Title: The Influence of Alkyl Nitrates from Anthropogenic and Biogenic Precursors on Regional Air Quality in Eastern Texas
Institution(s) Represented: The University of Texas at Austin - Elena McDonald-Buller, Ramboll Environ US Corporation - Gregory Yarwood
Lead PI: Elena McDonald-Buller
AQRP Project Manager: David Sullivan
TCEQ Project Liaison: Jim Smith
Awarded Amount: $180,641.00
Abstract
Mono and multifunctional alkyl nitrates (ANs) are formed from the oxidation of biogenic or anthropogenic volatile organic compound (VOC) precursors and serve as a reservoir or sink of nitrogen oxides (NOx). Alkyl nitrates have sufficiently long atmospheric chemical lifetimes (hours to days), such that they can influence tropospheric ozone and secondary organic aerosol (SOA) formation over regional to global spatial scales. Their functionalities, yields, and fates are known to depend upon the size and structure of the VOC. Depending on their structure, ANs can be transported, chemically processed, removed by deposition to vegetation and other surfaces, or undergo partitioning to and from the aerosol phase where hydrolysis is thought to be a loss mechanism. Although knowledge gaps still exist, recent laboratory and field studies have provided new insights on these processes for ANs formed from biogenic and anthropogenic hydrocarbon precursors. An ongoing need will be to incorporate these findings into the chemical mechanisms of photochemical models used to assess regional air quality. The objectives of this work are to apply the findings of ongoing experimental studies examining alkyl nitrates formed from the OH-initiated oxidation of C8-C11 alkanes at the University of Texas at Austin in addition to those of new publications that have focused on other hydrocarbon precursor classes relevant to Texas emissions inventories to improve how ANs are represented in the version 6 of the Carbon Bond mechanism (CB6). Revision 4 of CB6 (CB6r4) will soon be available in version 6.32 of the Comprehensive Air quality Model with extensions (CAMx v6.32). Sensitivity tests with CAMx will evaluate the formation and fate of ANs in central and southeastern Texas, the influence of ANs on regional ozone by recycling NOx, and dependencies on organic aerosol concentrations.
Work Plan: projectinfoFY16_17\16-019\16-019 Scope.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Oct 2016.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Nov 2016.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Dec 2016.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Jan 2017.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Feb 2017.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Mar 2017.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Apr 2017.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR May 2017.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Jun 2017.pdf
Technical Report(s): projectinfoFY16_17\16-019\16-019 MTR Jul 2017.pdf
QAPP: projectinfoFY16_17\16-019\16-019 QAPP.pdf
Final Report: projectinfoFY16_17\16-019\16-019 Final Report.zip
