DMI operates a regional 3D ocean model BSHcmod for the North Sea - Baltic, in order to provide information about the physical state of the Danish and nearby waters in the near future.

The model code is originally developed at Bundesamt für Seeschifffahrt und Hydrographie (BSH) in Hamburg, Germany. The code has kindly been provided to DMI by BSH. The model code has undergone extensive revision in the DMI implementation, in co-operation between the two model groups. Basically the same code is used in the Baltic HIROMB co-operation, where the Danish institute Farvandsvæsenet participates.

The Figure to the right shows the model domain for the 3D grid. The parameter shown is the water depth.

Input:
BSHcmod is forced by DMI's numerical weather predicition model
DMI-HIRLAM. The 6 forcing parameters are 10 meter wind speed and direction, msl atmospheric pressure, surface air temperature and humidity, and cloud cover. Surface energy fluxes (mechanical, radiative, thermodynamic) are calculated using bulk parameterisation formulae. BSHcmod is further forced by freshwater fluxes from 79 rivers, either real-time, obtained from a hydrological model, or climatological. Finally, the open boundary conditions are tidal sea surface elevation and climatological hydrography.

Output:
BSHcmod is run twice daily, and provides a forecast for the full 3D ocean state every 15 minutes, 60 hours ahead. The model gives information about sea level variations, sea temperature, salinity, currents and ice coverage. Sea level at selected, coastal points is calculated in 1½ minute time resolution.

Output parameter table.

The BSHcmod model code complex consists of 3 model domains:

NOAMOD: a 2D, coarse grid model covering the north-eastern part of the Atlantic. This model calculates the external surge contribution to the (otherwise purely tidal) surface elevation along the two open boundaries in the North Sea.

BSHcmod North Sea - Baltic Sea: 3D model covering the North Sea - Baltic Sea. A coarse grid is set up for the whole domain with a grid size of 6 n.m. (11 km).

BSHcmod Danish Coastal Area: Within the North Sea - Baltic Sea grid a finer grid is set up with a resolution of 1 n.m. (1.8 km) covering the German Bight and the inner Danish Waters (the southern part of Kattegat, the Belts, the Sound and the western part of the Baltic Sea).

Model	BSHcmod North Sea - Baltic Sea	BSHcmod Danish Coastal Area	NOAMOD
Space grid	1/10° lat 1/ 6° lon	1/60° lat 1/ 36° lon	1/10° lat 1/ 6° lon
Time step: Barotropic processes: Baroclinic processes: Ice processes:	90 sec 450 sec 3600 sec	45 sec 450 sec 3600 sec	15 sec - -
Atm. forcing	Hirlam S03	Hirlam S03	Hirlam T15
Area: longitude	4W-30E	6E-15E	21W-13E
Area: latitude	Baltic Sea: 48N-66N North Sea: 48N-59N	53N-56N	48N-66N
Boundary	Surge contribution from NOAMOD tidal wave (17 constituents) monthly climatology fields for T and S via a sponge layer	3D fields from the larger model	Radiation condition