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J.J. Gibbons

Bio: J.J. Gibbons is an academic researcher from Pennsylvania State University. The author has contributed to research in topics: Simultaneous equations & Ionospheric absorption. The author has an hindex of 2, co-authored 3 publications receiving 12 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the Rydbeck coupling region was subdivided into slabs of uniform media; by matching the fields between adjacent slabs, N − 1 simultaneous equations (for N slabs) were obtained.

6 citations

Journal ArticleDOI
TL;DR: In this paper, a formula is derived from which the group index for normal incidence, including collision effects, can be easily computed as a function of μ and χ for frequencies below one megacycle.

4 citations

Journal ArticleDOI
TL;DR: In this article, the differential equation for the reflection coefficient in the deviative region is solved approximately and the expression is tested on cases of known reflection coefficient and then applied to recently proposed models of the E and D layers.

2 citations


Cited by
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Journal ArticleDOI
01 Apr 1962
TL;DR: In this paper, the propagation of a radio signal and the propagation in the time domain is reviewed for linear amplitude systems, and the particular case of a ground wave pulse is considered in detail.
Abstract: The propagation of a radio signal and the propagation in the time domain is reviewed for linear amplitude systems. The particular case of the propagation of a ground wave pulse is considered in detail. A stretching in the form or shape of the pulse is noted as a result of the filtering action of the propagation medium. Theoretical transfer characteristics for the media of propagation of LF signals are introduced and methods of computation are considered. The particular case of a signal transmitted between two points on the earth's surface is considered from the viewpoint of propagation in the time domain. The field of LF waves propagated around the earth is, in large measure, influenced by the reflection and transmission processes at the ionosphere. Such processes are evaluated theoretically with the aid of Maxwell's equations together with an equation which describes the electron motion in the presence of a static magnetic field, a superposed electrodynamic field together with mechanical collisions between electrons and ions, such as the Langevin equation of motion of the electron. The use of full mathematical rigor in the application of these equations is feasible and indeed desirable at LF. Thus, the application of these equations to an electron-ion model plasma with arbitrary orientation of the superposed magnetic induction results in anisotropic transmission and reflection properties. The full rigor can be applied to model plasmas in which the electron density and collision frequency vary with altitude.

45 citations

Book ChapterDOI
01 Jan 1964
TL;DR: A comprehensive bibliography with over one thousand entries and abstracts has been prepared by Brock-Nannestad (1962) and a chapter of a recent book by Wait as mentioned in this paper discusses ELF waves and also contains a number of references to published papers.
Abstract: Numerous papers have been dealing with extremely low frequency (ELF) phenomena recently and a comprehensive bibliography with over one thousand entries and abstracts has been prepared by Brock-Nannestad (1962). A chapter of a recent book by Wait (1962a) discusses ELF waves and it also contains a number of references to published papers. It will not be attempted to relist here all the references of the above publications. Instead, after a brief historical review of the work on ELF propagation and a summary of the fundamental concepts, much of the discussion will be devoted to recent analytical and experimental results.

23 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined a solar-terrestrial storm that occurred in 1946 March and quantitatively evaluated its parameters, based on measurements in four known mid-latitude and relatively complete magnetograms, which caused an initial phase with the H-component amplitude of ≥80 nT, followed by a main phase whose intensity was reconstructed as ≤−512 nT using most negative Dst* estimates.
Abstract: Major solar eruptions occasionally cause magnetic superstorms on the Earth. Despite their serious consequences, the low frequency of their occurrence provides us with only limited cases through modern instrumental observations, and the intensities of historical storms before the coverage of the Dst index have been only sporadically estimated. Herein, we examine a solar-terrestrial storm that occurred in 1946 March and quantitatively evaluate its parameters. During the ascending phase of Solar Cycle 18, two moderate sunspot groups caused a major flare. The H α flaring area was recorded to be ≥600–1200 millionths of solar hemisphere, suggesting that this was an M- or X-class flare in soft X-ray intensity. Upon this eruption, a rapid interplanetary coronal mass ejection (ICME) with an average speed of ≈1590 km s−1 was launched. Based on measurements in four known mid-latitude and relatively complete magnetograms, the arrival of this extreme ICME caused a magnetic superstorm, which caused an initial phase with the H-component amplitude of ≥80 nT, followed by a main phase whose intensity was reconstructed as ≤−512 nT using most negative Dst* estimates. Meanwhile, the equatorial boundary of the auroral oval extended down to ≤41${^{\\circ}_{.}}$8 in invariant latitude and formed a corona aurora in Watheroo, Australia. Interestingly, during this magnetic superstorm, larger magnetic disturbances were recorded at dusk and near the dip equator on the dayside. Its cause may be associated with a strong westward equatorial electrojet and field-aligned current, in addition to the contribution from the storm-time ring current.

16 citations

Journal ArticleDOI
TL;DR: In this article, the effect of the electron collision frequency ν on the group refractive index, for both the ordinary and extraordinary rays, under a wide variety of conditions, was shown.

11 citations

Journal ArticleDOI
TL;DR: In this article, the use of the generation of extremely low frequency (ELF) from heating of the D region of the ionosphere at high latitudes to estimate the degree of electron density ionization was described.
Abstract: This paper describes the use of the generation of extremely low frequency (ELF) from heating of the D region of the ionosphere at high latitudes to estimate the degree of electron density ionization of the D region. In particular, the heating facility near Fairbanks, Alaska, known as the high-power auroral simulation (HIPAS) facility, was used in this work. The theory of electron density synthesis is described, results of actual data presented, and electron densities determined. A new future ionospheric measurement technique is discussed.

5 citations