Observation of mesospheric waves with an all-sky camera in Korean peninsula

Abstract

We have carried out all-sky imaging of OH Meinel and OI 557.7 nm airglow layers in the period of July, 2001 through March, 2002 at Mt. Bohyun, Korea (36.2degrees N, 128.9degrees E). The all-sky camera consists of a 37 mm/F4.5 fisheye lens with a 180degrees field of view, 4 inch diameter narrow band filters and a back-illuminated 1024 X 1024 CCD. Mesospheric wavelike activities were recorded only for 6.4% of a total of 243 hours of clear moonless nights, which is much fewer than other studies in Japan and North America. We, however, cannot exclude the possibility, that our observation has missed frequent wave activity during summer observed in other sites due to cloudy weather. We detected 12 events of small wave packets, known as the ripple type wave and 10 events of horizon-to-horizon waves, known as the band type wave. The ripple type waves occur for less time but more often than the band type waves. We find that the ripple type waves can be classified into three different kinds in terms of their local environments: (1) ripples generated from a propagating band type wave, (2) ripples associated with a band type wave crest, and (3) ripples in isolation. We discuss different causes for the three kinds of the ripples. The characteristics of observed band type waves are consistent with internal gravity waves, as other studies noted. No southward propagation of band type waves was observed in our dataset. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.