Airborne night airglow measurements in the South Atlantic Magnetic Anomaly

Abstract

Dessler [1959] devised a mechanism to account for the appearance of a gap in the outer Van Allen radiation belt that appeared as Outward projection horns' in the contours of constant radiation intensity. The mechanism involves the influence of the earth's negative magnetic anomaly near Capetown, South Africa, which, he suggested, would cause a lowering of the mirroring point of radiation. This hypothesis, that a negative magnetic anomaly would cause charged particles to penetrate to a lower altitude than normal, appears to be substantiated with the discovery from satellite measurements of the South Atlantic radiation anomaly (35:00°S; 25:00°W) near the maximum of the South Atlantic magnetic anomaly off the coast of Brazil [Kurnosova et al., 1962]. Cole [1961], considering Dessler's hypothesis, suggested that, in the regions of the magnetic anomaly, owing to a predicted increase in electron flux of several orders of magnitude, the intensity of the night airglow should be significantly greater than in regions outside the magnetic anomaly.