Coordinated rocket and satellite measurements of an auroral event, 2. The rocket observations and analysis

Abstract

Auroral optical emission rates, thermal ion and electron densities, and low‐energy electron fluxes were measured in an IBC I aurora by a rocket‐borne payload, simultaneously with the overpass of the Atmosphere Explorer C satellite. Auroral ionization rates deduced from the rocket payload and neutral gas densities measured by an instrument on the satellite are used in a model calculation of the thermospheric manifestation of the aurora. The internal consistency of the electron and photometric measurements is demonstrated for the particle‐induced emission of 3371‐Å. A quenching rate of the N2(A³Σu+) state is deduced, by using the measured oxygen densities, and found to be 1.2−.2+.7 × 10−10 cm³ s−1. A discrepancy between the calculated and measured ionospheric densities is discussed in terms of the abundance of nitric oxide. A discrepancy between calculated and measured low‐energy electron fluxes (E <100 eV) is attributed to local plasma processes. The major source of 5577‐Å emission is found to be energy transfer from the N2(A³Σu+) state. The 6300‐Å is found to be unexplained by both electron impact on atomic oxygen and dissociative recombination of O2+.