HR: 0800h
AN: SM51A-06    [Abstracts]
TI: Effects of Electron Pressure Tensor and Heat Flux on Magnetic Reconnection from PIC and Hybrid Simulations
AU: * Main, D S
EM: dmain@lanl.gov
AF: Los Alamos National Lab, Division X-1-PTA, Los Alamos, NM 87545, United States
AU: Yin, L
EM: lyin@lanl.gov
AF: Los Alamos National Lab, Division X-1-PTA, Los Alamos, NM 87545, United States
AU: Winske, D
EM: winske@lanl.gov
AF: Los Alamos National Lab, Division X-1-PTA, Los Alamos, NM 87545, United States
AB: Thin current sheets lead to rapid magnetic reconnection and conversion of magnetic energy to particle energy. Two-dimensional (2D) simulations performed with different physical models and an initial planar current sheet (the GEM and Newton challenge studies) showed similar fast reconnection rates. In this paper, we discuss in detail simulations of 2D reconnection carried out with a full particle-in-cell (PIC) code and a hybrid (particle ions, massless fluid electrons) code that was part of the Challenge study (Birn et al., GRL, 32, L06105, 2005). In the hybrid code, the electron model contains the full electron pressure tensor in the electron momentum equation to break the frozen-in condition. We compare quantitatively the effects of the electron pressure tensor in the two types of simulations and show both how they evolve in time and where in the thin current sheet the electron off-diagonal pressure tensor terms become important. In addition, we make quantitative comparisons between reconnection rates and flow velocities obtained from the two codes. It is still an open question how best to evolve the pressure tensor and include the effects of electron heat flux in the hybrid model. The evolution equation for the pressure tensor has several terms and the effects of some of these terms on the reconnection dynamics will be examined. In particular, PIC simulations will be used to examine the role of heat flux in reconnection events in the absence of a guide field.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 4400 NONLINEAR GEOPHYSICS (3200, 6944, 7839)
DE: 6944 Nonlinear phenomena (4400, 7839)
DE: 7526 Magnetic reconnection (2723, 7835)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly