イオノゾンデおよびファブリ・ペロー干渉計によって観測された子午面熱圏風の比較

• Nishioka Michi

  National Institute of Information and Communications Technology, Nukui-Kitamachi 4-2-1, Koganei, Tokyo 184-8795.

• Maruyama Takashi

  National Institute of Information and Communications Technology, Nukui-Kitamachi 4-2-1, Koganei, Tokyo 184-8795.

• Otsuka Yuichi

  Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601.

• Tsugawa Takuya

  National Institute of Information and Communications Technology, Nukui-Kitamachi 4-2-1, Koganei, Tokyo 184-8795.

• Ishibashi Hiromitsu

  National Institute of Information and Communications Technology, Nukui-Kitamachi 4-2-1, Koganei, Tokyo 184-8795.

• Shiokawa Kazuo

  Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601.

• Ishii Mamoru

  National Institute of Information and Communications Technology, Nukui-Kitamachi 4-2-1, Koganei, Tokyo 184-8795.

Bibliographic Information

Other Title

• Comparison of meridional thermospheric winds observed by ionosondes and Fabry-Perot interferometers

Abstract

電離圏ダイナミクスに大きく寄与する熱圏風についての理解を深めるため,イオノゾンデの磁気共役点観測により推定された南北方向の熱圏風(推定熱圏風)と,ファブリ・ペロー干渉計(FPI)観測により直接測定された南北方向の熱圏風との相関を調べた.推定熱圏風は,磁気共役点における熱圏風は等しい(赤道横断風モードが卓越する)という仮定のもとで導出される.2 つの手法で観測された夜間の熱圏風を比較するのは本研究が初めてである.2010 年のチェンマイ(タイ)とコトタバン(インドネシア)のイオノゾンデとFPI データを比較した結果,両者はおおむね良い相関を示したが,相関が悪い日もあった.相関が悪い事例は,赤道から収束・発散する成分を無視できず,赤道横断風モードが卓越するという仮定が成立しないと解釈されるものである.また,2 つの手法で求めた熱圏風の相関を季節別に調べると,2-4 月に両者の相関が高い一方,5-7 月に両者の相関が低いことがわかった.
To comprehend ionospheric-thermospheric coupling, one must understand the thermospheric wind system. However, measuring the thermospheric wind using a Fabry-Perot interferometer (FPI) is not an easy task. Because of this difficulty, some researchers have estimated meridional wind velocities using data obtained from a pair of ionosonde stations near the geomagnetic conjugate points, under the assumption that the meridional wind is the same at the two ionosonde stations (transequatorial mode wind). In this paper, we construct the first comparison of the estimated meridional wind velocitieswith meridional wind observed with FPIs. We analyzed data from the ionosondes and FPIs installed at Chiang Mai, Thailand, and Kototabang, Indonesia, from 2010. We found that the estimated and observed wind velocities were generally in good agreement on most nights, although on some nights, the wind velocities were different. The assumption that the meridional wind is equal anywhere between the two ionosonde stations would not be suitable for the days when the winds were not in good agreement. We also investigated the seasonal dependence of the correlation between the estimated and observed meridional winds. They were in good agreement from February to April and were not in good agreement from May to July.

Journal

• Antarctic record

  Antarctic record 57 (3), 357-368, 2013-11-29

  National Institute of Polar Research

Details

• CRID: 1572824502696283520
• NII Article ID: 110009673735
• NII Book ID: AN00181831
• ISSN: 00857289
• Text Lang: en
• Data Source:
  • CiNii Articles