TY - GEN
T1 - Theoretical and hybrid modeling studies of quasi-perpendicular shocks in the heliosphere
AU - Ofman, L.
AU - Gedalin, M.
PY - 2013/12/1
Y1 - 2013/12/1
N2 - Collisionless shocks result from Coronal Mass Ejections propagating in
the heliosphere, and in regions of interaction between the solar wind
and solar system bodies. The magnetized shocks efficiently convert the
energy of the directed ion flow into gyration energy of particles behind
the shock front. Downstream ions play the key role in the postshock
dynamics, including development of instabilities and eventual
thermalization of the plasma. We use theory and 2D hybrid modeling to
study the formation of the downstream ion distributions, on the basis of
ion dynamics in a stationary shock fronts. The study is motivated by
STEREO observations of interplanetary shocks, as well as by Cluster, and
THEMIS measurements at the Earth bow shock. We study low-Mach number
shocks dominated by 1D evolution, as well as high-Mach number shocks
where shock-front distortion and rippling takes place. The rippling
affects ion acceleration and heating. Higher-Mach number shocks are no
longer planar at the scales of the ion convective gyroradius and the
local shock normal may differ substantially from the global normal. The
2D hybrid modeling approach allows full kinetic nonlinear description of
the proton and ion motions, wave-particle interactions for parallel
propagating and oblique waves, and velocity distributions in the
magnetized plasma of the shocks, thus advancing our understanding of the
rippling mechanism and the effects on the ions. We find that the angle
between the local normal and the global normal may be as large as 40
degrees within the front of a rippled heliospheric shock.
AB - Collisionless shocks result from Coronal Mass Ejections propagating in
the heliosphere, and in regions of interaction between the solar wind
and solar system bodies. The magnetized shocks efficiently convert the
energy of the directed ion flow into gyration energy of particles behind
the shock front. Downstream ions play the key role in the postshock
dynamics, including development of instabilities and eventual
thermalization of the plasma. We use theory and 2D hybrid modeling to
study the formation of the downstream ion distributions, on the basis of
ion dynamics in a stationary shock fronts. The study is motivated by
STEREO observations of interplanetary shocks, as well as by Cluster, and
THEMIS measurements at the Earth bow shock. We study low-Mach number
shocks dominated by 1D evolution, as well as high-Mach number shocks
where shock-front distortion and rippling takes place. The rippling
affects ion acceleration and heating. Higher-Mach number shocks are no
longer planar at the scales of the ion convective gyroradius and the
local shock normal may differ substantially from the global normal. The
2D hybrid modeling approach allows full kinetic nonlinear description of
the proton and ion motions, wave-particle interactions for parallel
propagating and oblique waves, and velocity distributions in the
magnetized plasma of the shocks, thus advancing our understanding of the
rippling mechanism and the effects on the ions. We find that the angle
between the local normal and the global normal may be as large as 40
degrees within the front of a rippled heliospheric shock.
KW - 7811 SPACE PLASMA PHYSICS Discontinuities
KW - 7807 SPACE PLASMA PHYSICS Charged particle motion and acceleration
KW - 7851 SPACE PLASMA PHYSICS Shock waves
KW - 7827 SPACE PLASMA PHYSICS Kinetic and MHD theory
M3 - Conference contribution
VL - 52
T3 - American Geophysical Union, Fall Meeting 2013
BT - American Geophysical Union, Fall Meeting 2013
ER -