scholarly journals First artificial periodic inhomogeneity experiments at HAARP

2015 ◽  
Vol 42 (5) ◽  
pp. 1297-1303 ◽  
Author(s):  
D. L. Hysell ◽  
M. J. McCarrick ◽  
C. T. Fallen ◽  
J. Vierinen
Keyword(s):  
Periodic Inhomogeneity ◽  
Artificial Periodic Inhomogeneity

A Fourier-space description of oscillations in an inhomogeneous plasma. Part 2. Discrete approach

1994 ◽  
Vol 52 (2) ◽  
pp. 265-296 ◽  
Author(s):  
P. S. Cally ◽  
Z. Sedláček
Keyword(s):  
Inhomogeneous Plasma ◽  
Fourier Space ◽  
Energy Propagation ◽  
Phase Mixing ◽  
Periodic Inhomogeneity ◽  
Discrete Approach ◽  
Natural Context ◽  
Almost Everywhere ◽  
Cold Plasmas ◽  
Space Description

The process of phase mixing in inhomogeneous MHD or cold plasmas is interpreted as one of energy propagation in discrete Fourier space. Three instructive scenarios are examined: (i) an isolated inhomogeneity with zero boundary conditions; (ii) a periodic inhomogeneity; and (iii) a monotonic inhomogeneity sandwiched between two semi-infinite uniform regions. In each case the coefficients of the associated wave equation in Fourier space for an appropriately chosen dependent variable are very nearly constant almost everywhere, so the propagation is like that of a free unreflected wave. An exception may arise in the coupling of the lowest modes, which can be highly reflective. It is argued that Fourier space is the simplest and most natural context in which to discuss the development of fine-scale oscillations.

scholarly journals Some observational manifestations of the periodic inhomogeneity of absorbing and scattering atmospheres

2019 ◽  
pp. 46-51
Author(s):  
A. Nikoghossian
Keyword(s):  
Optical Properties ◽  
Optical Thickness ◽  
Diffuse Radiation ◽  
Numerical Results ◽  
Line Profiles ◽  
Periodic Inhomogeneity

We consider frequency and directional features of the reflectance and transmittance of an inhomogeneous scattering and absorbing atmosphere with the scattering albedo periodically varying with depth. The dependence of global optical properties of such media on optical thickness is found. Two different kind of problems are considered dependent on that by monochromatic or continuum, mono-directional or diffuse radiation illuminate the medium. The numerical results show how the observed intensities and line-profiles respond to the medium inhomogeneity with an uniform increase in optical thickness. Astrophysical aspects of these features are discussed.

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