Parameterization of dry deposition in MATCH

Type: Report
Series: RMK 100
Author: Thomas Klein, Robert Bergström, Christer Persson


The present report describes the calculation of dry deposition in the Multi scale Atmospheric Transport and Chemistry modeling system (MATCH) applied in environmental monitoring studies. For this type of applications dry deposition is parameterized by means of a resistance concept. Modeled dry deposition velocities for different surface types, a variety of meteorological conditions and several chemical species are presented. The deposition's dependence on the individual partial resistances and their variation with the meteorological conditions are illustrated by means of time-series. The details of the resistance concept are discussed in a pedagogical way in order to both facilitate understanding and to point out different deposition paths. Sensitivity studies have been performed for the laminar sub-layer resistance of particles for which two different settings of resistance values are compared. The importance of SO2 and NO2 uptake by the stomata of plants and the deposition of SO2 to the external parts of plants have also been investigated by means of sensitivity studies. In addition, horizontal maps and monthly mean values of dry deposition velocities based on meteorological data for 1998 are presented