Abstract:

By using daily visibility and relative humidity data in 78 meteorological stations of Anhui Province during 1971-2010,this paper analyzed the temporal and spatial distribution characteristics of haze days.It also analyzed the climate variation of haze days in recent 40 years in Anhui province by using EOF decomposition method. The results show as follows.There was a significant increasing trend of haze days in Anhui Province. The most concentrated period of time for haze was in winter, the daily variation of haze days mainly showed twopeak structure,one peak was in January, and the second peak was in May to June.The heavest haze offen occured in June. The diurnal variation showed haze more happened in day time than night,peaking at 08〖DK〗∶00 BT. The spatial distribution characteristics of haze days was were very inhomogeneous,haze more happened in plains and around major cities than in mountains. The heavest haze days most happened in Huaibei. The annual haze days was highest at 2007 in 40 years.The contribution of the first four modal cumulative variance of EOF decomposition of haze days up to 793%. The spatial distribution of haze days was increasing with years in most areas in Anhui province.The time coefficient showed the haze days had significant annual variation of 3-4 years oscillatory growth