Abstract:
Based on the cloud-to-ground (CG) lighting location data as well as tropical cyclone (TC) intensity and path data from Guangdong typhoon real-time release system, we analyzed the spatiotemporal distribution characteristics of lightning activity and its relationship with TC intensity changes in seven severe typhoons and one super typhoon that landed in Guangdong from 2008 to 2018. The results show that the increase or decrease of TC lightning activity is not directly related to whether the TC makes landfall or not. The daily variation of TC lightning activity presents a single peak distribution, with a peak at 17: 00 BT and a valley at 07: 00 BT. TC exhibits three distinct circles of radial lightning density, with active lightning in the inner core and outer rainband, but inactive lightning in the inner rainband. The differences in microphysical characteristics and updrafts within different regions of TC are responsible for the "three-circle" structure of TC lightning activity. Whether before or after TC landing, the outer rainband has an overwhelming majority of lightning, and there is a trend for lightning activity to converge towards the center of the TC after landing. TC lightning activity displays a spatially asymmetric distribution. There is no significant correlation between the intensity of TC lightning activity and the intensity level of the TC at the time of lightning occurrence. It is not the case that the stronger the TC intensity, the more active the lightning. Lightning activity is most likely to occur during the typhoon stage, and as the intensity of the TC increases, the lightning activity gradually weakens. In the inner core, lightning activity surges with the intensification of the TC, and the weakening of the TC is accompanied with the decrease of lightning activity, indicating that lightning activity in the inner core has good indicative significance for changes in TC intensity. During the weakening period of the TC, the inner core and inner rainband experience the strongest lightning activity, while during the intensification period of the TC, lightning activity is most active in the outer rainband.