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1994
Conference Paper
Titel
Numerical investigations of the dry deposition of reactive trace gases
Abstract
Results from numerical investigations regarding the dry deposition of reactive trace gases like NO, NO2, and O3 are presented. The investigations were carried out with a numerical model of the atmospheric boundary layer, which simulates the meteorological and photochemical processes as well as the heat and moisture transport processes within the vegetation-soil system as a function of height (depth) and time. The model is briefly described here. The model results show that the dry deposition fluxes of reactive trace gases are not only influenced by meteorological and plant-physiological parameters, but also by chemical reactions. In most cases, the trace gas fluxes vary strongly with height and often even show a change in the direction. The fluxes differ considerably from those obtained with the widely used "big leaf" multiple resistance approach. Hence, the constant flux approximation, on which this resistance approach is based, seems to be inappropriate for determining dry deposition fluxes and deposition velocities of reactive trace gases.