Production of primary marine aerosol at the ocean surface is a major process in the earth's climate system, with important implications for the physicochemical evolution of the troposphere and feedbacks on upper ocean biogeochemistry. Newly formed marine aerosol are number-dominated by sub-ìm diameter, hygroscopic, organic-rich particles that scatter solar radiation and serve as condensation nuclei. Photolysis of the associated marine-derived organic matter (OM) produces reactive oxygen species and other oxidized species. The nature, magnitude, and consequences of the production and evolution of marine aerosol are highly uncertain, precluding development of a reliable predictive capability for associated influences on tropospheric chemistry, upper ocean biogeochemistry, and climate.
To address some of these uncertainties, an interdisciplinary research team from the SUNY College of Environmental Science and Forestry, the University of Virginia, and the Scripps Institute of Oceanography will participate on a multidisciplinary research cruise from the US to Bermuda in the summer of 2012 to study fluxes of marine aerosols as a function of seawater characteristics. In particular they will characterize size- and composition-resolved marine aerosols by comparison of measurements made with their own custom-designed UVA aerosol generator with parallel measurements with the NOAA SeaSweep aerosol generator and eddy covariance techniques. Comparative studies will be carried out at two or three optically distinct stations with seawater characteristics that are compositionally distinct. These results will also be compared with similar data already in-hand to yield a more thorough synthesis and to serve as the basis for developing numerical models of the aerosol transport system. An important outcome of this project will be a thorough characterization of the aerosol material generated by the UVA instrument for future aerosol work at sea.
Broader Impacts: Results of the proposed research are expected to advance further study of the influences of the surface ocean on the size-resolved organic and inorganic composition and flux of nascent and ambient marine aerosol, and the related influences of these aerosol in the multiphase chemical and physical evolution of the marine boundary layer, surface ocean biogeochemistry, and Earth's radiation balance. The project will also provide for the training and support of one or more graduate and undergraduate students.