The model employs a regular grid in the horizontal with 2.5km resolution, and an irregular topography-following vertical coordinate system for the ocean consisting of 42 layers, while the ice is modelled in 5 thickness categories, each with 7 vertical layers and a single snow layer on top. The ocean and sea ice is forced by atmospheric fields from MET Norway’s in-house 2.5km AROME-Arctic model, a great advantage as the atmosphere forcing is on the same domain and resolution as the ocean and sea ice. Furthermore, boundary conditions comes from TOPAZ4, tides from TPXO tidal model, river runoff climatology from NVE data (mainland Norway) and AHYPE hydrological model (Svalbard+Russia) and the bottom topography is taken from the IBCAO v3 dataset. The model runs a 24 hours analysis for assimilating AMSR2 sea ice concentration from the University of Bremen and then runs a subsequent 66 hours forecast from the produced analysis. Daily updated validation results for the sea ice forecast are available here.

The model has a horizontal resolution of 4km and is forced by atmospheric forcing from the MEPS 2.5km atmospheric model. Five days Forecasts (120 hours) produced and updated every 6 hour. The Forecasts are postprocessed and nudged towards observations from Norwegian coastal stations. In addition to this setup, a similar setup is run in ensemble mode (EPS). This produces a 50+1 forecast for +120h twice per day based on the full ECMWF ensemble forecast system. Results are made available through api.met.no (https://api.met.no/weatherapi/tidalwater/1.1/documentation) and can also be viewed on SeHavnivå.

Norkyst-800 is our coastal and shelf sea ocean circulation model. The setup is based on ROMS with a horizontal resolution of 800m and 35 vertical layers, hence permitting mesoscale eddies. The most dominant features of the coastline are resolved including all major fjords, yet not the smallest islands and bays. It receives tidal forcing from a global inverse barotropic model of ocean tides,TPXO7.26, through prescription of amplitude and phase for sea surface elevation and currents for the major eight primary harmonic constituents (M2, S2, N2, K1, K2, O1, P1, Q1) of diurnal and semidiurnal frequencies. Atmospheric forcing is provided by surface fields from AROME-MetCoOP. Lateral boundary conditions for Norkyst-800 are provided by Topaz and the CMEMS Baltic sea model for temperature and salinity in the Kattegat area. "For the Norwegian rivers, real-time runoff data based on daily observed runoff are collected from The Norwegian Water Resources and Energy Directorate (NVE)". Norkyst-800 calculates atmospheric fluxes through a bulk formula formulation based on atmospheric variables, and vertical turbulence is parameterized through the k-gen GLS mixing scheme.

The operational system uses the HYCOM model and a 100-member Ensemble Kalman Filter (EnKF) assimilation scheme, available from the Copernicus Marine Service's catalog as product: ARCTIC_ANALYSIS_FORECAST_002_001_a (registration required, access is free of charge). It is run daily to provide 10 days of forecast (from an average of 10 ensemble members) of the 3D physical ocean, including sea ice. In addition, the system provides a 10-day forecast of the ocean biogeochemical variables. Data assimilation is performed weekly to provide 7 days of analysis (ensemble average). Output products are interpolated on a grid of 12.5 km resolution at the North Pole (equivalent to 1/8 deg in mid-latitudes) on a polar stereographic projection. Results from weekly updated validation of forecasts are also available. Data from the following observational products are assimilated:

The SVIM archive was originally produced in a project funded by the Norwegian Research Council. The project's primary objective was "To better understand how and why the survival of fish larvae varies spatially and temporally through their first months of life, and to quantify uncertainty in drift trajectories in ocean circulation models". The Centre for Ecological and Evolutionary Synthesis (CEES) was leading the project, while the production of the SVIM archive was performed jointly by project partners at the Institute of Marine Research (IMR) and Met Norway. The Regional Ocean Modeling System (ROMS) was used for this purpose.      The SVIM archive was configured with atmospheric forcing from a regional reanalysis which is a high-resolution downscaling of global reanalysis results from the European Centre for Medium-Range Weather Forecasts. Results from the Simple Ocean Data Assimilation (SODA) dataset were used for initial and boundary values. For sea ice, initial and boundary values were taken from a regional simulation. The sea ice model used is similar to the sea ice implementation in the configuration of SVIM. Tidal forcing was applied based on a global ocean tides model. Freshwater from river discharges was based on monthly climatological runoff values, modified to take inter-annual variability into account. The results from the original SVIM archive was thoroughly evaluated by Lien et al. (2013). An analysis of results for currents (Melsom and Gusdal, 2015) revealed that the predictive skill for the situation at specific days are poor. Given the scales of a few km that dominate instantaneous distribution of circulation features, and the fact that there is no assimilation of observational data in SVIM, this is not surprising. It should be added that observations at these fine scales are lacking.