Lightning activity in tropical cyclones and its relationship to dynamic and thermodynamic parameters over the northwest Pacific

Tropical cyclones (TCs) over the northwest Pacific (NWP) Basin from 2005 to 2016 are used to investigate the characteristics of lightning activity and its relationship to environmental dynamic and thermodynamic parameters, which is based on lightning data from the World Wide Lightning Location Network (WWLLN), TC intensity and track, sea surface temperature (SST) and vertical wind shear (VWS) data. The highest lightning density in the inner core is found when TC is at tropical depression stage, whereas the secondary maximum occurs in super typhoon intensity stage. In the outer rainbands, lightning density changes slightly with TC intensity. The 6-hourly flash rate shows a distinctly positive correlation with the SST in the outer rainbands, and lightning activity in the inner core is less sensitive to the SST when the SST exceeds 27 °C. Asymmetric lightning distribution with respect to the VWS is observed. In the inner core, the asymmetric distribution of lightning activity is relative to the integrated effects of the VWS and TC motion vectors; however, the outer rainbands asymmetry is more sensitive to the VWS.