HR: 0800h
AN: SA51A-1123    [Abstracts]
TI: Quasi-periodic southward-moving waves in 630-nm airglow images in the equatorial thermosphere
AU: * Shiokawa, K
EM: shiokawa@stelab.nagoya-u.ac.jp
AF: Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13, Honohara, Toyokawa, Aichi, 442-8507 Japan
AU: Otsuka, Y
EM: otsuka@stelab.nagoya-u.ac.jp
AF: Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13, Honohara, Toyokawa, Aichi, 442-8507 Japan
AU: Ogawa, T
EM: ogawa@stelab.nagoya-u.ac.jp
AF: Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13, Honohara, Toyokawa, Aichi, 442-8507 Japan
AB: We report quasi-periodic southward-moving waves, which are commonly observed in the OI 630-nm airglow images (emission altitudes: 200-300 km) near the geomagnetic equator, in two-year airglow observations at Kototabang, Indonesia (0.2°S, 100.3°E, geomagnetic latitude: -10.4°). The waves have predominantly east-west phase fronts, and repeatedly propagate southward (toward higher geomagnetic latitudes) with a velocity of ~310 ± 110 m/s and a period of ~40 ± 15 min. They are frequently observed in May-July with an occurrence rate of 53 %, and are also observed in other seasons with occurrences of ~20 %. The waves are observed in and to the south (geomagnetically equatorward) of the equatorial ionospheric anomaly, which is identified as an airglow enhancement region moving gradually to lower geomagnetic latitudes at the premidnight local times. We suggest that gravity waves in the lower thermosphere are a possible cause of the observed quasi-periodic waves in the airglow images.
DE: 0310 Airglow and aurora
DE: 2415 Equatorial ionosphere
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2435 Ionospheric disturbances
DE: 2439 Ionospheric irregularities
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005