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Citation
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HERO ID
3842979
Reference Type
Journal Article
Title
Evidence of 1991-2013 decrease of biogenic secondary organic aerosol in response to SO2 emission controls
Author(s)
Marais, EA; Jacob, DJ; Turner, JR; Mickley, LJ
Year
2017
Is Peer Reviewed?
Yes
Journal
Environmental Research Letters
EISSN:
1748-9326
Publisher
IOP PUBLISHING LTD
Location
BRISTOL
Volume
12
Issue
5
Page Numbers
054018
Language
English
DOI
10.1088/1748-9326/aa69c8
Web of Science Id
WOS:000402550600002
URL
https://iopscience.iop.org/article/10.1088/1748-9326/aa69c8
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Abstract
Air quality policy to decrease fine particulate matter mass concentrations (PM2.5) in the US has mainly targeted sulfate aerosol through controls on sulfur dioxide (SO2) emissions. Organic aerosol (OA) instead of sulfate is now the dominant component of total PM2.5. Long-term surface observations (1991-2013) in the Southeast US in summer show parallel decreases in sulfate (2.8%-4.0% a(-1)) and OA (1.6%-1.9% a(-1)). Decline of anthropogenic OA emissions is uncertain but is unlikely to fully explain this trend because most OA in the Southeast US in summer is biogenic. We conducted a 1991-2013 simulation with the GEOS-Chem chemical transport model including inventory decreases in anthropogenic SO2, NOx, and volatile organic compounds (VOCs) emissions, constant anthropogenic primary OA emissions, and a new mechanism of aqueous-phase SOA formation from isoprene. This simulation reproduces the observed long-term decreases of sulfate and OA, and attributes the OA decrease to decline in the OA yield from biogenic isoprene as sulfate decreases (driving lower aqueous aerosol volume and acidity). Interannual OA variability in the model (mainly driven by isoprene) is also well correlated with observations. This result provides support for a large air quality co-benefit of SO2 emission controls in decreasing biogenic OA as well as sulfate.
Keywords
isoprene; SOA; sulfate; Southeast US; air quality; GEOS-Chem
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ISA-PM (2019)
1st Draft
Chapter 2
Chapter 13
Final ISA
Chapter 2
Chapter 13
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