| Title: | Elucidating severe urban haze formation in China |
| Author(s): | Guo S; Hu M; Zamora ML; Peng J; Shang D; Zheng J; Du Z; Wu Z; Shao M; Zeng L; Molina MJ; Zhang R; |
| Address: | "State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Departments of Atmospheric Sciences and Chemistry, Center for the Atmospheric Chemistry and the Environment, Texas A&M University, College Station, TX 77843; and. State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; renyi-zhang@tamu.edu minhu@pku.edu.cn mjmolina@ucsd.edu. Departments of Atmospheric Sciences and Chemistry, Center for the Atmospheric Chemistry and the Environment, Texas A&M University, College Station, TX 77843; and. State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093 renyi-zhang@tamu.edu minhu@pku.edu.cn mjmolina@ucsd.edu. State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Departments of Atmospheric Sciences and Chemistry, Center for the Atmospheric Chemistry and the Environment, Texas A&M University, College Station, TX 77843; and renyi-zhang@tamu.edu minhu@pku.edu.cn mjmolina@ucsd.edu" |
| ISSN/ISBN: | 1091-6490 (Electronic) 0027-8424 (Print) 0027-8424 (Linking) |
| Abstract: | "As the world's second largest economy, China has experienced severe haze pollution, with fine particulate matter (PM) recently reaching unprecedentedly high levels across many cities, and an understanding of the PM formation mechanism is critical in the development of efficient mediation policies to minimize its regional to global impacts. We demonstrate a periodic cycle of PM episodes in Beijing that is governed by meteorological conditions and characterized by two distinct aerosol formation processes of nucleation and growth, but with a small contribution from primary emissions and regional transport of particles. Nucleation consistently precedes a polluted period, producing a high number concentration of nano-sized particles under clean conditions. Accumulation of the particle mass concentration exceeding several hundred micrograms per cubic meter is accompanied by a continuous size growth from the nucleation-mode particles over multiple days to yield numerous larger particles, distinctive from the aerosol formation typically observed in other regions worldwide. The particle compositions in Beijing, on the other hand, exhibit a similarity to those commonly measured in many global areas, consistent with the chemical constituents dominated by secondary aerosol formation. Our results highlight that regulatory controls of gaseous emissions for volatile organic compounds and nitrogen oxides from local transportation and sulfur dioxide from regional industrial sources represent the key steps to reduce the urban PM level in China" |
| Keywords: | China Pm2.5 nucleation pollution secondary aerosols; |
| Notes: | "PubMed-not-MEDLINEGuo, Song Hu, Min Zamora, Misti L Peng, Jianfei Shang, Dongjie Zheng, Jing Du, Zhuofei Wu, Zhijun Shao, Min Zeng, Limin Molina, Mario J Zhang, Renyi eng Research Support, Non-U.S. Gov't 2014/11/26 Proc Natl Acad Sci U S A. 2014 Dec 9; 111(49):17373-8. doi: 10.1073/pnas.1419604111. Epub 2014 Nov 24" |
