10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
A Near-Global Analysis of In-Situ Profiles of Seasalt Aerosol
STEVEN HOWELL, Steffen Freitag, Nikolai Smirnow, University of Hawaii
Abstract Number: 1109 Working Group: Aerosol Transport and Transformation
Abstract Seasalt-derived particles are the largest contributor to aerosol mass on a global basis. Particularly in areas of the remote ocean, they are important contributors to light scattering and cloud droplet nuclei. Vertically-resolved atmospheric concentrations of sea-spray aerosol over the open ocean are sparse and are not well represented in chemical transport models. We have analyzed particle size distribution data from 14 NASA and NSF-sponsored airborne projects to assemble a collection of latitude-, longitude-, altitude-, and time-referenced SSA size distributions stretching over 20 years and including most of the world’s ocean basins. Seasalt particle size distributions are determined with a variety of aerodynamic and optical instruments, including thermal treatment to drive off volatile materials. Where possible, they are referenced to chemical measurements and are generally correct to within 30%. Inlet corrections have been made, but only particles <10μm are considered. We show that chemical transport models can have large, systematic errors in both mixed layer SSA and the efficiency with which they are transported higher in the boundary layer and the free troposphere.