Influence of temporal changes in relative humidity on dry deposition velocities and fluxes of aerosol particles bearing trace elements

To estimate the significance of temporal changes in RH on dry deposition to a water surface, size-segregated particulate aerosol samples were collected with nine-stage micro-orifice impactors at average RH ranging from <60 to 95% at a shoreline site along the Chesapeake Bay. These were analyzed by instrumental neutron activation for up to 44 elements including Al, As, Br, Cd, Cr, Cu, Fe, Mn, S, Sb, Se, V, and Zn. Distribution parameters, e.g., mass median aerodynamic diameters (mmad) were calculated from the resulting size spectra for each element and used to characterize particle growth as a function of RH. The spectra were used in an adaptation of the μm, i.e. comparable to those measured previously in College Park, MD