Dry deposition measured with a water surface sampler: a comparison to modeled results

In this study, a water surface sampler (WSS) and a knife-leading-edge surrogate surface (KSS) covered with both a Nylasorb filter, and a greased strip were used to directly measure nitrate, sulfate, and ammonium dry fluxes in Chicago between May and October 1997. Concurrently, an annular denuder system was used to measure the ambient concentration of gaseous nitric acid, sulfur dioxide, and ammonia gases. Water evaporation and relative humidity were also simultaneously measured. The measured fluxes and ambient concentrations were used to calculate the mass transfer coefficients of all four species