Airborne transport of sulphur dioxide from the U.K.

Abstract

Sulphur dioxide and sulphate have been sampled from aircraft flying along specified tracks off the east coast of England in relatively simple westerly meteorological conditions. The implied fluxes have been related to estimated emissions of sulphur dioxide into the air as it passed earlier over the source regions of Britain. The results imply that typically about 30 per cent is lost by dry deposition to the surface before reaching the tracks, corresponding to a velocity of deposition about 0.8 cm s −1, a further 50–60 per cent typically leaves the country as sulphur dioxide in dry conditions and the remainder as sulphate. The fraction converted to sulphate appears to depend quite sensitively on relative humidity. In rainy situations not only is this fraction quite high but the subsequent wash-out appears to be highly effective.