Estimating Atmospheric Inputs of Trace Constituents to the North Sea: Methods and Results

Abstract

The North Sea is surrounded by heavily industrialized countries which also have high population densities. Rivers like the Rhine, Meuse, Thames and Elbe deliver a permanent load of pollutants such as heavy metals, nutrients, chlorinated organics and pesticides, which - under the influence of North Sea currents - end up to a large extend in the shallow waters of the Dutch Wadden Sea and the German Bight. The importance of the atmospheric pathway to the pollution of the North Sea has been emphasized by a number of studies during the last decade. Cambray et al. (1979) and van Aalst et al. (1983) inferred atmospheric fluxes to the North Sea from measurements at platforms and coastal stations and Injuk et al. (1990) applied the same method on the basis of aircraft measurements. Estimates based on model calculations were reported by van Jaarsveld et al. (1986), Krell and Roeckner (1988) and Warmenhoven et al, (1989). Although the results of the different approaches confirm the importance of the atmospheric flux, they also indicate that there are still large uncertainties in these fluxes.