Generation of ELF and ULF electromagnetic waves by modulated heating of the ionospheric F2 region

Eliasson, Bengt; Chang, C. L.; Papadopoulos, K.

doi:10.1029/2012ja017935

Cited by 21 publications

(26 citation statements)

References 35 publications

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“…(25) are similar in form yet their physical meanings are completely different. According to Eliasson et al (2012), the term ∂∇δT e ∂t mainly generates the waves of non-propagating modes which are not studied in this paper. In the meantime, the magnetosonic wave is directly excited by the diamagnetic ring current due to the perpendicular electron temperature pressure gradient, while the Alfvén wave is generated by mode conversion from the magnetosonic wave through Hall conductivity.…”

Section: Model Of Ulf Wave Generation and Propagationmentioning

confidence: 99%

“…In our simulation, the generation model of ULF waves proposed by Eliasson et al (2012) is used to calculate the following propagation of ULF waves excited by modulated HF heating. The model is built under the following assumption: firstly, the frequency of the artificially generated ULF wave is far less than the electron cyclotron frequency; secondly, O + is considered as the only ion dominating the propagation of the plasma wave and the condition of quasi-neutrality n 0 = n i = n e for ion and electron number densities is satisfied; thirdly, the electron-neutral and ion-neutral collisions are the main collision mechanism when calculating the wave dynamics.…”

Section: Model Of Ulf Wave Generation and Propagationmentioning

confidence: 99%

“…In Sect. 2, we first briefly introduce the physical mechanism of the ULF wave generation in the F region by modulated HF heating proposed by Papadopoulos et al (2011a) and Eliasson et al (2012). Then we introduce the HF heating model and the following model of ULF wave generation and propagation.…”

Section: Introductionmentioning

confidence: 99%

“…In a series of experiments conducted from 2009 to 2010 at HAARP, artificial ULF and lower ELF signals generated by the modulated heating ionospheric F region in the absence of electrojets were received on the ground far away from the heating facility, and the dependence on the heating conditions differs from the low-frequency waves generated by modulating the ionospheric currents (Papadopoulos et al, 2011a, b;Eliasson and Papadopoulos, 2012). This artificial generation of ULF waves relates to the oscillating diamagnetic drift current in the upper ionosphere due to the modulated heating, which is based on the ICD (ionospheric current drive) theory proposed by Papadopoulos et al (2007).…”

Section: Introductionmentioning

confidence: 99%

“…By modifying the model developed by Lysak (1997), Papadopoulos et al (2011b) built a new model to study the ICD in the polar ionosphere by F region heating in cylindrical geometry. Eliasson et al (2012) performed a theoretical and numerical study of the ICD based on a numerical model of the generation and propagation of ULF and ELF waves. The simulation results agree with the HAARP experimental measurements.…”

Section: Introductionmentioning

confidence: 99%

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Numerical study of the generation and propagation of ultralow-frequency waves by artificial ionospheric F region modulation at different latitudes

Xu¹,

Zhou²,

Shi³

et al. 2016

Ann. Geophys.

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Abstract. Powerful high-frequency (HF) radio waves can be used to efficiently modify the upper-ionospheric plasmas of the F region. The pressure gradient induced by modulated electron heating at ultralow-frequency (ULF) drives a local oscillating diamagnetic ring current source perpendicular to the ambient magnetic field, which can act as an antenna radiating ULF waves. In this paper, utilizing the HF heating model and the model of ULF wave generation and propagation, we investigate the effects of both the background ionospheric profiles at different latitudes in the daytime and nighttime ionosphere and the modulation frequency on the process of the HF modulated heating and the subsequent generation and propagation of artificial ULF waves. Firstly, based on a relation among the radiation efficiency of the ring current source, the size of the spatial distribution of the modulated electron temperature and the wavelength of ULF waves, we discuss the possibility of the effects of the background ionospheric parameters and the modulation frequency. Then the numerical simulations with both models are performed to demonstrate the prediction. Six different background parameters are used in the simulation, and they are from the International Reference Ionosphere (IRI-2012) Jicamarca (11.95 • S, 76.87 • W) at 02:00 and 14:00 LT. A modulation frequency sweep is also used in the simulation. Finally, by analyzing the numerical results, we come to the following conclusions: in the nighttime ionosphere, the size of the spatial distribution of the modulated electron temperature and the ground magnitude of the magnetic field of ULF wave are larger, while the propagation loss due to Joule heating is smaller compared to the daytime ionosphere; the amplitude of the electron temperature oscillation decreases with latitude in the daytime ionosphere, while it increases with latitude in the nighttime ionosphere; both the electron temperature oscillation amplitude and the ground ULF wave magnitude decreases as the modulation frequency increases; when the electron temperature oscillation is fixed as input, the radiation efficiency of the ring current source is higher in the nighttime ionosphere than in the daytime ionosphere.

