Stability Analysis of Interface Conditions for Ocean-Atmosphere Coupling

TL;DR

This paper investigates the stability of different interface conditions in coupled ocean-atmosphere models, crucial for climate simulations, focusing on how numerical and physical parameters influence stability.

Contribution

It provides a stability analysis of interface conditions in ocean-atmosphere coupling, highlighting the effects of parameterization and numerical strategies on model stability.

Findings

Bulk interface condition stability depends on parameterization.

Large time steps can cause numerical instability.

Dirichlet-Neumann condition stability varies with parameters.

Abstract

In this paper we analyze the stability of different coupling strategies for multidomain PDEs that arise in general circulation models used in climate simulations. We focus on fully coupled ocean-atmosphere models that are needed to represent and understand the complicated interactions of these two systems, becoming increasingly important in climate change assessment in recent years. Numerical stability issues typically arise because of different time-stepping strategies applied to the coupled PDE system. In particular, the contributing factors include using large time steps, lack of accurate interface flux, and singe-iteration coupling. We investigate the stability of the coupled ocean-atmosphere models for various interface conditions such as the Dirichlet-Neumann condition and the bulk interface condition, which is unique to climate modeling. By analyzing a simplified model, we demonstrate how the parameterization of the bulk condition and other numerical and physical parameters affect the coupling stability.