Calculation of the Discharge through Øresund at the Drogden Sill by Measurements at two Fixed Stations

The paper aims at relating the discharge through Øresund (the sound between Denmark and Sweden) to measured current and stratification at the two fixed stations Nordre Røse (St. 24) and Flinten SW (St. 21). The information on the discharge is gained from ship-based ADCP measurements carried out on board R/V Sensor. Close to the sill area, Saltholm island divides the flux into two parts: One part through the Drogden Channel (where St. 24 is located), and the other through the Flinten Channel (where St. 21 is located). The establishment of a relationship between discharge and current measurements at two fixed stations is based on three basic assumptions: 1) the stratification in the Drogden and Flinten channels is considered to be one- or two-layered; 2) the flow to be driven by a constant energy gradient across each channel; and 3) by simplifying the bathymetry of the cross-sections. The study of the water discharge through Øresund reveals a close relationship of hydrographic measurements (current profile, salinity profile and water level) at Nordre Røse (St. 24) and Flinten SW (St. 21). From the investigation an interface friction factor (f_i/2) for the Drogden Channel is found to be 5.6 × 10⁻³. This value is applied for the Flinten channel analysis as well.