Ion production and effective loss rate in the mesosphere and lower thermosphere during the Western European Winter Anomaly Campaign 1975/76

Abstract

As part of a campaign to study the middle latitude ionosphere during winter anomaly conditions, rocket ‘salvoes’ were launched from ‘El Arenosillo’, Spain, on 4 and 21 January 1976. On each of these days the rocket instrumentation measured solar X-ray and H-Lyman-α intensities, energetic particle precipitation, and also the height distribution of the minor constituents NO and O 2( 1Δ g) . On this basis the ion production q( h) in the height range 50–120 km was estimated. The main contribution to q( h) were X-rays (above 90 km), H-Lyman-α (70–90 km), ionization of O 2( 1Δ g (80–90 km), particles, and galactic cosmic rays (below 70 km). Combining the ion production with simultaneously measured values of electron density N ϵ ( h) an estimate of the effective electron loss rate ψ(h) = q N ϵ 2 was obtained. On both days, ψ( h) showed a characteristic rapid decrease from values about 10 −11–10 −10 m 3s −1 below 78 km to values in the range 2 × 10 −13–3 × 10 −12m 3s −1 above this height.