Numerical simulation of large-scale ocean circulation based on the multicomponent splitting method

Abstract

The problem of mathematical modelling of the baroclinic dynamics of the World Ocean and its large areas is considered. The mathematical model has been developed at the Institute of Numerical Mathematics RAS (INMRAS) and is based on the equations of general circulation represented in the generalized σ-system of coordinates with a free surface in the hydrostatics and Boussinesq approximation. The computational solution technique for this problem is based on multicomponent splitting and has a flexible, hierarchically scalable modular structure. The main ‘cycle’ is the decomposition of a complicated system of equations into a series of large and energetically balanced subsystems called modules, according to physical processes. The complete numerical model is determined by the set of split subsystems and approximate the original model with some order of time accuracy. Along with the solution of direct prognostic problems, the method of multicomponent splitting can be efficiently used for solution of four-dimensional problems of observation data variational assimilation. The computing methodology is illustrated by several problems of large-scale ocean circulation, including the problem with four-dimensional variational initialization of hydrophysical fields.