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Photochemical production of hydroxyl radical and hydroperoxides in water extracts of nascent marine aerosols produced by bursting bubbles from Sargasso seawater
Author(s) -
Zhou Xianliang,
Davis Andrew J.,
Kieber David J.,
Keene William C.,
Maben John R.,
Maring Hal,
Dahl Elizabeth E.,
Izaguirre Miguel A.,
Sander Rolf,
Smoydzyn Linda
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl035418
Subject(s) - seawater , environmental chemistry , chemistry , aerosol , photochemistry , photodissociation , hydroxyl radical , radical , oceanography , organic chemistry , geology
Marine aerosols produced by bursting bubbles at the ocean surface are highly enriched in organic matter (OM) relative to seawater. The importance of this OM in the photochemical evolution of marine aerosols, particularly as a source of reactive oxidants, is unknown but likely significant. To investigate oxidant production, nascent aerosols were generated by bubbling zero air through flowing Sargasso seawater and photochemical production of OH radical and hydroperoxide were quantified in aqueous aerosol extracts exposed to solar radiation. Extrapolation to ambient conditions indicates that OM photolysis was the primary in situ source for both OH (1.1 × 10 −8 M s −1 ) and hydroperoxides (1.7 × 10 −8 M s −1 ) in nascent aerosols; NO 3 − photolysis was the primary source in aged, acidified aerosols (1.4 × 10 −7 and 4.1 × 10 −8 M s −1 , respectively). In situ OH photoproduction was comparable to gas‐phase uptake whereas H 2 O 2 photoproduction was slower. Results provide important constraints for poorly quantified oxidant sources in marine aerosols.