UKESM1 is a fully-coupled Earth System model with various Earth system components, including a chemical and aerosol scheme, coupled with a physical climate model. The model has an atmospheric horizontal resolution of ~135 km (1.875 x 1.25) with 85 levels in the vertical. Further details UKESM1 can be found in Chapter 6 (Model Evaluation) of the 2021 AMAP Assessment report and also in the following publications:
Sellar et al., (2019)  J. Adv. Model. Earth Syst., 2019MS001739, doi:10.1029/2019MS001739, 2019
Archibald et al., (2020) Geosci. Model Dev., 13, 1223-1266, doi:10.5194/gmd-2019-246, 2020
Mulcahy et al., (2020) Geosci. Model Dev. Discuss., (March), 1-59, doi:10.5194/gmd-2019-357, 2020

UKESM1 data for type0 simulations was based on the atmosphere only UKESM1 configuration used for AMIP simulations in CMIP6 at N96 resolution and nudged to atmospheric wind above the boundary layer. This model configuration is a copy of the UKESM1 version used for the CMIP6 AMIP experiments, apart from using nudged meteorology and the anthropogenic emissions and CH4 concentrtions based on the ECLIPSE v6b historical scenarios. The code base used from the unified model is UM11.1

The same model configuration was used for present day type1 radiative forcing experiments.

For type3 experiments UKESM1 was run in full Earth System Model configuration with a coupled atmosphere and ocean model at N96 resolution in the atmosphere and 1 degree resolution in the ocean. This is a direct copy of the model configuration used for the SSP2-4.5 experiments in CMIP6, apart from using the anthropogenic emissions and CH4 concentrations based on the ECLIPSE v6b scenarios. The code base used from the unified model is UM11.2


Important points to note when using UKESM1 data:

- Where available please use the "... V1.nc" of any variables which supercede the original data

- Type 0 experiments were conducted from 1990 to 2015. Monthly mean data is provided for variables across this time period although specific years have higher time resolution output provided. 

- For Type1 data files the data points are monthly mean values averages over a three year period (2012-14) and as such first time point represents January mean and the last a December mean. The time dimension in the data files are not correct and should be just treated as 12 monthly means covering January to December.

- for Type 3 experiments the CLE scenarios is conducted from 2015 to 2050 and the MFR scenario is only run from 2020 to 2050 as the future 2015-2020 period is the same at the CLE sceanrio. Three ensemble members are run for each future scenraio and are initialised in 2015 from the CMIP6 UKESM1 historical experiments with the variant ID of r1i1p1f2, r2i1p1f2, r3i1p1f2.