Simultaneous Observation of Wave Packet of the Atmospheric Gravity Waves by ISS-IMAP and All-sky Imager

Friday, 19 December 2014
Hideko Yukino1, Akinori Saito1, Takeshi Sakanoi2 and Yuichi Otsuka3, (1)Kyoto University, Kyoto, Japan, (2)Tohoku University, Sendai, Japan, (3)Nagoya Univ, Nagoya, Japan
The spatial scale of the atmospheric gravity wave in the mesosphere and the lower thermosphere was analyzed using the simultaneous observational data of ISS-IMAP and an all-sky imager at Hawaii. There are a plenty of previous studies that discuss the relationship between the wave structures of the mesospheric airglow and the tropospheric events. The problem of the ground-based observation of the airglow is that it cannot distinguish spatial variations from temporal variations for the structures whose scale size is larger than its field-of-view. ISS-IMAP started the observation in October, 2012 to survey the atmospheric gravity waves whose horizontal scale size is 50 km and longer. The spatial resolution of the VIsible-light and infrared Spectrum Imager (VISI) of ISS-IMAP/VISI imaging observation is from 10 km to 25 km. Simultaneous observations start from March 14, 2013. The atmospheric gravity waves that detected by VISI in 762 nm were compared with the observations of ground-based all-sky imagers in 557.7 nm. The generation and the propagation of the atmospheric gravity waves were investigated with this simultaneous observation. The relationship between the tropospheric events and the atmospheric gravity waves in the mesosphere is studied with the wide field-of-view observation by VISI/ISS-IMAP, and the continuous observation of the ground-based imagers. VISI frequently observed wave packets whose scale size is 1,000-2,000 km. These wave packets were observed by the ground-based imager as a series of waves whose wave length is 20-40 km, and that continue for 5-6 hours. The generation, the propagation and the distraction of the atmospheric gravity waves will be discussed in this presentation.