Ryan Williams is currently a Research Fellow in Atmospheric Dynamics at the University of Leeds, working with Prof. Amanda Maycock in the School of Earth and Environment. Ryan is investigating the role of the Northern Hemisphere strong stratospheric polar vortex during the winter 2021/22 on extratropical cyclone clustering that occurred over the North Atlantic during February 2022 as part of the NERC StratClust project. Through partnership with the Met Office, this influence is being examined by analysing a series of sub-seasonal to seasonal hindcasts, including bespoke simulations in which the stratospheric dynamics are constrained to closely match the observed state.
Ryan acquired both a BSc (Hons) in Physical Geography (2014) and MRes Science (2016) from the University of Portsmouth. In 2021, Ryan was awarded a PhD in Atmosphere, Oceans and Climate from the Department of Meteorology at the University of Reading, in producing his thesis on the regional and seasonal influences of the stratospheric contribution to tropospheric ozone. Ryan subsequently worked at ECMWF (2021) in evaluating the impact of a novel stratospheric ozone scheme upon forecast skill within their operational weather forecasting system, before working at BAS on the EU Horizon 2020 PolarRES project (2022-2023).
Whilst working at BAS, Ryan worked to construct and refine a set of climate storylines for the end-of-the-century over the Antarctic. Using of a large suite of climate models from CMIP6, plausible scenarios (storylines) were derived according to the amount of projected sea ice loss and strengthening of the stratospheric polar vortex simulated across the range of models. This approach helped to better understand the origins of the large model uncertainty across CMIP6 models and further our understanding of how climate change may manifest regionally across the Southern Hemisphere polar region.
Ryan continues to work closely with several former colleagues at BAS, particularly but not exclusively within the Atmosphere, Ice and Climate team. In particular, Ryan is working with Gareth Marshall in applying the climate storylines to assess future changes in the Southern Annular Mode and actively supporting those working within the Polar Climate and Prediction (PCAP) group. For example, his expertise in CMIP6 and its use as a climate model dataset is of help in the delivery of the BAS-led contribution to international projects such as SURFEIT.
Publications from NERC Open Research Archive
Williams, R.S., Hegglin, M.I., Jöckel, P., Garny, H., Shine, K.P.. (2024) Air quality and radiative impacts of downward-propagating sudden stratospheric warmings (SSWs). Atmospheric Chemistry and Physics, 24. 25 pp. 10.5194/acp-24-1389-2024
Williams, Ryan S., Marshall, Gareth J. ORCID record for Gareth J. Marshall, Levine, Xavier, Graff, Lise S., Handorf, Dörthe, Johnston, Nadine M., Karpechko, Alexey Y., Orr, Andrew ORCID record for Andrew Orr, Van de Berg, Willem J., Wijngaard, René R., Mooney, Priscilla A.. (2024) Future Antarctic Climate: Storylines of mid-latitude jet strengthening and shift emergent from CMIP6. Journal of Climate. 10.1175/JCLI-D-23-0122.1