Two sea ice-ocean forced modelling datasets (hindcasts and projections) were produced to analyse oceanic impacts on retreat of the Arctic sea-ice pack in the high Arctic, from areas of the Transpolar drift, north of Greenland and in the Fram Strait in the present and future climates and how those are linked to the changes in the Arctic ecosystems. The model outputs span the Arctic Ocean proper and the sub-Arctic seas, covering the near-present (2008-2021: hindcasts) and future climate (2000-2050: projections).

The forced modelling hindcasts were generated using the Global Ocean and Sea Ice GO8p7, developed under the Joint Marine Modelling Programme (JMMP), a collaboration between NOC, BAS and the UK Met Office. GO8p7 is based on NEMO v4.0 and the SI3 sea ice model and includes a package of modifications, including a scale-dependent Gent & McWilliams parameterisation, partial slip lateral boundary conditions south of 50°S and 4th-order horizontal tracer advection. The present simulation done under the ACSIS NCLTS-M programme was integrated with the Japanese 55-year atmospheric analysis JRA55 (v1.3-do) from 1958 to 2021. The monthly and 5-day averages of the key sea-ice and ocean fields for the pan-Arctic and Greenland regions were created and combined into 4-D files for easy data handling.

The forced modelling projections were generated using the NEMOv4.2-SI3 common NOC-UK MetOffice configuration (G8.7) coupled to the MEDUSA ecosystem model. The forcing fields were from the UK ESM1.1 model SSP370 integrations. Monthly averages of the key sea-ice, ocean and biogeochemical fields for the pan-Arctic and Greenland regions for the end of each of the decades 2020, 2030, 2040, and 2050 were created and combined into 4-D files for easy data handling.

The sea ice model output for both datasets were validated against the AMSR-E satellite sea-ice concentrations, as well as the CryoSat-2 and SMOS sea-ice thickness datasets. These data were produced by National Oceanography Centre (NOC) scientists under Natural Environment Research Council (NERC) project PRE-MELT (grant references NE/T001399/1, NE/T000260/1, NE/T000546/1).

Additional funding also came from NERC projects APEAR (grant reference NE/R012865/1), ARISE (grant reference NE/P006000/1), and Arctic PrIZE (grant reference NE/P006078/1), funded under the NERC/BMBF Changing Arctic Ocean Programme, from NERC NCLTS-M programmes ESM (grant reference NE/N018036/1) and ACSIS (grant reference NE/N018044/ 1). and from NCLTS-S programme CLASS (grant reference NE/R015953/1), from the European Commission grant CRESCENDO (grant no. 641816) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement 820989 (Project COMFORT—Our common future ocean in the Earth system - quantifying coupled cycles of carbon, oxygen, and nutrients for determining and achieving safe operating spaces with respect to tipping points).