Japan Geoscience Union Meeting 2015

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Symbol P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM28] Dynamics in magnetosphere and ionosphere

Thu. May 28, 2015 4:15 PM - 6:00 PM 302 (3F)

Convener:*Yoshizumi Miyoshi(Solar-Terrestrial Environement Laboratory, Nagoya University), Hiroshi Hasegawa(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Shin'ya Nakano(The Institute of Statistical Mathematics), Yoshimasa Tanaka(National Institute of Polar Research), Tomoaki Hori(Nagoya University Solar Terrestrial Environment Laboratory Geospace Research Center), Chair:Yoshimasa Tanaka(National Institute of Polar Research)

5:45 PM - 6:00 PM

[PEM28-17] Seasonal dependence of the plasmaspheric density along the 210MM: Continuous observations by ground magnetometers

*Hideaki KAWANO1, Tetsuro YAMADA2, Yuichiro KITAGAWA3, Boris Shevtsov4, Sergey Khomutov4, Igor Poddelskiy4, Akimasa YOSHIKAWA1, group MAGDAS/CPMN5 (1.Department of Earth and Planetary Sciences, Kyushu University, 2.Department of Earth and Planetary Sciences, Kyushu University, 3.Department of Earth and Planetary Sciences, Kyushu University, 4.IKIR FEB RAS, Russia, 5.International Center for Space Weather Science and Education, Kyushu University)

In this paper we have applied the cross-phase method and the amplitude-ratio method to the MAGDAS/CPMN ground magnetometers MGD (Magadan) and PTK (Paratunka, Kamchatka), located in the Russian Far East along the 210MM (Magnetic Meridian), and identified FLR (field-line resonance) events. MGD is located at (53.6, 219.1) magnetic latitude and longitude [deg], and PTK is located at (46.2, 226.2). Their L values are 2.9 and 2.1. We have identified the FLR events by using both visual inspection and an automatic-identification computer code.

Although the two magnetometers are separated by about seven degrees in magnetic latitudes, which is larger than the typical separation (about 1-2 degrees) for which the cross-phase and amplitude-ratio methods are efficient, but we could identify more than a hundred FLR events a year from the MGD/PTK-pair data, and the FLR events had a fairly continuous coverage from January to December.

In this paper we estimate the plasmaspheric density from thus obtained FLR frequencies, and examine their seasonal dependence. The result suggests a weak, but marginally significant seasonal dependence with maxima in winter and minima in summer. More details will be discussed at the presentation.