Double resonance excitation in the ionosphere

Wong, A. Y.; DiVergilio, W. F.; Iizuka, Keigo

doi:10.1016/0375-9601(79)90306-2

Cited by 14 publications

(5 citation statements)

References 12 publications

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“…Plasma line altitude studies have shown the HF-enhanced plasma line height to be above that of the photoelectron-enhanced plasma line during and immediately following HF turn-on [Muldrew and $howen, 1977]. In addition, multiple pump studies show mutual interaction effects even when the two pump waves are sufficiently separated both in frequency (50-100 kHz) and altitude (up to several kilometers) to virtually exclude the double resonance interaction [Wong et al, 1979]. These observations indicate that the development and structure of the early-time HF interaction region are significantly more complex than previously described.…”

Section: Introductionmentioning

confidence: 99%

High‐resolution studies of the HF ionospheric modification interaction region

Duncan

Sheerin

1985

J. Geophys. Res.

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Incoherent backscatter radar studies were conducted of the HF ionospheric modification interaction region using the facilities of the Arecibo Observatory. Very high relative spatial and temporal resolutions were achieved. These measurements resolve the miniovershoot (2-10 ms after HF on) and main overshoot (20-40 ms after HF on) plasma wave excitation features. The main overshoot phenomenon is observed to develop very reproducibly with enhancements of a factor of 10 greater than the steady state HF-enhanced plasma line intensity. However, this main overshoot effect is strongly suppressed for HF off times of less than 100 ms. In general, the miniovershoot excitation is found to occur 800-1000 m below the main overshoot excitation height. In addition, in one case, a small plasma line enhancement is detected at very early times (< 1 ms) distinct from the miniovershoot and originating at a greater height. The main overshoot and the steady state enhanced plasma line both develop at essentially the same altitude. However, the interaction layer is observed to broaden by several hundred meters during the main overshoot relaxation. Possible explanations for these effects are proposed using a combination of the theories of soliton formation and collapse, wave ducting, profile modification, parametric instabilities, and other interactive processes.

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Section: Introductionmentioning

confidence: 99%

High‐resolution studies of the HF ionospheric modification interaction region

Duncan

Sheerin

1985

J. Geophys. Res.

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“…aL, 1973, Wong, et. al., 1970, 1979. The fundalnental or harmonics of electrostatic ion cyclotron waves that were excited by this method were first observed in the laboratory [Wong et al, 1970].…”

Section: Introductionmentioning

confidence: 67%

Experimental study of double resonance parametric excitations in the ionosphere

Song¹,

Wong²,

Villaseñor³

et al. 1995

Radio Science

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We report the double resonance excitation of two pump waves with frequencies separated from 5 to several hundred Hz. The cyclotron frequencies of NO+ and O2+, abundant at the bottom of the F layer (∼ 150 km), are within this range. The nonlinear mode coupling takes place at ∼ 150 km where the pump frequency matches the plasma frequency. The experiments show that when the beat frequency is close to the NO+ cyclotron frequency at ∼ 30 Hz, the energy transfer from the higher frequency to the lower frequency wave is enhanced through parametric coupling. When the two pump waves have equal power, discrete sidebands are symmetrically distributed around the pump frequencies. However, a burst of lower‐frequency sidebands, lasting for several seconds, frequently breaks the symmetry. We attribute this asymmetry to the cascade parametric process. The asymmetric spectra only occur only during O mode experiments.

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“…Since the coefficients of this equation are constants, its Laplace transform yields a simple dispersion equation, a quadratic in w 2 , whose solution gives the results stated.…”

Section: Introductionmentioning

confidence: 99%

“…the minimum value of (E 1 2 + E 2 2 ) required to amplify a noise signal, we examine here the growth rate as a function of w1, w2, El and E 2 . Experimental observations on both experimental and ionospheric plasmas 2 have shown a complicated dependence of the wave amplitudes on pump frequencies. Although most steady-state experiments sample the nonlinearly saturated state of the instability, it is important to determine the properties of the early linear growth stage.…”

Section: Introductionmentioning

confidence: 99%

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Growth rates of parametric instabilities driven by two pumps

Milovich

Fried

Morales

1984

The Physics of Fluids

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The parametric instability growth rate of ion-acoustic and Langmuir waves, driven unstable by two uniform pumps near the Bohm–Gross frequency, is calculated as a function of pump amplitudes and frequencies. Two instability mechanisms can be identified: one corresponds to the usual, single pump parametric instabilities (decay and oscillating two stream), while the other is similar to that found in the Mathieu equation. The interaction between these two mechanisms results in a nonmonotonic dependence of the growth rate on the pump amplitudes and frequencies: both cancellation and enhancement are obtained for various values of the parameters. An analytic study of the relevant dispersion relation using Hill’s method is complemented by numerical studies in both the frequency and time domains.

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Double resonance excitation in the ionosphere

Cited by 14 publications

References 12 publications

High‐resolution studies of the HF ionospheric modification interaction region

High‐resolution studies of the HF ionospheric modification interaction region

Experimental study of double resonance parametric excitations in the ionosphere

Growth rates of parametric instabilities driven by two pumps

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