All simulations in the historical scaled aerosol emissions ensemble were conducted with a development version of the HadGEM3-GC3.1-LL global climate model at N96-ORCA1 resolution, corresponding to 135 km resolution in mid-latitudes and 1º in the ocean (Williams et al., 2018). The low-resolution version of this model (used here) is documented in Kuhlbrodt et al. (2018). Information on the representation of aerosol processes and aerosol radiative forcing in this model can be found in Mulcahy et al. (2018).

The model is related to this model: http://catalogue.ceda.ac.uk/uuid/014568b39a754538a27e25f24e7f1fca

The only difference between the model version used here and the CMIP6 version linked above is in the treatment of prescribed ozone. In the development version (used for this dataset), there is a known issue that causes stratospheric ozone concentrations to occur in the upper troposphere as the tropopause rises with warming, causing a small amount of unphysical warming. This issue has been resolved in the UK's contribution to CMIP6 (Andrews et al., 2020 under review).