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HERO ID
91026
Reference Type
Journal Article
Title
Comparison of the carbon bond and SAPRC photochemical mechanisms under conditions relevent to southeast Texas
Author(s)
Faraji, M; Kimura, Y; McDonald-Buller, E; Allen, D
Year
2008
Is Peer Reviewed?
1
Journal
Atmospheric Environment
ISSN:
1352-2310
EISSN:
1873-2844
Volume
42
Issue
23
Page Numbers
5821-5836
Language
English
DOI
10.1016/j.atmosenv.2007.07.048
Web of Science Id
WOS:000258365300008
URL
http://linkinghub.elsevier.com/retrieve/pii/S1352231007006565
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Relationship(s)
is also published as
1756670
Comparison of the carbon bond and SAPRC photochemical mechanisms under conditions relevant to southeast Texas
Abstract
Gridded, regional photochemical models use simplified photochemical reaction mechanisms, and two commonly used mechanisms are the SAPRC and the carbon bond (CB) mechanism. Versions of the mechanisms currently in use include SAPRC99 and the CB-IV mechanism. For most urban areas, the CB-IV and SAPRC mechanisms yield similar results, but for the modeling done of the summer of 2000 in southeast Texas, the SAPRC mechanism leads to concentrations of ozone that are 30–45 ppb higher than with CB-IV. The differences are due to differences in both reaction rate/stoichiometry parameters and condensation methods in the mechanisms. Major reasons for the differences are: (1) the products of the reactions of aromatics with hydroxyl radical, which are more reactive in the SAPRC formulation, (2) the overall balancing of radical generation and termination reactions, which lead to higher radical concentrations in the SAPRC formulation,
and (3) the production of higher aldehydes, which is greater in the SAPRC formulation. The differences between the mechanisms is particularly relevant for evaluating attainment with the National Ambient Air Quality Standard (NAAQS) for ozone concentrations averaged over 8 h.
Keywords
Photochemical mechanisms; Atmospheric chemistry; Ozone; Air quality models
Tags
NAAQS
•
ISA-NOx (2016)
2008 Final
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