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Title: Sources and composition of submicron organic mass in marine aerosol particles

Recent studies have proposed a variety of interpretations of the sources and composition of atmospheric marine aerosol particles (aMA) based on a range of physical and chemical measurements collected during open-ocean research cruises. To investigate the processes that affect marine organic particles, this study uses the characteristic functional group composition (from Fourier transform infrared (FTIR) spectroscopy) of aMAP from five ocean regions to show that: (i) The organic functional group composition of aMAP that can be identified as atmospheric primary marine (ocean-derived) aerosol (aPMA) is 65±12% hydroxyl, 21±9% alkane, 6±6% amine, and 7±8% carboxylic acid functional groups. Contributions from photochemical reactions add carboxylic acid groups (15%-25%), shipping effluent in seawater and ship emissions add additional alkane groups (up to 70%), and coastal emissions mix in alkane and carboxylic acid groups from coastal pollution sources. (ii) The organic composition of aPMA is nearly identical to model generated primary marine aerosol particles (gPMA) from bubbled seawater (55% hydroxyl, 32% alkane, and 13% amine functional groups), indicating that its overall functional group composition is the direct consequence of the organic constituents of the seawater source. (iii) While the seawater organic functional group composition was nearly invariant across all three ocean regions studied, themore » gPMA alkane group fraction increased with chlorophyll-a concentrations (r = 0.79). gPMA from productive seawater had a larger fraction of alkane functional groups (35%) compared to gPMA from non-productive seawater (16%), likely due to the presence of surfactants in productive seawater that stabilize the bubble film and lead to preferential drainage of the more soluble (lower alkane group fraction) organic components. gPMA has a hydroxyl group absorption peak location characteristic of monosaccharides and disaccharides, where the seawater OM hydroxyl group peak location is closer to that of polysaccharides. This may result from the larger saccharides preferentially remaining in the seawater during gPMA and aPMA production« less
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [4]
  1. Univ. of California, San Diego, CA (United States). Scripps Inst. of Oceanography.
  2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC).
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. National Oceanic and Atmospheric Administration (NOAA), Seattle, WA (United States). Pacific Marine Environmental Lab. (PMEL).
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 2169-897X; KP1703020
Grant/Contract Number:
AGS-1013423; OCE-1129580; AGS-1360645
Accepted Manuscript
Journal Name:
Journal of Geophysical Research: Atmospheres
Additional Journal Information:
Journal Volume: 119; Journal Issue: 22; Journal ID: ISSN 2169-897X
American Geophysical Union
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23);
Contributing Orgs:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
Country of Publication:
United States
58 GEOSCIENCES; 54 ENVIRONMENTAL SCIENCES submicron organic mass; atmospheric marine aerosol particles (aMA); FTIR spectroscopy