HR: 12:00h
AN: A52B-08    [Abstracts]
TI: Main Ionospheric Trough and Equatorial Ionization Anomaly During Substorm With Current Wedge
AU: * Klimenko, M V
EM: maksim.klimenko@mail.ru
AF: Kaliningrad State Technical University, Sovetsky Av., 1, Kaliningrad, 236000, Russian Federation
AU: Klimenko, V V
EM: pcizmiran@gazinter.net
AF: West Department of IZMIRAN, Pobedy Av., 41, Kaliningrad, 236017, Russian Federation
AU: Bryukhanov, V V
EM: bryukhanov@klgtu.ru
AF: Kaliningrad State Technical University, Sovetsky Av., 1, Kaliningrad, 236000, Russian Federation
AB: In the given work results of numerical calculations of ionospheric effects of modeling substorm which have begun in 18 UT are presented. Calculations are executed on the basis of Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere, developed in WD IZMIRAN, added by the new block of calculation of electric fields in the ionosphere. In calculations we considered superposition of magnetospheric convection electric field (at set of field aligned currents of the first and second zones and substorm current wedge with taking into account of particle precipitation) and dynamo field generated by thermospheric winds. It is shown, that at early stage of substorm development the longitudinal extent of main ionospheric trough increases. The trough is stretched in evening sector of southern hemisphere as narrow formation. There is increase foF2 in southern polar cap that leads to increase in steepness of trough polar edge. Longitudinal extent of equatorial anomaly in evening sector decreases. It occurs due to occurrence of area of strong negative foF2 disturbances on geomagnetic equator in vicinity of midnight meridian. In quiet conditions in southern hemisphere main ionospheric trough is the deepest in post-midnight sector. During substorm the additional minimum in evening sector is formed. In northern polar cap the substorm without taking into account current wedge leads to little changes foF2. The substorm with taking into account of current wedge causes negative disturbances foF2 in night and evening sectors of northern polar cap. Depth of main ionospheric trough in northern hemisphere decreases. Reduction of longitudinal extent of equatorial anomaly in post-sunset sector is strongly developed during substorm calculated without taking into account current wedge. In due course there are negative disturbances foF2 in subauroral latitudes of northern hemisphere in the afternoon and positive disturbances at low latitudes in both hemispheres. In the further depth of main ionospheric trough is decreased. After substorm termination there are night areas of negative disturbances foF2 on equator and day time areas of positive disturbances in the middle and low latitudes.
DE: 2407 Auroral ionosphere (2704)
DE: 2411 Electric fields (2712)
DE: 2415 Equatorial ionosphere
DE: 2447 Modeling and forecasting
DE: 2790 Substorms
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly