Characterization of lightning observed by multiple high-speed cameras

Abstract

This study aims to analyze the visible parameters of the cloud-to-ground discharges such as the average multiplicity, continuing current duration and interstroke interval. Several authors already analyzed these parameters for groups of thunderstorms in some regions. Although some authors did not find differences between those characteristics between different regions, there has not been a comprehensive amount of lightning recordings from the same thunderstorm, in order to evaluate such parameters in a storm-to-storm basis. The lightning data for this work was obtained by four high-speed cameras (Phantom v9.1) set to record 2500 frames per second. They were located in Sao Jose dos Campos, Brazil, as part of the project RAMMER (Automated Multi-Camera Network for Monitoring and Study of Lightning Flashes). Five thunderstorm days were selected for this study and some of the data were recorded manually, which provided a higher number of confirmed cloud-to-ground lightning records. A total of 357 flashes were recorded. As far as the authors know, this is the first time that four high-speed cameras are looking to the same thunderstorm from different locations. Because of the number of cameras and their positions, the coverage area is larger, thereby increasing the number of flashes recorded from the same thunderstorm. These samples allow a more representative analysis of the lightning parameters mentioned above.