近10年武汉市大雾变化特征及2006年一次大雾个例分析

为了了解近一个时期武汉市大雾的时空变化特征、大气环流背景及有关物理要素场的分布情况,根据1995～2005年武汉市大雾观测记录,统计分析了这一时期武汉市大雾的变化特点,并对2006年3月10日出现在武汉市的一次大雾天气过程进行了分析。结果表明:近11年来,武汉市大雾日数继续下降,冬季大雾出现频率最高,春、秋季大雾频率次之,大雾持续时间明显延长;高空弱的偏西气流,中低层弱的暖湿气流,近地面有逆温层,地面为均压场等条件,是大雾形成的有利环流形势。

Characteristics of Dense Fog Variation in Recent 10 years and a Case Analysis in Wuhan

In order to find out the temporal and spatial variation characteristics,the background of atmospheric circulation and the relevant physical element distribution of dense fog,the climatic variation of dense fog is statistically analyzed on the base of the dense fog observational data from l995 t0 2005 in Wuhan and a dense fog case on March l0,2006 is specially studied.The results show that the day numbers of dense fog continuously decreases;the maximum frequency of the dense fog occurs in winter,the frequencies in spring and in autumn take the second place;and the endurance period remarkably increases.The upper weak westerly air flow,the warm-wet air flow at the middle-low layer,the inversion layer close to the ground and the uniform pressure field on the ground surface are the favorable circulation situations for the formation of dense fog.