The Impact of Polar Stratospheric Clouds when Modelling the Future Recovery of the Polar Ozone Layer

The UM-UKCA (Unified Model coupled to the United Kingdom Chemistry and Aerosol module) global chemistry-climate model includes a parameterisation scheme describing stratospheric mountain-wave-induced temperature fluctuations, which is coupled to the models PSC scheme. Novel developments such as this that make interactive chemistry-climate models more physically based and comprehensive are needed to improve our ability to make accurate predictions of stratospheric ozone and reduce uncertainties in the current and future climate. The model will be used to understand the sensitivity of projections of twenty-first century stratospheric polar ozone levels and climate in both hemispheres to inclusion of realistic representation of PSCs, and especially whether the timing of the recovery of the Antarctic ozone hole (and its role in offsetting the effects of increasing greenhouse gases) is affected. The project will involve close collaboration with an ongoing complementary project between BAS, NASA, and other international partners.