HR: 1340h
AN: SH44A-1718    [Abstracts]
TI: A Statistical Model of Reconnecting Magnetic Islands in a Current Layer
AU: * Fermo, R L
EM: rfermo@umd.edu
AF: University of Maryland, IREAP University of Maryland, College Park, MD 20742, United States
AU: Drake, J F
EM: drake@plasma.umd.edu
AF: University of Maryland, IREAP University of Maryland, College Park, MD 20742, United States
AU: Swisdak, M
EM: swisdak@umd.edu
AF: University of Maryland, IREAP University of Maryland, College Park, MD 20742, United States
AB: Full particle 2-D simulations of magnetic reconnection with an ambient guide field show that secondary magnetic islands develop in long electron current layers. Observational evidence in the magnetotail and in the magnetopause also supports the formation of magnetic islands. However, the dynamics of these magnetic islands in large-scale current layers, such as those seen in the magnetopause or inferred in the corona, are not easily determined by simulations. To retain the small-scale physics of PIC codes for these large-scale systems, a statistical model is developed for the island distribution. Magnetic islands are characterized by the flux ψ contained in the island and the area A enclosed by it. These are used as the independent parameters for a distribution function of magnetic islands which evolves in time. The time evolution is governed by certain rules (verified by particle-in-cell simulations) concerning the generation of secondary islands, the rates of island growth, and island merging. An evolution equation for the distribution function of magnetic islands based on these rules is derived. Because of the complexity of the island merging rules, the evolution equation includes integral terms which prevent an analytic solution. The distribution of magnetic islands is therefore solved numerically.
DE: 7524 Magnetic fields
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7833 Mathematical and numerical techniques (0500, 3200)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting