STRUCTURE IN THE LAMBDA-557.7 NM[OI] AIRGLOW

The application of a four field photometer for study of structure in the airglow is described. Records of the λ557.7 nm [OI] emission from the 95km level frequently show quasi periodic structures. Drift velocities of these structures, typically in the range 50 to 100 ms-1, differ in magnitude, and direction from wind velocities inferred from Doppler shift of the emission line measured with a Fabry-Perot interferometer. The power spectrum of the intensity fluctuations typically cuts off at a period of about 4 min, consistent with the hypothesis that gravity waves are a major cause of the structure. On one night much shorter periods were observed; these were attributed to turbulence generated in the dissipation of large amplitude gravity waves. It is suggested that the major fluctuations with periods of tens of minutes are due to gravity waves generated in the vicinity of tropospheric fronts. © 1979.