A localized structure in OH airglow images near the mesopause region

[1] An intense localized airglow-depletion structure was observed in OH airglow images (emission altitude similar to86 km) at Shigaraki (34.9degrees, 136.1degrees) on 19 December 1998. The structure was a single-band airglow depletion with a small horizontal width (similar to15 km) but a large amplitude (similar to34% from the average intensity). Airglow rotational temperature indicated a large temperature lapse rate at this time as a result of strong semidiurnal variation. We suggest that nonlinear wave-wave interaction is the most likely cause of this localized structure.