Please use this identifier to cite or link to this item:
Title: Aqueous-phase reactive uptake of dicarbonyls as a source of organic aerosol over eastern North America
Authors: Fu, TM
Jacob, DJ
Heald, CL
Issue Date: 2009
Source: Atmospheric environment, 2009, v. 43, no. 10, p. 1814-1822
Abstract: We use a global 3-D atmospheric chemistry model (GEOS-Chem) to simulate surface and aircraft measurements of organic carbon (OC) aerosol over eastern North America during summer 2004 (ICARTT aircraft campaign), with the goal of evaluating the potential importance of a new secondary organic aerosol (SOA) formation pathway via irreversible uptake of dicarbonyl gases (glyoxal and methylglyoxal) by aqueous particles. Both dicarbonyls are predominantly produced in the atmosphere by isoprene, with minor contributions from other biogenic and anthropogenic precursors. Dicarbonyl SOA formation is represented by a reactive uptake coefficient gamma = 2.9 x 10(-3) and takes place mainly in clouds. Surface measurements of OC aerosol at the IMPROVE network in the eastern U.S. average 2.2 +/- 0.7 mu g C m(-3) for July-August 2004 with little regional structure. The corresponding model concentration is 2.8 +/- 0.8 mu g C m(-3), also with little regional structure due to compensating spatial patterns of biogenic, anthropogenic, and fire contributions. Aircraft measurements of water-soluble organic carbon (WSOC) aerosol average 2.2 +/- 1.2 mu g C m(-3) in the boundary layer (<2 km) and 0.9 +/- 0.8 mu g C m(-3) in the free troposphere (2-6 km), consistent with the model (2.0 +/- 1.2 mu g C m(-3) in the boundary layer and 1.1 +/- 1.0 mu g C m(-3) in the free troposphere). Source attribution for the WSOC aerosol in the model boundary layer is 27% anthropogenic, 18% fire, 28% semi-volatile SOA, and 27% dicarbonyl SOA. In the free troposphere it is 13% anthropogenic, 37% fire, 23% semi-volatile SOA, and 27% dicarbonyl SOA. Inclusion of dicarbonyl SOA doubles the SOA contribution to WSOC aerosol at all altitudes. Observed and simulated correlations of WSOC aerosol with other chemical variables measured aboard the aircraft suggest a major SOA source in the free troposphere compatible with the dicarbonyl mechanism.
Keywords: Secondary organic aerosol
Organic carbon
Publisher: Pergamon Press
Journal: Atmospheric environment 
ISSN: 1352-2310
EISSN: 1873-2844
DOI: 10.1016/j.atmosenv.2008.12.029
Appears in Collections:Journal/Magazine Article

View full-text via PolyU eLinks SFX Query
Show full item record


Last Week
Last month
Citations as of Aug 14, 2020


Last Week
Last month
Citations as of Sep 18, 2020

Page view(s)

Last Week
Last month
Citations as of Sep 21, 2020

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.