中国雾区的分布及其季节变化

用中国范围604个台站1961年1月￣2000年12月的地面观测雾日资料,分析了雾的地理分布,讨论了不同区域雾的月年变化特征。结果表明:中国地区主要有6个雾区:长江中游区、海岸区、云贵高原区、陇东-陕西区、淮河流域、天山及其北疆区。大多数区域雾日年际变化有下降的趋势,特别是20世纪80年代之后下降趋势更明显,雾日显著趋势区呈西南-东北走向,上升和下降趋势区相间分布,自东南向西北呈波列结构;中国大多数雾区秋冬季雾日最多,春夏季雾日较少。黄海岸区和北疆月际变化相似,都呈双峰型分布,其他区域为单峰型分布。

The Distribution and Seasonal Variations of Fog in China

The geographic distribution features and monthly/yearly variation rule of foggy days in China are analyzed based on the monthly mean fog data collected from 604 observational stations for the period 1961-2000. It is shown that there are six fog regions in China: the middle reaches of the Yangtze River, coastal area, Yunnan-Guizhou Plateau, eastern Gansu-western Shaanxi, Huaihe River Valley, Tianshan mountainous area and northern Xinjiang. On the whole the yearly variation trend of foggy days is descending, it is especially obviously after the 1980s. The areas where the foggy days have obvious tendency present a southwest-northeast trend. The rising trend regions alternate with descending trend regions, having a SE-NW directional wave structure formed. In general, the number of foggy days in autumn and winter is larger than in spring and summer over most fog districts. The monthly variation curves of foggy days are bimodal in the shore area of the Yellow Sea and northern Xinjiang, and unimodal in other regions.