Lightning Initiation and Propagation Relative to Turbulence and Hydrometeor Categories

The collision and separation of ice hydrometeors such as graupel and ice crystals inside storms can create layers of charge with opposite polarity resulting in enhanced electric field and lightning. Flash propagation and size is dependent on the morphology of charge layers, which is directly affected by storm kinematics including regions with enhanced turbulence. In this study, we aim to investigate the initiation and propagation of lightning flashes in relation to inferred turbulence inside the storm as well as microphysical properties from radar measurements. We use the NASA MSFC Lightning Mapping Array and the DOE CSAPR-2 radar datasets, deployed during the RELAMPAGO-CACTI Field Campaign in Cordoba, Argentina in late 2018. This study is performed on the 5 December 2018 thunderstorm, which presents unique lightning and charge structure characteristics, such as intense flash rates confined to the lower half of the mixed-phase layer, and a low-level anomalous charge structure. PyTDA is used to infer Eddy Dissipation Rate (EDR) from Spectrum Width data, and csu_RadarTools is used to retrieve hydrometeor classification based on dual-polarimetric variables. VHF sources are matched with the nearest radar beam in order to retrieve the EDR value and the hydrometeor category associated with each VHF source. Preliminary results suggest no difference between flash initiation and propagation turbulence distributions, but temporal variation in these distributions is noticeable. Also, most VHF sources are associated with regions of graupel and hail, as expected, followed by ice aggregates.