Ionosphere Electrodynamics and its Influence on the Main Ionospheric Trough and Equatorial Ionization Anomaly

In the given work the numerical simulation results of global distributions of the zonal current in the Earth's ionosphere and the critical frequency of the F2-layer of the ionosphere are presented. The calculations are executed with use of the Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP) developed in West Department of IZMIRAN and added by the new block of calculation of the electric field of the dynamo and magnetospheric origin. The calculations are executed for quiet geomagnetic conditions during various seasons and levels of Solar activity without taking into account the electric field, and also with taking into account only dynamo-field or superposition of a dynamo-field and magnetospheric convection field with and without taking into account the shielding by field aligned currents of the second zone. It is shown, that the Main Ionospheric Trough is formed without taking into account the electric field as a result of joint action of processes of ionization, recombination and diffusion. The account of the dynamo-field alters this trough, and magnetospheric convection completes formation of the trough. Equatorial Ionization Anomaly is not formed in the absence of the electric field. The main part in formation of Equatorial Ionization Anomaly plays a dynamo-field. Zonal component of dynamo-field together with diffusion of thermal plasma along geomagnetic field lines under action of the pressure gradients in the Earth's gravity field cause a fountain effect at geomagnetic equator. Equatorial Electrojet is formed by the dynamo-field. Magnetospheric convection at presence of shielding weakly influences on behavior of Equatorial Electrojet. Without the shielding of magnetospheric convection electric field by Alfven layer electric field the magnetospheric convection influence on Equatorial Electrojet becomes stronger. It occurs during magnetospheric disturbances when the shielding is broken due to fast changes of the field aligned currents of the first zone. The Auroral Electrojet is formed mainly by magnetospheric convection electric field and depends on conditions of shielding and conductivity of a high-latitude ionosphere which depends on photoionization and ionization by fluxes of precipitating particles. There are presented the seasonal, Solar-cyclic and UT-variations of Equatorial and Auroral Electrojets, Main Ionospheric Trough and Equatorial Ionization Anomaly.