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Section: Model Of Ulf Wave Generation and Propagationmentioning

confidence: 99%

Section: Model Of Ulf Wave Generation and Propagationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Numerical study of the generation and propagation of ultralow-frequency waves by artificial ionospheric F region modulation at different latitudes

Xu¹,

Zhou²,

Shi³

et al. 2016

Ann. Geophys.

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Investigation of ionospheric stimulated Brillouin scatter generated at pump frequencies near electron gyroharmonics

et al. 2013

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[1] Stimulated Electromagnetic Emissions (SEEs), secondary electromagnetic waves excited by high power electromagnetic waves transmitted into the ionosphere, produced by the Magnetized Stimulated Brillouin Scatter (MSBS) process are investigated. Data from four recent research campaigns at the High Frequency Active Auroral Research Program (HAARP) facility is presented in this work. These experiments have provided additional quantitative interpretation of the SEE spectrum produced by MSBS to yield diagnostic measurements of the electron temperature and ion composition in the heated ionosphere. SEE spectral emission lines corresponding to ion acoustic (IA) and electrostatic ion cyclotron (EIC) mode excitation were observed with a shift in frequency up to a few tens of Hz from the pump frequency for heating near the third harmonic of the electron gyrofrequency 3f ce . The threshold of each emission line has been measured by changing the pump wave power. The excitation threshold of IA and EIC emission lines originating at the reflection and upper hybrid altitudes is measured for various beam angles relative to the magnetic field. Variation of strength of MSBS emission lines with pump frequency relative to 3f ce and 4f ce is also studied. A full wave solution has been used to estimate the amplitude of the electric field at the interaction altitude. The estimated instability threshold using the theoretical model is compared with the threshold of MSBS lines in the experiment and possible diagnostic information for the background ionospheric plasma is discussed. Simultaneous formation of artificial field-aligned irregularities (FAIs) and suppression of the MSBS process is investigated. This technique can be used to estimate the growth time of artificial FAIs which may result in determination of plasma waves and physical process involved in the formation of FAIs.Citation: Mahmoudian, A., W. A. Scales, P. A. Bernhardt, H. Fu, S. J. Briczinski, and M. J. , Investigation of ionospheric stimulated Brillouin scatter generated at pump frequencies near electron gyroharmonics, Radio Sci., 48,[685][686][687][688][689][690][691][692][693][694][695][696][697]

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EMIC waves observed by the low‐altitude satellite DEMETER during the November 2004 magnetic storm

et al. 2015

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This paper presents an analysis of ULF (0-20 Hz) waves observed by the low-altitude satellite Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) during the magnetic storm of November 2004. Since these ULF waves are measured by both electric and magnetic antennas, they may be identified as electromagnetic ion cyclotron (EMIC) waves. While EMIC waves have been previously observed in the low-altitude ionosphere, this is the first time that they are observed for such extensive time periods and at such high frequencies. A common feature of these emissions is that their observation region in the low-altitude ionosphere extends continuously from the high-latitude southern trough in one side up to the high-latitude northern trough. The analysis of wave propagation points to the possible source region placed in the inner magnetosphere (L∼2-3). Observed wave frequencies indicate that waves must be generated much farther from the Earth compared to the satellite orbit. Exceptionally high frequencies of about 10 Hz can be explained by the source region placed in the deep inner magnetosphere at L ∼2.5. We hypothesize that these waves are generated below the local helium gyrofrequency and propagate over a large range of wave normal angles to reach low altitudes at L ∼1.11. In order to investigate this scenario, a future study based on ray tracing simulations will be necessary.

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Generation of ELF and ULF electromagnetic waves by modulated heating of the ionospheric F2 region

Cited by 21 publications

References 35 publications

Numerical study of the generation and propagation of ultralow-frequency waves by artificial ionospheric F region modulation at different latitudes

Numerical study of the generation and propagation of ultralow-frequency waves by artificial ionospheric F region modulation at different latitudes

Investigation of ionospheric stimulated Brillouin scatter generated at pump frequencies near electron gyroharmonics

EMIC waves observed by the low‐altitude satellite DEMETER during the November 2004 magnetic storm

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