Results of studying the sporadic E layer by the method of resonant scattering of radio waves by artificial periodic inhomogeneities of the ionospheric plasma

Abstract

UDC 551.510.536We report on the results of studying the lower ionosphere by a method based on the resonant scattering of radio waves by artificial periodic inhomogeneities of the ionospheric plasma. Different aspects of studying the sporadic E layer such as the influence of the vertical transfer on its formation, the possibility of examination of its ion composition, and the influence of the ionosphere heating on the layer characteristics are discussed. The results of determining the parameters of the E s layer and some characteristics of the lower ionosphere during the creation of artificial periodic inhomogeneities at two frequencies are presented.

Artificial periodic irregularities, wave phenomena in the lower ionosphere, and the sporadic E layer

“…The maxima at altitudes of 90 and 100 km, which are also present in the profile A(h), are due to the presence of the sporadic E layer at these altitudes [13]. Below 85 km, shorter relaxation times of the scattered signals are observed, which is related to the turbulent phenomena [7,13] that destroy the periodic structure and reduce the lifetime of the irregularities. The slight increase in the amplitude near the height 110 km is due to the maximum of the electron density in the E region.…”

“…The results of studying the sporadic E layer, which were obtained in the experiment of October 2006, as well as the electron-density profiles obtained in these measurements by the two-frequency method are presented in [11,13,14]. The disadvantages of the above-said measurements include the technical impossibility of using the data about the phase of the scattered signal, which are used to determine the vertical velocity of the plasma motion.…”

“…The altitude gradient (shear) of the vertical velocity at altitudes 80-120 km was from 1-8 · 10 −4 s −1 to 4 · 10 −3 s −1 . According to [3,9,13], such a velocity shear can ensure the formation of the sporadic E layer due to a drift of the metal ions driven by ionospheric wind.…”

“…Although the latter ion is not a metal, but it is also a long-living atomic ion and is detected in sporadic layers [4,5]. In [12,13], we proposed a method for evaluation of the mass of the ions prevailing in the E s layer, and in [8,9], of the densities of all metal and molecular ions NO + and O + 2 , which are the main atmospheric ions at the altitudes of the E region in the absence of sporadic layers.…”

“…This leads to longer times of diffuse spreading of the irregularities. The method and results of determination of the molecular mass, i.e., the sort of metal ions in the E s layer are described in [12,13].…”