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Observational constraints on glyoxal production from isoprene oxidation and its contribution to organic aerosol over the Southeast United States
- Source :
- Journal of Geophysical Research: Atmospheres. 121:9849-9861
- Publication Year :
- 2016
- Publisher :
- American Geophysical Union (AGU), 2016.
-
Abstract
- We use a 0-D photochemical box model and a 3-D global chemistry-climate model, combined with observations from the NOAA Southeast Nexus (SENEX) aircraft campaign, to understand the sources and sinks of glyoxal over the Southeast United States. Box model simulations suggest a large difference in glyoxal production among three isoprene oxidation mechanisms (AM3ST, AM3B, and MCM v3.3.1). These mechanisms are then implemented into a 3-D global chemistry-climate model. Comparison with field observations shows that the average vertical profile of glyoxal is best reproduced by AM3ST with an effective reactive uptake coefficient γglyx of 2 × 10−3, and AM3B without heterogeneous loss of glyoxal. The two mechanisms lead to 0–0.8 μg m−3 secondary organic aerosol (SOA) from glyoxal in the boundary layer of the Southeast U.S. in summer. We consider this to be the lower limit for the contribution of glyoxal to SOA, as other sources of glyoxal other than isoprene are not included in our model. In addition, we find that AM3B shows better agreement on both formaldehyde and the correlation between glyoxal and formaldehyde (RGF = [GLYX]/[HCHO]), resulting from the suppression of δ-isoprene peroxy radicals (δ-ISOPO2). We also find that MCM v3.3.1 may underestimate glyoxal production from isoprene oxidation, in part due to an underestimated yield from the reaction of IEPOX peroxy radicals (IEPOXOO) with HO2. Our work highlights that the gas-phase production of glyoxal represents a large uncertainty in quantifying its contribution to SOA.
- Subjects :
- Atmospheric Science
Box model
010504 meteorology & atmospheric sciences
Radical
Formaldehyde
010501 environmental sciences
01 natural sciences
Article
Lower limit
Aerosol
chemistry.chemical_compound
Geophysics
chemistry
Space and Planetary Science
Yield (chemistry)
Environmental chemistry
Earth and Planetary Sciences (miscellaneous)
Environmental science
Glyoxal
Isoprene
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 21698996 and 2169897X
- Volume :
- 121
- Database :
- OpenAIRE
- Journal :
- Journal of Geophysical Research: Atmospheres
- Accession number :
- edsair.doi.dedup.....cca08513b83e30efbd78e8951aa60f98