Electric characteristics of atmosphere in Yuxi region and its application of the CG lightning warning

The characteristics of atmospheric electric in fair weather and thunderstorm in Yuxi region have been analyzed by using the data obtained from Yunnan Lightning Location System and electric field mill from July 2006 to June 2007. It has been found the diurnal and monthly of atmospheric electric evolution in fair weather showed variation in Yuxi region. The charge structures of thunderstorm are both dipole and tripole, but most of charge structure of thunderstorm is dipolar. Different charge structure of thunderstorm is different discharge, the negative polarity of electric field underneath thunderstorm is main negative discharge, the activity of the cloud-to-ground(CG) flash is very active, the positive polarity of electric field underneath thunderstorm is main positive discharge, the activity of the cloud-to-ground flash is very weak. The methods of the CG lightning warning by the electric field mill are studied based on the variation characteristic of thunderstorm electric field, the polarity reversal warning method is applied, its POD and LT are more better than the threshold warning method.