中文摘要：

根据1971－2010年567个中国地面观测站点的雾曰数和霾日数资料，分析了我国雾日数和霾日数的空间分布、季节变化以及年代际变化特征，并且利用REOF（旋转经验函数正交）分解对雾日数进行气候区划。结果表明：（1）雾主要分布在东南沿海地区、四川盆地地区、湘黔交界、山东沿海以及云南南部等地区。霾主要集中于华北、河南以及珠三角和长三角地区。（2）在季节变化上：秋、冬季雾和霾的分布大于春夏。（3）雾日数和霾日数年代际变化明显，雾目数在20世纪70至90年代较多，20世纪90年代以后减少；霾曰数自2001年以来急剧增长。（4）雾日数可以共可分为10个区，其中华北区、川渝区以及长江中下游区是雾出现频率较高的几个重点区域。

英文摘要：

Using observed fog and haze data from 567 stations during 1971-2010 in China, the general distribution and the seasonal and decadal variations of fog days and haze days were demonstrated. A rotated empirical orthogonal function was used to classify the fog days in China according to climate. The results show that： （1） Fog days were distributed mainly over the southeastern coastal area, the Sichuan Basin, the border between Hunan and Guizhou, the Shandong coastal area, and southern Yunnan. Haze days were concentrated over North China, Henan, the Pearl River Delta, and the Yangtze River Delta area. （2） Seasonal variations appeared： The numbers of fog days and haze days in autumn and winter are larger than those in spring and summer. （3） Fog days and haze days in China exhibit obvious decadal variations. There are more fog days from the 1970s to the 1990s, and fewer from the 1990s to 2010. The yearly variation trend of haze days was ascending rapidly from 2001. （4） The entire area of China can be divided into 10 parts. The north China, Sichuan, Chongqing, and the middle and lower reaches of the Yangtze River areas are major fog regions.