Abstract

Sprites are an atmospheric event that until now has been studied with a limited number of events as data points. We investigated the global characteristics to further understand the interactions between sprites and thunderclouds that coincide with them. We analyzed the frequency distribution, morphology, location, and altitude of 525 sprites observed by the cameras located at Sagamihara, Japan, from December 2016 to March 2021. The majority of sprites were observed during winter. The column type sprites commonly occurred during winter. In contrast, sprites with complex morphologies are frequently observed in summer. Using the triangulation of simultaneously observed sprites at multiple locations, the average height of sprites was determined to be 81.6 km, and one instance occurred where the sprites horizontally spread in a range of tens of kilometers. For sprites of triangulation, precipitation maps by radar observations were made, and the location of lightning was investigated. We also investigated the correlation of the sprites to the gamma-ray emissions associated to thunderclouds.