One of important tasks in studying the ionosphere is to determine its perturbation level. Determining and predicting the ionosphere perturbation degree is necessary for solving practical problems, as ...well as for a theoretical study of processes occurring in it. There is also an urgent problem of creating a new daily-seasonal ionospheric perturbation scale. One of approaches to solve these problems can be to determine the distribution laws for deviations in the critical frequencies of the F2 layer from their median values calculated for previous 27 days. The optimal method for calculating polynomial dependencies for determining the probability distribution laws for deviations in the critical frequency of the ionospheric F2 layer for the longitude chain of observation stations in cases when they are different from the normal one is suggested in this article. The optimal degree of the approximating polynomial is determined. Polynomial coefficients are calculated. The percentage of data from the present period that exceeds the limits of the obtained dependencies in each case is calculated. The analysis of the obtained results is carried out, as a result of which the possibility of describing the behavior of the ionosphere by the obtained dependencies is determined.
A possibility of correcting ionosphere climate models based on data from a single observation station equipped with the vertical radio sounding ionosonde is studied to monitor the Earth plasma shell ...in the vicinity of this measuring instrument. The SIMP-STANDARD and IRI models are used for the study. The probabilities of the fact that relative deviations of corrected models are below 10% are taken as criteria of the efficiency of ionosphere climate model correction. The size of the areas around each ionosonde of the state ionospheric network is determined, where an increase in the quality of ionospheric monitoring is possible by correcting the ionosphere climate model based on the data of this particular ionosonde.
A scenario is proposed for replenishing the Earth’s exosphere with atomic hydrogen of cosmic origin. An assessment was made, and the coincidence of the total atomic hydrogen content in the exosphere ...with the number of protons (after thermolization converted into hydrogen ions) precipitated in the SAA zone over a year according to the data of the Meteor M and NOAA-19 satellites was confirmed. The observed coincidence indicates that the rates of replenishment of hydrogen due to precipitation from radiation belts and dissipation into outer space coincide in the order of magnitude. It is concluded that the exosphere hydrogen is mainly of cosmic origin and its main source is the thermalized protons of galactic cosmic rays, solar cosmic rays, and in part, the solar wind.
Numerical values of the criteria for the efficiency of the determination of the critical frequency of the
F
2 layer of ionosphere over European Russia are calculated with ionospheric models corrected ...based on vertical-incidence sounding data from an ionosonde. Two correction techniques are considered: the selection of an effective value of the input heliogeophysical index and linear-correlation correction of ionospheric models with respect to the critical frequency of the
F
2 layer of the ionosphere. Domains in which model correction by one point is effective are found. They determine the current coverage of the European Russia by the Russian ionospheric observation network. The regions in which the correction of median models is noticeable in comparison with the median models without correction are shown to be 7° in latitude and 15° in longitude at the midlatitudes. It is ascertained that it is mainly impossible to determine the ionospheric parameters at northern points and points in the region of the main ionospheric trough via correction based on data from midlatitude ionospheric observation sites. In these cases, the climate models without correction are more effective.
Further development of the method of transionospheric radiosounding of the ionosphere in the range of its plasma frequencies is presented. The trajectories of radiowaves with a reflection from the ...Earth are newly included in the consideration. A modeling of the transionospheric radiosounding was performed in conditions of an irregular ionosphere including moderate-dimensional irregularities with drawing possible trajectories, as well as the obtainment and analysis of the corresponding transionograms.
The satellite ionosondes in highly elliptical orbits are proposed to be used for the task of continuous monitoring of the Arctic ionosphere. The monitoring scheme with the ionosonde location aboard ...the
Arktika-M
satellites is presented. The calculations of the vertical topside and transionospheric sounding using the SIMP1 ionospheric model are performed, which show the feasibility of continuous monitoring.
The results of a comparison of the critical frequency values measured by an ionosonde of the Mir manned station (MS) and ground-based automatic ionospheric stations in various regions of the globe ...are presented in the paper. A comparison with European stations showed a coincidence of the results with a high significance level. The distributions of the critical frequencies in the regions of the equator in South America and in Southeast Asia obtained on the basis of the Mir results are qualitatively compared with the data of the International GPS Service (IGS) for the determination of the total electron content. The picture of the electron density distribution coincides qualitatively with the IGS data. The intervals of the strongest changes in the electron density in these regions were accompanied by the appearance of extra traces with large group delays in ionograms.
Previously unknown phenomenon was detected during the ionospheric radiosounding on board the MIR space station when the station was below the
F
region maximum. The work is devoted to describing the ...most general properties of this phenomenon in terms in concepts prescribed by the
URSI Handbook of ionogram Interpretation and Reduction
in order to consider and analyze the phenomenon using the known categories and concepts of this handbook.
We explain a hypothesis on the origin and propose a model of the specific formation of the electron density in the polar ionosphere in the form of relatively thin vertical and inclined layers and ...sheets. Modeling has confirmed that the main features noted in the experiment are successfully depicted in the proposed model, namely, the significant group lag at the low-frequency end of the track, splitting into common and uncommon rays, and the presence of a sharp boundary at the limiting frequency of the track. An analogy with the sporadic
Es
layer of the “
c
” type is noted.
The mathematical model of radio sounding of the horizontally inhomogeneous ionosphere is proposed. Its validity is confirmed by the results of the experiment carried out onboard the Mir orbital ...station at heights below the electron density maximum in the ionosphere. In its turn, the mathematical model makes it possible to explain the appearance of new traces on ionograms obtained in this experiment as the result of the existence of backward trajectories toward the satellite during the radiowave propagation in the inhomogeneous ionosphere.PUBLICATION ABSTRACT
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