Abstract
VLF emissions such as hiss, chorus, oscillating tones, hiss-triggered chorus and whistler triggered emissions have been observed at low latitude Indian stations. In this paper we present dynamic spectra of these emissions and discuss their various observed features. It is argued that most of the emissions are generated during Doppler shifted cyclotron resonance interaction between the whistler mode wave and counter streaming energetic electrons. Resonance energy of the participating electron and interaction length are evaluated to explain the generation mechanism of some of these emissions observed at Indian stations.
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References
R K Burton and R E Holtzer, The origin and propagation of chorus in the onter magnetosphere. J. Geophys. Res. 79, 1014–1023 (1974)
C R Carlson, R A Helliwell and U S Inan, Space-time evolution of whistler mode wave growth in the magnetosphere. J. Geophys. Res. 95, 15073–15089 (1990)
S K Dikshit, Lalmani, V V Somayajulu and B A P Tantry, Riser whistler at a ground station at low latitude, Nature 230, 115–116 (1971)
K Hattori and M Hayakawa, Consideration of dynamic spectra and direction finding results of hiss triggered chorus emission, Proc. NIPR Symp. Upper Atoms. Phys. 7, 40–52 (1994)
R A Helliwell, A theory of discrete VLF emission from the magnetosphere, J. Geophys. Res. 72, 4773–4789 (1967)
R A Heilliwell, Controlled stimulation of VLF emissions from siple station: Antarctica, Radio Science 18, 801–814 (1983)
Y Hobara, V Y Trakhtengerts, A G Demekhov and M Hayakawa, Cyclotron amplification of whistler waves by electron beams in an inhomogeneous magnetic field, J. Geophys. Res. 103, 20499–20458 (1998)
P N Khosa, Lalmani and M M Ahmad. Discrete chorus emissions observed at Nainital, J. Geophys. 52, 106–108 (1983a)
P N Khosa, Lamani and M M Ahmad, Discrete chorus emissions observed at Varanasi, J. Geophys. Res. 54, 76 (1983b)
I Kimura, On observations and theories of the VLF emissions. Planet. Space Sci. 15, 1427–1462 (1967)
H C Koons, The role of hiss in magnetospheric chorus emissions, J. Geophys. Res. 86, 6745–6754 (1981)
D Nunn, A nonlinear theory of sideband stability in ducted whistler mode waves, Planet. Space Sci. 34, 429 (1984)
D Nunn and A J Smith, Numerical simulation of whistler-triggered VLF emissions observed in Antarctica, J. Geophys. Res. 101, 5261–5277 (1996)
D Nunn, Y Omura, H Matsumoto, I Nagano and S Yagitani, The numerical simulation of VLF chorus and discrete emissions observed on Geotail Satellite using a Vlasov code, J. geophys. Res. 102, 27083–27097 (1997)
Y Omura and H Matsumoto, Computing processes of whistler and electrostatic instabilities in the magnetosphere, J. Geophys. Res. 92, 8469 (1987)
Y Omura, D Nunn, H Matsumoto and M J Rycroft, A review of observational, theoretical and numerical studies of VLF triggered emissions, J. Armos. Terr. Phys. 53, 351–368 (1991)
M Rao, Lalmani, V V Somayajulu and B A P Tantry, Dependence of whistler activity on geomagnetic latitude. Indian J. Radio Space Phys. 1, 192–194 (1972)
S S Sazhin and M Hayakawa, Magnetospheric chorus emissions: A review, Planet. Space Sci. 40, 681–697 (1992)
S S Sazhin, K Bullough and M Hayakawa, Auroral hiss: a review, Planet. Space Sci. 41, 153–166 (1993)
R P Singh, Lalmani and U P Singh, Discrete emissions and whistler precursors recorded at low latitude ground station Gulmarg, Earth Moon and Planets 60, 225–232 (1993)
D K Singh, Ashok K Singh, R P Patel, R P Singh and A K Singh, Two types of ELF hiss observed at Varanasi, India: Ann. Geophysicae 17, 1260–1267 (1999a)
R Singh, R P Patel, R P Singh and Lalmani, An experimental study of hiss triggered chorus emissions at low latitude, Earth Planet. Space 51, (1999b)
D K Singh, Study of whistler waves and VLF emissions observed at Varanasi, Ph.D. Thesis (Banaras Hindu University, Varanasi, India, 1999)
J L Vomvoridis, T L Crystal and J Denavit, Theory and computer simulations of magnetospheric very low frequency emissions, J. Geophys. Res. 87, 1473–1489 (1982)
W W L Taylor and S D Shawhan, A test of incoherent Cerenkov radiation for VLF hiss and other magnetospheric emissions, J. Geophys. Res. 79, 105–117 (1974)
V Y Trakhtengerts, M J Rycroft and A G Demekhov, Interaction of noise like and discrete ELF/VLF emissions generated by cyclotron interactions, J. Geophys. Res. 101, 13293–13301 (1996)
B T Tsurutani, E J Smith and R M Thorne, Electromagnetic hiss and relativistic electron losses in the inner zone, J. Geophys. Res. 80, 600–607 (1975)
B T Tsurutani and G S Lakhina, Some basic concepts of wave-partiele interactions in collision-less plasmas, Rev. Geophys. 35, 491–502 (1997)
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Patel, R.P., Singh, R.P. VLF emissions from ionospheric/magnetospheric plasma. Pramana - J Phys 56, 605–613 (2001). https://doi.org/10.1007/s12043-001-0085-x
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DOI: https://doi.org/10.1007/s12043-001-0085-x