日本地球惑星科学連合2015年大会

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インターナショナルセッション(口頭発表)

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

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

2015年5月26日(火) 16:15 〜 18:00 A01 (アパホテル&リゾート 東京ベイ幕張)

コンビーナ:*Huixin Liu(九州大学理学研究院地球惑星科学専攻 九州大学宙空環境研究センター)、大塚 雄一(名古屋大学太陽地球環境研究所)、Libo Liu(Institute of Geology and Geophysics, Chinese Academy of Sciences)、新堀 淳樹(京都大学生存圏研究所)、座長:大塚 雄一(名古屋大学太陽地球環境研究所)

17:56 〜 17:58

[PEM06-P05] Topside Ionospheric Plasma Temperatures Retrieved From FORMOSAT-3/COSMIC Observations

ポスター講演3分口頭発表枠

*Jack C. WANG1Loren C. CHANG1Jann-yenq LIU1 (1.Graduate Institute of Space Science, National Central University, Taiwan)

キーワード:Ionosphere, Topside ionosphere, Plasma temperature, Formosa-3/COSMIC

Bottom-side ionospheric electron profiles now can be well-determined thanks to mature development of ground-based instruments, such as ionosonde, or incoherent radar. However, the topside ionosphere, located above the F2 layer peak to the exobase (from 200~400 km to 600~1000km, depending on solar activity) is still not well understood. Previously, the electron density distribution and plasma temperatures in the topside ionosphere could only be measured by incoherent scatter radar, in-situ sounding rocket, or certain satellite instruments, making it hard to draw a global map of electron density and plasma temperatures in the topside ionosphere. FORMOSAT-3/ Constellation Observing System for Meteorology, Ionosphere, and Climate (F3/C) using the GPS radio occultation method (GPS-RO) now can give us great opportunities to determine the global electron density profiles above the F2 layer peak. We also present results showing how the plasma temperatures may be estimated from such GPS-RO observations.

This study first examines the structure and variability of electron densities in topside ionosphere. Seasonal F3/C observations will first be assimilated into a gridded model in latitude, longitude, altitude, and local time. The resulting vertical profiles at each gridpoint will then be used to infer the vertical scale height of the topside ionosphere. Next, we retrieved the seasonal and local-time variabilities of topside plasma temperature from the scale height of topside ionospheric electron densities. This is one of the first times that topside plasma temperatures can be globally determined using remote sensing techniques.