Open AccessTransient changes in magnetospheric‐ionospheric currents caused by the passage of an interplanetary shock: Northward interplanetary magnetic field case
Author(s) -
Samsonov A. A.,
Sibeck D. G.,
Yu Yiqun
Publication year - 2010
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009ja014751
Subject(s) - physics , magnetosphere , interplanetary magnetic field , geophysics , ionosphere , magnetopause , interplanetary spaceflight , ionospheric dynamo region , solar wind , bow shock (aerodynamics) , transient (computer programming) , magnetohydrodynamics , computational physics , magnetic field , mechanics , shock wave , quantum mechanics , computer science , operating system
We use results from a global MHD simulation to study the interaction of an interplanetary shock with the Earth's magnetosphere for a northward interplanetary magnetic field orientation. We connect intensifications of the transient northward Bz (NBZ) and Region 1 currents in the ionosphere with the appearance of two strong dynamo regions in the magnetosphere: the first on the high‐latitude magnetopause near and behind the cusps and the second near the equatorial plane on the flanks. The ionospheric and magnetospheric transients are well synchronized and move antisunward gradually. According to the results obtained, the source of energy for the transient NBZ current is related to shock‐intensified lobe reconnection, while the transient Region 1 current corresponds to the reflected fast shock predicted by Samsonov et al. (2007). We speculate that the electric circuits for the quasi‐stationary field‐aligned currents are similar to the transient electric circuits obtained in this paper.