[P-EM06] Mesosphere-Thermosphere-Ionosphere Coupling in the Earth's Atmosphere

[PEM06-22] リチウム放出実験による昼間および月夜の熱圏中性大気風プロファイル

*山本 真行¹、木原 大城¹、柿並 義宏¹、渡部 重十²、ラーセン ミゲル³、山本 衛⁴、羽生 宏人⁵、阿部 琢美⁵、パフ ロバート⁶ (1.高知工科大学、2.北海道情報大学、3.Clemson University、4.京都大学生存研研究所、5.JAXA宇宙科学研究所、6.NASA/Goddard Space Flight Center)

キーワード：熱圏, 中性大気風プロファイル, リチウム放出, 航空機観測, 手法, 観測ロケット

Neutral wind profiles were observed in lower thermosphere at about between 90 km and 130 km altitude by using resonance scattering light of sunlit and moonlit Lithium (Li) vapor released from sounding rockets in daytime and midnight (almost full moon condition) in 2013. As a target of the Daytime Dynamo campaign, Li release experiment was operated at Wallops Flight Facility (WFF) of NASA, U.S.A. in July, 2013, while the same kind of experiment in midnight was carried out in Uchinoura Space Center (USC) of JAXA, Japan also in July 2013. Since imaging signal-to-noise (S/N) condition of the both experiments was so severe, we conducted to apply airborne observation for Li tracers imaging so as to reduce the illuminating intensity of background skies as an order of magnitude.
Two independent methods for calculating the wind profile were applied to the image sequences obtained by the airborne imaging by special Li imagers aboard the airplanes in order to derive precise information of Li tracers motion under the condition of single observation site moving along the aircraft path in the lower stratosphere. Slight feedback motion of the aircraft 3-axes attitude changes (rolling, yawing and pitching) was considered for obtaining precise coordinates on each snapshot. Another approach is giving a simple mathematic function for wind profile to resolve the shape displacement of the imaged Li tracers. As a result, a wind profile in daytime thermosphere was calculated in a range between 20 and 95 m/s with some fluctuated parts possibly disturbed by wind shears. In this paper, we will introduce the method of wind profile calculation and final result of the profiles.