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Vol. 1 (1998 year), No. 2
Namgaladze A.A., Martynenko O.V., Volkov M.A., Namgaladze A.N., Yurik R.Yu.
High-latitude version of the global numerical model of the Earth's upper atmosphere
The global numerical model describing the thermosphere, ionosphere and protonosphere of the Earth as a single system has been modified for the polar upper atmosphere studies. The spatial and time resolution of the model has been significantly enhanced by the use of the variable latitudinal steps of numerical integration. The model is being developed to encompass modelling of the inner part of the magnetosphere confined by the closed geomagnetic field lines and the mesosphere. The results of the model calculations for the quiet magnetic conditions have been compared with the data of the empirical ionospheric and thermospheric models as well as with the EISCAT data and, in general, reasonable agreement between theoretical and empirical data has been found. The new high-latitude version of the model has been applied as well to the investigations of the disturbed behaviour of the Earth’s upper atmosphere during geomagnetic substorms and storms and during disturbances in the cusp region. The physical mechanisms of the upper atmosphere responses to the solar wind and magnetospheric forcings have been understood by the use of the model in several case studies.
(in English, стр.62, fig. 44, tables. 0, ref 145, MS Word 95, MS Word 95 956 Kb)
Vol. 7 (2004 year), No. 1
Volkov M.A., Romanova N.Yu.
The simulation of the magnetosphere-ionosphere convection using the open magnetospheric model
The simulation of the magnetosphere-ionosphere convection has been produced using the open magnetospheric model with the ellipsoidal form of the magnetopause for the homogeneous interplanetary magnetic field (IMF), penetrating into the Earth magnetosphere. The open magnetospheric model Tsyganenko 96 has been used. The modelling calculations have been compared with the ionospheric ion drift data. The calculations correctly reproduce a "throat" in the convection pattern in the dayside ionosphere, the convection direction depending from the sign of the IMF component By in the polar cap and convection near midnight. However, the modelling calculations predict the location of the convective focuses in more late hours for By<0 then the experimental data and in more early hours for By>0. The conclusion has been made that it is impossible to explain these features of the convection by the magnetospheric model Tsyganenko 96.
(in Russian, стр.3, fig. 1, tables. 0, ref 5, MS Word 95, MS Word 95 344 Kb)
Vol. 16 (2013 year), No. 1
Volkov M.A.
Effect of the tailward magnetic field lines on the convection in the Harang discontinuity
The formation of the electric fields and currents in the Harang discontinuity during the substorm growth phase has been considered. The charge separation in this region of the magnetosphere is the result of various protons and electrons drift in the inhomogeneous magnetic field. As a consequence, the gradients of the plasma pressure and the magnetic field (or the volume of magnetic flux tubes) are no collinear and the field-aligned currents appear. Calculations of the electric fields and currents for the model of the magnetosphere with the tailward magnetic field lines and for the dipole magnetic field model have been performed for the plasma pressure distribution model. It has been shown that stretching of the magnetic field lines in the tail leads to the increasing convection and currents in the Harang discontinuity, it can explain the observations of the currents and the electric fields in this region during the substorm growth phase.
(in Russian, стр.4, fig. 3, tables. 0, ref 11, Adobe PDF, Adobe PDF 0 Kb)
Vol. 16 (2013 year), No. 1
Volkov M.A., Romanova N.Yu.
The appearance of the electric currents during dipolarization of the Earth magnetic field lines
The appearance of the currents in the ionosphere and magnetosphere of the Earth during the expansive phase of the substorm have been studied in this work. It has been shown that the formation of the field-aligned currents and westward Cowling currents in the ionosphere can be generated by dipolarization of the magnetic field lines. The model distribution of the plasma pressure balanced with the magnetic field during the growth phase of the substorm has been taken. The conditions of formation of the currents wedge have been obtained. In the work the density of the field-aligned currents in the midnight sector of the auroral ionosphere has been estimated within the adiabatic approach.
(in Russian, стр.4, fig. 3, tables. 0, ref 13, Adobe PDF, Adobe PDF 0 Kb)