Ozone air quality during the 2008 Beijing Olympics: effectiveness of emission restrictions
A series of aggressive measures was launched by the Chinese government to reduce pollutant emissions from Beijing and surrounding areas during the Olympic Games. Observations at Miyun, a rural site 100 km downwind of the Beijing urban center, show significant decreases in concentrations of O<...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2009-07-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/9/5237/2009/acp-9-5237-2009.pdf |
| Summary: | A series of aggressive measures was launched by the Chinese government to reduce pollutant emissions from Beijing and surrounding areas during the Olympic Games. Observations at Miyun, a rural site 100 km downwind of the Beijing urban center, show significant decreases in concentrations of O<sub>3</sub>, CO, NO<sub>y</sub>, and SO<sub>2</sub> during August 2008, relative to August 2006–2007. The mean daytime mixing ratio of O<sub>3</sub> was lower by about 15 ppbv, reduced to 50 ppbv, in August 2008. The relative reductions in daytime SO<sub>2</sub>, CO, and NO<sub>y</sub> were 61%, 25%, and 21%, respectively. Changes in SO<sub>2</sub> and in species correlations from 2007 to 2008 indicate that emissions of SO<sub>2</sub>, CO, and NO<sub>x</sub> were reduced at least by 60%, 32%, and 36%, respectively, during the Olympics. Analysis of meteorological conditions and interpretation of observations using a chemical transport model suggest that although the day-to-day variability in ozone is driven mostly by meteorology, the reduction in emissions of ozone precursors associated with the Olympic Games had a significant contribution to the observed decrease in O<sub>3</sub> during August 2008, accounting for 80% of the O<sub>3</sub> reduction for the month as a whole and 45% during the Olympics Period (8–24 August). The model predicts that emission restrictions such as those implemented during the Olympics can affect O<sub>3</sub> far beyond the Beijing urban area, resulting in reductions in boundary layer O<sub>3</sub> of 2–10 ppbv over a large region of the North China Plain and Northeastern China. |
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| ISSN: | 1680-7316 1680-7324 |