Scientist
Research, Earth System Assimilation, Coupled Assimilation
Summary:
Tsz Yan Leung is a data assimilation scientist currently working on developing new capabilities to assimilate freeboard observations for sea ice into the ECMWF model, which will better constrain the model's sea-ice thickness and snow depth over sea ice. He joined ECMWF in January 2025 with about 8 years of prior experience in numerical weather prediction-related topics, including data assimilation methodology, coupled data assimilation, ensemble forecasting and predictability studies.
Professional interests:
- Coupled data assimilation (atmosphere—ocean—sea-ice)
- Data assimilation methodology
- Ensemble forecasting, data assimilation and verification
- Predictability of the Earth system
Career background:
- April 2022 – December 2024: Scientist / Senior Scientist at the UK Met Office working on developing a new data assimilation system based on the Joint Effort for Data assimilation Integration (JEDI) framework, with a specific focus on ensemble data assimilation
- September 2020 – March 2022: Postdoctoral Research Assistant at the University of Reading (Department of Mathematics and Statistics), specialising in coupled atmosphere-ocean data assimilation for numerical weather prediction
- September 2016 – November 2020: MRes and PhD student at the EPSRC Centre for Doctoral Training (CDT) in the Mathematics of Planet Earth (MPE), joint between Imperial College London and the University of Reading
- PhD thesis (2020): Weather Predictability: Some Theoretical Considerations
- MRes thesis (2017): Role of Initial and Model Errors in the Uncertainty of Weather Forecasts
- September 2013 – June 2016: BSc (Mathematics) student at Imperial College London
- 2022
- Tsz Yan Leung, Amos S. Lawless, Nancy K. Nichols, Daniel J. Lea, Matthew J. Martin (July 2022) The impact of hybrid oceanic data assimilation in a coupled model: A case study of a tropical cyclone, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.4309
- 2021
- Tsz Yan Leung, Polly J. Smith, Amos S. Lawless, Nancy K. Nichols, Matthew J. Martin (March 2021) The role of flow-dependent oceanic background-error covariance information in air-sea coupled data assimilation during tropical cyclones: a case study. DOI: 10.5194/egusphere-egu21-3170
- Tsz Yan Leung, Martin Leutbecher, Sebastian Reich, Theodore G. Shepherd (July 2021) Forecast verification: Relating deterministic and probabilistic metrics, Quarterly Journal of the Royal Meteorological Society n. 739, pp. 3124-3134. DOI: 10.1002/qj.4120
- 2020
- Tsz Yan Leung, Martin Leutbecher, Sebastian Reich, Theodore G. Shepherd (November 2020) Impact of the Mesoscale Range on Error Growth and the Limits to Atmospheric Predictability, Journal of the Atmospheric Sciences. DOI: 10.1175/JAS-D-19-0346.1
- 2019
- Tsz Yan Leung, Martin Leutbecher, Sebastian Reich, Theodore G. Shepherd (December 2019) Atmospheric Predictability: Revisiting the Inherent Finite-Time Barrier, Journal of the Atmospheric Sciences n. 12, pp. 3883-3892. DOI: 10.1175/JAS-D-19-0057.1