Dataset Information

Understanding the Rising Phase of the PM_2.5 Concentration Evolution in Large China Cities.

ABSTRACT: Long-term air quality observations are seldom analyzed from a dynamic view. This study analyzed fine particulate matter (PM_2.5) pollution processes using long-term PM_2.5 observations in three Chinese cities. Pollution processes were defined as linearly growing PM_2.5 concentrations following the criteria of coefficient of determination R²?>?0.8 and duration time T???18?hrs. The linear slopes quantitatively measured pollution levels by PM_2.5 concentrations rising rates (PMRR, ?g/(m³·hr)). The 741, 210 and 193 pollution processes were filtered out, respectively, in Beijing (BJ), Shanghai (SH), and Guangzhou (GZ). Then the relationships between PMRR and wind speed, wind direction, 24-hr backward points, gaseous pollutants (CO, NO₂ and SO₂) concentrations, and regional PM_2.5 levels were studied. Inverse relationships existed between PMRR and wind speed. The wind directions and 24-hr backward points converged in specific directions indicating long-range transport. Gaseous pollutants concentrations increased at variable rates in the three cities with growing PMRR values. PM_2.5 levels at the upwind regions of BJ and SH increased at high PMRRs. Regional transport dominated the PM_2.5 pollution processes of SH. In BJ, both local contributions and regional transport increased during high-PMRR pollution processes. In GZ, PM_2.5 pollution processes were mainly caused by local emissions.

SUBMITTER: Lv B

PROVIDER: S-EPMC5404509 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

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Understanding the Rising Phase of the PM2.5 Concentration Evolution in Large China Cities.

Lv Baolei B Cai Jun J Xu Bing B Bai Yuqi Y

Scientific reports 20170425

Long-term air quality observations are seldom analyzed from a dynamic view. This study analyzed fine particulate matter (PM2.5) pollution processes using long-term PM2.5 observations in three Chinese cities. Pollution processes were defined as linearly growing PM2.5 concentrations following the criteria of coefficient of determination R2 > 0.8 and duration time T ≥ 18 hrs. The linear slopes quantitatively measured pollution levels by PM2.5 c ...[more]

PMID: 28440282

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Dataset Information

Understanding the Rising Phase of the PM_2.5 Concentration Evolution in Large China Cities.

Publications

Understanding the Rising Phase of the PM<sub>2.5</sub> Concentration Evolution in Large China Cities.

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