Title: | Drought Impacts on Secondary Organic Aerosol: A Case Study in the Southeast United States |
Author(s): | Zhao Z; Wang Y; Qin M; Hu Y; Xie Y; Russell AG; |
Address: | "Department of Earth System Science , Tsinghua University , Beijing 100084 , China. Department of Earth and Atmospheric Sciences , University of Houston , Houston , Texas 77204 , United States. School of Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States" |
ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
Abstract: | "Secondary organic aerosol (SOA) is a significant component of fine particulate matter, and it has increased during past drought periods in the U.S. Here, we use the Community Multiscale Air Quality (CMAQ) model to characterize the complex effects of drought on SOA through a case study comparing a drought period (June 2011) and a wet period (June 2013) over the southeast U.S. The model simulates a 68% (1.7 mug/m(3)) higher SOA concentration at the surface during drought and attributes 98% of this increase to biogenic SOA. Through model sensitivity simulations, the SOA increase associated with drought is attributed to 54% from accelerated gas-phase reactions oxidizing volatile organic compounds (VOCs) to SOA, 45% from higher emissions of biogenic VOCs, 18% from enhanced acid-catalyzed production of isoprene SOA in aerosol water due to changing sulfate, 3% from enhanced in-cloud aqueous phase chemistry. Because the higher SOA levels overwhelm the reduced precipitation, there is an increase in wet deposition flux in the drought month which offsets 20% of the total SOA increase. If anthropogenic emissions are held constant, anthropogenic SOA is 51% higher during drought, highlighting the importance of meteorological impacts on chemistry" |
Keywords: | Aerosols *Air Pollutants Droughts Particulate Matter Southeastern United States United States; |
Notes: | "MedlineZhao, Zijian Wang, Yuxuan Qin, Momei Hu, Yongtao Xie, Yuanyu Russell, Armistead G eng Research Support, Non-U.S. Gov't 2018/12/01 Environ Sci Technol. 2019 Jan 2; 53(1):242-250. doi: 10.1021/acs.est.8b04842. Epub 2018 Dec 12" |