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...
Main Authors: | , , , , |
---|---|
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
|
Subjects: | |
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 |
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. |
---|