AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Effect of Rain on Evolution of Aerosol Concentration Distribution in Air Pollution Plumes
BORIS KRASOVITOV, Tov Elperin, Andrew Fominykh, Ben-Gurion University of the Negev
Abstract Number: 191 Working Group: Aerosols, Clouds, and Climate
Abstract Although it is commonly accepted that air pollution is dominated by local emissions many studies report that plumes of harmful pollutants can waft across oceans and continents and warn about the growing danger of long-distance smog. Scavenging of aerosols by rain contributes to the evolution of concentration distribution of aerosols and reduces concentration of aerosols in pollutants emissions. In the present study we suggest a model of scavenging of aerosol particles by rain in Gaussian air pollution plume. Analytical approach was developed using a Gaussian plume dispersion model and taking into account raindrops size distribution by using the Monte Carlo simulation. In simulations we used the log-normal size distribution of raindrops with Feingold and Levin parameterization based on the long-time measurements of rain drops size spectra in Israel. The developed model allows analyzing spatial and temporal evolution of aerosol concentration in the gaseous phase as well as in the raindrops. In the calculations we use as input parameters for a Gaussian plume dispersion model meteorological data such as wind speed, wind direction and atmospheric stability class. It is shown that the dynamics of below-cloud scavenging of aerosols is described by an explicit analytical expression. Aerosol concentration distributions are calculated for different values of rain intensity and different sizes of aerosol particles in the plume. The obtained results can be useful in the analysis of different meteorology-chemistry models including scavenging of aerosols in air pollution plumes by rain and, in particular, in various parameterizations of global air pollution scavenging by precipitation.