scholarly journals Wet deposition and scavenging ratio of air pollutants during an extreme rainstorm in the North China Plain

2017 ◽  
Vol 10 (5) ◽  
pp. 348-353 ◽  
Author(s):  
Yue-Peng Pan ◽  
Xia-Ying Zhu ◽  
Shi-Li Tian ◽  
Li-Li Wang ◽  
Guo-Zhong Zhang ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Wet Deposition ◽  
North China Plain ◽  
North China ◽  
The North ◽  
The North China Plain ◽  
Scavenging Ratio

scholarly journals Modeling study of the 2010 regional haze event in the North China Plain

2015 ◽  
Vol 15 (16) ◽  
pp. 22781-22822 ◽  
Author(s):  
M. Gao ◽  
G. R. Carmichael ◽  
Y. Wang ◽  
P. E. Saide ◽  
M. Yu ◽  
...  
Keyword(s):  
Air Pollutants ◽  
North China Plain ◽  
North China ◽  
Weather Conditions ◽  
Air Pollution Control ◽  
Wind Speeds ◽  
The North ◽  
The North China Plain ◽  
Haze Event ◽  
Regional Haze

Abstract. The online coupled Weather Research and Forecasting-Chemistry (WRF-Chem) model was applied to simulate a haze event that happened in January 2010 in the North China Plain (NCP), and was validated against various types of measurements. The evaluations indicate that WRF-Chem provides reliable simulations for the 2010 haze event in the NCP. This haze event is mainly caused by high emissions of air pollutants in the NCP and stable weather conditions in winter. Secondary inorganic aerosols also played an important role and cloud chemistry had important contributions. Air pollutants outside Beijing contributed about 47.8 % to the PM2.5 levels in Beijing during this haze event, and most of them are from south Hebei, Shandong and Henan provinces. In addition, aerosol feedback has important impacts on surface temperature, Relative Humidity (RH) and wind speeds, and these meteorological variables affect aerosol distribution and formation in turn. In Shijiazhuang, Planetary Boundary Layer (PBL) decreased about 300 m and PM2.5 increased more than 20 μg m-3 due to aerosol feedback. Feedbacks associated to Black Carbon (BC) account for about 50 % of the PM2.5 increases and 50 % of the PBL decreases in Shijiazhuang, indicating more attention should be paid to BC from both air pollution control and climate change perspectives.

scholarly journals Distribution and Sources of Air pollutants in the North China Plain Based on On-Road Mobile Measurements

2016 ◽  
Author(s):  
Yi Zhu ◽  
Jiping Zhang ◽  
Junxia Wang ◽  
Wenyuan Chen ◽  
Yiqun Han ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Ultrafine Particles ◽  
North China Plain ◽  
North China ◽  
Regional Transport ◽  
Large Cities ◽  
Model Studies ◽  
The North ◽  
The North China Plain ◽  
Local Emissions

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 June 11 to July 15, 2013. High median concentrations of sulphur 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 would have a diluting effect on pollutants, while south winds would bring in pollutants 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.

scholarly journals Aerosol–radiation feedback deteriorates the wintertime haze in the North China Plain

2019 ◽  
Vol 19 (13) ◽  
pp. 8703-8719 ◽  
Author(s):  
Jiarui Wu ◽  
Naifang Bei ◽  
Bo Hu ◽  
Suixin Liu ◽  
Meng Zhou ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Air Pollutants ◽  
North China Plain ◽  
North China ◽  
Near Surface ◽  
The North ◽  
The North China Plain ◽  
Incoming Solar Radiation ◽  
Haze Pollution ◽  
Pm2.5 Concentration

Abstract. Atmospheric aerosols scatter or absorb a fraction of the incoming solar radiation to cool or warm the atmosphere, decreasing surface temperature and altering atmospheric stability to further affect the dispersion of air pollutants in the planetary boundary layer (PBL). In the present study, simulations during a persistent and heavy haze pollution episode from 5 December 2015 to 4 January 2016 in the North China Plain (NCP) were performed using the Weather Research and Forecasting model with Chemistry (WRF-Chem) to comprehensively quantify contributions of aerosol shortwave radiative feedback (ARF) to near-surface (around 15 m above the ground surface) PM2.5 mass concentrations. The WRF-Chem model generally performs well in simulating the temporal variations and spatial distributions of air pollutants concentrations compared to observations at ambient monitoring sites in the NCP, and the simulated diurnal variations of aerosol species are also consistent with the measurements in Beijing. Additionally, the model simulates the aerosol radiative properties, the downward shortwave flux, and the PBL height against observations in the NCP well. During the episode, ARF deteriorates the haze pollution, increasing the near-surface PM2.5 concentrations in the NCP by 10.2 µg m−3 or with a contribution of 7.8 % on average. Sensitivity studies have revealed that high loadings of PM2.5 attenuate the incoming solar radiation reaching the surface to cool the low-level atmosphere, suppressing the development of the PBL, decreasing the surface wind speed, further hindering the PM2.5 dispersion, and consequently exacerbating the haze pollution in the NCP. Furthermore, when the near-surface PM2.5 mass concentration increases from around 50 to several hundred µg m−3, ARF contributes to the near-surface PM2.5 by more than 20 % during daytime in the NCP, substantially aggravating the heavy haze formation. However, when the near-surface PM2.5 concentration is less than around 50 µg m−3, ARF generally reduces the near-surface PM2.5 concentration due to the consequent perturbation of atmospheric dynamic fields.

