Spatial distribution of the field-aligned current density in the polar ionosphere and the contribution of magnetosound waves     

Mishin  V. M.  Saifudinova  T. I.  Karavaev  Yu. A.  Kurikalova  M. A.  Bazarzhapov  A. D. 《Geomagnetism and Aeronomy》2009,49(7):975-982

The regular appearance of the chain of oppositely directed field-aligned current (FAC) pairs near the noon-midnight meridian during three considered substorms has been described. The FAC pairs (FACs flowing into the ionosphere in the morning and flowing out of this region in the evening and vice versa) are observed in each of three Iijima and Potemra zones. The FAC direction in the fixed LT sector periodically varies along the chain. The scenario, according to which each FAC pair (seven pairs) is identified with a hump or trough of one of the waves propagating from the Earth and toward the Earth in different magnetospheric domains, has been described. The estimated wave velocities differ from ∼100 to >1000 km/s depending on the propagation region but everywhere agree with the corresponding velocities of magnetosound waves (MSWs). The hypothesis is proposed, according to which these MSWs are excited by plasma ejection during current disruption and reconnection near the dayside magnetopause and in the near/middle regions of the nightside tail.  相似文献   

Electric circuits and their generators in the earth’s magnetosphere: The concept of electric circuits as applied to the first phase of the April 6, 2000, superstorm     

V. M. Mishin  M. A. Kurikalova  M. Förster 《Geomagnetism and Aeronomy》2010,50(8):978-987

{1} The first phase of the superstorm on April 6, 2000 was studied based on the analogy between systems of magnetospheric currents and wire electric currents. The conventional dataset supplemented with maps of ionospheric equivalent currents (ECs) and field-aligned currents (FACs) was also used. The application of this analogy made it possible to introduce spatial R.N inhomogeneities into FAC distributions in the two-dimensional ionosphere and three types of meridional current systems, MCS-0, MCS-1, and MCS-2, providing electric coupling of three Iijima and Potemra FAC Regions. This basis was used to describe the formation and observed dynamics of ionospheric auroral electrojets and three-dimensional current systems in a disturbed magnetosphere-ionosphere system. The results the modify known paradigms of the substorm current wedge (SCW). A new important fact was noted: simultaneously with the beginning of the disturbance expansion phase due to the stepwise growth in the dynamic pressure of the solar wind (SW), the stepwise growth in the area of polar cap and in the electromagnetic energy flux coming to the magnetosphere from the SW were observed.  相似文献