The dataset is a 40 year control run of a NEMO-based 1/12 degree grid spacing model of the Southern Ocean as part of the ORCHESTRA (Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports) LTS-M project. It uses the NEMO "extended" grid, although ice cavities are closed. The model was run on Archer, the national HPC platform. The dataset covers the full length of the model run and includes regular (5 day mean) output of the model state, as well as more frequent (1 day mean) output of surface variables and fluxes and 1 month mean of more extensive transport diagnostics. This is the second of two control runs and was initialised from the end of the 30th year (nominally 1978) of CORE2NYF (Munday et al., 2021), a 3+37 year control run forced with CORE2 (corrected normal year forcing version 2.0) normal year forcing.

Forced by JRA55-do, an interannually-varying forcing set (Tsujino et al., 2018). With some additional forcing as supplied by the UK Met Office (freshwater runoff, tidal friction, geothermal heating) and additional freshwater runoff to suppress polynya formation.