Graduate School in Nonlinear Science

Sponsored by The Danish ResearchAgency

 
MIDIT                              OFD                          CATS
Modelling, Nonlinear Dynamics      Optics and Fluid Dynamics    Chaos and Turbulence Studies
and Irreversible Thermodynamics    Risø National Laboratory     Niels Bohr Institute and
Technical University of Denmark    Building 128                 Department of Chemistry
Building 321                       P.O. Box 49                  University of Copenhagen
DK-2800 Lyngby                     DK-4000 Roskilde             DK-2100 Copenhagen Ø
Denmark                            Denmark                      Denmark

SELF-ORGANIZED TURBULENCE IN THE EARTH'S MAGNETOTAIL: CRITICAL
CURRENT SYSTEMS AND MAGNETOSPHERIC SUBSTORM ONSET

Alexander V. Milovanov
Space Research Institute
Moscow, Russia

Thursday, April 26, 2001, 13.30 h
at OFD Meeting Room, Building 130, Risų National Laboratory

Abstract: Structural properties of the magnetotail current systems near the marginal nonequilibrium stationary state are analyzed in connection with the fractal geometry of percolation near the critical threshold. The strong magnetic field and plasma coupling at the marginal state is described in terms of topologically conjugated fractals representing, self-consistently, the turbulent magnetic field and current density patterns in the magnetotail current sheet. The violation of the conditions of critical percolation is shown to result in a topological phase transition in the turbulent system. The phenomenon has features enabling to associate it with the magnetospheric substorm onset.

References:
A.V. Milovanov, L.M. Zelenyi, G. Zimbardo, J. Geophys. Res. 101, 19,903 (1996).
A.V. Milovanov, L.M. Zelenyi, P. Veltri, G. Zimbardo, A.L. Taktakishvili, J. Atm. Sol. Terr. Phys. 63, 705 (2001).
A.V. Milovanov, L.M. Zelenyi, G. Zimbardo, P. Veltri, J. Geophys. Res. 106 (2001) (in press).