scholarly journals Observation of regional air pollutant transport between the megacity Beijing and the North China Plain

2016 ◽  
Author(s):  
Yingruo Li ◽  
Chunxiang Ye ◽  
Jun Liu ◽  
Yi Zhu ◽  
Junxia Wang ◽  
...  
Keyword(s):  
Air Quality ◽  
Air Pollutants ◽  
North China Plain ◽  
North China ◽  
Pollutant Transport ◽  
Air Pollutant ◽  
The North ◽  
The North China Plain ◽  
Transport Flux

Abstract. Megacities have strong interactions with the surrounding regions through transport of air pollutants. It has been frequently addressed that the air quality of Beijing was influenced by the influx of air pollutants from the North China Plain (NCP). However, estimations of air pollutant transport between megacities and surrounding regions using long–term observations are very limited. Using the observational results of the gaseous pollutants SO2, NO, NO2, O3, and CO from August 2006 to October 2008 at the Yufa site, a rural site south of Beijing, together with meteorological parameters, we evaluated the transport flux between Beijing and the NCP, as part of the “Campaign of Air Quality Research in Beijing and Surrounding Region 2006–2008” (CAREBeijing 2006–2008). The bivariate polar plots showed the dependence of pollutant concentrations on both wind speed and wind direction, and thus inferred their dominant transport directions. Surface flux calculations further demonstrated the transport directions and the seasonal variations in the cumulative transport strengths. The cumulative transport strengths of SO2, NO, NO2, NOx (NOx = NO +  NO2), O3, Ox (Ox = O3 + NO2), and CO were 92.6, –62.2, –8.9, –71.0, 217.3, 213.8, and 1038.1 mg s−1 m−2 during the observation period, respectively. For SO2, CO, and O3, the transport fluxes were from the NCP to Beijing in all seasons except winter, with the strongest fluxes largely in summer. The transport flux of NOx was from Beijing to the NCP except in summer, with the strongest flux in winter. Finally, our analysis suggests a profound influence of regional transport between Beijing and the NCP on the air quality of the megacity Beijing. Our study also suggested that various factors, such as the wind field, emission inventory, and photochemical reactions, could influence the transport of air pollutants between Beijing and the NCP. Therefore, both local emission reduction and regional cooperation must be considered in air quality management of the megacity Beijing.

scholarly journals Modeling study of the 2010 regional haze event in the North China Plain

2016 ◽  
Vol 16 (3) ◽  
pp. 1673-1691 ◽  
Author(s):  
M. Gao ◽  
G. R. Carmichael ◽  
Y. Wang ◽  
P. E. Saide ◽  
M. Yu ◽  
...  
Keyword(s):  
Air Pollutants ◽  
North China Plain ◽  
North China ◽  
Weather Conditions ◽  
Air Pollution Control ◽  
Wind Speeds ◽  
The North ◽  
The North China Plain ◽  
Haze Event ◽  
Tianjin City

Abstract. The online coupled Weather Research and Forecasting-Chemistry (WRF-Chem) model was applied to simulate a haze event that happened in January 2010 in the North China Plain (NCP), and was validated against various types of measurements. The evaluations indicate that WRF-Chem provides reliable simulations for the 2010 haze event in the NCP. This haze event was mainly caused by high emissions of air pollutants in the NCP and stable weather conditions in winter. Secondary inorganic aerosols also played an important role and cloud chemistry had important contributions. Air pollutants outside Beijing contributed about 64.5 % to the PM2.5 levels in Beijing during this haze event, and most of them are from south Hebei, Tianjin city, Shandong and Henan provinces. In addition, aerosol feedback has important impacts on surface temperature, relative humidity (RH) and wind speeds, and these meteorological variables affect aerosol distribution and formation in turn. In Shijiazhuang, Planetary Boundary Layer (PBL) decreased about 278.2 m and PM2.5 increased more than 20 µg m−3 due to aerosol feedback. It was also shown that black carbon (BC) absorption has significant impacts on meteorology and air quality changes, indicating more attention should be paid to BC from both air pollution control and climate change perspectives.

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

2016 ◽  
Vol 16 (19) ◽  
pp. 12551-12565 ◽  
Author(s):  
Yi Zhu ◽  
Jiping Zhang ◽  
Junxia Wang ◽  
Wenyuan Chen ◽  
Yiqun Han ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Ultrafine Particles ◽  
North China Plain ◽  
North China ◽  
Regional Transport ◽  
Large Cities ◽  
Model Studies ◽  
The North ◽  
The North China Plain ◽  
Local Emissions

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.

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