[en] Ionospheric effects of substorms are considered using the networks of the vertical probing stations during SUNDIAL periods. Calculations of electron concentration distribution and comparison of calculation results with experimental data are conducted on the basis of the developed technique of simulation of large-scale internal gravitational wave effects

No abstract available

[en] A method is proposed for operative estimation of the AE index with the error ∼ 25% at night hours 22-04 LT using the current magnetic data of an auroral observatory. For very intensive substorms at AE ≥ 1500 nTl the method is applicable from 20 to 10 LT. Comparison with the AE measured values and indirect checking by ionospheric data testify to the method reliability and possibility of its application for simulation of the ionosphere and conditions of radio wave propagation during substorms

[en] A model is presented for forecasting ionosphere during the passage of internal gravitation waves in the periods of substorms; the model enables forecasts of changes in the shadowed ionosphere at subauroral, medium and low latitudes using for this purpose the data on current magnetic state of the auroral zone. Two aspects of ionosphere modelling are considered: isolated substorms and complex substorms consisting of a series of substorms. The modelling of ionospheric effects of the isolated substorms is performed in the form of corrective additions to the available background ionospheric models

[en] According to the data obtained at the stations of vertical probing located at 0 < or approx. φ < or approx. 30 deg N and 15 deg W < or approx. λ < or approx. 150 deg E the appearance and development of large-scale regions (zones) of increased or decreased electron concentration during 24 hours in February 1980 are investigated. It was concluded that over territories of Africa, India and south of Japan certain zones can be singled out, in which f_oF2 and h_mF2 undergo different variations. For 24 hours 4 periods of 6 h duration of F2 layer parameter variability in the zones are singled out. On days with moderate disturbances deviations of f_oF2 from the median manifest a clear contrast: in zones with decreased f_oF2 further decrease takes place and vice versa in zones with increased ones - the increase. Besides, in periods of disturbances the extension of the zones in the latitude occurs

[en] It is shown that after magnetospheric substorms on 14.02.1980 considerable fluctuations of F2 layer critical frequency deviations from the median values (Δf₀F2=+(15-40) both in time and space are observed in case of a relatively quiet magnetic field during subsequent days. There are fluctuations with periods of 6 and 24h in the time variations. The longitudinal variations Δf₀F2 have shown that a spatial wave with one maximum is observed at middle latitudes. Distributions with one or two maxima can be observed at low latitudes, Φ≅20±10 degN. The latitudinal variations Δf₀F2 have maximum values at Φ∼30-50deg N and close to zero near the auroral and equatorial zones in the longitudinal ranges, where the Δf₀F2 extreme values are observed

[en] The origination possibility of ionosphere spatially heterogeneous structure during the magnetospheric substorms 14.11.1980, when the generation of the inner gravity waves (IGW) occurs from the north and south auroral current systems, is shown. Ionosphere essential changes during these storms have occured in the darkened hours, when at IGW passage the changes in values of deviation from median h_m attained ∼15-25%. Fields, approximately doubled as compared to Δh_m and Δf₀F₂ deviation mean latitudes, were found within the Φ∼20±10deg N and S region. These field dimensions attained ∼ 10 Mm along the parallel, ∼ 2.5-3.0 Mm - along the meridian. Their lifetime is ∼ three hours. For substorms following one another, the space-heterogeneous structure is of relative stability within the Sun-Earth coordinate system. It is suggested to connect the interpretation of this phenomenon with IGW space superposition, which come from the opposite hemisphere auroral zones. Theoretical calculations agree satisfactorily with the experimental data

No abstract available