Evaluation of the Accuracy with Which Dry Deposition Can Be Measured with Current Micrometeorological Techniques

By reviewing the physics of the processes leading to dry deposition in the atmospheric surface layer, a number of corrections and possible errors in the determination of the dry deposition fluxes are identified. The concept of deposition velocity is examined, its usefulness discussed, and some pitfalls are pointed out. An overview is given of the various micrometeorological methods with which dry deposition can be determined and some of their limitations are indicated. With this background a number of recent publications on dry deposition have been analyzed. It is apparent that in most cases a more complete documentation is needed of the structure of the surface layer and the adjacent planetary boundary layer. Errors related to advection and entrainment are especially difficult or impossible to assess because of inadequate information about the surroundings and the height of the boundary layer.