Multi‐hop whistler‐mode ELF/VLF signals and triggered emissions excited by the HAARP HF heater

Inan, U. S.; Gołkowski, Mark; Carpenter, D. L.; Reddell, Noah; Moore, R. C.; Bell, T. F.; Paschal, E. W.; Kossey, Paul; Kennedy, Edward J.; Meth, S. Z.

doi:10.1029/2004gl021647

Cited by 47 publications

(47 citation statements)

References 20 publications

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“…2. We can see that the artificial ELF/VLF waves, once entering into the magnetosphere, bounce back and forth between the Southern and Northern hemispheres, propagate outwards, and finally settle down at certain higher L shell, which is consistent with the results of Inan et al (2003) and Bortnik (2005). Figure 2 also shows that the frequency and initial launch latitude strongly affects the details of ray path.…”

Section: Ray Tracing Simulations Of Elf/vlf Waves Generated By Modulasupporting

confidence: 90%

“…This approach is different than the method of Inan et al (2003). Our study is also different from Kulkarni et al (2008) that modeled the potential electron precipitation signatures produced by ground-based single-frequency (10-40 kHz) VLF sources based on the methodology of Bortnik et al (2006a, b).…”

Section: Test Particle Simulation Resultsmentioning

confidence: 84%

“…Being aware of the potential of controlling energetic electron lifetimes using artificial ELF/VLF waves, provided estimates of the potential effects of a satellite-based ELF/VLF transmitter at a few kHz operating at the magnetic equatorial plane of L = 2 and concluded that cyclotron resonances with the artificially injected whistler-mode waves can significantly reduce the lifetime of energetic electrons in the inner radiation belt. To estimate the wave-induced pitchangle scattering rates, Inan et al (2003) followed the quasilinear formulae of Lyons (1974) and Albert (1999) in the limit of vanishing width of the frequency and wave-normal angle distribution. Later, Kulkarni et al (2008) followed the methodology of Bortnik et al (2006a, b), which assumed that the wave-particle interactions are linear and transformed the wave-induced pitch angle changes to precipitating flux using a novel convolution method.…”

Section: S S Chang Et Al: Resonant Scattering Of Energetic Electronsmentioning

confidence: 99%

“…1, when ELF/VLF waves are generated as a result of periodic modulation of the ionospheric currents by HF heating (Ferraro et al, 1982;Barr and Stubbe, 1991;Inan et al, 2004;Platino et al, 2006;Piddyachiy et al, 2008), some waves propagate directly upwards and others propagate within the Earth-ionosphere waveguide and leak up progressively with each reflection off the ionosphere (James et al, 1984;Inan et al, 2004;Platino et al, 2006;Piddyachiy et al, 2008). Subsequently, these leaked waves propagate outwards and encounter energetic electrons that can potentially undergo resonant wave-particle interactions.…”

Section: Ray Tracing Simulations Of Elf/vlf Waves Generated By Modulamentioning

confidence: 99%

“…Generation of extremely low-frequency (ELF)/very lowfrequency (VLF) waves by modulated heating of the D region ionosphere in the presence of naturally forming ionospheric currents is by now a well-established technique (e.g., Ferraro et al, 1982;Barr and Stubbe, 1991;Inan et al, 2004;Platino et al, 2006;Piddyachiy et al, 2008;and references therein). Periodic heating of the ionospheric region with a high-frequency (HF) transmitter modulates the conductivity of the region and, in turn, modulates these naturally forming (and pre-existing) currents, constituting what amounts to a giant radiating antenna at ∼ 60-100 km altitude.…”

Section: Introductionmentioning

confidence: 99%

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Resonant scattering of energetic electrons in the plasmasphere by monotonic whistler-mode waves artificially generated by ionospheric modification

Chang

Bortnik

et al. 2014

Ann. Geophys.

