Title: A localized structure in OH airglow images near the mesopause region
Abstract: An intense localized airglow‐depletion structure was observed in OH airglow images (emission altitude ∼86 km) at Shigaraki (34.9°, 136.1°) on 19 December 1998. The structure was a single‐band airglow depletion with a small horizontal width (∼15 km) but a large amplitude (∼34% 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.