1970~2009年安徽省大雾气候特征分析

ANALYSIS OF FOG CLIMATIC CHARACTERISTICS IN ANHUI PROVINCE DURING 1970-2009

为了弄清安徽省大雾时空演变规律,利用安徽地面气象站1970~2009年40a的气象观测资料,对安徽省大雾的气候特征进行了系统的分析。研究发现安徽省大雾具有显著的年代际、季节性和区域性变化特征,结果表明：（1）年代际变化,安徽省雾日数在80年代达到最高,由于城市发展和气候变化的影响,雾日数不断减少。同时,雾生时间年代际变化不大,而雾消时间则不断后延,直接导致雾的持续时间不断增加,40a间雾的持续时间增加将近1h;（2）安徽省大雾四季特征分明,空间分布不均。冬季是安徽大雾的高发期,大雾日数最多,持续时间最长,雾中最小能见度最低,雾的影响最为严重。在夏季,大雾日数最少,持续时间最短,雾中最小能见度最大,雾的影响最弱;（3）空间分布上,皖北和皖南山区雾日数和雾的持续时间都较长,雾中最小能见度都较低。而在中部地区则相反,雾的影响较弱。

In this study,climatic features of fogs in Anhui Province were systematically analyzed,based on the data provided by surface observation stations from 1970 to 2009.The results showed that fogs in Anhui Province expressed a notable decadal variability.Foggy days peaked in 1980’s,after which foggy days decreased continuously from 1980’s to 2000’s.Meanwhile,decadal variability of fog generation time was not evident,but delayed fog dissipation time was obvious.As a result,fog duration increased approximately one hour during the forty years.Besides,the seasonal variation was obvious and the spatial distribution was not uniform.The season of high-frequency fog was winter,with most foggy days,longest fog duration and lowest fog visibility.The effect of fog in winter was the largest in the whole year.In the opposite,the season of low-frequency fog was summer,with least foggy days shortest fog duration,lowest fog visibility.The effect of fog in summer was the weakest in the whole year.In terms of spatial variation,fogs mainly occurred in the north region and the south mountainous region.