Christopher Hennigan receives new NSF award

Congratulations to Assistant Professor Chris Hennigan, who has received a new research grant from the National Science Foundation.

Agency: NSF, Atmospheric Chemistry Program, within the Division of Atmospheric and Geospace Sciences
Title: Collaborative Research: Effects of Ammonia on the Chemical and Physical Properties of Atmospheric Secondary Organic Aerosol
Start Date: July 15, 2017
Duration: 3 years
Funding (Hennigan): $335,713 
Funding (collaborating professor at UC Irvine): $298,191

ABSTRACT

This project will investigate the effects of ammonia on the chemical and physical properties of small particles in the atmosphere. It will also look at the effects of ammonia on brown carbon in the atmosphere. The approach will combine ambient measurements, 3-D chemical transport modeling, and the analysis of past field campaign data. This work will provide important insight into the sources and formation processes of secondary organic aerosol, critical for a better understanding of both air quality and climate.

The objectives of the proposal are to: (1) Characterize the effects of NH3 on the concentration and reversible/irreversible nature of aqueous SOA (aqSOA); (2) Characterize the effect of NH3 on atmospheric BrC formation; and (3) Determine the spatial and temporal scales of the NH3 impacts on aqSOA and BrC formation. The two processes that will be evaluated include aqueous reactions that are either catalyzed by or directly involve NH4 and represent a significant source of highly oxidized, lower-volatility SOA, and the reaction of NH4 with organic compounds and the production of SOA that may be light-absorbing.

Ambient measurements will be made at an urban site in the eastern U.S. that is heavily influenced by biogenic VOC emissions, mobile sources, and regional NH3 emissions from agriculture. Modeling studies, using WRF-CMAQ, will provide an analysis of temporal and spatial variability in the NH3 effects on SOA and BrC formation and the impacts on air quality and climate.


Posted: September 18, 2017, 12:39 PM