Parameterisation of gravity wave induced stratospheric temperature disturbances in HadGEM3-UKCA

Orographic gravity wave induced temperature disturbances of more than +/-10 K are observed in the lower stratosphere over the Antarctic Peninsula. In winter and early spring these disturbances are known to drive the formation of polar stratospheric clouds (PSCs). A new parameterisation scheme to represent these temperature disturbances has been implemented into a chemistry-climate model (HadGEM3-A+UKCA) where the impact on stratospheric ozone chemistry can be investigated. Studies indicate that the parameterised disturbances compare relatively well with satellite Atmospheric Infrared Sounder (AIRS) data and a high-resolution regional model. Realistically simulating PSCs could potentially lower model biases in Spring-time polar stratospheric ozone concentrations, and reduce uncertainty in future model projections.