A 200-year present-day control simulation (for the year 2000) has been downscaled with the shelf seas climate version of the Nucleus for European Modelling of the Ocean (NEMO) Coastal Ocean model (CO6), and we refer to the downscaled present-day control simulation as PDCtrl. The Met Office Global Coupled model version 3.05 (HadGEM3-GC3.05) was run for 200 years with the atmospheric constituents fixed to the values of the year 2000. The present-day control simulation provides an estimate of the unforced internal variability in the climate system that can arise in the absence of time-varying external forcings. The PDCtrl simulation was performed as part of the United Kingdom’s Climate Projections of 2018 (UKCP18) with full details available in Tinker et al. (2020). CO6 was run at a 7 km resolution, with 51 vertical levels using s-coordinates. This data collection includes 2D fields of monthly mean output for the full period, as well as regional mean time series for the full 200 year period.

NEMO has three model grids, the T, U and V grids, and we output variables in three files, respecting their native model grid. In practice, all our variables are on the T grid, apart from the Eastward and Northward components of the depth mean velocities (DMU, DMV), which are in the U and V grid files respectively. The T grid files have Sea Surface, Near Bed, and the Difference between the surface and bed Temperature and Salinity (SST, NBT, DFT, SSS, NBS, DFS), Potential Energy Anomaly (PEA), Mixed Layer Depth (MLD), the barotropic current magnitude interpolated onto the T grid (DMUV).