Field measurements of wet deposition in an extended region of complex topography

A model designed to predict the enhancement of rainfall and the wet deposition of aerosol in complex terrain has been extended and compared with field data. The results of five separate field studies performed over an extensive region of complex terrain in northern England are presented and compared with the model predictions. It is found that the main features of the data are predicted by the model in widely varying conditions but the full details of a particular case-study cannot be reproduced quantitatively owing to the complexities of the meteorology over the extended distances and collection periods. The main physical processes controlling the deposition pattern have been established and it is concluded that a simple model of the seeder-feeder process is able to give reasonable descriptions of deposition patterns in complex terrain both for individual episodes and for longer-period averages. -Authors