Temporal and latitudinal 5577 Å airglow variations

Abstract

From 32 000 [O1] 5577 Å airglow limb observations made between April 1971 and December 1972 from the ISIS-2 satellite, the major temporal and spatial night airglow features have been identified. Two methods of analysis were employed: harmonic fitting and global correlation. Airglow emission rate maxima occurred in mid-October and mid-April at all latitudes. The intensities peaked near 35° in the winter and near 25° in the summer and showed a symmetry with latitude centred about 5° in the winter hemisphere. The mean intensity at mid-latitudes was 175 R and near the equator was 120 R. From the global correlation analysis it was shown that there are two distinct contributions to the temporal and spatial airglow variations: one is from local production which dominates during the post-solstice period, and the other is from large scale meridional transport which dominates during the post-equinox period.