Japan Geoscience Union Meeting 2015

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Symbol M (Multidisciplinary and Interdisciplinary) » M-TT Technology & Techniques

[M-TT41] Brand-new scope of coupling geophysics being established by infrasound and associated waves

Tue. May 26, 2015 9:00 AM - 10:45 AM 203 (2F)

Convener:*Masa-yuki Yamamoto(Department of systems engineering, Kochi University of Technology), Nobuo Arai(Disaster Mitigation Research Center, Nagoya University), Chair:Masa-yuki Yamamoto(Department of systems engineering, Kochi University of Technology), Nobuo Arai(Disaster Mitigation Research Center, Nagoya University)

9:30 AM - 9:45 AM

[MTT41-03] SWARM observation of small scale field-aligned currents generated by acoustic waves and their signature on the ground

*Toshihiko IYEMORI1, Kunihito NAKANISHI1, Tadashi AOYAMA1, Hermann LUEHR2, Yoshihiro YOKOYAMA1, Yoko ODAGI1, Masato IGUCHI3 (1.Graduate School of Science, Kyoto University, 2.GFZ Potsdam, 3.DPRI, Kyoto University)

Keywords:acoustic gravity wave, ionospheric dynamo, field-aligned current, SWARM satellites, micro-barometric oscillation, magnetic oscillation

From the SWARM satellite observations during the initial two months after the launch, we could confirm that the small magnetic fluctuations with apparent period about 10-30 seconds along the orbit observed in middle and low latitudes are the manifestation of small spatial scale (50-250km) field-aligned currents. We estimated the temporal scale of the variation of the field-aligned currents to be roughly 200 - 350 seconds or less. That is, the source of the current is suggested to be the acoustic mode atmospheric waves. In this paper, we show the method of the estimation, its results and a comparison with the ground magnetic and micro-barometric observations.