Generation of the kinetic alfven wave and lower hybrid wave in space plasma

1Yukhimuk, AK, Fedun, VM, 2Voitenko, Yu., Sirenko, OK, 3Yukhimuk, VA
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Solar-Terrestrial Centre of Excellence, BIRA-IASB, Brussels, Belgium
3Taras Shevchenko National University of Kyiv, Kyiv, Ukraine; Newcastle University , Newcastle, Australia
Косм. наука технол. 2001, 7 ;(Suppl. 2):059-066
Мова публікації: англійська
Satellite observations show close relationship between the whistlers and lower-hybrid waves in space plasmas. Intense whistler waves generated by lightning discharges [Kelley, 1990] or by quasimonochromatic VLF (very low frequency) transmitters can be unstable and cause the three-wave parametric interaction. Work [Bell, 1994] demonstrates experimental results of excited lower hybrid waves by VLF whistler mode waves in the topside ionosphere and near magnetosphere. The Kinetic Alfven waves are often observed by satellites [Louran], [Volokitin, 1989]. In this paper we analytically consider a possible mechanism of this Relationship, i.e., parametric interaction of whistler pump waves with lower-hybrid and the Alfven waves in magnetized plasma with small plasma parameter. In the dynamics of the Alfven waves the kinetic effects (finite ion Larmor radius and electron inertia) are taken into account A nonlinear dispersion equation describing three-wave interaction is obtained in the framework of two-fluid magnetohydrodynamics. The instability growth rates and the time of instability development are found. Our theoretical investigation shows, that the whistler mode will be an effective source of the lower hybrid and the Alfven waves in the magnetospheric plasma. This nonlinear process can take place in the Earth magnetosphere and in the Sun atmosphere. The products of the decay, i.e., the lower-hybrid and the kinetic Alfven waves, can effectively interact with magnetospheric and sun plasmas.