Adjoint Modeling and Source Attribution of Air Pollutants
Air pollutants such as ozone (O3) and particulate matter (PM) play key roles in atmospheric chemistry and have detrimental impacts on human health. However, identifying sources of such species is very challenging because they are secondary pollutants which are not directly emitted but chemically produced by numerous reactions of various precursors. In order to attribute sources of air pollutants efficiently and quantitatively, we use a global chemical transport model (CTM) GEOS-Chem and its adjoint model. The adjoint model calculates adjoint sensitivities of a scalar model response function with respect to numerous model parameters including initial conditions, emissions and reaction rates. Using this efficient tool, we investigate adjoint sensitivities of air pollutants to precursor emissions in the model.