Simultaneous Temperature, Intensity and Imaging Measurements of Short Period Wave Structure in the OH Nightglow Emission

A low light TV camera co-aligned with a narrow field Michelson interferometer have been used to investigate how variations in the intensity and temperature of the near infrared hydroxyl nightglow emission are related to the passage of short period mesospheric gravity waves. The observations were made from Sacramento Peak, NM (32.8°N, 105.8°W) on the night of 14/15 June 1983, during a spectacular nightglow display that also exhibited wave structure visible to the dark adapted eye. A coherent wave-like pattern of horizontal wavelength 23 ± 1 km moving uniformly with a velocity of 28 ± 2 m s−1 (apparent period 13.7 ± 1.2 min), was measured at several azimuths over an interval of 2.5 h. The induced intensity and temperature perturbations were wave-like in nature and exhibited a high degree of correlation. The intensity variations were large, up to 30%, yet the brightest wave forms were ⩽ 10 K hotter than the adjacent dark forms. The amplitude of the intensity fluctuation was found to be ∼ 8 times larger than the temperature variation. In all cases the intensity wave led the thermal wave, but only by a small amount. High contrast wave patterns of this type are uncommon and are a principal feature of “bright night” displays