HR: 13:40h
AN: SH43A-01    [Abstracts]
TI: Observational evidence for an elongated (>50 ion skin depths) electron diffusion region during fast magnetic reconnection
AU: * Phan, T D
EM: phan@ssl.berkeley.edu
AF: University of California, Berkeley, SSL, Berkeley, ca 94720, United States
AU: Drake, J F
EM: drake@glue.umd.edu
AF: University of California, Berkeley, SSL, Berkeley, ca 94720, United States
AU: Drake, J F
EM: drake@glue.umd.edu
AF: University of Maryland, U of Maryland, College Park, MD 20742, United States
AU: Shay, M A
EM: shay@udel.edu
AF: University of Delaware, Dept of Physics and Astronomy, Newark, DE 19716, United States
AU: Mozer, F S
EM: fmozer@ssl.berkeley.edu
AF: University of California, Berkeley, SSL, Berkeley, ca 94720, United States
AU: Eastwood, J P
EM: eastwood@ssl.berkeley.edu
AF: University of California, Berkeley, SSL, Berkeley, ca 94720, United States
AB: We report observational evidence for an elongated electron reconnection diffusion region during fast reconnection. The Cluster in-situ observations in a magnetosheath reconnecting current sheet reveal a broad current layer (width around 12 ion skin depths) supporting the reversal of the reconnecting magnetic field with an embedded intense outflow current that implies a super-Alfvenic electron outflow jet with a transverse scale of ~8 electron skin depths. The oblique trajectory of the spacecraft through the reconnection layer allows the deduction of a fast reconnection rate of 9% of the upstream Alfven speed as well as the minimum extent of the super-Alfvenic electron outflow jet of 50 ion skin depths downstream from the X-line. The deduced reconnection rate is consistent with the directly measured rate of 8% based on the tangential electric field and the inflow plasma velocity. These observations confirm and extend the surprising finding from recent large-scale full particle simulations of the presence of an elongated (> 20 ion skin depths) electron diffusion region even during fast reconnection [Shay et al., 2007; Karimabadi et al., 2007].
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7835 Magnetic reconnection (2723, 7526)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting