Airborne measurements of air pollution over Denmark and the adjacent seas

Airborne measurements of concentrations of gaseous and particulate sulphur and of Aitken nuclei were performed as part of an international project to assess the role of long-range transport of air pollution in Europe.

A description is given of the measuring equipment installed in the aircraft and some of the results are presented and discussed. A definite correlation was found between the concentrations of sulphate and sulphur dioxide; moreover, during different pollution episodes the relations between these substances were almost identical. It was also found that the concentration of Aitken nuclei correlated well with the concentration of sulphur dioxide, but that the correlation with sulphate concentration was dubious. In quite remote areas, such as over the ocean, under meteorological conditions favourable to long-range transport, it was found that pollution levels can be comparable to those encountered in large cities.