A Global Climatology of Tropical Cyclone Lightning

Previous studies suggest that lightning activity could be an indicator of Tropical Cyclones (TC) intensity change but their relationships vary from basin to basin. This study leverages the 16-yr total lightning data collected from the Lightning Imaging Sensor (LIS) onboard TRMM to investigate globally the TC lightning characteristics, lightning-TC intensity change relationships, and relations between TC lightning and environmental factors. Of the six basins examined, the Atlantic (ATL) and the Northern Indian Ocean (NINO) have the highest TC lightning density where environmental wind shear is also the greatest. Lightning activity increases dramatically when TCs move close to land possibly due to land influence and TC-aerosol interaction. Lightning density increases as SST increases but decreases after SST becomes warmer than 30 C. Similarly, moderate wind shear boosts lightning but strong shear is detrimental to lightning. All basins exhibit similar relationships between lightning activity and TC intensity change: rapidly weakening TCs produce the least lightning, TCs with average intensity change the most, with rapid intensifying TCs in between, which is different from previous studies based on cloud-to-ground (CG) lightning data. This study additionally examines the six hourly evolution of CG lightning, TC intensity, environmental data (e.g., SST), and aerosol concentration for some rapidly intensifying and weakening TCs (lightning data from the World Wide Lightning Location Network). One particular case, the rapid intensification phase of Hurricane Earl (2010) was lead by an outbreak of CG lightning after it moved over areas of warmer SST and greater aerosol concentration.