Modeling air pollution by atmospheric desert

Abstract

High concentrations of aeolian dust affect the air quality and climate in large regions across Northern Africa, the Middle East, and parts of Asia. To assess the environmental impacts, numerical models have been developed that include mineral dust emissions, atmospheric transport and chemistry, and deposition processes. Since the dust can disperse across continents and oceans, there is a need to model a large geographical area. Here we present a state-of-the-art global atmospheric chemistry–climate model, with detailed representations of these processes. One unique model feature is the chemical interaction of dust with air pollution (chemical aging), which alters the microphysics of particles relevant for their atmospheric lifetime, e.g., the hygroscopic growth behavior, optical properties, and aerosol–cloud interactions, thus influencing the hydrologic cycle and climate. Based on recent developments and published results, we present a comparison of model calculations with satellite and ground-based remote sensing data as well as surface observations of dust concentrations and deposition. The model results are used to evaluate the consequences of aeolian dust for climate and public health.