Ps6 propagation in the earth magnetosphere tail after magnetic substorms
|1Agapitov, AV |
1Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
|Kosm. nauka tehnol. 2004, 10 ;(5-6):117-121|
|Publication Language: Russian|
The ULF geomagnetic pulsations in the Earth magnetosphere tail display themselves as localized in time wave pockets, with fill frequency in the range of Ps5 or Ps6. Therefore, it is expedient to apply wavelet analysis to these phenomena research. Wavelet-spectra of magnetometric and plasma measurements made by Interball-1 (tail) satellite demonstrate presence of magnetosonic component: oscillations of plasma pressure and magnetic field pressure are in phase opposition. Wave frequency is less than frequency of same events in the inner magnetosphere (so called field line resonance). Ps6 high-amplitude waves in outer magnetosphere have direct relation to substorm evolution. Wave amplitude depends on geomagnetic activity and magnetosphere region confirmed it. These structures are also observed by Earth-based magnetometer systems. CANOPUS magnetometers system data are used. Due to multipoint observations, it is possible to obtain spatial and temporary event parameters. Transversal to magnetic field size of wave pocket is about (1–3)RE. It moves transverse to magnetic field with a speed of about 2-6 km/s.
1. Agapitov A. V., Verkhoglyadova O. P., Ivchenko V. M. Compression waves in the Earth's magnetosphere: interpretation of "Interball 1" observations. Kosm. nauka tehnol., 7 (5-6), 64—70 (2001) [in Ukrainian].
2. Vorob'ev V. I., Gribunin V. G. Theory and practice of wavelet transform, 180 p. (St. Petersburg, 1999) [in Russian].
3. Gulelmi A. V., Repin V. N. MHD solitons in the magnetospheric tail. Geomagnetizm i Aeronomiia, 18 (6), 1089—1092 (1978) [in Russian].
4. Ivanov V. V., Rotanova N. M. Investigation of the structure of Ps 6 geomagnetic pulsations by spectral methods. Geomagnetizm i Aeronomiia, 31 (4), 625— 629 (1991) [in Russian].
5. Connors M., Rostoker G., et al. Ps disturbances: relation to substorms and the auroral oval. Annal. Geophisicae, 493—508 (2003).
6. Khrushchinsky A. A., Gustafsson G., Korth A., et al. The SAMBO-GEOS experiment: A Ps-6 event from ground-satellite observations. In: Achievements of the Intern. Magnetospheric Study (IMS): Proc. Conf., ESA, SP 217, 26–28 June 1984, Graz, Austria, 625—627 (1984).
7. Steen A., Collis B. T., et al. Observations of a gradual transition between Ps6-activity with auroral torches and surgelike pulsations during strong geomagnetic disturbances. J. Geophys. Res., 93, 8713—8733 (1988).
8. Tsyganenko N. A. Modeling the Earth's magnetospheric magnetic field confined within a realistic magnetopause. J. Geophys. Res., 100A (4), 5599—5612 (1995).
9. Zhu X., Kivelson M. Compressional ULF Waves in the Outher Magnetosphere. 1. Statistical Study. J. Geophys. Res., 99A (1) (1994).
10. Zhu X., Kivelson M. Compressional ULF Waves. 2. Case Study. J. Geophys. Res., 99A (1), 241—252 (1994).