HR: 1340h
AN: SH33A-1196    [Abstracts]
TI: A New Procedure of Shock Fittings to the MHD Rankine-Hugoniot Relations
AU: * Chao, J K
EM: jkchao@jupiter.ss.ncu.edu.tw
AF: Institute of Space Science, National Central University, No.300, Jhong-da Road, Chung-li, 32001 Taiwan
AU: Lin, C C
EM: dannylin@jupiter.ss.ncu.edu.tw
AF: Institute of Space Science, National Central University, No.300, Jhong-da Road, Chung-li, 32001 Taiwan
AU: Lee, L C
EM: loulee@plasma.phys.ncku.edu.tw
AF: Department of Physics, National Cheng Kung University, National Cheng Kung University No.1, University Road, Tainan, 701 Taiwan
AU: Lee, L C
EM: loulee@plasma.phys.ncku.edu.tw
AF: National Applied Research Laboratories, No. 106, Section 2, Ho-Pen East Road, Taipei, 106 Taiwan
AU: Lyu, L H
AF: Institute of Space Science, National Central University, No.300, Jhong-da Road, Chung-li, 32001 Taiwan
AB: In study the MHD shock-discontinuity interactions, it is essential to use accurate shock parameters in the analysis. These shock parameters are derived from the Rankine-Hugoniot (RH) relations based on observed solar wind plasmas and magnetic fields on both sides of the shock. In this study, we present a novel procedure of shock fitting. To minimize the difficulties due to the uncertainty of the shock frame reference and fluctuations of the vector quantities of solar wind velocity and magnetic field, we choose only the scalar parameters $m$, $\theta_{Bn}$ and $y$ to fit the RH shock jump relations, where $m=B_2/B_1$ and $y=n_1/n_2$ are the ratios of magnetic field strength and solar wind proton number density across the shock, and "1" and "2" refer to up- and down-stream states of the shock, respectively. The $\theta_{Bn}$ is the angle between the shock normal and upstream magnetic field, $\bf {B_1}$ derived from the shock coplanetary theorem. With these three scalar parameters, we propose a procedure to derive a set of best-fit values of $m$, $\theta_{Bn}$, $y$, $\beta_1$ and $\beta_2$ to the RH relations, where beta is the ratio of solar wind thermal energy over magnetic energy. The physical parameters of the shock are also calculated from the best-fit values. Shocks with anisotropic temperatures, heat flow and additional momentum flux due to waves and/or turbulence on both sides of the shock are also included in our analysis. Applications of this procedure will be given in this study.
DE: 7811 Discontinuities
DE: 7839 Nonlinear phenomena
DE: 7851 Shock waves
DE: 6025 Interactions with solar wind plasma and fields
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting