An alternative coordinate system for solving finite difference ocean models

An alternative ‘compressed’ coordinate system for representing finite difference grids in ocean models is presented and compared with the traditional Cartesian method. The alternative method represents any arbitrary three-dimensional domain as a one-dimensional vector. Advantages of using this method include the exclusion of all land ‘dry’ points from the computational grid, leading to savings in the memory used and increased execution speed where domains have a low ratio of wet to total computational cells. The Cartesian and compressed models are applied to a variety of domains to assess the performance of each in terms of memory use and computational speed.