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Abstract. Modulated high-frequency (HF) heating of the ionosphere provides a feasible means of artificially generating extremely low-frequency (ELF)/very low-frequency (VLF) whistler waves, which can leak into the inner magnetosphere and contribute to resonant interactions with highenergy electrons in the plasmasphere. By ray tracing the magnetospheric propagation of ELF/VLF emissions artificially generated at low-invariant latitudes, we evaluate the relativistic electron resonant energies along the ray paths and show that propagating artificial ELF/VLF waves can resonate with electrons from ∼ 100 keV to ∼ 10 MeV. We further implement test particle simulations to investigate the effects of resonant scattering of energetic electrons due to triggered monotonic/single-frequency ELF/VLF waves. The results indicate that within the period of a resonance timescale, changes in electron pitch angle and kinetic energy are stochastic, and the overall effect is cumulative, that is, the changes averaged over all test electrons increase monotonically with time. The localized rates of wave-induced pitch-angle scattering and momentum diffusion in the plasmasphere are analyzed in detail for artificially generated ELF/VLF whistlers with an observable in situ amplitude of ∼ 10 pT. While the local momentum diffusion of relativistic electrons is small, with a rate of < 10 −7 s −1 , the local pitchangle scattering can be intense near the loss cone with a rate of ∼ 10 −4 s −1 . Our investigation further supports the feasibility of artificial triggering of ELF/VLF whistler waves for removal of high-energy electrons at lower L shells within the plasmasphere. Moreover, our test particle simulation results show quantitatively good agreement with quasi-linear diffusion coefficients, confirming the applicability of both methods to evaluate the resonant diffusion effect of artificial generated ELF/VLF whistlers.

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Section: Ray Tracing Simulations Of Elf/vlf Waves Generated By Modulasupporting

confidence: 90%

Section: Test Particle Simulation Resultsmentioning

confidence: 84%

Section: S S Chang Et Al: Resonant Scattering Of Energetic Electronsmentioning

confidence: 99%

Section: Ray Tracing Simulations Of Elf/vlf Waves Generated By Modulamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Resonant scattering of energetic electrons in the plasmasphere by monotonic whistler-mode waves artificially generated by ionospheric modification

Chang

Bortnik

et al. 2014

Ann. Geophys.

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Modulation Analysis of Whistler Mode Sidebands in VLF‐Triggered Emissions and Implications for Conditions of Nonlinear Growth

2017

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Experimental observations of very low frequency (VLF) triggered emissions are an important resource in investigation of nonlinear wave‐particle interactions between whistler mode waves and energetic electrons in the Earth's radiation belts. Magnetospherically generated whistler mode sidebands observed during the Siple Station wave injection experiment are analyzed using a mixed modulation model and the MINUIT minimization package. The observed sidebands are found to exhibit features of both amplitude and frequency modulation of the input carrier wave with frequency modulation becoming more prominent as the observed amplitudes of the carrier and sidebands increase. A nonlinear whistler mode wave growth formulation based on phase bunching of counterstreaming electrons within a well‐defined phase trap is shown to reproduce the salient features of the sideband observations. Whistler mode sideband amplitude is shown to be affected by the shape and uniformity of the trap.

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Numerical Modeling of Ionospheric Current Artificial Modulation at Low Latitudes

Feng¹,

Zhao²,

Zhang³

2009

Chinese J of Geophysics

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Powerful high‐frequency radio waves can efficiently heat the lower ionosphere. If using HF heater modulated at ELF/VLF, the electron temperature will oscillate with the modulation frequency and lead to periodic changes of the electric conductivity, resulting in periodically variations of the current present in the heated region which can act as a equivalent ELF/VLF virtual antenna for the generation of electromagnetic waves at the modulation frequency. These early researches mainly focused on the high latitudes and polar area. In this paper, the possibility of the ionospheric artificial modulation at low latitudes is discussed. The theoretical analysis and numerical modeling show that the periodical modification will lead to the conductivities at low latitudes periodically changing efficiently and the heated ionospheric area acts as a radiation current source of the ELF/VLF waves. Furthermore, the effects of different parameters and incident conditions on modulation are also analyzed.

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Multi‐hop whistler‐mode ELF/VLF signals and triggered emissions excited by the HAARP HF heater

Cited by 47 publications

References 20 publications

Resonant scattering of energetic electrons in the plasmasphere by monotonic whistler-mode waves artificially generated by ionospheric modification

Resonant scattering of energetic electrons in the plasmasphere by monotonic whistler-mode waves artificially generated by ionospheric modification

Modulation Analysis of Whistler Mode Sidebands in VLF‐Triggered Emissions and Implications for Conditions of Nonlinear Growth

Numerical Modeling of Ionospheric Current Artificial Modulation at Low Latitudes

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