Pi 2 waves simultaneously observed by Cluster and CPMN ground-based magnetometers near the plasmapause

H. Kawano, S. Ohtani, T. Uozumi, T. Tokunaga, A. Yoshikawa, K. Yumoto, E. A. Lucek, M. André

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4 Citations (Scopus)


We have analyzed an event on 14 February 2003 in which Cluster satellites and the CPMN ground magnetometer chain made simultaneous observations of a Pi 2 pulsation along the same meridian. Three of the four Cluster satellites were located outside the plasmasphere, while the other one was located within the plasmasphere. By combining the multipoint observations in space and the multipoint observations on the ground, we have obtained a detailed L-profile of the Pi 2 signatures, which has not been done in the past. In addition, we have used a method called Independent Component Analysis (ICA) to separate out other superposed waves with similar spectral components. The result shows that the wave phase of the Pi 2 was the same up to L ∼ 3.9 (corresponding to the plasmasphere), became earlier up to L ∼ 4.1 (corresponding to the plasmapause boundary layer), and showed a delaying tendency up to L ∼ 5.9 (corresponding to the plasmatrough). This systematic phase pattern, obtained for the first time by a combination of a ground magnetometer chain and multisatellites along a magnetic meridian with the aid of ICA, supports the interpretation that a Pi 2 signal propagated from a farther source and reached the plasmasphere.

Original languageEnglish
Pages (from-to)1663-1672
Number of pages10
JournalAnnales Geophysicae
Issue number9
Publication statusPublished - 2011

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Geology
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science


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