Analytical solution for a pollutant dispersion model with photochemical reaction in the atmospheric boundary layer

Abstract

This paper presents an analytical solution for the three-dimensional advection-diffusion equation applied to the dispersion of pollutants that form in the Atmospheric Boundary Layer (ABL). Some substances, when emitted in ABL suffer photochemical reactions producing secondary pollutants, so that a source term is included in the advection-diffusion equation to represent this reaction. The model was applied to simulate the dispersion and transport of ozone (O3) produced by photochemical reactions from nitrogen dioxide (NO2), pollutant emitted by burning fossil fuels by automotive vehicles. The pollutant concentration fields obtained by the proposed solution are compared with mixing ratio data obtained by monitoring the air quality in the metropolitan area of Porto Alegre. From the analysis of the results one verifies that the inclusion of the term proposed to represent a photochemical reaction of a reactive pollutant allows to predict ozone concentrations in the ABL.