HR: 1340h
AN: SM13A-0325    [Abstracts]
TI: Computing the Topology of Magnetic Reconnection in Earth's Magnetotail
AU: Loring, B
EM: burlen@apollo.sr.unh.edu
AF: University of New Hampshire EOS Space Science Center, 39 College Road, Durham, NH 03801 United States
AU: * Dorelli, J C
EM: john.dorelli@unh.edu
AF: University of New Hampshire EOS Space Science Center, 39 College Road, Durham, NH 03801 United States
AU: Raeder, J
EM: J.Raeder@unh.edu
AF: University of New Hampshire EOS Space Science Center, 39 College Road, Durham, NH 03801 United States
AB: We investigate the topological properties of magnetic reconnection in Earth's magnetotail for various IMF orientations. In particular, we address the following question: What is the role of magnetic nulls, and associated separatrix surfaces which define different topological classes of field lines, in constraining the dynamics of reconnection in the tail? By computing the topological degree (which relates the topology of a vector field within a surface to the integral of the vector field over the surface) at each cell of the computational grid, we track the magnetic nulls in the system. Computing magnetic field streamlines which pass local to the nulls allows us to visualize the separatrix surfaces associated with the nulls. These separatrix surfaces intersect along special field lines -- separator lines -- which join pairs of nulls. Such separator lines are the three-dimensional analogue of X lines in two-dimensional reconnection scenarios; thus, one might expect that such separator lines have a tendency to collapse into thin current sheets, just as their two-dimensional counterparts do. We test this hypothesis by comparing the locations of current sheets in the simulated magnetotail with the locations of the separator lines. Implications for observations of plasmoids in the tail are discussed.
DE: 7827 Kinetic and MHD theory
DE: 7833 Mathematical and numerical techniques (0500, 3200)
DE: 7835 Magnetic reconnection (2723, 7526)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005