Search for lightning‐induced electron precipitation with rocket‐borne photometers

Abstract

Photometers at 3914Å and 5577Å and an optical imager were part of an experimental package launched on a sounding rocket in the 1987 Wave Induced Particle Precipitation (WIPP) campaign at Wallops Island, Virginia. The objective was to measure lightning‐induced electron precipitation (LEP) by means of its optical signature. This was the first attempt to measure LEP using rocketborne optical instrumentation. Launch criteria included nearby thunderstorm activity and ground‐based observations of Trimpi events. Lightning flashes are clearly discernible in the data. The photometer data was also characterized by large spin and precession modulations in the photon count rate, consistent with elevated steady particle fluxes in the northern portion of the instrument field of view. No evidence of LEP was observed by the photometers or onboard particle detectors [Arnoldy and Kintner, 1989]. Analysis of the data has enabled us to place an upper limit of 8 × 10−4 ergs‐cm−2‐sec−1 on any burst precipitation energy flux that may have occurred during the rocket flight in the regions explored by the photometers.