2013年12月上旬江苏大范围持续性雾霾成因分析

Analysis of the Sustained Fog and Haze Event Resulting of Jiangsu Province in Early December 2013

利用常规气象观测资料和NCEP/NCAR再分析资料,从污染实况、气象要素特征、环流背景、水汽条件、动热力条件等方面,对江苏2013年12月上旬持续雾霾天气成因进行分析,结果表明:(1)持续性雾霾天气发生时江苏大部分地区空气质量达到重度污染,首要污染物为PM2.5,大量的气溶胶粒子长时间悬浮于空中;(2)这段时间内影响江苏的冷空气势力较弱,中高层冷空气未能完全破坏底层相对稳定的层结,而近地层湿度较大且风速较小利于霾的发展,重度霾时相对湿度在80%以上,且风速多维持在3 m/s以下;(3)逆温层的长时间维持结使得大气中上下的湍流热量和动量交换减弱,不利于垂直上升运动的发生发展,进一步有利于将近地层的污染物和水汽粒子不断积聚,使得雾霾得以发生和长时间维持。

By using conventional observation data and NCEP reanalysis data, the sustained fog and haze occurred in the early November were analyzed from several aspects, such as pollution, circulation background, meteorological characteristics, vapour conditions, thermal and dynamic conditions. The results showed that：When persistent fog and haze occurred, the air quality in most parts of Jiangsu achieved high levels of pollution, the primary pollutant was PM2.5. This time the cold air forces was weak, high-level cold air cannot completely destroy the underlying relatively stable stratification. The smaller wind speed and larger relative humidity were favorable for the development of the fog and haze, while because of the wind speed under 3 m/s and the relative humidity above 80%. Long maintained temperature inversion in the atmosphere made the exchange of turbulence heat and momentum weakened, which was not conducive to the development of upward movement, but conducive to the accumulation of the pollutant particles and water vapor at TROPOSHERE, promoted the occurrence and maintain of fog and haze.