Design considerations for a finite element coastal ocean model

Numerical models for flow problems must be adapted to a wide range of physical processes and a corresponding wide range of temporal and spatial scales. The large number of different models is thus not surprising because the models must be tailored to specific problem types. The design considerations presented here are aimed toward coastal ocean models. There are several fundamental choices that must be made: form of the equations, discretisation in time and space, and physics to include. Of these, choice of the specific finite element to use and advection scheme are two longstanding issues. Another pivotal issue is whether to satisfy mass continuity locally, in patches, and/or globally. The choices presented here result in a model that is applicable to a range of coastal problems from short time-scale tsunami propagation and runup, to long time-scale flows.