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| The origin of crop residue burning impact on air quality of Nanjing |
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Abstract The regional transport and local sources of air pollution inducing by crop residue burning was discussed by using satellite remote sensing of fire hot spots data, cloud cover information and back trajectory analysis. The results showed that the polluted air mass could dispersion in regional scale in certain meteorological condition and the relationship between upstream fire hot spots and downstream city Air Pollution Index was obviously. We categorized the air pollution events into three types, which were local(e.g., 31May 2006, 8November 2009), regional(e.g., 28October 2008), and the integration of the two(e.g., 14June 2006, 5June 2007, 2June 2008) respectively. By using fire hot spots and air mass back trajectory analysis, the source of pollutants could be conformed in cloudy days. Weather conditions of air pollution analysis showed that crop residue burning accompanies 500hPa trough (in or in front), low shear and weak convergence in atmospheric boundary layer, sparse isobar, low wind speed/calm wind, are not convenience for air pollutants dispersion. On the other hand, inversion layer confined the pollutants in the mixing layer and high relative humidity was in favor of the formation of haze, intensifying air pollution.
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Received: 09 June 2010
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