摘要:

The North China Plain and the Yangtze River Delta are the two of the most heavily polluted regions in China. Observational studies revealed that 'explosive' PM2.5 mass concentration growths frequently occurred in the two regions. This study analyzed all the PM2.5 mass concentration growth processes from clean condition (i.e., <35 mu g m(-3)) to heavy pollution condition (i.e., >150 mu g m(-3)) in Beijing (BJ) and Shanghai (SH), two representative cities of the two regions, using hourly monitored PM2.5 concentrations during 2013-2016. 173 and 76 growth processes were identified in BJ and SH, respectively. PM2.5 rising rates (PMRR) and dynamic growth durations were calculated to illustrate the characteristics of the growth processes. Hourly particulate chemical composition data and meteorological data in BJ and SH were further analyzed. The 4-year averaged PMRR of PM2.5 total mass were similarly of 7.11 +/- 9.82 mu g m(-3) h(-1) in BJ and 6.71 +/- 6.89 mu g m(-3) h(-1) in SH. A decreasing trend was found for the PM2.5 growth processes in two cities from 2013 to 2016, reflecting the effectiveness of emission controls implemented in the past years. The contributions of particulate components to the PM2.5 total mass growth were different in BJ and SH. Average PMRR value of PM1 organic aerosols (OA), SO24-, NO3-, and NH4+ in BJ was 1.90, 0.95, 0.82, and 0.53 mu g m(-3) h(-1), respectively. Average PMRR of PM2.5 OA, SO42-, NO3-, and NH4+ in SH was 1.70, 1.18, 1.99 and 1.14 mu g m(-3) h(-1), respectively. Based on the contributions of different components, the PM2.5 mass concentration growth processes in BJ and SH were proposed to be classified into 'other components-dominant growth processes', 'all components-contributing growth processes', 'one or more explosive secondary components-dominant growth processes', and 'mixed-factor growth processes'. Potential source contribution function analysis and the meteorological condition analysis showed that source origins and prevailing wind for the two cities during different categories of growth processes had substantial difference. The important source areas included Hebei and Shandong for BJ, and Jiangsu and Anhui for SH. The dominant wind directions during growth processes were northeast, south and southwest in BJ, and were west to north in SH. The results suggested the contributing components, the prevailing wind conditions, and the formation processes were substantially different in the two cities, despite the similar PMRR of PM2.5 total mass during the growth processes between BJ and SH. Future research is needed to study the detailed formation mechanisms of the different PM2.5 mass concentration growth processes in the two cities. (C) 2019 Elsevier Ltd. All rights reserved.

附注:

ISI Document Delivery No.: HO1ZHTimes Cited: 4Cited Reference Count: 74Sun, Jinjin Liang, Mingjie Shi, Zhihao Shen, Fuzhen Li, Jingyi Huang, Lin Ge, Xinlei Chen, Qi Sun, Yele Zhang, Yanlin Chang, Yunhua Ji, Dongsheng Ying, Qi Zhang, Hongliang Kota, Harsha Hu, JianlinGe, Xinlei/F-5672-2010; Ji, Dongsheng/E-3807-2018; Sun, Yele/F-1314-2010Ge, Xinlei/0000-0001-9531-6478; Sun, Yele/0000-0003-2354-0221National Key R&D Program of China [2016YFC0203500, 2]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China [41675125, 91544221]; Natural Science Foundation of Jiangsu ProvinceJiangsu Planned Projects for Postdoctoral Research FundsNatural Science Foundation of Jiangsu Province [BK20150904]; Jiangsu Distinguished Professor Project [2191071503201]; Jiangsu Six Major Talent Peak Project [2015-JNHB-010]; Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)This work was supported by the National Key R&D Program of China (2016YFC0203500, Task #2); the National Natural Science Foundation of China (41675125, 91544221); the Natural Science Foundation of Jiangsu Province under contract no. BK20150904; Jiangsu Distinguished Professor Project 2191071503201; Jiangsu Six Major Talent Peak Project 2015-JNHB-010; and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).53266Pergamon-elsevier science ltdOxford1879-1298