Drivers and Impacts of Extreme Weather Events in Antarctica: Recent Results and Future Plans of the ExtAnt Project

In recent years a number of record-breaking, even record shattering, extreme weather and climate events have occurred over Antarctica. Such events can drive increased surface melt, thinning and even break-up of Antarctica’s ice shelves. They also pose threats to Antarctic species, ecosystems and the globally important services they provide. However, our knowledge and understanding of how extreme events over Antarctica may respond under climate forcing is lacking. To addresses this gap, the ExtAnt project is an ambitious four-year programme of research that brings together leading UK and international scientists to use new modelling resources and methods to elucidate drivers of extreme events in Antarctica. It aims to provide a comprehensive assessment of present day and future high impact extreme weather events in Antarctica, and associated risks. Key foci for impacts are surface melt on ice shelves and the highly specialised Antarctic biodiversity.

Recent science highlights will be presented on characteristics and drivers of extreme events and a new database of Antarctic extremes. An example of current early initial analysis relates to large ensembles, which shows that global climate models exhibit larger biases in mid-tropospheric daily meridional wind extremes at 65°S in summer (too weak) than in winter, in contrast to larger winter biases in the mean climatology. There is a fairly small, but clear, increase in the magnitude of meridional wind extremes in summer in the ozone hole period compared with the pre-ozone period. Wider implications the results so far will be discussed along with future plans for the project in downscaling (using both machine learning and traditional approaches), event attribution and surface melt modelling.