@article{oai:nipr.repo.nii.ac.jp:00010185,
 author = {Ozaki, M. and Yagitani, S. and Nagano, I. and Kasahara, Y. and Yamagishi, H. and Satom, N. and Kadokura, A. and Ozaki, M. and Yagitani, S. and Nagano, I. and Kasahara, Y. and Yamagishi, H. and Satom, N. and Kadokura, A.},
 issue = {3},
 journal = {Polar science, Polar science},
 month = {Dec},
 note = {To investigate downward ionospheric-penetration characteristics of VLF (several hundred Hz to 17.8 kHz) whistler-mode waves, we conducted simultaneous observations (in 2006) of natural VLF waves using both ground stations in Antarctica and the Japanese Akebono satellite. The ground-based and satellite observations included an interesting event for which both observed similar VLF waves. In this study, we theoretically calculate down-going whistler-mode wave propagation based on ground-satellite observations using the full-wave analysis. In a case study, the observed wave-normal angles were approximately 140-160 degrees for a dayside chorus event on 15 March 2006. The theoretical calculation showed that the wave-normal angles for ionosphericpenetration should be around 155.6 degrees, with its angular width of approximately 2 degrees. Moreover, the wave-energy loss due to ionospheric penetration is estimated at 20.4 dB based on our theoretical calculation, in accordance with the observed 17-19 dB., ホイスラモード波の電離層透過特性を詳細に調べるために、2006年南極において地上とあけぼの衛星によるVLF（数百Hz～17.8 kHz）帯の自然電磁波動の同時観測を行った。この観測において、地上とあけぼの衛星で波動強度の周波数特性がよく似た自然VLF波動のイベントを得た。本研究では、この同時観測結果に基づきfull-wave解析を用いることによって理論的にホイスラモードの下降伝搬を計算している。事例解析として2006年3月15日のコーラスの同時観測イベントに対して、あけぼの衛星で観測された波動伝搬ベクトルは140～160度に分布した。一方で理論計算では、電離層透過のための波動伝搬ベクトルは155.6度、その角度幅約2度になる必要があるという結果を得た。さらに、電離層透過に対する波動エネルギーの減衰は、観測値の17～19 dBに一致して理論計算では20.4 dBと推定された。},
 pages = {431--441},
 title = {Simultaneous ground-based and satellite observations of natural VLF waves in Antarctica: A case study of downward ionospheric penetration of whistler-mode waves},
 volume = {4},
 year = {2010}
}