An external view of the Met Office building at night.

Dr John Hemmings

Areas of expertise

  • Software development
  • Environmental modelling
  • Data assimilation in biogeochemical modelling
  • Ocean data analysis

Publications by John Hemmings

Current activities

John is carrying out development work aimed at improving the representation of aerosols in weather forecast and climate models. Current work focuses on technical developments to UKCA - a community atmospheric chemistry and aerosol model - in preparation for implementing a unified aerosol modelling approach at all scales within LFRic - the next generation replacement for the Unified Model. The aerosol component of UKCA is GLOMAP-mode and related work includes the development of a testbed for performing detailed analyses, inter-comparison and calibration of different GLOMAP-mode aerosol parameterizations in a single column framework.

Career background

With a BSc in Computer Science and Cybernetics, John started his career in the software industry, working as a developer in the transport and defence sectors. He then joined a biogeochemical modelling team at the Institute of Oceanographic Sciences in 1990, where he worked as a data analyst. During this time, he carried out research on the role of bio-physical interactions in determining spatial variability in the spring phytoplankton bloom, leading to a PhD in Oceanography in 1999. Subsequently, he specialized in the application of data assimilation and uncertainty quantification techniques to marine biogeochemistry models at the National Oceanography Centre.

John’s post-doctoral research focused primarily on investigating ways of using satellite data to improve marine ecosystem models and their state estimates. A particular goal was to improve the representation of the carbon cycle in ocean and Earth system models with a view to better understanding its role in global change. Data assimilation research included collaborative work with the Met Office to develop an assimilation scheme for improving estimates of air-sea carbon dioxide flux and with the National Centre for Earth Observation to develop new methods and software for calibrating biogeochemistry models in the presence of uncertainty in their environmental drivers.

John joined the Met Office’s Atmospheric Dispersion and Air Quality group as a software engineer in 2015, where he worked on the development, maintenance and evaluation of modelling systems for UK air quality forecasting before moving to the Atmospheric Processes and Parametrizations group in 2018.