9414293 Galloway Recent modeling studies indicate that anthropogenic and natural aerosols impact climate through direct (radiation absorption and scattering) and indirect (cloud albedo, frequency, and extent) effects. Scavenging and removal by precipitation are the principal sinks for radiatively important aerosols. To develop a predictive capability for the influence of aerosols on climate, the deposition flux of non-sea salt (nns) SO4 =, black carbon, and mineral aerosol, and the corresponding influences on optical characteristics of the scavenged air parcel must be quantified over space and time. As part of Theme 2 of the Atmosphere/Ocean Chemistry Experiment (AEROCE), Phase III, the University of Virginia 1) measure the chemical composition of precipitation at Bermuda and Barbados; 2) measure, as a function of wavelength, the optical extinction coefficient for insoluble aerosol scavenged by precipitation at the two site; 3) quantify the influence of scavenging and removal by precipitation on the aerosol burden and associated radiative properties of S, N, C, and mineral aerosol over the western North Atlantic Ocean; and 4) provide data for the chemical composition of precipitation to evaluate and refine atmospheric model calculations proposed under AEROCE and as ancillary studies to the program.
