Non-orthogonal version of the arbitrary polygonal C-grid and a new diamond grid

Weller, H. ORCID: https://orcid.org/0000-0003-4553-7082 (2013) Non-orthogonal version of the arbitrary polygonal C-grid and a new diamond grid. Geoscientific Model Development, 7. pp. 779-797. ISSN 1991-959X doi: 10.5194/gmd-7-779-2014

Abstract/Summary

Quasi-uniform grids of the sphere have become popular recently since they avoid parallel scaling bottle- necks associated with the poles of latitude–longitude grids. However quasi-uniform grids of the sphere are often non- orthogonal. A version of the C-grid for arbitrary non- orthogonal grids is presented which gives some of the mimetic properties of the orthogonal C-grid. Exact energy conservation is sacrificed for improved accuracy and the re- sulting scheme numerically conserves energy and potential enstrophy well. The non-orthogonal nature means that the scheme can be used on a cubed sphere. The advantage of the cubed sphere is that it does not admit the computa- tional modes of the hexagonal or triangular C-grids. On var- ious shallow-water test cases, the non-orthogonal scheme on a cubed sphere has accuracy less than or equal to the orthog- onal scheme on an orthogonal hexagonal icosahedron. A new diamond grid is presented consisting of quasi- uniform quadrilaterals which is more nearly orthogonal than the equal-angle cubed sphere but with otherwise similar properties. It performs better than the cubed sphere in ev- ery way and should be used instead in codes which allow a flexible grid structure.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/35337
Identification Number/DOI	10.5194/gmd-7-779-2014
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Copernicus
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