Abstract:In terms of the observations from the LS8000 lightning location system, Cloud to Ground (CG) lightning activities in Shanghai and its circumjacent regions are studied. The percentage of positive CG lightning in total CG lightning is about 85% and that of large current CG lightning (with the absolute value of current larger than 50 kA) is 56%. CG lightning activities highly centralized in the period from June to September, and peaked in August; for the temporal distribution of CG lightning, 13:00 to 21:00BT is an active periods, with peaks at 14:00BT and valleys in the morning. The monthly and hourly distributions of the percentage of the PCG (positive cloud to ground) lightning in total CG lightning present negative relationship to CG lightning. Setting 31°N as the boundary, the CG lightning density is generally 6 to 12 flushes/(km2〖DK〗·a) in the northern part of the analysis area and 24 to 48 flushes/(km2〖DK〗·a) in the southern part. At the same time, the CG lightning density on land is higher than those in lake and oceanic areas, while the percentage of PCG lightning and the large current CG lightning in the oceanic area is significantly higher than those on land. The time changes of spatial distribution of CG lightning show that CG lightning activities mainly appear on the land in afternoon and near the water in the morning, while in other periods presents the characters of transition, which is closely related to the heating effect of the underlying surface.