Transport Pathways and Potential Source Region Contributions of PM2.5 in Weifang: Seasonal Variations

Chengming Li,Zhaoxin Dai,Pengda Wu,Xiaoli Liu

doi:10.3390/app10082835

Abstract

As air pollution becomes progressively more serious, accurate identification of urban air pollution characteristics and associated pollutant transport mechanisms helps to effectively control and alleviate air pollution. This paper investigates the pollution characteristics, transport pathways, and potential sources of PM2.5 in Weifang based on PM2.5 monitoring data from 2015 to 2016 using three methods: Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT), the potential source contribution function (PSCF), and concentration weighted trajectory (CWT). The results show the following: (1) Air pollution in Weifang was severe from 2015 to 2016, and the annual average PM2.5 concentration was more than twice the national air quality second-level standard (35 μg/m3). (2) Seasonal transport pathways of PM2.5 vary significantly: in winter, spring and autumn, airflow from the northwest and north directions accounts for a large proportion; in contrast, in summer, warm-humid airflows from the ocean in the southeastern direction dominate with scattered characteristics. (3) The PSCF and CWT results share generally similar characteristics in the seasonal distributions of source areas, which demonstrate the credibility and accuracy of the analysis results. (4) More attention should be paid to short-distance transport from the surrounding areas of Weifang, and a joint pollution prevention and control mechanism is critical for controlling regional pollution.

Highlights

With rapid socioeconomic development, accelerated industrialization, and continuously increasing energy consumption, particulates have become major urban air pollutants in China [1,2,3]
Existing studies on the spatiotemporal characteristics of PM2.5 and transport mechanisms have mostly focused on geo-statistics analysis [11], air quality models
Based on nine air quality monitoring locations in Qingdao in winter, Li et al (2017) analyzed the characteristics of atmospheric pollution and pollutant sources, the results revealed that PM2.5 is a major urban atmospheric pollutant in Qingdao, and the greatest contributions are from Shanxi, the southern part of Hebei, and the western part of Shandong [23]

Summary

Introduction

With rapid socioeconomic development, accelerated industrialization, and continuously increasing energy consumption, particulates have become major urban air pollutants in China [1,2,3]. Studies have indicated that urban air pollution levels and their spatiotemporal distributions are associated with local emissions and influenced by cross-regional transport from sources in surrounding areas [7,8,9]. Accurate identification of urban atmospheric pollution characteristics and transport mechanisms is critical to control and mitigate air pollution [10]. Existing studies on the spatiotemporal characteristics of PM2.5 and transport mechanisms have mostly focused on geo-statistics analysis [11], air quality models Research and Forecasting (WRF) model) [12], and back-trajectory clustering-based mechanism analysis. For back-trajectory clustering-based transport analysis, previous research has mostly focused on hotspots [13,14], while there is limited research on small but seriously polluted cities in China

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Results

Conclusion