Study of Oblique Propagating Whistler Mode Waves in Presence of Parallel DC Electric Field in Magnetosphere of Saturn
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Abstract
In this paper whistler mode waves have been investigated in magnetosphere of Saturn. The derivation for perturbed distribution function, dispersion relation and growth rate have been determined by using the method of characteristic and kinetic approach. Analytical expressions for growth rate and real frequency of whistlers propagating oblique to magnetic field direction are attained. Calculations have been performed at 6 radial distances in plasma sheet region of Saturn’s magnetosphere as per data provided by Cassini. Work has been extended for bi-Maxwellian as well as Loss-cone distribution function. Parametric analysis show that temperature anisotropy, increase in number density, energy density and angle of propagation increases the growth rate of whistler waves along with significant shift in wave number. In case of Loss-cone distribution, increase in growth rate of whistlers is significantly more than for bi-Maxwellian distribution function. Generation of second harmonics can also be seen in the graphs plotted. It is concluded that parallel DC field stabilizes the wave and temperature anisotropy, angle of propagation, number density and energy density of electrons enhances the growth rate. Thus the results are of importance in analyzing observed VLF emissions over wide spectrum of frequency range in Saturnian magnetosphere. The analytical model developed can also be used to study various types of instabilities in planetary magnetospheres.
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References
Gurnett D. A., Kurth W. S. and Scarf F. L. 1981. Plasma Waves near Saturn: Initial results from Voyager 1. Science 212 (4491): 235.
Scarf F. L., Gurnett D. A., Kurth W. S. and Poynter R. L. 1982. Voyager2 Plasma Wave Observations at Saturn. Science 215: 587
Krimigis S.M., Carbary J.F., Keath E.P., Armstrong T.P., Lanzerotti L.J., Gloeckler G. 1983. General characteristics of hot plasma and energetic particles in the Saturnian magnetosphere: Results from the Voyager spacecraft. J. Geophys. Res. 88: 8871
Gurnett D. A., et al. 2004. The Cassini radio and plasma wave investigation. Space Sci. Rev. 114: 395
Gurnett, D. A., et al. 2005. Radio and plasma wave observations at Saturn from Cassini’s approach and first orbit. Science 307: 1255
Storey L.R.O. 1953. An investigation of whistling atmospherics, Philos. Trans. R. Soc. London, Ser. A 246: 113
Akalin, F., Gurnett D. A., Averkamp T. F., Persoon A. M., Santolik O., Kurth W. S., and Hospodarsky G. B. 32 2006. First whistler observed in the magnetosphere of Saturn. Geophys. Res. Lett. 33: L20107
Scarf F.L., Gurnett D.A and Kurth W.S. 1979. Jupiter plasma wave observations: An initial Voyager 1 overview, Science 204: 991
Kurth W.S., Strayer B.D., Gurnett D.A. and Scarf F.L. 1985. A summary of whistlers observed by Voyager 1 at Jupiter, Icarus 61: 497
Gurnett, D.A., Kurth, W.S., Scarf, F.L., Poynter, R.L. 1986. First plasma wave observations at Uranus. Science 233: 106
Pandey R.S. and Kaur R. 2014. Study of Whistler Mode Wave by Injection of Relativistic Hot Electron Beam in the Magnetosphere of Uranus. Progress in Electromagnetic Research M, Vol. 35: 77
Gurnett D.A., Kurth W.S., Cairns I.H. and Granroth L.J. 1990. Whistlers in Neptune’s magnetosphere: Evidence of atmospheric lightening, J. Geophys. Res. 95: 20967
Marklund et al. 2001. Temporal evolution of the electric field accelerating electrons away from the auroral ionosphere. Nature 414: 724-727.
Hull A.J., Scudder J.D., Fitzenreiter R.J., Ogilvie K.W., Newbury J.A. and Russell C.T. 2000. Electron temperature and de Hoffmann-Teller potential change across the Earth's bow shock: New results from ISEE 1. J. Geophys. Res., 105(A9): 20957
Ergun et al. 2001. Direct observation of localized parallel electric fields in a space plasma. Phys. Rev. Lett. 87: 45003
Crary F.J. 2005. Solar wind dynamic pressure and electric field as the main factors controlling Saturn’s aurorae. Nature 433: 720
Horne et al. 2005. Wave acceleration of electrons in the Van Allen radiation belts. Nature 437: 227
Misra K.D. and Pandey R.S. 1995. Generation of whistler emissions by injection of hot electrons in the presence of perpendicular AC electric field. J. Geophys. Res. 100 A(10): 19405
Dory R.A., Guest G. E. and Harris E. G. 1965. Unstable Electrostatic Plasma Waves Propagating Perpendicular to a Magnetic Field. Phys. Rev. Lett. 14: 131
Sazhin S. S. 1988. Oblique whistler Mode Growth and Damping in a Hot Anisotropic Plasma. Planet Space Science, 36: 663
Juhl B. and Treumann R.A. 1985. VLF emission stimulated by parallel electric fields. Journal of Plasma Physics 34(1): 47
Pandey R.S. and Kaur R. 2015. Oblique Electromagnetic Electron Cyclotron Waves for Kappa Distribution with A.C Field in Planetary Magnetospheres. Advances in Space Research 56: 714
Misra R. and Tiwari M.S. 2006. Effect of parallel electric field on electrostatic ion-cyclotron instability in anisotropic plasma in the presence of ion beam and general distribution function—Particle aspect analysis, Planetary and Space Science 54(2): 188.
Pandey R.S. and Kaur R. 2015b. Theoretical study of Electromagnetic Electron Cyclotron Waves in the Presence of AC Field in Uranian Magnetosphere. New Astronomy 40: 41
Pandey R.S., Rajbir Kaur, S. Kumar and B.S. Tomar. 2014. Study of Electromagnetic Electron-Cyclotron Waves with Kappa Distribution Function in the Magnetosphere’, Journal of Advanced Physics. 3(4) 334
Pandey R.S. and Kaur R. 2016. Analytical Study of Whistler Mode waves in Presence of Parallel DC Electric Field for Relativistic Plasma in the Magnetosphere of Uranus. Advances in Space Research, Vol. 58: 1417