Ion Production and Effective Loss Rate in the Mesosphere and Lower Thermosphere During the Western European Winter Anomaly Campaign 1975/76

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 O2(1Δg). 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 O2(1Δg (80-90 km), particles, and galactic cosmic rays (below 70 km). Combining the ion production with simultaneously measured values of electron density Nε{lunate}(h) an estimate of the effective electron loss rate ψ(h) = q Nε{lunate}2 was obtained. On both days, ψ(h) showed a characteristic rapid decrease from values about 10-11-10-10 m3s-1 below 78 km to values in the range 2 × 10-13-3 × 10-12m3s-1 above this height.