HR: 12:05h
AN: A21G-07    [PDF]
TI: Source Fluxes of Remote Oceanic Aerosol: Ultrafine Sea-Salt, Sulfates and Clouds
AU: * Clarke, A D
EM: tclarke@soest.hawaii.edu
AF: University of Hawaii, School of Ocean and Earth Science and Technology, 1000 Pope Rd., MSB500, Honolulu, HI 96822 United States
AB: We have characterized particles produced from oceanic breaking waves that have diameters as small as 0.01 $\mu$m with peak number concentrations between 0.02-0.06 $\mu$m. Typically 60% are formed below 0.1 $\mu$m, about an order of magnitude smaller than previously documented for oceanic sea-salt. Their stability upon heating implies they are sea-salt nuclei and evolve from an externally mixed to internally mixed aerosol in the marine boundary layer. This production from breaking bubbles and the highly nonlinear dependence of bubble production on wind speed implies strong regional and temporal differences in their surface flux. The comparative strength of this flux to the flux of sulfate aerosol, often entrained into the marine boundary layer from the free troposphere, is critical to their relative role as atmospheric condensation nuclei and cloud condensation nuclei, CCN. Their relative contribution to CCN is expected to be regionally variable ranging from less than 10% to more than 90% of marine boundary layer CCN. Here we show that their size and flux can have significant impact on the origin and evolution of marine boundary layer aerosol under diverse conditions.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0312 Air/sea constituent fluxes (3339, 4504)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting