Physics
Scientific paper
Nov 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993jgr....9819005d&link_type=abstract
Journal of Geophysical Research (ISSN 0148-0227), vol. 98, no. A11, p. 19,005-19,025
Physics
64
Cosmic Rays, Dynamic Models, Heliosphere, Particle Acceleration, Shock Discontinuity, Shock Wave Attenuation, Shock Waves, Steady State, Interplanetary Gas, Interplanetary Magnetic Fields, Interstellar Gas, Magnetohydrodynamic Turbulence, Magnetohydrodynamic Waves, Radio Emission, Solar Wind, Time Dependence
Scientific paper
A hydrodynamic model is developed for the structure of a cosmic-ray-modified termination shock. The model is based on the two-fluid equations of diffuse shock acceleration (Drury and Volk, 1981). Both the steady state structure of the shock and its interaction with outer heliospheric disturbances are considered. Under the assumption that the solar wind is decelerated by diffusing interstellar cosmic rates, it is shown that the natural state of the termination shock is a gradual deceleration and compression, followed by a discontinuous jump to a downstream state which is dominated by the pressure contribution of the cosmic rays. A representative model is calculated for the steady state which incorporates both interstellar cosmic ray mediation and diffusively accelerated anomalous ions through a proposed thermal leakage mechanism. The interaction of large-scale disturbances with the equilibrium termination shock model is shown to result in some unusual downstream structure, including transmitted shocks and cosmic-ray-modified contact discontinuities. The structure observed may be connected to the 2-kHz outer heliospheric radio emission (Cairns et al., 1992a, b). The time-dependent simulations also demonstrate that interaction with solar wind compressible turbulence (e.g., traveling interplanetary shocks, etc.) could induce the termination shock to continually fluctuate between cosmic-ray-dominated and gas-dynamic states. This fluctuation may represent a partial explanation of the galactic cosmic ray modulation effect and illustrates that the Pioneer and Voyager satellites will encounter an evolving shock whose structure and dynamic properties are strongly influence by the mediation of interstellar and anomalous cosmic rays.
Donohue D. J.
Zank Gary P.
No associations
LandOfFree
Steady state and dynamical structure of a cosmic-ray-modified termination shock does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Steady state and dynamical structure of a cosmic-ray-modified termination shock, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Steady state and dynamical structure of a cosmic-ray-modified termination shock will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-810940