Studies of Convection and Lightning

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This research centers on the study of convection, specifically Mesoscale Convective Systems (MCS's), which are responsible for the bulk of the warm season precipitation in many locations in the central U.S. In addition to producing heavy rainfall, they also produce severe weather in the form of damaging winds (including tornadoes), hail and copious amounts of lightning. Another type of electrical activity associated with MCS's are Transient Luminous Events (TLE's), identified as sprites, elves, and blue jets. These are forms of electrical discharges occurring in the upper atmosphere at great heights above the tops of the MCS's that often appear to be triggered by lightning activity within the cloud, or between cloud and ground. The broad objective of this work is to better understand the linkages between storm dynamics, precipitation formation, lightning generation, and TLE's. The research team will carry out a large, statistically-based study combining NEXRAD and research weather radar data with available data from VHF lightning mapping arrays and the National Lightning Detection Network, to further understand charge separation in thunderstorms, the organization of charge layers in storms, the resulting distribution of lightning and TLE discharges, and how these characteristics may be related to the physical characteristics of the storm environment. Another specific aspect of this work is to study bow echo MCS's and determine if there is more than just a casual relationship between bow development and evolution of storm cloud-to-ground lightning patterns. The intellectual merit of this work is to advance understanding of precipitation development processes, cloud electrification and lightning. Broader impacts of this work include determining how lightning observations may reveal physical processes in convection, as well as assisting in the analysis and nowcasting of severe weather characteristics. This effort is also unique in that it will pave the way for combining the future polarimetric NEXRAD radar network with operational lightning mapping systems to provide better real-time characterization of convective weather.