Moisture with Gusto: towards moist shallow water test cases using the Gusto dynamical core toolkit

The shallow water equations are widely used in the development of weather and climate models, being computationally cheap while still retaining many pertinent features of atmospheric dynamics. The usual shallow water equations, however, model a ‘dry’ atmosphere and so neglect moist processes and moisture effects. Including moisture in the shallow water system offers a framework in which to develop more challenging test cases for parallel time-stepping schemes, arising through numerical complexities that moisture introduces and relevant because of changing trends in supercomputer architectures necessitating interest in parallel-in-time. This talk will discuss the implementation of moist shallow water models in the dynamical core toolkit Gusto, which mirrors the compatible finite element approach being taken in the next-generation UK Met Office model. We will highlight the advantages Gusto offers for rapid prototyping and flexible implementation of different moist shallow water models and describe progress towards running moist shallow water tests cases (both from the literature and newly-devised for this purpose) in Gusto.