Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6330971 | Science of The Total Environment | 2014 | 7 Pages |
Abstract
A severe air pollution event in the Xianlin District of Nanjing City, China during 23-24 December 2012 was analyzed in terms of aerosol extinction coefficient and AOT retrieved from Mie scattering LiDAR data, in conjunction with in situ particulate concentrations measured near the Earth's surface, and the Weather Research Forecast-derived meteorological conditions. Comprehensive analyses of temperature, humidity, wind direction and velocity, and barometric pressure led to the conclusion that this pollution event was caused by advection inversion. In the absence of temperature inversion, the atmosphere at a height of 0.15Â km has a relatively large extinction coefficient. In situ measured particulates exhibited a very large diurnal range. However, under the influence of turbulences, AOT was rather stable with a value <Â 0.2 at an altitude below 0.8Â km. Advection inversion appeared at 9:00Â AM on 24 December, and did not dissipate until 22:00Â PM. This temperature inversion, to some degree, inhibited the dispersion of near-surface particulates. Affected by this temperature inversion, the atmospheric extinction coefficient near the surface became noticeably larger. Near-surface particulates hardly varied at a concentration around 0.2Â mg/m3. AOT at an altitude below 0.8Â km rose to 0.31.
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Authors
Wanning Wu, Yong Zha, Jiahua Zhang, Jay Gao, Junliang He,