Arctic Ocean Physics Reanalysis

Overview

The current version of the TOPAZ system - TOPAZ4b - is nearly identical to the real-time forecast system run at MET Norway. It uses a recent version of the Hybrid Coordinate Ocean Model (HYCOM) developed at University of Miami (Bleck 2002). HYCOM is coupled to a sea ice model; ice thermodynamics are described in Drange and Simonsen (1996) and the elastic-viscous-plastic rheology in Hunke and Dukowicz (1997). The model's native grid covers the Arctic and North Atlantic Oceans, has fairly homogeneous horizontal spacing (between 11 and 16 km). 50 hybrid layers are used in the vertical (z-isopycnal), more than the TOPAZ4 system (28 layers). TOPAZ4b uses the Deterministic version of the Ensemble Kalman filter (DEnKF; Sakov and Oke 2008) to assimilate remotely sensed as well as temperature and salinity profiles. The output is interpolated onto standard grids and depths. Daily values are provided at all depths. Data assimilation, including the 100-member ensemble production, is performed weekly.

DOI (product):
https://doi.org/10.48670/moi-00007

Documentation

Classification

Full name
Arctic Ocean Physics Reanalysis
Product ID
ARCTIC_MULTIYEAR_PHY_002_003
Source
Numerical models
Spatial extent
Arctic OceanLat 50° to 90°Lon -180° to 179.88°
Spatial resolution
12.5 × 12.5 km
Temporal extent
1 Jan 1991 to 31 Dec 2022
Temporal resolution
DailyMonthlyYearly
Elevation (depth) levels
40
Processing level
Level 4
Variables
Ocean barotropic streamfunctionOcean mixed layer thickness (MLD)Sea floor depth below sea levelSea ice area fractionSea ice thickness (SIT)Sea ice x velocity (SIUV)Sea ice y velocity (SIUV)Sea surface elevationSea water potential temperature (T)Sea water potential temperature at sea floor (bottomT)Sea water salinity (S)Surface snow thickness (SNOW)X sea water velocity (UV)Y sea water velocity (UV)
Feature type
Grid
Blue markets
Polar environment monitoringPolicy & governanceScience & innovationExtremes, hazards & safetyCoastal servicesNatural resources & energyTrade & marine navigation
Projection
Polar stereographic North
Data assimilation
SSTSea LevelSea Ice Concentration and/or ThicknessIn-Situ TS Profiles
Update frequency
Biannually
Format
NetCDF-4
Originating centre
NERSC (Norway)
Last metadata update
30 November 2023