Grantee Research Project Results
2013 Progress Report: Understanding regional oxidation capacity by comprehensive observations to constrain hydroxyl radical sources and sinks during the Southern Oxidant Aerosol Study (SOAS)
EPA Grant Number: R835400Title: Understanding regional oxidation capacity by comprehensive observations to constrain hydroxyl radical sources and sinks during the Southern Oxidant Aerosol Study (SOAS)
Investigators: Kim, Saewung
Institution: University of California - Irvine
EPA Project Officer: Chung, Serena
Project Period: April 1, 2013 through March 31, 2016
Project Period Covered by this Report: April 1, 2013 through April 30,2014
Project Amount: $299,895
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:
- Provide high-resolution datasets of OH, HO2+RO2, H2SO4, NOx, and OH reactivity to the SOAS study participants and the entire scientific community.
- Constrain OH sources including photolytic and recycling sources and OH chemical sinks by measurements.
- Understand HOx budget and implications for SOA production by comparing measured OH ([OH]MEA), measurement constrained steady-state model calculated OH ([OH]SS) and University of Washington Chemical Mechanism (UWCM), which embedded the near-explicit chemical mechanism (MCM 3.2) calculated OH ([OH]UWCM) to assess our current HOx and SOA modeling capacity in isoprene rich environments for various NOX levels.
Progress Summary:
Progress has been made on the following activities:
- Deploying a H2SO4, OH, and HO2+RO2 chemical ionization mass spectrometer (CIMS) to the SOAS campaign.
- Deploying a comparative reactivity method (CRM)-OH reactivity system to the SOAS campaign.
- Deploying a commercial CRDS NO2 analyzer (Los Gatos) to the SOAS campaign.
- Participating FIX (Focused Isoprene-chemistry eXperiment) for CRM OH reactivity intercomparison.
- Reporting preliminary results of above observational parameters to the community data server.
- Presenting preliminary results and discussion at the SAS (Southern Atmospheric Study) data meeting.
Future Activities:
The following activities will be conducted in the next year:
- Further laboratory calibration for OH and especially HO2+RO2 in various isoprene conditions.
- Quantitative evaluations of the roles of Cregee bi-radical and SO2 reaction dynamics in sulfuric acid formation.
- Systematic intercomparison between CRDS NO2 and other NO2 observational results especially in different NOY conditions.
- In depth analysis of FIX datasets and follow up laboratory experiments to characterize the CRM-OH reactivity system.
- Quantitative evaluation of roles of multifunctional isoprene oxidation products in missing OH reactivity.
Journal Articles:
No journal articles submitted with this report: View all 6 publications for this projectSupplemental Keywords:
ambient air, tropospheric OH, SOA, observation, SoutheastProgress and Final Reports:
Original AbstractThe 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.