Structure of the quasi-parallel bow shock: Results of numerical simulations
Quasi-parallel bowshock structures are simulated by using a one-dimensional nonperiodic hybrid code in which the ion dynamics are treated exactly while the electron dynamics are omitted by neglecting the electron inertia (m/sub e/ = 0) and pressure. The simulations are initialized with the upstream condition specified by theta/sub 1/ = 10/sup 0/, ..beta../sub 1/ = 0.5, and M/sub A/1 = 2 to 4 with 0.5 increment while the downstream condition is obtained from the Rankine-Hugoniot relations, where theta/sub 1/ is the angle between the shock normal and the magnetic field, ..beta../sub 1/ is the ratio of kinetic to magnetic pressures, and M/sub A/1 is the Alfven Mach number. The main results of our simulations follow: (1) For M/sub A/1<3, the magnetic field profile of the shock is laminar or quasi-laminar. The upstream waves are right-hand polarized whistlers with ..omega..approx. =3.2..cap omega../sub n/i in the plasma frame, where ..cap omega../sub n/i is the ion gyrofrequency based on the normal field component B/sub n/. This corresponds to a wave frequency fapprox. =0.25 Hz and wavelength lambdaapprox. =310 km under solar wind conditions. The downstream waves are absent or low in amplitudes. (2) For M/sub A/1 >3, the magnetic field profile of the shock is turbulent. The upstream waves are again right-hand polarized whistlers with wavelengths varying from lambdaapprox.310 km upstream to lambda> or approx. =1250 km downstream. The downstream waves are predominantly the right-hand polarized fast magnetosonic waves (..omega..< or approx. =..cap omega../sub i/).
- Research Organization:
- Geophysical Institute, University of Alaska
- OSTI ID:
- 5667779
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 88:A9
- Country of Publication:
- United States
- Language:
- English
Similar Records
Bow shock and magnetosheath waves at mercury
Ion waves associated with solar wind beam-plasma interactions
Related Subjects
GENERAL PHYSICS
MAGNETOSPHERE
SHOCK WAVES
HEAT FLUX
HIGH-BETA PLASMA
HOSE INSTABILITY
ION DRIFT
MACH NUMBER
MAGNETOACOUSTIC WAVES
MAGNETOSHEATH
NUMERICAL SOLUTION
ONE-DIMENSIONAL CALCULATIONS
PLASMA SIMULATION
SOLAR WIND
TURBULENCE
WHISTLERS
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
HYDROMAGNETIC WAVES
INSTABILITY
NOISE
PLASMA
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
SIMULATION
SOLAR ACTIVITY
VELOCITY
640203* - Atmospheric Physics- Magnetospheric Phenomena- (-1987)