Observations of gravity wave propagation in the OI (557.7 nm), Na (589.2 nm) and the near infrared OH nightglow emissions

Abstract

Images of wave-like structure in three nightglow emissions with different height profiles [the OI (557.7 nm) and Na (589.2 nm) lines and the OH bands between 715 and 810 nm] have been obtained with a low light TV system. A bright, well defined, curved wave pattern seen in these emissions on the evening of 14 August 1980 from the Gornergrat Observatory, Switzerland (45.98°N, 7.78°E) has been identified as the signature of a short period gravity wave propagating freely through the upper atmosphere in the height interval 80–100 km from a region over South-West France. The best fit parameters of the wave disturbance which produced the structures in the three airglow layers are wavelength = 6.5 ± 1.5 km, phase velocity = 5 ± 2 ms −1 (period = 21 ± 1 min) and phase propagation angle = 75° ± 3°, and were obtained by assuming a background wind with a horizontal component of 18 ms −1.