An experimental investigation of nonlinear interactions between shear Alfvén waves in a laboratory plasma is presented. Two Alfvén waves, generated by a resonant cavity, are observed to beat together, driving a pseudomode at the beat frequency. The pseudomode then scatters the Alfvén waves, generating a series of sidebands. The observed interaction is very strong, with the normalized amplitude ...

Alfvén waves, discontinuities, proton perpendicular acceleration and magnetic decreases (MDs) in interplanetary space are shown to be interrelated. Discontinuities are the phase-steepened edges of Alfvén waves. Magnetic decreases are caused by a diamagnetic effect from perpendicularly accelerated (to the magnetic field) protons. The ion acceleration is associated with the dissipation of phasest...

We show that 5-minute acoustic oscillations may resonantly convert into Alfvén waves in the β∼1 region of the solar atmosphere. Considering the 5-minute oscillations as pumping standing acoustic waves oscillating along unperturbed vertical magnetic field, we find on solving the ideal MHD equations that amplitudes of Alfvén waves with twice the period and wavelength of acoustic waves exponential...

We discuss the parametric instabilities of large-amplitude parallel propagating Alfvén waves using the 2-D PIC simulation code. First, we confirmed the results in the past study [Sakai et al., 2005] that the electrons are heated due to the modified two stream instability and that the ions are heated by the parallel propagating ion acoustic waves. However, although the past study argued that suc...

We perform numerical simulations of nonlinear MHD waves in a gravitationally stratified molecular cloud that is bounded by a hot and tenuous external medium. We study the relation between the strength of the turbulence and various global properties of a molecular cloud, within a 1.5-dimensional approximation. Under the influence of a driving source of Alfvénic disturbances, the cloud is lifted ...

The linear and nonlinear physics of shear Alfvén waves are investigated using the 3D Braginskii fluid code BOUT++. The code has been verified against analytical calculations for the dispersion of kinetic and inertial Alfvén waves. Various mechanisms for forcing Alfvén waves in the code are explored, including introducing localized current sources similar to physical antennas used in experiments...

[1] Recent observations of particle distributions that are narrow in pitch angle and broad in energy have suggested that kinetic Alfvén waves are a significant contributor to auroral particle acceleration. Oscillations at frequencies near 1 Hz are a natural consequence of the propagation of Alfvén waves in the strongly varying Alfvén speed profile above the auroral ionosphere, the so-called ion...

In this paper we derive the equations for the continuous ideal magnetohydrodynamic (MHD) spectrum of twodimensional coronal loops, including gravity and expansion, in general curvilinear coordinates. The equations clearly show the coupling between Alfvén and slow magnetosonic continuum waves when both pressure and geodesic curvature of the magnetic field lines are present. Gravity always gives ...

We analyze mechanisms of the excitation of Alfvén wave in pulsar magnetospheres as a possible source of pulsar radio emission generation. We find that Cherenkov excitation of obliquely propagating Alfvén waves is inefficient, while excitation at the anomalous cyclotron resonance by the particles from the primary beam and from the tail of the bulk distribution function may have a considerable gr...

We demonstrate that nonlinear decay of obliquely propagating Langmuir waves into another Langmuir and Alfvén waves is possible in a one-dimensional, highly relativistic, streaming, pair plasma. Based on this we present a new mechanism of pulsar radio emission that involves development and quasilinear relaxation of two stream instability, induced scattering of generated Langmuir waves by plasma ...