A second generation model for regional-scale transport/chemistry/deposition

Abstract

The regional-scale transport, chemistry and deposition of acidifying compounds, photochemical oxidants, and their precursors are analyzed using a second-generation Eulerian model. The important atmospheric processes are incorporated using chemical, dynamical and thermodynamical parameterizations having sufficient detail to accommodate boundary layer-free troposphere exchange in cloudy and cloud-free environments, and in-cloud and below-cloud wet removal and chemistry. Forty-one species are considered, many of which are also present in the liquid-drop phases. In the regional scale transport, the advected species are NO, NO2, SO2, SO-24, O3, HNO3, NH3, PAN, H2O2, HCHO, alkanes, C2H4, other olefins, aromatics, RCHO, ROOH, HNO2, RONO2 and RO2NO2. The model capabilities are illustrated by showing simulations in which non-precipitating clouds are present to absorb gas-phase species, chemically alter these, and then release them to the atmosphere. © 1986.