50MHz auroral doppler radar observations associated with Pc 5 geomagnetic pulsations

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...

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Bibliographic Details
Main Authors: Kiyoshi Igarashi, Tadahiko Ogawa, Yasukazu Kuratani, Ryoichi Fujii, Natsuo Sato
Format: Report
Language:English
Published: Radio Research Laboratories/Radio Research Laboratorie/Radio Research Laboratories/National Institute of Polar Research/National Institute of Polar Research 1985
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Online Access:https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1750
http://id.nii.ac.jp/1291/00001750/
https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1750&item_no=1&attribute_id=18&file_no=1
Description
Summary: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.