午夜欧美大片免费观看,欧美激情综合五月色丁香,亚洲日本在线视频观看,午夜精品福利在线

Making use of the observation lightning data from the lightning location system of Heilongjiang Province from 2006 to 2008, in combination with the data from automatic stations, applying the method of statistical analysis，an analysis is made of the spatialtemporal intensity distributions of lightning activities, and the relationship between lightning and monthly mean precipitation and temperature. The results show that： in recent years, lightning activities in Heilongjiang Province increased year by year; lightning activities in summer were more frequent, but seldom in winter; the daily variation of lightning activities showed a doublepeak pattern mostly; there was evident regional difference in lightning density: larger in mountains and the neighboring areas，less in plain areas; the highdensity areas are within Daxing’an Mountains, with the highest density at Tahe; lightning density showed obvious latitudinal characteristic with season changing: moving northward from spring to summer, and southward from summer to autumn; positive lightning and total lightning intensities had the same spectral distribution, which was wider than that of negative lightning; there were two positive high density centers, both within the Daxing’an Mountains, and their seasonal moving regularity was similar to total lightning; the total number of lightning activities was linearly correlated with monthly mean precipitation, and exponentially correlated with monthly mean temperature.