Airglow intensities observed in the southern and northern hemispheres

Abstract

Meridian scanning observations of the intensities of the OI emissions at 630.0 and 557.7 nm were made with a tilting-filter photometer at Sutherland, South Africa, between 1973 and 1977. These intensities have been compared with the intensities observed more recently with a Fabry-Perot interferometer at Arecibo, Puerto Rico. At both stations, we find that post-midnight enhancements of the 630 nm intensity are more pronounced in the summer months. We also find at both stations that the intensity of the 558 nm emission has an equinoctial peak. We observe that the ratio between the 558 nm intensity to the North and to the South of Sutherland has an annual variation with the largest ratios being observed in the southern winter.