The chemistry of daytime sprite streamers – a model study

Abstract

Abstract. The chemical processes in daytime sprite streamers in the altitude range of 30–54 km are investigated by means of a detailed ion-neutral chemistry model (without consideration of transport). The model results indicate that ozone perturbations due to daytime sprites streamers differ considerably from the ones of nighttime events. Due to liberation of atomic oxygen there is an initial increase of ozone. In terms of relative ozone change, this effect decreases with altitude. While for nighttime conditions, reactive nitrogen produced during the electric breakdown is converted into less reactive NO2, in the sunlit atmosphere NOx causes catalytic ozone destruction. As a consequence, there is significant ozone loss in sprite streamers in the daytime atmosphere, in particular at higher altitudes. At an altitude of 54 km, ozone in the streamer column has decreased by about 15% fifteen minutes after the breakdown event.