50MHz auroral doppler radar observations associated with Pc 5 geomagnetic pulsations
P(論文) Radio auroral echo oscillations associated with Pc 5 geomagnetic pulsations are investigated using the 50MHz doppler radar installed in 1982 at Syowa Station, Antarctica. First, it is found that Pc 5 radar echo pulsations occur most frequently around dawn and dusk hours but do not appear aroun...
| Main Authors: | , , , , |
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| Language: | English |
| Published: |
1985
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| Subjects: | |
| Online Access: | https://nipr.repo.nii.ac.jp/record/1750/files/KJ00000012382.pdf https://nipr.repo.nii.ac.jp/records/1750 |
| Summary: | P(論文) Radio auroral echo oscillations associated with Pc 5 geomagnetic pulsations are investigated using the 50MHz doppler radar installed in 1982 at Syowa Station, Antarctica. First, it is found that Pc 5 radar echo pulsations occur most frequently around dawn and dusk hours but do not appear around noon and midnight. Then, the doppler power spectrum of the Pc 5 pulsating radio aurora is presented which indicates that the irregularities causing echo pulsations might be produced by the gradient-drift plasma instability in the disturbed E-region. It is also demonstrated by using the mean doppler velocity of the Pc 5 pulsating radio aurora that during the pulsations the north-south components of electric fields are far larger than the east-west components, being consistent with the Kelvin-Helmholtz instability hypothesis as a cause of Pc 5 geomagnetic pulsations. departmental bulletin paper |
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