安徽省大雾时空分布特征及其发生的气象条件

利用1961～2009年近50 a来安徽省80个台站大雾观测资料,分析安徽省大雾的时、空分布特征及其发生的气象条件。结果表明:多雾区主要位于大别山区和皖南山区。雾日有明显的季节变化和月际分布,秋、冬季雾的范围较大,春、夏季雾的范围较小,其中冬季最大,夏季最小;大部分地区主要为冬季峰值型雾,雾日集中在10月至次年l月;雾大多数开始于23时至次日8时,结束于5～12时(8时为生成、消散最高峰),持续时间多在0～3h,以1 h以内居多。近50 a安徽省雾日总体上先增后减,但各地变化特征存在差异;潮湿空气、微弱风速和适宜气温利于大雾形成。

Spatial and Temporal Characteristics and Meteorological Conditions for Fog Formation in Anhui Province

The spatial and temporal characteristics and meteorological conditions for fog formation were analyzed based on the fog data from 80 stations in the period 1971-2005 in Anhui Province.The results show that fogs were concentrated in the Dabie Mountain and the southern Anhui Province.Fog days were of obvious seasonal and inter-monthly variation with wide areas in autumn and winter(maximum),narrow areas in spring and summer(minimum),and most concentrated in October,December and January in most parts of Anhui.Fog usually began at 23:00-08:00 LST and ended at 05:00-12:00 LST(maximum both at 08:00 LST),with duration 1-3 h and maximum 1 h.The yearly variation trend of fog days,different in the spatial distribution,was overall decreasing after increasing in the recent 50 years.Moist air with high relative humidity,weak wind and appropriate temperature benifits the formation of fog.