scholarly journals Daytime Atmospheric Oxidation Capacity of Urban Beijing under Polluted Conditions during the 2008 Beijing Olympic Games and the Impact of Aerosols

SOLA ◽  
2011 ◽  
Vol 7 ◽  
pp. 73-76 ◽  
Author(s):  
Jie Li ◽  
Zifa Wang ◽  
Weiling Xiang
Keyword(s):  
Olympic Games ◽  
Atmospheric Oxidation ◽  
Beijing Olympic Games ◽  
Oxidation Capacity ◽  
2008 Beijing Olympic Games ◽  
The Impact

The impact of the pollution control measures for the 2008 Beijing Olympic Games on the chemical composition of aerosols

2011 ◽  
Vol 45 (16) ◽  
pp. 2789-2794 ◽  
Author(s):  
Tomoaki Okuda ◽  
Shinichiro Matsuura ◽  
Daisuke Yamaguchi ◽  
Tomoaki Umemura ◽  
Eriko Hanada ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Pollution Control ◽  
Olympic Games ◽  
Control Measures ◽  
Beijing Olympic Games ◽  
2008 Beijing Olympic Games ◽  
The Impact

Budget of nitrous acid (HONO) and its impacts on atmospheric oxidation capacity at an urban site in Guangzhou of China

2021 ◽  
Author(s):  
Yihang Yu ◽  
Peng Cheng ◽  
Huirong Li ◽  
Wenda Yang ◽  
Baobin Han ◽  
...  
Keyword(s):  
Nitrous Acid ◽  
Emission Rate ◽  
Chemical Mechanism ◽  
Atmospheric Oxidation ◽  
Urban Site ◽  
Homogeneous Reaction ◽  
Pearl River Delta Region ◽  
Oxidation Capacity ◽  
High Concentrations ◽  
The Impact

<p>Nitrous acid (HONO) can produce hydroxyl radicals (OH) by photolysis and plays an important role in atmospheric photochemistry. Over the years, high concentrations of HONO have been found in the Pearl River Delta region (PRD), which may be one of the reasons for the high atmospheric oxidation capacity. A comprehensive atmospheric observation was conducted at an urban site in Guangzhou from 27 September to 9 November 2018. During the period, HONO ranged from 0.02 to 4.43 ppbv with an average of 0.74±0.70 ppbv. The combustion emission ratio (HONO/NOx) of 0.9±0.4% was derived from 11 fresh plumes. The primary emission rate of HONO during night was calculated with the emission source inventory data to be between 0.04±0.02 and 0.30±0.15 ppbv/h. And the HONO produced by the homogeneous reaction of OH+NO at night was 0.26±0.08 ppbv/h, which can be seemed as secondary results from primary emission. They were both much higher than the increase rate of HONO (0.02 ppbv/h) during night. Soil emission rate of HONO at night was calculated to be 0.019±0.0003 ppbv/h. Deposition was the dominant removal process of HONO during night, and a deposition rate of at least 2.5 cm/s is required to balance the direct emissions and OH+NO reaction. Correlation analysis shows that NH<sub>3</sub> and relative humidity (RH) may participate in the heterogeneous transformation from NO<sub>2</sub> to HONO during night. In the daytime, the average primary emission P<sub>emis</sub> was 0.12±0.01 ppbv/h, and the homogeneous reaction P<sub>OH+NO</sub> was 0.79±0.61 ppbv/h, which was even larger than the unknown sources P<sub>Unknown</sub> (0.65±0.46 ppbv/h). The results showed that the direct and indirect contributions of primary emission to HONO are great at the site, both during daytime and nighttime. Similar to previous studies, P<sub>Unknown</sub> was suggested to be related to the photo-enhanced reaction of NO<sub>2</sub>. The mean OH production rates by photolysis of HONO and O<sub>3</sub> were 3.7×10<sup>6</sup> cm<sup>-3</sup>·s<sup>-1</sup> and 4.9×10<sup>6</sup> cm<sup>-3</sup>·s<sup>-1</sup>, respectively. We further studied the impact of HONO on the atmospheric oxidation by a Master Chemical Mechanism (MCM) box model. When constraining observed HONO in the model, OH and O<sub>3 </sub>increased 59% and 68.8% respectively, showing a remarkable contribution of HONO to the atmospheric oxidation of Guangzhou.</p><p> </p>

scholarly journals Emission controls versus meteorological conditions in determining aerosol concentrations in Beijing during the 2008 Olympic Games

2011 ◽  
Vol 11 (23) ◽  
pp. 12437-12451 ◽  
Author(s):  
Y. Gao ◽  
X. Liu ◽  
C. Zhao ◽  
M. Zhang
Keyword(s):  
Olympic Games ◽  
Regional Scale ◽  
Emission Control ◽  
Meteorological Conditions ◽  
Control Measures ◽  
Total Particulate Matter ◽  
Beijing Olympic Games ◽  
Budget Analysis ◽  
Emission Controls ◽  
2008 Beijing Olympic Games

Abstract. A series of emission control measures were undertaken in Beijing and the adjacent provinces in China during the 2008 Beijing Olympic Games on 8–24 August 2008. This provides a unique opportunity for investigating the effectiveness of emission controls on air pollution in Beijing. We conducted a series of numerical experiments over East Asia for the period of July to September 2008 using a coupled meteorology-chemistry model (WRF-Chem). Model can generally reproduce the observed variation of aerosol concentrations. Consistent with observations, modeled concentrations of aerosol species (sulfate, nitrate, ammonium, black carbon, organic carbon, total particulate matter) in Beijing were decreased by 30–50% during the Olympic period compared to the other periods in July and August in 2008 and the same period in 2007. Model results indicate that emission controls were effective in reducing the aerosol concentrations by comparing simulations with and without emission controls. In addition to emission controls, our analysis suggests that meteorological conditions (e.g. wind direction and precipitation) were also important in producing the low aerosol concentrations appearing during the Olympic period. Transport from the regions surrounding Beijing determined the daily variation of aerosol concentrations in Beijing. Based on the budget analysis, we suggest that to improve the air quality over Beijing, emission control strategy should focus on the regional scale instead of the local scale.

Sign in / Sign up

Export Citation Format

Share Document