Substructures with luminosity modulation and horizontal oscillation in pulsating patch: Principal component analysis application to pulsating aurora

DOI Web Site Web Site 被引用文献6件 参考文献51件
  • Takanori Nishiyama
    National Institute of Polar Research Tokyo Japan
  • Yoshizumi Miyoshi
    Institute for Space‐Earth Environmental Research Nagoya University Nagoya Japan
  • Yuto Katoh
    Department of Geophysics, Graduate School of Science Tohoku University Sendai Japan
  • Takeshi Sakanoi
    Planetary Plasma and Atmospheric Research Center, Graduate School of Science Tohoku University Sendai Japan
  • Ryuho Kataoka
    National Institute of Polar Research Tokyo Japan
  • Shoichi Okano
    Planetary Plasma and Atmospheric Research Center, Graduate School of Science Tohoku University Sendai Japan

この論文をさがす

説明

<jats:title>Abstract</jats:title><jats:p>We observed a mesoscale aurora (100 km × 100 km) with patchy structure and equatorward propagation at Poker Flat Research Range on 1 December 2011. Fast Fourier transform (FFT) analysis revealed that this pulsating patch clearly exhibited temporal variations that can be categorized into two types: on‐off pulsation (7.8–10 s) with large amplitudes and luminosity modulations excited during on phase with a frequency of about 3.0 Hz. In addition, we applied principal component analysis (PCA) to time series image data of the pulsating aurora for the first time. Time coefficients were estimated by PCA for the whole patch and the substructures were consistent with those obtained from the FFT analysis, and therefore, we concluded that PCA is capable of decomposing several structures that have different coherent spatiotemporal characteristics. Another new insight in this study is that the rapid variations were highly localized; they were excited in only the substructures embedded in the whole structure. Moreover, the whole patch propagated equatorward because of E × B drift of cold plasma, while the substructures did not show such systematic propagation but rather forward‐backward oscillations. The horizontal scale of the substructures was estimated to be no smaller than 410 km at the magnetic equator, which is comparable to that of the wave packet structure of a whistler mode chorus perpendicular to the field line. We suggest that the apparent horizontal oscillation of the substructures is associated with field‐aligned propagations of the whistler mode chorus in a duct.</jats:p>

収録刊行物

被引用文献 (6)*注記

もっと見る

参考文献 (51)*注記

もっと見る

関連プロジェクト

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