Research on measurement and source distribution of atmospheric NO2 concentration by ground-based MAX-DOAS system in Nanjing, China

2020 ◽  
Author(s):  
Bo ren ◽  
Pinhua Xie ◽  
jin Xu ◽  
Ang Li ◽  
Xin Tian ◽  
...  
Keyword(s):  
Air Pollution ◽  
Large Population ◽  
Pollution Prevention ◽  
Yangtze River Delta ◽  
Atmospheric Pollutants ◽  
Source Distribution ◽  
Distribution Model ◽  
Optical Absorption Spectroscopy ◽  
Different Seasons ◽  
And Control

<p>Nanjing, as one of the important cities in the Yangtze River Delta of China, has a developed economy and a large population. Although the concentration of air pollutants in Nanjing has declined with the introduction of China’s strict air pollution prevention and control policies, the situation of air pollution is still severe. Therefore, understanding the source and distribution of atmospheric pollutants has an important role in implementing the prevention and controlling of atmospheric pollutants. In this study, we observed the vertical distribution characteristics of tropospheric NO<sub>2</sub> by used the ground-based Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) technique in Nanjing. The contribution of transregional transport to NO<sub>2</sub> in different seasons and different altitudes (200m, 500m, and 1000m) was analyzed by combining the potential source distribution model (PSCF). The analysis results showed that the distribution of NO<sub>2</sub> sources were obvious seasonal changes. Due to the lower wind speed in spring, the distribution of NO<sub>2</sub> sources at all altitudes was not obvious. In summer and autumn, the source of NO<sub>2</sub> in the lower altitudes (200m) was concentrated in the urban area of ​​Nanjing and central Jiangsu Province. But for the winter, the NO<sub>2</sub> concentrations of lower altitudes were seriously affected by Chuzhou and Ma'anshan area. The sources distribution in the middle and upper altitude were relatively scattered and the WPSCF value was smaller than lower altitudes, which may be caused by the NO<sub>2</sub> concentrated in the near ground.</p>

The Message of “APEC Blue” for the Prevention and Control of Urban Air Pollution in China

2016 ◽  
Vol 04 (04) ◽  
pp. 1650027
Author(s):  
Rong ZHU
Keyword(s):  
Air Pollution ◽  
Emergency Response ◽  
Prevention And Control ◽  
Urban Air Pollution ◽  
Pollution Prevention ◽  
Warning System ◽  
Weather Conditions ◽  
Control Measures ◽  
Atmospheric Pollutant ◽  
And Control

Analysis of the meteorological conditions for atmospheric pollutant dispersion before and after the 2014 APEC meeting shows very significant effects of air pollution prevention and control measures on the meeting. It proves that the proper measures to control air pollution in the Beijing-Tianjin-Hebei Region are: establishing a regional emergency response mechanism to reduce emissions in the case of heavy air pollution, strengthening the local emergency response measures for emission reduction, and enhancing the early warning system for weather conditions conducive to heavy air pollution.

scholarly journals Long-term trends and drivers of aerosol pH in eastern China

2021 ◽  
Author(s):  
Min Zhou ◽  
Guangjie Zheng ◽  
Hongli Wang ◽  
Liping Qiao ◽  
Shuhui Zhu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Prevention And Control ◽  
Action Plan ◽  
Health Effect ◽  
Eastern China ◽  
Pollution Prevention ◽  
Control Action ◽  
Haze Pollution ◽  
Pollution Prevention And Control ◽  
And Control

Abstract. Aerosol acidity plays a key role in regulating the chemistry and toxicity of atmospheric aerosol particles. The trend of aerosol pH and its drivers are crucial in understanding the multiphase formation pathways of aerosols. Here, we reported the first trend analysis of aerosol pH from 2011 to 2019 in eastern China. The implementation of the Air Pollution Prevention and Control Action Plan leads to −35.8 %, −37.6 %, −9.6 %, −81.0 % and 1.2 % changes of PM2.5, SO42−, NHx, NVCs and NO3− in YRD during this period. Different from the fast changes of aerosol compositions due to the implementation of the Air Pollution Prevention and Control Action Plan, aerosol pH shows a moderate change of −0.24 unit over the 9 years. Besides the multiphase buffer effect, the opposite effects of SO42− and non-volatile cations changes play key roles in determining the moderate pH trend, contributing to a change of +0.38 and −0.35 unit, respectively. Seasonal variations in aerosol pH were mainly driven by the temperature, while the diurnal variations were driven by both temperature and relative humidity. In the future, SO2, NOx and NH3 emissions are expected to be further reduced by 86.9 %, 74.9 % and 41.7 % in 2050 according to the best health effect pollution control scenario (SSP1-26-BHE). The corresponding aerosol pH in eastern China is estimated to increase by ~0.9, resulting in 8 % more NO3− and 35 % less NH4+ partitioning/formation in the aerosol phase, which suggests a largely reduced benefit of NH3 and NOx emission control in mitigating haze pollution in eastern China.

scholarly journals Secondary organic aerosol enhanced by increasing atmospheric oxidizing capacity in Beijing-Tianjin-Hebei (BTH), China

2019 ◽  
Author(s):  
Tian Feng ◽  
Shuyu Zhao ◽  
Naifang Bei ◽  
Jiarui Wu ◽  
Suixin Liu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Secondary Organic Aerosol ◽  
Action Plan ◽  
Spatial Relationship ◽  
Pollution Prevention ◽  
Organic Aerosol ◽  
Temporal Variations ◽  
Sensitivity Studies ◽  
Distribution Studies ◽  
And Control

Abstract. The implementation of the Air Pollution Prevention and Control Action Plan in China since 2013 has profoundly altered the ambient pollutants in the Beijing-Tianjin-Hebei region (BTH). Here we show observations of substantially increased O3 concentration (about 30 %) and a remarkable increase in the ratio of organic carbon (OC) to elemental carbon (EC) in BTH during the autumn from 2013 to 2015, revealing an enhancement in atmospheric oxidizing capacity (AOC) and secondary organic aerosol (SOA) formation. To explore the impacts of increasing AOC on the SOA formation, a severe air pollution episode from 3 to 8 October 2015 with high O3 and PM2.5 concentrations is simulated using the WRF-Chem model. The model performs reasonably well in simulating the spatial distributions of PM2.5 and O3 concentrations over BTH and the temporal variations of PM2.5, O3, NO2, OC, and EC concentrations in Beijing compared to measurements. Sensitivity studies show that the change in AOC substantially influences the SOA formation in BTH. A sensitivity case characterized by a 31 % O3 decrease (or 36 % OH decrease) reduces the SOA level by about 30 % and the SOA fraction in total organic aerosol by 17 % (from 0.52 to 0.43). Spatially, the SOA decrease caused by reduced AOC is ubiquitous in BTH, but the spatial relationship between SOA concentrations and the AOC is dependent on the SOA precursor distribution. Studies on SOA formation pathways further show that, when the AOC is reduced, the SOA from oxidation, partitioning of semi-volatile POA and co-emitted intermediate volatile organic compounds (VOCs) decreases remarkably, followed by those from anthropogenic and biogenic VOCs. Meanwhile, the SOA decrease in the irreversible uptake of glyoxal and methylglyoxal on aerosol surfaces is negligible.

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