Organic components account for 20-40% of the mass of aerosol particles in the atmosphere. This study compares the chemical characteristics of the organic fraction of submicron particles from more than a dozen field measurement campaigns in and near North America, eastern Asia, western South America, and northern Europe. Each study spanned a period of 30 days or more in the years 2000-2008, typically showing very similar composition during each campaign despite varying atmospheric concentrations. In contrast, a comparison of the different campaigns shows significant differences with location. These differences with region and season have provided us the opportunity to attribute the relative contributions to different organic source types, providing important constraints for global climate models. For example, the organic hydroxyl groups are produced from primary marine particles, although some are associated with both biomass burning and biogenic emissions. The organic acid groups are more closely associated with recent fossil fuel combustion emissions. Organic sulfate groups have been measured most frequently in remote regions with low ammonium concentrations but significant transport of combustion emissions, and there is some evidence for both increased formation and increased removal in cloudy conditions.
Lynn M. Russell is Professor of Atmospheric Chemistry at Scripps
Institution of Oceanography on the faculty of University of
California at San Diego. She completed her undergraduate work at
Stanford University. She received a Ph.D. in Chemical Engineering
from the California Institute of Technology for her studies of
marine aerosols. Her postdoctoral work as part of the National
Center for Atmospheric Research Advanced Studies Program
investigated aerosol and trace gas flux and entrainment in the
marine boundary layer. Her research is in the area of aerosol
particle chemistry, including the behavior of particles in marine
and anthropogenically-influenced conditions. This research has been
supported by the Dreyfus Foundation, the National Science
Foundation, the Office of Naval Research, the National Aeronautics
and Space Administration, and the James S. McDonnell Foundation.
She received the Whitby Award of the American Association of Aerosol
Research in 2003 for her contributions on atmospheric aerosol
processes. Her research group at Scripps pursues both modeling and
measurement studies of atmospheric aerosols, with a focus on
understanding fundamental processes that affect atmospheric aerosols.