Estimation of the Electric Field Zonal Component Value and Particle Transfer Velocity Due To Electromagnetic Drift in the Ionosphere during Magnetic Storm on September 25, 2016 over Kharkiv

Background. Dynamic processes in plasma play a significant role in the formation of the spatial structure of the ionosphere at altitudes above the main ionization maximum. During geomagnetic disturbances, the dynamic mode of the ionospheric plasma noticeably changes, and these changes in the variations in the physical process parameters directly affect the spatial-temporal distribution of the main parameters of the ionosphere. One of the mechanisms affecting the behavior of the dynamic process parameters in the ionosphere is the penetration of electric fields of magnetospheric origin into the mid-latitude ionosphere during magnetic storms. The effects of the electric field, which are practically absent in quiet conditions, during geomagnetic storms lead to an additional transfer of charged particles due to electromagnetic drift. Accounting for these effects in variations in the dynamic process parameters and, as a consequence, in variations in the parameters of the ionosphere, is necessary for a more adequate prediction of the behavior of geospace parameters during geomagnetic disturbances. Development of ionospheric models of the disturbed ionosphere for solving applied problems in the field of radio communication, radio navigation and uninterrupted operation of telecommunication systems for various purposes. The aim of this work is to estimate the magnitude of the zonal component of the electric field in the ionosphere over Kharkiv during a weak magnetic storm on September 25, 2016, as well as to calculate the neutral wind velocity taking into account plasma transport in crossed electric and magnetic fields. Materials and methods. To calculate the parameters of dynamic processes in the ionosphere, the experimental data of the Kharkiv incoherent scatter radar were used. Results. The value of the zonal component of the electric field Ey was calculated during a weak magnetic storm on September 25, 2016. The maximum value of Ey took place around 23:00 EEST on September 25, 2016 and was equal to 5.9 mV/m. Calculated values of particle transfer velocity due to electromagnetic drift vEB during the September 25, 2016 magnetic storm are obtained. Variations in vEB correlate with variations in Ey, and the maximum velocity was –52 m/s. The calculation results showed that during weak magnetic storms (Kp = 4) it is necessary to take into account the plasma transfer due to electromagnetic drift. The contribution of the velocity vEB to the total velocity of charged particle transfer is significant. The neutral (thermospheric) wind velocity vnx is calculated without and taking into account the particle transfer velocity in crossed electric and magnetic fields. Conclusions. As shown by the results of the comparative analysis, taking into account the influence of the electric field made it possible to refine the values of the velocities vnx during a magnetic storm, which, in turn, makes it possible to explain the behavior of the main parameters of the F2 layer of the ionosphere under disturbed conditions.