Journal ArticleDOI
Spectral broadening of VLF radio signals traversing the ionosphere
TLDR
In this paper, two different source mechanisms that can cause the spectral broadening of VLF radio signals traversing the ionosphere, a phenomenon first observed by Bell et al. are proposed.Abstract:
Two different source mechanisms that can cause the spectral broadening of VLF radio signals traversing the ionosphere, a phenomenon first observed by Bell et al. (1983), are proposed. The first is a nonlinear scattering of the whistler-mode VLF signals by preexisting ionospheric density fluctuations that render a mode conversion to lower hybrid waves. In the absence of ionospheric irregularities, a second mechanism, that involves a parametric instability, can excite the lower hybrid waves, as was proposed by Lee and Kuo (1984). Since both types of spectra were recorded in experiments, it is concluded that the two suggested source mechanisms contribute additively to the observed spectral broadening of injected VLF waves.read more
Citations
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The magnetic field experiment IMSC and its data processing onboard DEMETER: Scientific objectives, description and first results
Michel Parrot,D. Benoist,Jean-Jacques Berthelier,Jan Blecki,Y. Chapuis,Francis Colin,F. Elie,P. Fergeau,D. Lagoutte,François Lefeuvre,C. Legendre,M. Lévêque,Jean-Louis Pinçon,B. Poirier,H. C. Seran,P. Zamora +15 more
TL;DR: In this article, the authors describe the electronic block named BANT onboard the micro-satellite DEMETER, which is connected to an onboard memory and performs a comprehensive study of the Earth electromagnetic environment at the altitude of the satellite.
Journal ArticleDOI
Electrostatic lower hybrid waves excited by electromagnetic whistler mode waves scattering from planar magnetic‐field‐aligned plasma density irregularities
Timothy F. Bell,H. D. Ngo +1 more
TL;DR: In this paper, a theoretical model for electrostatic lower hybrid waves excited by electromagnetic whistler mode waves propagating in regions of the magnetosphere and the topside ionosphere, where small-scale magnetic-field-aligned plasma density irregularities are thought to exist.
Journal ArticleDOI
Auroral radio emissions, 1. Hisses, roars, and bursts
James LaBelle,Rudolf A. Treumann +1 more
TL;DR: The Earth's auroral electrons produce copious nonthermal radio emissions of various types, including auroral kilometric radiation (AKR), whistler mode auroral hiss, mode conversion radiation such as auroral roar and MF-burst, and possibly HF/VHF emissions as mentioned in this paper.
Journal ArticleDOI
An explanation of ground observations of auroral hiss: Role of density depletions and meter‐scale irregularities
TL;DR: In this article, the authors show that the presence of density depletions along the field lines in the auroral zone and meter-scale density irregularities at altitudes 5000-20, 000 km propagates to lower altitudes (< 3000-5000 km) in two modes: (1) a ducted mode guided by field-aligned density deplets and (2) a nonducted mode.
Journal ArticleDOI
Physical mechanisms of man-made influences on the magnetosphere
Michel Parrot,Y. Zaslavski +1 more
TL;DR: In this article, a review of the different physical mechanisms which are relevant to such perturbations is presented, including waveparticle interaction, precipitation of radiation belt electrons, parametric coupling of EM whistler waves, triggered emissions, frequency shift and whistler spectrum broadening.
References
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Journal ArticleDOI
Vlf hiss and related plasma observations in the polar magnetosphere.
D. A. Gurnett,L. A. Frank +1 more
TL;DR: In this paper, a study of auroral-zone vlf hiss and low-energy charged-particle observations with the Injun 5 satellite is presented, and the results of this study provide a direct verification of the association between auroral zone vlfHiss and intense fluxes of low energy electrons with energies on the order of 100 eV to several keV.
Journal ArticleDOI
Observations of auroral hiss, LHR noise, and other phenomena in the frequency range 20 Hz–540 kHz on Ogo 6
TL;DR: Ionospheric electric and electromagnetic waves broadband characteristics, investigating auroral hiss and LHR noise were discussed in this article, where the authors investigated the effect of LHR noises.
Journal ArticleDOI
The apparent spectral broadening of VLF transmitter signals during transionospheric propagation
TL;DR: In this article, the authors show that initially narrow band upgoing signals from ground-based VLF transmitters undergo a significant spectral broadening as they propagate through the ionosphere and protonosphere, up to altitudes in the 600-3800 km range.
Journal ArticleDOI
Thresholds of parametric instabilities near the lower‐hybrid frequency
R. L. Berger,F. W. Perkins +1 more
TL;DR: In this paper, a pump wave with frequency ω0 near the lower-hybrid frequency ϑlh was analyzed with respect to the wavenumber k of the decay waves and the ratio ω 0/ωlh to determine the decay process with the minimum threshold.
Journal ArticleDOI
Some characteristics of the lower hybrid resonance noise bands observed by the alouette i satellite
D. J. McEwen,R. E. Barrington +1 more
TL;DR: In this paper, an investigation of the occurrence as a function of latitude and time of lower hybrid resonance (LHR) noise bands as recorded during 1963 and 1964 by the very-low-frequency receiver aboard the Alouette I satellite was made.
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