Dispersion conditions during an adverse meteorological situation in the Oeresund region

In this paper a weather situation of relatively long endurance is studied during which the COPENHAGEN area would have been highly exposed in case of a reactor accident at the Swedish nuclear power plant BARSEBAECK, 20 km east of Copenhagen. In the period considered, the stability was extremely high during the night, whereas a superadiabatic layer developed in the lowermost layer over land during the morning hours, a meteorological situation which in an accident case might cause locally severe pollution in the COPENHAGEN area due to fumigation. The risk of fumigation was further increased by the fact that very low values of the sea surface temperature at OERESUND separating BARSEBAECK and COPENHAGEN further stabilized the lowermost layer over the sea. In addition available wind observation indicate the existence of a complex local 'urban/sea' breeze circulation around COPENHAGEN causing a certain recirculation of air (and possible pollutants) in the period considered