Grantee Research Project Results

2014 Progress Report: The role of nitrate radicals (NO3) in aerosol life cycle: Secondary organic aerosol formation and aging of atmospheric organic aerosols

EPA Grant Number: R835403
Title: The role of nitrate radicals (NO3) in aerosol life cycle: Secondary organic aerosol formation and aging of atmospheric organic aerosols
Investigators: Ng, Nga Lee
Institution: Georgia Institute of Technology
EPA Project Officer: Chung, Serena
Project Period: April 1, 2013 through March 31, 2016 (Extended to March 31, 2017)
Project Period Covered by this Report: April 1, 2014 through March 31,2015
Project Amount: $300,000
RFA: Anthropogenic Influences on Organic Aerosol Formation and Regional Climate Implications (2012) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Climate Change , Air , Early Career Awards

Objective:

The goal of this project is to experimentally determine the extent to which NO₃ radicals (formed from anthropogenic NO₂ and ozone) affect organic aerosol (OA) loading and composition over its atmospheric lifetime, taking into account secondary organic aerosol (SOA) formation from NO₃ oxidation pathway and both daytime and nighttime aging processes.

Progress Summary:

Work proceeded well during this year. We have performed extensive laboratory experiments to investigate secondary organic aerosol (SOA) and organic nitrate formation from BVOC+NO₃. Specifically, we investigated SOA formation from β-pinene+NO₃ under dry vs. humid conditions, with ammonium sulfate vs. ammonium sulfate + sulfuric acid seeds, where either “RO₂+HO₂” or “RO₂+NO₃” reaction dominates. We used the results from these laboratory studies to evaluate the contributions of monoterpene+NO₃ reaction to organic aerosol measured in the southeastern United States, including the Southern Oxidant and Aerosol Study (SOAS) and the Southeastern Center for Air Pollution and Epidemiology (SCAPE) study. Finally, our laboratory results also are used in the development of a coupled gas and aerosol system to describe formation and subsequent aerosol-phase partitioning of organic nitrates in CMAQ. Notable results are:

Investigation of SOA and organic nitrate formation from β-pinene+NO₃ under reaction conditions (humidity, seed acidity, peroxy radical fate) relevant to southeast United States.
Determination of the contribution of monoterpenen+NO₃ reaction to ambient organic aerosols in the southeast United States.
Incorporation of findings from our laboratory experiments to improve representation and treatment of organic nitrate formation and fates in CMAQ.

Future Activities:

The main goals of Year 3 activities will be to understand how SOA and organic nitrates formed from NO₃+monoterpene evolve during the night-to-day transition. Specific tasks are:

Study the effects of dilution and temperature change on SOA and organic nitrates formed from NO₃+monoterpene
Investigate the effects of photolysis vs. OH oxidation on organic nitrates formed from NO₃+monoterpene.

Journal Articles on this Report : 3 Displayed | Download in RIS Format

Publications Views
Other project views:	All 47 publications	21 publications in selected types	All 20 journal articles

Publications
Type	Citation	Project	Document Sources
Journal Article	Boyd CM, Sanchez J, Xu L, Eugene AJ, Nah T, Tuet WY, Guzman MI, Ng NL. Secondary organic aerosol formation from the β-pinene+NO3 system: effect of humidity and peroxy radical fate. Atmospheric Chemistry and Physics 2015;15(13):7497-7522.	R835403 (2014) R835403 (2015) R835403 (Final) R834799 (Final)	Full-text: ACP-Full Text PDF Exit Abstract: ACP-Abstract Exit Other: ResearchGate-Full Text PDF Exit
Journal Article	Pye HOT, Luecken DJ, Xu L, Boyd CM, Ng NL, Baker KR, Ayres BR, Bash JO, Baumann K, Carter WPL, Edgerton E, Fry JL, Hutzell WT, Schwede DB, Shepson PB. Modeling the current and future roles of particulate organic nitrates in the Southeastern United States. Environmental Science & Technology 2015;49(24):14195-14203.	R835403 (2014) R835403 (2015) R835403 (Final) R835399 (Final) R835409 (Final) R835410 (2013)	Abstract from PubMed Full-text: ACS-Full Text HTML Exit Abstract: ACS-Abstract Exit Other: ACS-Full Text PDF Exit
Journal Article	Xu L, Guo H, Boyd CM, Klein M, Bougiatioti A, Cerully KM, Hite JR, Isaacman-VanWertz G, Kreisberg NM, Knote C, Olson K, Koss A, Goldstein AH, Hering SV, de Gouw JA, Baumann K, Lee S-H, Nenes A, Weber RJ, Ng NL. Effects of anthropogenic emissions on aerosol formation from isoprene and monoterpenes in the southeastern United States. Proceedings of the National Academy of Sciences of the United States of America 2015;112(1):37-42.	R835403 (2014) R835403 (2015) R835403 (Final) R834799 (2015) R834799 (2016) R834799 (Final) R834799C001 (2015) R834799C001 (Final) R835410 (2013) R835410 (2014) R835410 (2015) R835410 (Final)	Full-text from PubMed Abstract from PubMed Associated PubMed link Full-text: PNAS-Full Text HTML Exit Abstract: PNAS-Abstract Exit Other: PNAS-Full Text PDF Exit

Supplemental Keywords:

organic nitrates, partitioning, semivolatiles, multifunctional oxidation products

Relevant Websites:

School of Chemical & Biomolecular Engineering at Georgia Tech Exit

Progress and Final Reports:

Original Abstract

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.