A statistical study on Psc 4 and Psc 5 observed by geostationary satellites |
| |
| Authors: | H Nagano T Araki |
| |
| Institution: | Department of Physics, Gifu College of Dentistry, Gifu 501-02, Japan;Data Analysis Center for Geomagnetism and Spacemagnetism, Faculty of Science, Kyoto University, Kyoto 606, Japan |
| |
| Abstract: | Using magnetic data from the geostationary satellites of ATS 6 and SMS/GOES series, long-period geomagnetic pulsations, Psc 4 and Psc 5, associated with geomagnetic sudden commencements (SC's) were statistically analyzed. Local time and geomagnetic latitude dependence of the occurrence, and local time dependence of the period and the amplitude were examined for 218 SC's. For transverse Psc 5 pulsations which could be observed at all local times, the period was shorter and the amplitude was smaller near noon than in the morning and evening sides. Compressional Psc 5's, which were observed mainly from about 09.00 L.T. to midnight, had larger amplitude near noon. The period seemed to be longer near noon. As for Psc 4 pulsations the period tended to be shorter near noon. Psc 4's with the largest amplitude appeared near noon, but on the whole Psc 4's in the evening side had larger amplitude. The compressional Psc occurred more frequently near the geomagnetic equator (geomagnetic latitude ) than at higher latitude (). We suggest that the transverse Psc 5 pulsations can be considered to be magnetic field-line resonant oscillations excited by impulsive waves, while the compressional Psc 5's may be oscillations localized near the geomagnetic equator. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
