Unprecedented Look at Lightning Propagation and Ground Attachment in Ultraviolet

Abstract Development of hot lightning channels is facilitated by essentially cold streamers emanating from their extremities. Thus, streamers play a crucial role in lightning, yet they are poorly understood, because they emit primarily ultraviolet (UV) light, which usually goes undetected. Here, we present unique UV images of lightning, including interaction between positive and negative streamers, leading to new inferences on lightning propagation and attachment. We observed an abrupt change in the lightning propagation path to ground, which resulted in an aborted attachment process and a different ground connection point, 200 m away from the expected one. This change was likely due to the self‐choking effect of large negative space charge that was suddenly introduced by the intense streamer burst ahead of the lower end of the descending negatively‐charged channel. Further, the unique UV images show that positive and negative streamer zones are an order of magnitude longer than previously thought.