Altitude‐time development of sprites

Abstract

Data from sprites using a 16‐channel, multi‐anode photometer (MAP) have been recorded at 0.1 ms resolution. The majority of the sprites have onsets at an altitude of 70–75 km and subsequently propagate both upward and downward from this initial altitude. The statistical lifetime of the emissions measured by the blue‐sensitive MAP is approximately 1.3 ms. The velocities of propagation are between 10 7 and 10 8 m s −1 , with larger velocities being measured at higher altitudes. The larger propagation velocities of the upward and downward sprite luminosity channels are consistent with the characteristics of highly over‐voltage streamers in the mesosphere.