Along with the Nansen Environmental and Remote Sensing Center (NERSC) and the Institute of Marine Research (Havforskningsinstituttet - HI), the Norwegian Meteorological Institute produces forecasts which are disseminated by the pan-European Copernicus Marine Service. The collaboration with NERSC and HI takes place in the Service' Arctic Monitoring and Forecasting Center (Arctic MFC). The Arctic MFC nominal forecast system is the TOPAZ system based on an advanced sequential data assimilation method (the Deterministic Ensemble Kalman Filter, DEnKF; Sakov and Oke, 2009) and the Hybrid Coordinate Ocean Model (HYCOM; Chassignet et a., 2007), coupled to a sea ice model.


TOPAZ general circulation forecasts
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. Data from the following observational products are assimilated:
  • Sea Ice Concentration from OSISAF passive microwave data
  • Thickness of thin sea ice from SMOS
  • Blended Optimum Interpolation SST data
  • Temperature and salinity profiles from Argo drifters
  • Sea Level from multiple altimeter missions

Results from weekly updated validation of forecasts are also available.

TOPAZ forecasts for surface currents and sea level
A higher horizontal grid resolution version of the TOPAZ system at ~3km forced with astronomical tides is run daily to provide a product consisting of 10-day forecasts of the ocean tides and surface currents for the pan-Arctic region. These forecasts are given at 15 minutes instantaneous profiles and can be accessed from the Copernicus Marine Service's catalog as product: ARCTIC_ANALYSISFORECAST_PHY_TIDE_002_015, where documentation and information on how to download the product are given.