Lightning Characteristics Associated With Storm Modes Observed During RELAMPAGO

Global satellite studies show a maximum in deep convection and lightning downstream of the Andes in subtropical South America. The Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign was designed to investigate the physical processes that contribute to the rapid development of deep convection and mesoscale convective systems (MCSs) in Argentina. A lightning mapping array (LMA) was deployed to Argentina as part of RELAMPAGO to collect lightning observations from extreme storms in the region. This study combines lightning data from the LMA and the Geostationary Lightning Mapper onboard GOES-16 with 1-km gridded radar data to examine the electrical characteristics of a variety of convective storms throughout their life cycle observed during RELAMPAGO. Results from the full campaign show 48% of flashes are associated with deep convection that occurs along the eastern edge of the Sierras de Cordoba (SDC) overnight. These flashes are 65 km2 smaller on average compared to stratiform flashes, which occur most frequently 50-100 km east of the SDC in the early morning hours, consistent with the upscale growth of MCSs off the terrain. Analysis of the 13-14 December MCS shows that sharp increases in flash rates correspond to deep and wide convective cores that have high graupel and hail mass, 35-dBZ volume, and ice water path. This work validates previous satellite studies of lightning in the region, but also provides higher spatial and temporal resolution information across the convective life cycle that has not been available in previous studies. Satellites have shown a hotspot in extreme lightning in subtropical South America that is associated with some of the deepest thunderstorms on Earth. A ground-based lightning observing platform was deployed to central Argentina to better understand the characteristics and three-dimensional structure of lightning in the region and how lightning flashes vary with storm intensity and life cycle. Results show the majority of lightning flashes are associated with the deepest, widest, and most intense parts of the storms. These flashes are concentrated near the higher terrain and tend to occur most frequently in the evening and overnight hours. Further analysis of a case study shows that a rapid increase in lightning activity is related to an increase in graupel and hail mass in the column below the flash centers. We find lightning characteristics including flash area, duration, and energy vary as the storm evolves and can be separated into distinct periods when the storm is developing, maturing, and decaying. Lightning characteristics associated with storm life cycles are analyzed using a lightning mapping array in subtropical South America Lightning flashes in deep convection are smaller in size, shorter in duration, and are less energetic compared to flashes in stratiform Rapid increases in lightning flash rates are associated with increases in graupel and hail within the convective cores