SM51A-2526
First Investigation on the Magnetic Curvature Distribution in the Magnetic Diffusion Region
Friday, 18 December 2015
Poster Hall (Moscone South)
Yongcun Zhang, NSSC National Space Science Center, CAS, SKL of Space Weather, Beijing, China, Chao Shen, Chinese Academy of Sciences, Beijing, China, Zhenxing Liu, NSSC National Space Science Center, CAS, Beijing, China, Aurelie Marchaudon, IRAP, Toulouse, France and Zhaojin Rong, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
Abstract:
We report first results of magnetic curvature distribution in the diffusion region of a unique magnetic reconnection event. This event is exceptional since all four Cluster spacecraft are crossing the diffusion region. Magnetic curvature analysis shows that magnetic field lines are sharply curved with high curvature in the inner outflow regions between the two Hall regions and display nearly coplanar features of antiparallel reconnection. Combination of the decrease in curvature radius of magnetic field lines and the increase in electron gyro-radius induces curvature pitch angle scattering of initially trapped electrons, resulting in an isotropic electron distribution. In Hall regions, magnetic curvature decreases corresponding obviously to the presence of Y-directed Hall fields, which implies that the stress of reconnected field is released here, in agreement with whistler mediated-reconnection. The value and direction of curvature radius are not well organized due to the fluctuating Hall fields resulting from the temporal dynamical reconnection.Same analysis will be applied to MMS data to investigate the fine magnetic structure in diffusion region.
