An Alfvén resonator or Ionosphere Alfvén resonator is a spectral resonance structure found within geomagnetic fields in the frequency range of 0.1–10 Hz.[1] First reported in 1989, they are ionospheric short-period geomagnetic variations primarily seen as nighttime phenomena and rarely observed during the day.[2] The nighttime preference is due to lower electrical conductivity in the ionospheric dynamo region, which enables the feedback instability. [3]
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edit- ^ Belyaev, P. P., Polyakov, C. V., Rapoport, V. O., & Trakhtengerts, V. Y. (1989). Experimental studies of the spectral resonance structure of the atmospheric electromagnetic noise background within the range of short-period geomagnetic pulsations. Radiophysics and Quantum Electronics, 32(6), 491-501.
- ^ Nosé, M., Uyeshima, M., Kawai, J., & Hase, H. (2017). Ionospheric Alfvén resonator observed at low-latitude ground station, Muroto. Journal of Geophysical Research: Space Physics, 122(7), 7240-7255.
- ^ Pokhotelov, D.; Lotko, W.; Sreltsov, A.V. (2002). "Harmonic structure of field line eigenmodes generated by ionospheric feedback instability". Journal of Geophysical Research: Space Physics. 107 (A11). doi:10.1029/2001JA000134.