Overview of SCM Coupler and Its Application for Constructing Climate Models

Abstract

Numerical modeling is one of the leading research tools for the climate problems. Among numerical models, researchers use, in particular, coupled models, that are numerical models describing more than one climate component dynamics and their interactions. The simulation results with such models depend on the way how these interactions are configured. Therefore, a proper configuration of the exchanges is crucial. The software called a “coupler” is often used to configure these interactions. The coupler is most helpful if the model components are independent of each other modules, their number exceeds two, and they have their own computational grid and time integration step. Key functions of the coupler are managing data exchange between models, setting up synchronous interaction between them based on the time integration step, and interpolating data from one model’s computational grid to the other model’s grid. Additional functions can also be implemented, e.g., fluxes computation between model components, data assimilation, working with the file system, etc. The coupler has one crucial feature: if there is a set of different models of climate system components, one can construct new coupled models by coupling various subsets of these components with coupler. This paper gives an overview of the SCM (SibCIOM Coupling Module) coupler we first developed for the model SibCIOM (Siberian Coupled Ice and Ocean Model). The description of this coupler has not been published before. The SCM coupler is a separate module to which the main climate system model component, such as atmospheric, oceanic, sea ice and land components, can be attached. Additional functions of this coupler include computation of atmosphere-to-ocean and atmosphere-to-ice fluxes and ocean and sea ice state correction using a tidal model. This paper also gives examples of two models constructed with the SCM coupler.