Pc 3 magnetic pulsations observed at low latitudes: A possible model
It is recently demonstrated that Pc 3 magnetic polarizations observed at equatorial latitudes (|φ|<20°) are different from those at low-latitude Japan-Australia conjugate stations (|φ|∿35°). In order to interpret the Pc 3 polarization characteristics at lower latitudes (|φ|≲45°), we propose a pro...
Main Authors: | , , |
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Format: | Report |
Language: | English |
Published: |
Onagawa Magnetic Observatory and Geophysical Institute, Tohoku University/Onagawa Magnetic Observatory and Geophysical Institute, Tohoku University/Research Institute of Atmospherics, Nagoya University
1987
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Subjects: | |
Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2160 http://id.nii.ac.jp/1291/00002160/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2160&item_no=1&attribute_id=18&file_no=1 |
Summary: | It is recently demonstrated that Pc 3 magnetic polarizations observed at equatorial latitudes (|φ|<20°) are different from those at low-latitude Japan-Australia conjugate stations (|φ|∿35°). In order to interpret the Pc 3 polarization characteristics at lower latitudes (|φ|≲45°), we propose a probable, new qualitative model in which two (or more) superimposed ionospheric eddy currents, oscillating with slight differences in frequency in the Pc 3 range and in apparent azimuthal wave number, move azimuthally at low latitudes (|φ|≲45°). Near low latitudes of |φ|∿45°ionospheric rotational Hall currents should be induced by field-aligned currents associated with localized shear Alfven waves which are excited by compressional Pc 3 source waves near |φ|∿45°. Near the equatorial region ionospheric Pedersen eddy currents may be caused by inductive electric fields of compressional Pc 3 source waves which would propagate from the outer magnetosphere to the equatorial ionosphere. |
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