HR: 1340h
AN: SM53B-0426    [Abstracts]
TI: Debye Length Structures and Slow Shocks in Earth's Reconnection Layer: Observations and Simulations
AU: * Scudder, J D
EM: jack-scudder@uiowa.edu
AF: University of Iowa, Room 203 Van Allen Hall Jefferson at Dubuque St., Iowa City, IA 52240 United States
AU: Ma, Z W
AF: University of Iowa, Room 203 Van Allen Hall Jefferson at Dubuque St., Iowa City, IA 52240 United States
AU: Ma, Z W
AF: Institute of Plasma Physics, CAS , Hefei, Anhui, 230031 China
AU: Mozer, F S
AF: University of California, Berkeley , Space Sciences Laboratory, Berkeley, CA 94720 United States
AB: Frequently abrupt (7.5ms FWHM), strong (150mV/m) electrostatic structures are detected nearly perpendicular to {\bf B}, near local density depletions in magnetopause current layers. These electrostatic structures have been suggested [Mozer, et al., Geophys. Res. Lett., 31, L15802, doi:10.1029/2004GL020062,2004] to have either electron inertial or electron Debye length scales. Using a broader suite of observational diagnostics, tests of Rankine-Hugoniot conservation laws, and new, full particle simulations, we demonstrate that these structures are unanticipated Debye length substructures ($L \simeq 5\lambda_{De}$ ) adjoining slow switch-off shock transition layers within the magnetopause proper. The electrostatic structures are found just inside the local density minimum and are perpendicular to the coplanarity plane of the adjacent slow shock layer. Electric layers of scale $r\lambda_{De}$ will cause the demagnetization of thermal electrons of temperature $T_e$ , by pushing down the threshold for the electron demagnetization to $\beta_e > Min({{r^2kT_e}\over{m_ec^2}}, 1)$ , thereby assisting topology change and the formation of Petschek slow shocks away from the separator where $\beta_e$ is usually much less than unity.
DE: 7815 Electrostatic structures
DE: 7835 Magnetic reconnection
DE: 2712 Electric fields (2411)
DE: 2724 Magnetopause, cusp, and boundary layers
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting