Studies of Plume Transport and Dispersion Over Distances of Travel up to Several Hundred Kilometres

Abstract

In the United Kingdom the Meteorological Office is collaborating with the Central Electricity Research Laboratories (CERL) in a study of the long-range transport of pollutants over the North Sea. For these experiments the plume from Eggborough power station in South Yorkshire is “labelled” with sulphur hexafluoride so that it can be uniquely identified. The movement of the plume is predicted by a numerical trajectory model, and the Hercules aircraft of the Meteorological Research Flight, Farnborough is used to intercept and sample the gases at selected distances downwind. The usual meteorological, turbulence and cloud physics instrumentation on the aircraft (Nicholls, 1978) has been augmented by chemical sampling equipment (Crabtree and Marsh, 1981) in order to measure, on a time-scale short enough to reveal the detailed structure of the plume, the concentrations of the tracer gas, sulphur and nitrogen compounds, and ozone. Several flights have been carried out so far, including one experiment in which the same portion of the plume was sampled on two successive days. Plumes have been detected at distances up to more than 600 kilometres from the source.