Short-period fluctuations in the fair-weather electric field

Yerg, Donald G.; Johnson, Katy

doi:10.1029/jc079i015p02177

Cited by 22 publications

(5 citation statements)

References 8 publications

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“…The results for the spectral indexes of these pulsations, available in the literature, are based on episodic measurements and are quite fragmentary (see [ Anisimov et al , 2001] for a comprehensive review). Using twelve 1‐hour time series data, Yerg and Johnson [1974] pointed out that the fluctuation spectrum of the vertical component of the electric field falls as f −2.2 (in different experiments the spectral index varied from −2.4 to −2.0) at the frequencies of 0.004–0.06 Hz. Anderson [1982] presented the fluctuation spectra of the electric‐charge density, whose indexes varied from −7/3 to −5/3 in the case of ground‐based measurements and from −9/3 to −8/3 if measurements were performed above sea surface.…”

Section: Introductionmentioning

confidence: 99%

Universal spectra of electric field pulsations in the atmosphere

Anisimov¹,

Mareev

Shikhova³

et al. 2002

Geophysical Research Letters

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[1] Short-term ( f ' 10 À3 -1 Hz) electric field pulsations in the surface atmospheric layer have been measured during 1999 -2001 under the fair-weather and fog conditions. At the frequencies of 10 À2 -1 Hz these pulsations have a power-law spectrum with the spectral index varying in the range from À1.23 to À3.36 while the most probable values of the index fall into the range from À2.25 to À3.0, unlike the temperature fluctuation spectra which obey in the inertial subrange the Kolmogorov power law with the spectral index close to À5/3. Under the fog conditions the intensity of electric-field pulsations increases by about an order of magnitude compared to the fair-weather conditions. The relation of spectral characteristics to the formation of aeroelectric structures (AESs) is evident; the spectral index distribution during AES flyby has two maxima. Analysis of the mechanisms explains the relationship between electricfield spectra and the neutral-gas turbulence and AES formation.

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Section: Introductionmentioning

confidence: 99%

Universal spectra of electric field pulsations in the atmosphere

Anisimov¹,

Mareev

Shikhova³

et al. 2002

Geophysical Research Letters

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“…In a system moving with the mean flow velocity, changes of the structures of charge are relatively small even within the band of frequencies lower than considered in the present paper [Yerg and Johnson, 1974]. This is the reason for which, besides homogeneity and local isotropy, frozen turbulence approximation is assumed in this paper.…”

Section: Introductionmentioning

confidence: 74%

Some theoretical estimations of spectral densities of short‐period electric noises generated near the ground

Łosakiewicz¹

1995

J. Geophys. Res.

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The paper presents a theoretical analysis of spectral densities of noises generated by charge advection in a vertical electric field and air‐Earth current measured on the ground by point and linear sensors. The analysis is restricted only to short time‐scales so that the turbulence transporting the charge is close to its inertial subrange and can be considered as homogeneous and locally isotropic. Hence the Kolmogorov scaling law is applied. Next the frozen turbulence approximation is used to obtain frequency spectra. In comparison with point sensors for long antennas, electric noises are considerably damped, especially at high frequencies.

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“…These fluctuations may confuse and mislead a researcher upon a search of simultaneous geomagnetic and atmospheric electricity pulsations. Periodic fluctuations of the atmospheric potential gradient and vertical atmospheric current J z in the range of Pc4-5 frequencies were observed by Yerg and Johnson, (1974) and in the Pc1 and Pc3 bands by Anisimov et al (1984). These fluctuations were not coherent with geomagnetic pulsations, so authors suggested that they may be caused by nonmagnetospheric sources, e.g., infrasound emissions from distant meteorological sources.…”

Section: Discussionmentioning

confidence: 99%

Electric Mode Excitation in the Atmosphere by Magnetospheric Impulses and ULF Waves

et al. 2021

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Variations of vertical atmospheric electric field Ez have been attributed mainly to meteorological processes. On the other hand, the theory of electromagnetic waves in the atmosphere, between the bottom ionosphere and earth’s surface, predicts two modes, magnetic H (TE) and electric E (TH) modes, where the E-mode has a vertical electric field component, Ez. Past attempts to find signatures of ULF (periods from fractions to tens of minutes) disturbances in Ez gave contradictory results. Recently, study of ULF disturbances of atmospheric electric field became feasible thanks to project GLOCAEM, which united stations with 1 sec measurements of potential gradient. These data enable us to address the long-standing problem of the coupling between atmospheric electricity and space weather disturbances at ULF time scales. Also, we have reexamined results of earlier balloon-born electric field and ground magnetic field measurements in Antarctica. Transmission of storm sudden commencement (SSC) impulses to lower latitudes was often interpreted as excitation of the electric TH0 mode, instantly propagating along the ionosphere–ground waveguide. According to this theoretical estimate, even a weak magnetic signature of the E-mode ∼1 nT must be accompanied by a burst of Ez well exceeding the atmospheric potential gradient. We have examined simultaneous records of magnetometers and electric field-mills during >50 SSC events in 2007–2019 in search for signatures of E-mode. However, the observed Ez disturbance never exceeded background fluctuations ∼10 V/m, much less than expected for the TH0 mode. We constructed a model of the electromagnetic ULF response to an oscillating magnetospheric field-aligned current incident onto the realistic ionosphere and atmosphere. The model is based on numerical solution of the full-wave equations in the atmospheric-ionospheric collisional plasma, using parameters that were reconstructed using the IRI model. We have calculated the vertical and horizontal distributions of magnetic and electric fields of both H- and E-modes excited by magnetospheric field-aligned currents. The model predicts that the excitation rate of the E-mode by magnetospheric disturbances is low, so only a weak Ez response with a magnitude of ∼several V/m will be produced by ∼100 nT geomagnetic disturbance. However, at balloon heights (∼30 km), electric field of the E-mode becomes dominating. Predicted amplitudes of horizontal electric field in the atmosphere induced by Pc5 pulsations and travelling convection vortices, about tens of mV/m, are in good agreement with balloon electric field and ground magnetometer observations.

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Short-period fluctuations in the fair-weather electric field

Cited by 22 publications

References 8 publications

Universal spectra of electric field pulsations in the atmosphere

Universal spectra of electric field pulsations in the atmosphere

Some theoretical estimations of spectral densities of short‐period electric noises generated near the ground

Electric Mode Excitation in the Atmosphere by Magnetospheric Impulses and ULF Waves

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