Lightning flashes in 2005 - 2010 tropical cyclones: implications for intensity change and comparisons with convective and environmental parameters

The World Wide Lightning Location Network (WWLLN; http://wwlln.net), a real-time network that covers the entire globe, is used to investigate lightning flashes during the evolution of all tropical cyclones (TCs) from 2005 to 2010. The first objective of this presentation is to analyze both combined and individual results on the temporal and spatial distribution of lightning flashes associated with all of the TCs. For each storm, the temporal distribution of discharges outside and within 100-km range from the storm center (known as the inner core region) is compared to the changes in TC intensity. The intensification processes are quantified in terms of pressure and/or horizontal wind speed changes. The combined temporal distribution analysis emphasizes the lightning activity accompanying intensity changes, since several previous works have identified peaks in lightning count in the inner core just prior to, and during intensification and weakening processes. The spatial distribution of lightning is investigated specifically in terms of the combined results, which are compared to previous works that observed maxima of lightning flash densities in the eyewall and rainbands and a minimum in flash density between these regions. The second objective of this research is to compare lightning activity in the inner core with convective and environmental parameters. The convective parameters are obtained from TRMM (Tropical Rainfall Measuring Mission) passive microwave radar data in the 37- and 85-GHz channels and TRMM derived products (e.g., ice content and water content). Examples of environmental parameters discussed are sea surface temperature and sea surface height. The presentation shows several case studies including Cyclone Nargis in the North Indian Ocean, TCs near the Australian coast, and several intense Western North Pacific typhoons.