Our Aims

Conférence des Nations Unies sur les changements climatiques – COP21 (Paris, Le Bourget)

The UKESM project is charged with developing, and applying UK Earth system models (UKESM) and providing user support for these models to the wider NERC/academic community.

UKESM project aims are:

  • To apply UKESM1 to investigate a range of Earth system phenomena  and their sensitivity to future anthropogenic forcing
  • To scientifically evaluate and document the performance of UKESM1
  • To analyze and document UKESM1 future projections
  • To provide science-based guidance on future Earth system change
  • To provide the tools and user support for UK Earth system modelling research
  • To initiate the development of a future UKESM2 model

Structure and collaboration

UKESM1 has the global climate model HadGEM3 as its core, coupling in component models for:

Atmospheric Chemistry: UKCA interactive stratospheric-tropospheric chemistry including trop. isoprene chemistry (Morgenstern 2009, O’Connor 2014).

Atmospheric aerosols: UKCA-GLOMAP-mode, 2-moment, 5 species, 4-mode, stratosphere-tropospheric aerosol scheme (Mann 2014).

Ocean biogeochemistry: MEDUSA2 intermediate complexity plankton ecosystem model (including prognostic DIC, alkalinity, dissolved O2, detritus carbon with variable C:N) (Yool 2013).

Terrestrial biogeochemistry: TRIFFID vegetation dynamics (9 PFTs), prognostic soil carbon, Nitrogen-limitation scheme, diagnostic wildfire, improved permafrost treatment and wetland CH4 emission.

Ice sheets: BISICLES land ice sheets for Antarctica & Greenland (Cornforth 2013).

Diagram of UKESM component models

The UKESM project works closely with other NERC Long-term Science, Multi-centre (LTSM) projects concerned with global climate and Earth system change. In particular:

  • ACSIS (climate processes and predictability over the North Atlantic),
  • ORCHESTRA (carbon and heat uptake in the Southern Ocean) and
  • LOCATE (developing estimates and understanding of terrestrial carbon fluxes into the ocean).

Collaboration focuses on the provision of UKESM1 models and simulation data to these projects for advanced scientific analysis and conversely, the use of observations and process-understanding developed in these projects for analysis of UKESM1 and development of UKESM2.

We work closely with the Horizon 2020 project CRESCENDO, coordinated by the UKESM coordinator. CRESCENDO involves 7 European ESMs targeting improved representation and evaluation of biogeochemical and aerosol processes in ESMs.

We collaborated with the H2020 project PRIMAVERA (coordinated by MOHC) investigating the benefits of increased resolution in physical climate models, with project findings guiding the planning of UKESM2.

International collaboration is also through established links focusing on key CMIP6 experiments. Such cooperation facilitates the sharing of models, evaluation metrics and data sets, which helps to increase the productivity of the UKESM project.

Science and research themes

The UKESM project is structured into 5 Research Themes:

RT1 finalises development and release of UKESM1, including user support. RT1 will also carry out CMIP6 experiments that form the basis for the science objectives of the project.

RT2 emphasizes evaluation of UKESM1, performed both at the process-level (RT2.1), and for the fully coupled ESM (RT2.2).

RT3 emphasizes scientific analysis of Earth system projections, including investigation of emergent constraints to reduce uncertainty in future feedbacks.

RT4 develops the component models for future UKESM.

RT5 targets improvement of fully coupled versions of UKESM.

Planned resolutions of UKESM1:

  • UKESM1-N216ORCA025: 60km atmosphere, ¼° ocean
  • UKESM1-N96ORCA1: 130km atmosphere, 1° ocean
  • UKESM1-N216ORCA025hybrid

The following diagram shows how the research themes contribute to the development of the UK Earth System Modelling project and collaboration with other relevant organisations.