Efficient and scalable atmospheric dynamics simulations using non-conforming meshes

TL;DR

This paper introduces a highly scalable, parallel atmospheric simulation method using non-conforming mesh refinement, Discontinuous Galerkin discretization, and IMEX-RK time stepping, improving local flow accuracy without sacrificing performance.

Contribution

The paper presents a novel massively parallel atmospheric simulation approach combining non-conforming mesh refinement with DG and IMEX-RK methods, enhancing accuracy and scalability.

Findings

Non-conforming mesh refinement improves local flow accuracy.

The method maintains high parallel performance with local mesh refinement.

Scalability is achieved without performance degradation.

Abstract

We present the massively parallel performance of a $h$-adaptive solver for atmosphere dynamics that allows for non-conforming mesh refinement. The numerical method is based on a Discontinuous Galerkin (DG) spatial discretization, highly scalable thanks to its data locality properties, and on a second order Implicit-Explicit Runge-Kutta (IMEX-RK) method for time discretization, particularly well suited for low Mach number flows. Simulations with non-conforming meshes for flows over orography can increase the accuracy of the local flow description without affecting the larger scales, which can be solved on coarser meshes. We show that the local refining procedure has no significant impact on the parallel performance and, therefore, both efficiency and scalability can be achieved in this framework.