P. F. Denisenko

The global distribution of ionospheric small-scale irregularities from topside sounding data

Abstract This paper examines the global distribution of electron density irregularities with scales of the order of several tens to hundreds of meters in the ionosphere by using topside sounder data from the COSMOS-1809 satellite obtained in May–June and December 1987. The diffuse traces of Z -waves on topside ionograms in a frequency band just below the upper hybrid resonance are used for diagnostics. These traces are attributed to the scattering of sounder-generated ordinary and slow extraordinary mode waves.

Collisionless damping of ordinary electromagnetic waves in the ionospheric plasma with power spectrum of inhomogeneities

Collisionless absorption of ordinary waves in the ionosphere is considered due to scattering into the z-mode from random inhomogeneities in the resonance region. The non-Hermitian components of the effective dielectic permeability tensor are determined for an isotropic power spectrum with an exponential index of 2, and for a model of infinitely extended irregularities with a power spectrum exponential index of 2-4. The anomalous absorption of vertically probing ordinary waves is calculated for the irregularity spectra described above, as well as for a power spectrum with exponential index of 4.

Dielectric properties of a collisionless magnetoactive plasma with a power-law spectrum of random inhomogeneities

The dielectric properties of a randomly inhomogeneous magnetoactive plasma are investigated in the present study under conditions of extraordinary wave resonance. The electron concentration inhomogeneities are characterized by a spatial spectrum of the form r ~ (p2 + km2)-2 exp (-p2s where k m = 2~/L, with s and L being the minimum and maximum inhomogeneity scales. For s << L the spectrum has a power-law shape over a wide range of wave numbers. Taking into account spatial dispersion, the anti-Hermitian components of the effective dielectric permittivity are calculated.