Open AccessModel study of ground magnetic signatures of traveling convection vortices
Author(s) -
Zhu L.,
Gifford P.,
Sojka J. J.,
Schunk R. W.
Publication year - 1997
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 - 10.1029/96ja03682
Subject(s) - physics , convection , distortion (music) , vortex , ionosphere , rotation (mathematics) , electromagnetic induction , magnetic flux , polarity (international relations) , asymmetry , convection cell , computational physics , magnetic field , geophysics , mechanics , geometry , natural convection , amplifier , mathematics , optoelectronics , genetics , cmos , quantum mechanics , biology , cell , electromagnetic coil , combined forced and natural convection
We conducted a model study of ground magnetic signatures of traveling convection vortices (TCVs) that included both the ionospheric conductivity enhancement associated with the TCVs and the ground induction effect. We found that the localized conductivity enhancement can cause a significant distortion of the TCV current system and lead to a distortion of the ground magnetic disturbance patterns. The patterns of all three magnetic components are asymmetric, mainly in the E‐W direction, and the patterns of the Z component show the strongest asymmetry (20–30%). We also found that the effect of induction currents on ground magnetic signatures of the TCVs is insignificant (less than 5%). The results show that because of the presence of localized conductivity enhancements the polarity and speed of the TCVs can significantly influence the distortion features of ground magnetic patterns. The upward and downward current filaments of a TCV with a clockwise leading convection cell can wrap with each other, resulting in a rotation of the whole ground magnetic disturbance pattern. This rotation feature is most significant when the speed of the TCVs is high.