Background of UKESM

Our achievements:

• Developed and released the first version of the UK Earth system model (UKESM1) in February 2019
• Run a full set of CMIP6 simulations (contributing to the IPCC AR6)
• Contributed to the development and release of the ESMValTool evaluation software.
• Developed an improved model configuration UKESM1.1

UKESM1 (Sellar 2019) is a state-of-the-art Earth system model that consists of the following component models:

• The physical global climate model HadGEM3-GC3.1 (Williams 2018, Kuhlbrodt 2019), itself composed of the Unified Model atmosphere, NEMO ocean model and CICE sea ice model.
• Atmospheric Chemistry: UKCA interactive stratospheric-tropospheric chemistry model  (Morgenstern 2009, O’Connor 2014, Archibald 2019).
• Atmospheric aerosols: UKCA-GLOMAP-mode stratosphere-tropospheric aerosol scheme (Mann 2014, Mulcahy 2020).
• Ocean biogeochemistry: MEDUSA2 intermediate complexity plankton ecosystem model Yool 2013).
• Terrestrial biogeochemistry: TRIFFID vegetation dynamics prognostic soil and vegetation carbon with nitrogen limitation (Clark 2011, Wiltshire 2020)
• Ice sheets: BISICLES land ice sheets for Antarctica & Greenland (Cornforth 2013, Smith 2020).Model components are coupled together using the OASIS3-MCT coupler (Craig 2017)