[1] A comparison of modeled simulation results with in situ observations is presented in an effort to better understand the generation mechanism of short-burst radiation (AKR) observed in the Alfvénic acceleration region. The simulation is performed using a linear gyrofluid Alfvén model to generate propagating inertial Alfvén waves with a test particle scheme to study the behavior of electrons ...

The reflection of Alfvén waves from the ionosphere plays a crucial role because the reflected wave can reduce or enhance the electric field pattern of the incident wave. The ionosphere is typically treated as a conducting surface, which has a height integrated Pederson conductivity. This approximation is appropriate in considering the reflection of Alfvén waves because the wavelengths along the...

Alfvén waves propagate in electrically conducting fluids in the presence of a magnetic field. Their reflection properties depend on the ratio between the kinematic viscosity and the magnetic diffusivity of the fluid, also known as the magnetic Prandtl number Pm. In the special case Pm = 1, there is no reflection on an insulating, no-slip boundary, and the incoming wave energy is entirely dissip...

We apply a semi-classical approach of handling waves as quasiparticle gas in a slowly varying flow – analogous to ray tracing – to calculate the Alfvén wave transmission parameters, the resulting cross-helicity of the waves and the scatteringcentre compression ratio, for cases where the shock thickness is large enough for the turbulent waves in the plasma to see the transition of the background...

We investigate how the properties of the corona and solar wind in the open coronal holes depend on the properties of the magnetic fields and their footpoint motions at the surface. We perform one-dimensional magnetohydrodynamical (MHD) simulations for the heating and the acceleration in the coronal holes by low-frequency Alfvén waves from the photosphere to 0.3 or 0.1AU. We impose low-frequency...

Phase mixing was proposed by Heyvaerts and Priest (1983) as a mechanism for heating the plasma in open magnetic field regions of coronal holes. Here the basic model is modified to include a gravitationally stratified density and a diverging background magnetic field. We present WKB solutions and use a numerical code to describe the effect of dissipation, stratification and divergence on phase m...

Magnetohydrodynamic (MHD) turbulence in the solar wind is observed to show the spectral behavior of classical Kolmogorov fluid turbulence over an inertial subrange and departures from this at short wavelengths, where energy should be dissipated. Here we present the first measurements of the electric field fluctuation spectrum over the inertial and dissipative wavenumber ranges in a β & 1 plasma...

Magnetohydrodynamic (MHD) turbulence in the solar wind is observed to show the spectral behavior of classical Kolmogorov fluid turbulence over an inertial subrange and departures from this at short wavelengths, where energy should be dissipated. Here we present the first measurements of the electric field fluctuation spectrum over the inertial and dissipative wave number ranges in a Beta > or a...

The dynamics of long oblique MHD waves in a collisionless plasma permeated by a uniform magnetic field is addressed using a Landau-fluid model that includes Hall effect and electron-pressure gradient in a generalized Ohm’s law and retains ion finite Larmor radius (FLR) corrections to the gyrotropic pressure (Phys. Plasmas 10, 3906, 2003). This one-fluid model, built to reproduce the weakly nonl...

Abstract: Using observations from the FAST small explorer spacecraft we present fields and plasma observations above the dayside auroral oval showing the erosion of ionospheric plasmas from the topside ionosphere by the action of Alfvén waves. Using interferometric techniques the waves are shown to approximately obey the expected dispersion for Alfvén waves with transverse scales extending from...