Sub-Alfvenic/Super-Sonic Impulsive Structures in the Magnetosphere.
First Results from Hybrid Fluid-Kinetic Modeling and Comparison with MMS
Observations
Abstract
The magnetosphere of the Earth presents a large scale plasma physics
laboratory in which the complex interacting plasma phenomena are
involved: global convecting plasma dynamics, wave–particle interactions
in the bow shock and transmitted shock waves/impulses and magnetic field
reconnection in the plasma current sheets. The NASA magnetospheric
multiscale mission (MMS) provides unique observations of the thin
structures and wave–particles interactions at the shock-like impulses
while the spacecrafts were located at the dawn terminator (the time is
2016-03-07 20:00:00 UTC). It was assumed that these impulses may be
created by the interaction between the background flow and plasma
clouds. It was also assumed that those clouds were produced by either
flux-transfer events or by coalescence/reconnection processes at the
magnetopause current layer or by the mirror instabilities inside the low
latitude boundary layer. 3-D hybrid kinetic code with separate
description of the background and cloud ions was used for interpretation
of the observed impulse structures. In this report we will discuss the
effects of particle heating and acceleration inside the foreshock of the
shock-like impulses, effects of the ion and electron non-Maxwellian
velocity distributions, and particle finite gyroradius, and triggering
the electromagnetic instability.