Ultra-high-resolution ocean-sea ice model: a new capability to simulate shelf-ocean processes

With much focus on the local and regional changes in the ocean and marine biogeochemistry, high-resolution ocean-sea ice models became a widely desired tool for ocean research.We present analysis of the analysis of the kilometric scale resolution regional ocean model for the Arctic and North Atlantic developed at the National Oceanography Centre and aimed at resolving mesoscale circulation. The model ARC36 features NEMO ocean model coupled to the SI3 sea ice model [1].To assess model performance and demonstrate its applicability to the regional assessments, the two case studies has been chosen: (1) the Western Fram Strait and the East Greenland Shelf and (2) the Svalbard. For these areas eddy dynamics has been analysed and compared to the mooring data and satellite imagery. We have also assessed exchanges between the fjords, the shelf and the open ocean. The simulations are evident of fine structure in ocean currents and eddies, more detailed than in coarser resolution models. The model also simulates sea ice break-up at spatial scales from a few kilometres to several hundreds of kilometres, suggesting the usability of continuum sea ice models at high-resolution.This work is funded by the Natural Environment Research Council (NERC) LTS-M Programmes CANARI (NE/W004984/1) and BIOPOLE (NE/W004933/1), by UKRI/NERC HighLight Topic Projects “Interacting ice Sheet and Ocean Tipping – Indicators, Processes, Impacts and Challenges (ISOTIPIC)”, by the grant NE/Y503320/1, and by the Met Office Advancing Arctic meteorological and oceanographic capabilities & services project, which is supported by the Department for Science, Innovation & Technology (DSIT), and uses the ARCHER2 UK National Supercomputing Service (https://www.archer2.ac.uk).References[1] Rynders, S., Aksenov, Y., Coward, A., and Harle, J.: First look at Arctic eddies in a kilometric NEMO5 simulation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7121, https://doi.org/10.5194/egusphere-egu25-7121, 2025.