日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

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-EM12] Space Weather and Space Climate

2019年5月28日(火) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:片岡 龍峰(国立極地研究所)、Antti A Pulkkinen(NASA Goddard Space Flight Center)、草野 完也(名古屋大学宇宙地球環境研究所)、坂口 歌織(情報通信研究機構)

[PEM12-P26] A network of HF Doppler sounding systems in Japan

*細川 敬祐1中田 裕之2橋本 久美子3冨澤 一郎1坂井 純1菊池 崇4 (1.電気通信大学、2.千葉大学、3.吉備国際大学、4.名古屋大学宇宙地球環境研究所)

キーワード:短波ドップラー観測、電離圏

Since 2003, a network observation of HF Doppler sounding has been conducted in Japan for remote-sensing the atmospheric, ionospheric and magnetospheric processes. Currently, 1 transmitting station (Tx) and 7 receiving stations (Rx) are operative by a collaborative effort of four difference universities. The main transmitting station is located at Chofu, Tokyo, Japan in the Campus of University of Electro-Communications (JG2XA). JG2XA transmits continuous waves at 5006 kHz and 8006 kHz with a transmitting power of 200 W. By receiving this JG2XA signal at 7 Rx stations (Sugadaira, Oarai, Kure, Kashima, Iitate, Fujisawa and Sugito) we derive the Doppler shift imposed during the propagation and reflection in the ionosphere. In particular, the Doppler shift data can be used to detect vertical motion of the ionospheric F region with a temporal resolution of 10 s. At some stations, we also have observed signals from Radio Nikkei 1 (JOZ at 3925 kHz, JOZ2 at 6055 kHz, and JOZ3 at 9595 kHz) transmitted from Nagara, Chiba, Japan, which allows us to observe the vertical motion of the ionosphere at several altitude levels. The data obtained from this experiment since 2003 are all available at http://gwave.cei.uec.ac.jp/~hfd. Not only quick-look plots but also several types of digital data (raw wave form and Doppler shift data) can be retrieved from this database. The experiment covers various ionospheric phenomena in the Magnetosphere-Ionospheric (M-I) coupling system, such as sporadic E-layer (Es), medium-scale traveling ionospheric disturbances (MSTIDs), large-scale traveling ionospheric disturbances (LSTIDs), global-scale electric field variation, geomagnetic pulsations, and sudden commencement (SC). The data can also be used for the studies of vertical coupling between the lower atmosphere and ionosphere, for example, observations of ionospheric variation after large earthquakes, volcanic eruptions and typhoons. To facilitate analyses of the phenomena listed above, it is desired to observe a wider area in latitude and longitude. For this purpose we plan to extend the network covering the entire ionosphere over Japan in the near future. In the presentation, we will give a brief introduction to the experiments and online database, and then discuss the future direction of the studies of atmosphere, ionosphere and magnetosphere using the HF Doppler sounding in a framework of international collaborations.