Distribution and sources of air pollutants in the North China Plain based on on-road mobile measurements

Yi Zhu,Wenxing Wang,Yiqun Han,Jiping Zhang,Yingruo Li,Jun Liu,Wenyuan Chen,Junxia Wang,Jianmin Chen,Tong Zhu,Yusheng Wu,Xinfeng Wang,Limin Zeng,Chunxiang Ye

doi:10.5194/acp-16-12551-2016

Abstract

Abstract. The North China Plain (NCP) has been experiencing severe air pollution problems with rapid economic growth and urbanisation. Many field and model studies have examined the distribution of air pollutants in the NCP, but convincing results have not been achieved, mainly due to a lack of direct measurements of pollutants over large areas. Here, we employed a mobile laboratory to observe the main air pollutants in a large part of the NCP from 11 June to 15 July 2013. High median concentrations of sulfur dioxide (SO2) (12 ppb), nitrogen oxides (NOx) (NO + NO2; 452 ppb), carbon monoxide (CO) (956 ppb), black carbon (BC; 5.5 µg m−3) and ultrafine particles (28 350 cm−3) were measured. Most of the high values, i.e. 95 percentile concentrations, were distributed near large cities, suggesting the influence of local emissions. In addition, we analysed the regional transport of SO2 and CO, relatively long-lived pollutants, based on our mobile observations together with wind field and satellite data analyses. Our results suggested that, for border areas of the NCP, wind from outside this area would have a diluting effect on pollutants, while south winds would bring in pollutants that have accumulated during transport through other parts of the NCP. For the central NCP, the concentrations of pollutants were likely to remain at high levels, partly due to the influence of regional transport by prevalent south–north winds over the NCP and partly by local emissions.

Highlights

The North China Plain (NCP) is a geographically flat region in the northern part of eastern China, which includes Beijing, Tianjin, most of Hebei, Henan and Shandong provinces and the northern parts of Anhui and Jiangsu provinces
Instrumentation was powered by two sets of uninterruptible power systems (UPS), consisting of three series of 48 V/110 Ah lithium batteries, which could support all of the equipment operations without interruption for up to 5 h
The concentrations observed were at the highest levels in the world and were distributed unevenly in the NCP

Summary

Introduction

The North China Plain (NCP) is a geographically flat region in the northern part of eastern China, which includes Beijing, Tianjin, most of Hebei, Henan and Shandong provinces and the northern parts of Anhui and Jiangsu provinces. This region is surrounded by the Yan Mountains to the north, the Taihang Mountains to the west and the Bohai Sea to the east. The NCP is the political, economic and agricultural centre of China. Along with rapid economic growth and urbanisation, the NCP has been experiencing severe air pollution problems (Donkelaar et al, 2010). The concentrations of PM with an aerodynamic diameter ≤ 2.5 μm (PM2.5) and PM10 in the NCP are much higher

Methods

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Discussion

Conclusion