Group and Phase Velocities of a Travelling Disturbance in the F Region of the Ionosphere

Nature ◽  
1961 ◽  
Vol 191 (4784) ◽  
pp. 157-157 ◽  
Author(s):  
L. H. HEISLER ◽  
J. D. WHITEHEAD
Keyword(s):  
Phase Velocities ◽  
F Region ◽  
Group And Phase Velocities

Nonlinear wave equation with intrinsic wave particle dualism

1976 ◽  
Vol 54 (13) ◽  
pp. 1383-1390 ◽  
Author(s):  
J. J. Klein
Keyword(s):  
Wave Equation ◽  
Nonlinear Wave ◽  
Nonlinear Wave Equation ◽  
Gordon Equation ◽  
Classical Mechanics ◽  
Carrier Wave ◽  
Sine Gordon Equation ◽  
Wave Speeds ◽  
Phase Velocities ◽  
Group And Phase Velocities

A nonlinear wave equation[Formula: see text]derived from the sine–Gordon equation is shown to possess a variety of solutions, the most interesting of which is a solution that describes a wave packet travelling with velocity uc modulating a carrier wave travelling with velocity uc. The envelop and carrier wave speeds agree precisely with the group and phase velocities found by de Broglie for matter waves. No spreading is exhibited by the soliton, so that it behaves exactly like a particle in classical mechanics. Moreover, the classically computed energy E of the disturbance turns out to be exactly equal to the frequency ω of the carrier wave, so that the Planck relation [Formula: see text] is automatically satisfied without postulating a particle–wave dualism.

Energy characteristics of spin waves with noncollinear group and phase velocities in an infinite ferrite medium

2016 ◽  
Author(s):  
Локк ◽  
Edvin Lokk
Keyword(s):  
Velocity Vector ◽  
Uniform Magnetic Field ◽  
Spin Waves ◽  
Angular Width ◽  
Energy Characteristics ◽  
Phase Velocities ◽  
Inflection Points ◽  
Isotropic Media ◽  
Group And Phase Velocities ◽  
Vector Orientation

Group velocity vector orientation ψ versus wave vector orientation  ´ is calculated for spin waves propagating in an infinite ferrite medium magnetized to saturation by uniform magnetic field H0. It is found that dependence ψ( ´) can have both extremum points and inflection points, in which derivative dψ/d is equal to zero. It means, that superdirected spin wave beams can arise in this medium. In the plane, containing vector H0, the angular width of such beams is not change during propagation and in the perpendicular plane the angular width of these beams, as in the isotropic media, is equal to λ/D.

scholarly journals Characteristics of very large aspect angle E-region coherent echoes at 933 MHz

1997 ◽  
Vol 15 (1) ◽  
pp. 54-62 ◽  
Author(s):  
B. J. Jackel ◽  
D. R. Moorcroft ◽  
K. Schlegel
Keyword(s):  
Phase Velocity ◽  
Scattering Layer ◽  
Aspect Angle ◽  
Ion Drift ◽  
Phase Velocities ◽  
F Region ◽  
E Region ◽  
Inversion Techniques ◽  
Coherent Backscatter ◽  
Uhf Radar

Abstract. The EISCAT UHF radar system was used to study the characteristics of E-region coherent backscatter at very large magnetic aspect angles (5–11°). Data taken using 60 μs pulses during elevation scans through horizontally uniform backscatter permitted the use of inversion techniques to determine height profiles of the scattering layer. The layer was always singly peaked, with a mean height of 104 km, and mean thickness (full width at half maximum) of 10 km, both independent of aspect angle. Aspect sensitivities were also estimated, with the Sodankylä-Tromsø link observing 5 dB/degree at aspect angles near 5°, decreasing to 3 dB/degree at 10° aspect angle. Observed coherent phase velocities from all three stations were found to be roughly consistent with LOS measurements of a common E-region phase velocity vector. The E-region phase velocity had the same orientation as the F-region ion drift velocity, but was approximately 50% smaller in magnitude. Spectra were narrow with skewness of about +1 (for negative velocities), increasing slightly with aspect angle.

scholarly journals On the new modes of planetary-scale electromagnetic waves in the ionosphere

2004 ◽  
Vol 22 (4) ◽  
pp. 1203-1211 ◽  
Author(s):  
G. D. Aburjania ◽  
K. Z. Chargazia ◽  
G. V. Jandieri ◽  
A. G. Khantadze ◽  
O. A. Kharshiladze
Keyword(s):  
Electromagnetic Waves ◽  
Large Scale ◽  
Low Frequency ◽  
Planetary Scale ◽  
Phase Velocities ◽  
F Region ◽  
E Region ◽  
General Dispersion ◽  
Fast Waves ◽  
The Waves

Abstract. Using an analogy method the frequencies of new modes of the electromagnetic planetary-scale waves (with a wavelength of 103 km or more), having a weather forming nature, are found at different ionospheric altitudes. This method gives the possibility to determine spectra of ionospheric electromagnetic perturbations directly from the dynamic equations without solving the general dispersion equation. It is shown that the permanently acting factor-latitude variation of the geomagnetic field generates fast and slow weakly damping planetary electromagnetic waves in both the E- and F-layers of the ionosphere. The waves propagate eastward and westward along the parallels. The fast waves have phase velocities (1–5)km s–1 and frequencies (10–1–10–4), and the slow waves propagate with velocities of the local winds with frequencies (10–4–10–6)s–1 and are generated in the E-region of the ionosphere. Fast waves having phase velocities (10-1500)km s–1 and frequencies (1–10–3)s–1 are generated in the F-region of the ionosphere. The waves generate the geomagnetic pulsations of the order of one hundred nanoTesla by magnitude. The properties and parameters of the theoretically studied electromagnetic waves agree with those of large-scale ultra-low frequency perturbations observed experimentally in the ionosphere. Key words. Ionosphere (ionospheric disturbances; waves propagation; ionosphere atmosphere interactions)

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