Mass-conserving implicit-explicit methods for coupled compressible Navier-Stokes equations

Earth system models are composed of coupled components that separately model systems such as the global atmosphere, ocean, and land surface. While these components are well developed, coupling them in a single system can be a significant challenge. Computational efficiency, accuracy, and stability are principal concerns. In this study we focus on these issues. In particular, implicit-explicit (IMEX) tight and loose coupling strategies are explored for handling different time scales. For a simplified model for the air-sea interaction problem, we consider coupled compressible Navier-Stokes equations with an interface condition. Under the rigid-lid assumption, horizontal momentum and heat flux are exchanged through the interface. Several numerical experiments are presented to demonstrate the stability of the coupling schemes. We show both numerically and theoretically that our IMEX coupling methods are mass conservative for a coupled compressible Navier-Stokes system with the rigid-lid condition. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Earth system models consist of coupled components modeling systems like the global atmosphere, ocean, and land surface. This study focuses on the challenges of coupling these components, including computational efficiency, accuracy, and stability, exploring tight and loose coupling strategies for handling different time scales. Numerical experiments demonstrate the stability and mass conservation of the coupling schemes in a simplified model for the air-sea interaction problem with compressible Navier-Stokes equations.