Open AccessSelf‐organized branching of magnetotail current systems near the percolation threshold
Author(s) -
Milovanov Alexander V.,
Zelenyi Lev M.,
Zimbardo Gaetano,
Veltri Pierluigi
Publication year - 2001
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 - 10.1029/1999ja000446
Subject(s) - substorm , fractal , physics , criticality , topology (electrical circuits) , statistical physics , current (fluid) , directed percolation , phase transition , geophysics , magnetic field , condensed matter physics , critical exponent , magnetosphere , quantum mechanics , mathematics , mathematical analysis , combinatorics , nuclear physics , thermodynamics
This paper advocates an application of the fractal topology formalism to an analysis of the magnetotail current systems. Our main attention is concentrated on the magnetotail regions with the considerably stretched background magnetic field; such conditions can be the case in the distant tail, as well as in the near‐Earth tail at the late substorm growth phase. Structural properties of the current system at the self‐organized (quasi)stationary states are analyzed in relationship with the universal fractal geometry of the percolating fractal sets near the critical threshold. We found that the violation of the criticality character leads to the topological phase transition in the system; this transition has features of a structural catastrophe and is associated with the magnetospheric substorm onset. A comparison with various observational studies is given, and the possible directions of the future research are outlined.