Study on spatial relationship among cloud-to-ground lightning, precipitation and number of thunderstorm day in Chongqing

Through the study of relationship among cloud-to-ground lightning, precipitation and thunderstorm day the understanding of cloud-to-ground lightning regular in this area was increased, and it provided the science basis for warning and forecasting and risk assessment of lightning protection. Using the ground meteorological data of 34 stations from 1971 to 2010 and monitoring data of lightning location system from 2007 to 2011 in Chongqing, this paper analyzed the spatial relationship among precipitation, rainstorm, number of thunderstorm day and cloud-to-ground lightning density in this area. The area where had more annual average thunderstorm days coincided with the area where had more annual average precipitations and rainstorm times, and didn´t consist with the area where had more cloud-to-ground lightning densities. The accumulative frequencies of annual top-ten thunderstorm day were almost more than 50% of all year. The spatial distribution of cloud-to-ground density coincided with the big range of rainstorm in the same day. he result showed that the spatial distributions of number of years of annual average thunderstorm day and years of annul average precipitation were not entirely consistent. The monitoring data of lightning locator was first considered to determine the cloud-to-ground lightning density when the lightning protection design and risk assessment were made for the construction. In Chongqing, the cloud-to-ground lightning was mainly from the systemic thunderstorm. And the southwest vortex was the major provider of cloud-to-ground lightning in this area.