Atmospheric dispersal and deposition of radioactive material from Chernobyl

This paper reports on the results of studies undertaken in the wake of the fire at the Chernobyl nuclear power station. Published upper air charts and the findings of scientists engaged in monitoring the fallout are used to reconstruct the clouds' trajectories. The results reveal the role of the various features of weather systems in determining the dispersal, transportation and ultimate fallout of radioactive matter. Most importantly, the situation over Europe at the time of the fire was such as to disperse the radioactive clouds northwards to Scandinavia and later westwards to Britain; directions counter to the dominant westerlies of these latitudes. However, eastwards global dispersal took place rapidly in the weeks following the fire. The paper also emphasizes the importance of rainfall in explaining the geographical variation in the deposition of radioactive material.