Ryan Williams is currently a Polar Atmospheric Scientist, working on the NERC-funded ExtAnt project.

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 on PolarRES, 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.

Before starting on ExtAnt, Ryan worked in the Institute for Climate and Atmospheric Science at the University of Leeds. He investigated 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 was 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.

Research interests

Atmospheric Dynamics

Climate Change

Extreme Events

Stratosphere-Troposphere Coupling

Chemistry-Climate Interactions

Polar Meteorology

Publications from NERC Open Research Archive

2026

Marshall, Gareth ORCID record for Marshall, Gareth. Williams, Ryan ORCID record for Williams, Ryan. Graff, Lise. Handoff, Dörthe. Karpechko, Alexey. Köhler, Raphael. Levine, Xavier. Orr, Andrew ORCID record for Orr, Andrew. Mooney, Priscilla. (2026) The Southern Annular Mode and its relationship with Antarctic temperature in contrasting future storylines.

Graff, Lise seland. Landgren, Oskar A. Parding, Kajsa M. Levine, Xavier. Williams, Ryan S. ORCID record for Williams, Ryan S.. Mooney, Priscilla A. (2026) Selecting CMIP6 Models for Future Arctic Storylines Using a Novel Performance Score.

2025

Williams, Ryan S. ORCID record for Williams, Ryan S.. Maycock, Amanda C. ORCID record for Maycock, Amanda C.. Charnay, Vincent. Knight, Jeff ORCID record for Knight, Jeff. Polichtchouk, Inna. (2025) Strong polar vortex favoured intense Northern European storminess in February 2022.

Athanase, Marylou. Köhler, Raphael. Heuzé, Céline. Lévine, Xavier. Williams, Ryan ORCID record for Williams, Ryan. (2025) The Arctic Beaufort Gyre in CMIP6 Models: Present and Future.

2024

Levine, Xavier J. Williams, Ryan S. ORCID record for Williams, Ryan S.. Marshall, Gareth ORCID record for Marshall, Gareth. Orr, Andrew ORCID record for Orr, Andrew. Seland Graff, Lise. Handorf, Dörthe. Karpechko, Alexey. Köhler, Raphael. Wijngaard, René R. Johnston, Nadine ORCID record for Johnston, Nadine. Lee, Hanna. Nieradzik, Lars. Mooney, Priscilla A. (2024) Storylines of summer Arctic climate change constrained by Barents–Kara seas and Arctic tropospheric warming for climate risk assessment.

Williams, R.S. ORCID record for 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).

Williams, Ryan S. ORCID record for Williams, Ryan S.. Marshall, Gareth J. ORCID record for Marshall, Gareth J.. Levine, Xavier. Graff, Lise S. Handorf, Dörthe. Johnston, Nadine M. ORCID record for Johnston, Nadine M.. Karpechko, Alexey Y. Orr, Andrew ORCID record for Orr, Andrew. 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.

First Author

• Williams, R. S., Hogan, R. J., Polichtchouk, I., Hegglin, M. H., Stockdale, T. & Flemming, J. (2021). Evaluating the impact of prognostic ozone in IFS NWP forecasts. ECMWF Technical Memorandum, 887, 10.21957/rakfo1qo3.
• Williams, R. S., Hegglin, M. I., Kerridge, B. J., Jöckel, P., Latter, B. G. & Plummer, D. A. (2019). Characterising the seasonal and geographical variability in tropospheric ozone, stratospheric influence and recent changes. Atmospheric Chemistry and Physics, 19(6), 3589-3620, doi:10.5194/acp-19-3589-2019.

Co-Author

• Levine, X., Williams, R., Marshall, G., Orr, A., Seland Graff, L., Handorf, D., Karpechko, A., Köhler, R., Wijngaard, R., Johnston, N., Lee, H., Nieradzik, L., and Mooney, P. (2023). Storylines of Summer Arctic climate change constrained by Barents-Kara Sea and Arctic tropospheric warming for climate risks assessment, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2023-2741.
• Pepin, N. C., Pike, G., Read, S. & Williams, R. (2019). The ability of moderate resolution imaging spectroradiometer land surface temperatures to simulate cold air drainage and microclimates in complex Arctic terrain. International Journal of Climatology, 39(2), 953-973, doi:1002/joc.5854.
• Pepin, N. C., Maeda, E. E. & Williams, R. (2016). Use of remotely sensed land surface temperature as a proxy for air temperatures at high elevations: Findings from a 5000 m elevational transect across Kilimanjaro. Journal of Geophysical Research: Atmospheres, 121(17), 9998, doi:1002/2016JD025497.
• Williams, R. & Thorp, T. (2015). Characteristics of springtime nocturnal temperature inversions in a high latitude environment. Weather, 70(S1), S37-S43, doi:1002/wea.2554.

8. Polar regions in the Earth system

   PolarRES investigates polar climate processes in the Arctic and Antarctic, improving global climate projections and reducing uncertainties to better assess environmental and social impacts.

   Read more of: Polar regions in the Earth system

   

ExtAnt

Investigating drivers and impacts of Antarctic weather extremes on the NERC-funded ExtAnt project. The project aims to exploit multiple datasets (in situ, reanalysis and model simulations) and statistical approaches to help understand the characteristics of extreme weather events (e.g., atmospheric rivers) both in the present-day and future climate. Cross-scale linkages will be examined on timescales ranging from hours to multi-decadal. A key focus is understanding how the localised (<15 km) evolution of extreme events, particularly over key vulnerable ice shelves along the coastal margin, relates to large-scale processes (e.g., teleconnections with remote regions such as the tropical Pacific).

• ECR Board Member, Wiley: Meteorological Applications (RMetS Journal)