Comparative analysis of electron density and electric field fluctuations in highly active auroras observed by a sounding rocket S-310JA-12: Preliminary results

• Main Authors: Mori, Hirotaka, Sagawa, Eiichi, Ogawa, Tadahiko, Ogawa, Toshio, Yamagishi, Hisao, Fukunishi, Hiroshi
• Language: English
• Published: National Institute of Polar Research 1988
• Subjects: Faraday; Syowa Station; Antarc*; Antarctica
• Online Access: https://nipr.repo.nii.ac.jp/record/4030/files/KJ00000035876.pdf; https://doi.org/10.15094/00004030; https://nipr.repo.nii.ac.jp/records/4030

P(論文) The S-310JA-12 rocket was launched geomagnetically northward from Syowa Station, Antarctica, during a strong substorm period. The onboard instruments were a Faraday cup for measuring electron density and its fluctuations up to 8kHz together with total flux of electrons with energies above 105eV and a pair of double probes for measuring DC electric field and electric field fluctuations of 5-220Hz, which detected various kinds of ELF-VLF band fluctuations during the flight. During the ascent, the Faraday cup observed strong VLF fluctuations in the E region and burst-like fluctuations over the region from 140 to 200km in altitude. The former might be caused by the two-stream instability and/or the cross-field instability, while the latter is considered to be generated artifitially around the rocket. Around the height of 220km, quasi-sinusoidal waves with the frequency of about 150Hz were observed by the both instruments. They are found to be right-hand circularly or elliptically polarized waves by crosscorrelation analysis. During the descent, the rocket passed through highly active auroras and the both instruments observed strong ELF fluctuations. It is suggested by the Faraday cup measurement that the rocket was considerably charged up by the precipitating electrons in the auroras. departmental bulletin paper