Numerical Modeling of PM2.5 Propagation in Tbilisi Atmosphere in Winter. I. A Case of Background North Light Wind

Abstract

PM2.5 propagation at Tbilisi territory in winter period in case of background north light wind is numerically modeled and analyzed through combined integration of 3D regional model of atmospheric processes evolution and equation of admixtures transfer-diffusion. Motor transport moving at city streets and trunk lines is a main source of atmosphere pollution. There are investigated the main peculiarities, which characterize the process of microaerosols spatial distribution under rugged terrain conditions. PM2.5 high concentration zones are established at the territory of city, time intervals, when high air pollution forms or air self-purification takes place, are determined. Temporal and spatial variations of PM2.5 concentration in the lower part of atmospheric boundary layer are studied. It is established that 25 mkg/m3 and higher concentration is obtained from 11AM to 1PM and from 7PM to 10PM in the surroundings of Ponichala situated in the eastern part of the city.