吉林省雾的气候特征及变化成因分析

The Climatic Characteristics and Causes of Fog Days in Jilin Province

利用1961-2010年吉林省雾日统计资料,对吉林省雾日的时空分布特征、变化趋势进行了详细分析,并分析了雾日变化的原因。结果表明：近50 a来,吉林省年和四季雾日的空间分布均呈东南部地区多、西部地区少的分布特征;雾日季节变化特征表现为8-9月多,10月至次年5月少,西部和中部地区雾日数月季变化呈现双峰型,东南部和东部地区呈现单峰型;雾大多数开始于夜间21时至次日早晨09时,结束于夜间22时至次日午后13时,持续时间多在6 h以下。近50 a来,除了春季雾日没有明显变化外,全省平均及各区域年和四季雾日均呈减少趋势;在2000年前后雾日数发生了一次明显的突变。雾日空间分布与海拔高度有密切关系;雾日趋于减少有人类活动导致的＂热岛效应＂、＂干岛效应＂、气溶胶密度加大等原因,也有气候趋于暖干化的自然原因。

By using the data of fog days in the period of 1961-2010 in Jilin Province, the characteristics and changes of spatial and temporal distribution of fog days as well as reasons are analyzed. Results show that the spatial pattern of annual and seasonal fog days presents more in southeastern areas and less in western areas of Jilin Province. The seasonal characteristics appear more during Aug. to Sep., but less during Oct. to May. The inter-monthly variation of fog days in western and middle areas appears bimodal pattern, and that in southeast-ern and eastern areas appears unimodality. Fog usually begins at 21：00-09：00 LST and ends at 22：00-13：00 LST, with duration 0-6 h. In recent 50 years, the annual and four seasonal fog days of the province＇s average and all areas exhibited decreasing trends. The fog days appear obvious sudden change in 2000.The spatial dis-tribution of fog days have relations with altitude. The causes of fog days decreasing are that the＂heat island ef-fect＂,＂dry island effect＂and the increase of aerosol, and that the climate becaming warm and dry.