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

• Main Authors: Igarashi, Kiyoshi, Ogawa, Tadahiko, Kuratani, Yasukazu, Fujii, Ryoichi, Sato, Natsuo
• Language: English
• Published: 1985
• Subjects: Syowa Station; Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/record/1750/files/KJ00000012382.pdf; https://nipr.repo.nii.ac.jp/records/1750

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