Total lightning flash characteristics observed from TRMM Lightning Imaging Sensor (LIS) and their relationship with regional convection and precipitation type

Lightning activity in thunderstorms are deeply related to the microphysical and kinematic properties of convective clouds, but the relationship between the amount of precipitation and lightning flash rate is not linear and strongly dependent on the local convective regime. As an example, great amounts of precipitation are found over the tropical oceans while lightning is more frequent over the continents, varying from a moderate precipitation-lightning efficiency over the Amazon to regions over the Central Africa with low rainfall but extremely high flash rate activity. These differences are well documented but poorly understood. In this scope, the TRMM satellite has collected for over 12 years detailed measurements of tropical convective cloud systems and their electrification throughout the Precipitation Radar (PR), the TRMM Microwave Imager (TMI) and the Lightning Imaging Sensor (LIS). In particular, the LIS sensor identifies total lightning (intracloud and cloud-to-ground) activity by detecting changes in the brightness of clouds as they are illuminated by lightning electrical discharges. Therefore, LIS operates as a lightning event detector, where several events are grouped in space and time to determine a “flash”. Flash initiation rate is related to the recharging rate of a local electric field in deep convective cores, while the extent of a flash indicates the extent of charged regions defined primarily by advective processes in the storm updraft. The total flash and group footprint are related to the overall flash extent, and so may indicate important information about ice hydrometeor trajectories into stratiform or anvil regions. We focus our analyses on individual flash and convective areas characteristics from LIS (such as, number of events, groups, total radiance, area footprint, etc.) to identify possible differences in the energetics of the flashes and/or the optical scattering properties of the storms cell due to changes in the microphysics of the clouds (i.e., convective or stratiform rainfall observed from PR and TMI). This type of analyses is important to and can be applied to quantitative precipitation estimation (QPE) using lightning information as constrain for convective and stratiform rainfall partition. Multi-sensor and multi-platform algorithms provide a more complete view of the precipitation processes and aid the procedure of rainfall retrievals.