Extremes of Antarctic sea ice in observations and climate models
Lead supervisors: Dr Caroline Holmes, Dr Tom Bracegirdle, Prof John Turner
Location: British Antarctic Survey, Cambridge
Duration: 8 weeks
Suitable undergraduate degrees: Mathematics, Physics or Statistics
In contrast to the Arctic, satellite-based observations of Antarctic sea ice extent (SIE) since 1979 reveal a statistically significant increase before a rapid decline in 2016/17, reaching its minimum extent for the satellite era in summer 2016/7. Estimates of how Antarctic sea ice may change in the future are critical for understanding the future uptake of heat and carbon by the Southern Ocean, as well as having implications for atmospheric circulation and ecosystems. However, the majority of the latest state-of-the-art climate models used in the Coupled Model Intercomparison Project phase 6 (CMIP6) experiments simulated a decline in the satellite era. Furthermore, the models exhibit a wide range of behaviours in simulations of the past and future, challenging our ability to make reliable projections.
This project will investigate one aspect of climate model behaviour, the simulation of mimima or sudden declines in Antarctic sea ice.
To gain an understanding of the sea ice system, the student will first analyse the evolution of another record or near-record sea ice minima in the satellite record. One possibility is summer 1998/9, the season of record minimum SIE in the Weddell sea (60°W to 20°E).
Secondly, the student will have opportunity to analyse a database of regional and hemispheric CMIP6 sea ice time-series that have been generated by Caroline Holmes. The student will be encouraged to choose a small subset of models (for example the UK contributions to CMIP6, UKESM1, HadGEM3-GC31-LL, and HadGEM3-GC31-MM) in which to investigate the seasonal evolution and regional characteristics of extremes.
This analysis will contribute to ongoing work at BAS investigating the simulation of sea ice in CMIP6 models, guided by an understanding of the drivers of recent extremes.
The project will involve:
- An introduction to the literature
- An introduction to key datasets and analysis tools
- Producing a short report, and presenting the main findings of the work to the group