The resolution can be easil y controlled through the definition of three analytical functions whic h can increase resolution and/or maintain a low ratio of anisotropy. T he mesh has been implemented in the LODYC general circulation ocean mo del. Results of a semi-diagnostic simulation are shown.