Observations and Modeling of the Longest-Recorded Delayed Sprite

Transient luminous events (TLEs), such as sprites, have been investigated via observations and simulations for decades. Recent TLE research has focused on effects leading to the delay of a sprite from its parent lightning flash. Here we investigate a sprite with by far the longest recorded delay to date, a delay of almost a full second (916.6 ± 16.6 ms) from the onset of the parent flash, as observed from the ISS during the ILAN-ES campaign on 6 February 2024. Based on meteorological, satellite, and ground-based ELF data, we reconstruct a realistic charge configuration for the parent thunderstorm. We input this reconstructed charge configuration to a 3D quasi-electrostatic model in order to simulate regions of possible sprite inception as a function of time corresponding to this sprite event following the lightning. We demonstrate how the observed delayed sprite could have been incepted by a prolonged piecewise pattern of the current in the parent flash.