江西省雾日数的时空分布特征分析

摘要

利用1960—2012年江西省89个气象站逐日雾的观测资料以及高速交通气象站的能见度观测资料，采用经验正交函数（EOF）方法，分析了江西省雾日数的时空分布特征。结果表明，江西省雾日数的空间分布特征与江西的地形地貌密切相关，分布特点总体是高海拔地区或山区雾日数多，丘陵平原湖泊地区雾日数少。雾日数最多的季节为冬季，其次为秋季和春季；20世纪70年代中期至80年代中期雾日数明显偏多，21世纪以来雾日数呈明显减少的趋势。雾日数的年际变化受地形的影响较大，高海拔地区或山区雾日数变化比丘陵平原湖泊地区的要大，属于雾日数异常敏感区域；在20世纪60年代至80年代中期表现为丘陵、平原、湖泊等地区的雾日数偏少，高海拔地区或山区的雾日数偏多，80年代以后则呈相反的分布型式。%Based on the 1960-2012 daily fog data from 89 meteorological stations in Jiangxi province and the visibility data from traffic weather stations along Jiangxi Taijing freeway , the temporal and spatial distribution of seasonal fog days was discussed by using the empirical orthogonal function (EOF) method. The results showed that the spatial distribution of foggy days in Jiangxi was closely related to the local landform condition. Generally, more fog days occurred in high altitude or mountainous areas, while less fog days appeared in hilly, plain and lake areas. The highest number of seasonal fog days occurred in winter, followed by in spring and autumn. More fog days occurred abnormally during the middle 1970s-the middle 1980s, however, from the beginning of this century, fog days decreased significantly. The analyses of EOF showed that compared with that in hilly, plain and lake areas, the interannual variation of fog days in Jiangxi was largely effected in high altitude or mountainous areas. During 1960s to the mid-1980s, the fog days in hilly area, plain and lake areas presented lower probability, and higher probability in high altitude or mountainous areas. However, it showed the opposite distribution pattern after 1980s.