Glaciology and climate modelling

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This project will investigate the future trends in surface melt in Antarctica, exploring the drivers and impacts of such trends through the utilization of cutting-edge ESMs. Research to date indicates that the Antarctic Ice Sheet (AIS) has the potential to contribute up to 58 m to global sea level rise if it were to melt entirely (Morlighem et al., 2020). The AIS is fringed by ice shelves along three-quarters of its perimeter and while iceberg calving from these shelves or ice shelf collapse do not directly contribute to sea level rise, they play a critical role in buttressing glacier flow from the AIS, making it essential to reduce uncertainties surrounding their future to predict global sea level rise accurately (Mitcham et al., 2022).Satellite observations have revealed recent instabilities and calving events in the Antarctic ice shelves, signalling ongoing changes in the region (Fyke et al., 2018). Currently, melting driven by rising ocean temperatures stands as the primary driver of ice shelf instability (Holland et al., 2008). However, as global temperatures continue to increase, surface melting is expected to play an increasingly significant role in ice shelf instability, driven by surface meltwater-induced instability and hydro fracture, potentially exacerbated by surface albedo feedbacks (Banwell et al., 2023; Gilbert & Kittel, 2021). Recent advances in ESMs offer a promising avenue for enhanced simulations of future trends over Antarctica, with capability of conducting long-term simulations extending to 2500 and beyond to capture the complex dynamics of key atmospheric processes that influence surface air temperature and, consequently, surface melting in the region. The UKESM incorporates an interactively coupled ice sheet model which provides potential for enhanced investigation of atmosphere-cryosphere interactions and feedbacks (Smith et al., 2021).Reliably predicting the future trends of surface melt in Antarctica requires the accurate representation in ESM models of key atmospheric circulation features in the region, such as the Southern Annular Mode (SAM), the circumpolar westerly winds, and the Amundsen Sea Low (ASL) (Hosking et al., 2016; Saunderson et al., 2024). Improved understanding of these key atmospheric circulation features and how they impact surface melting dynamics is necessary to clarify which ice shelves are susceptible to instability and rapid changes in the future.