Alfv En Wave Solitons and Solar Intermediate Drift Bursts

We investigate stationary solutions for Alfv en solitons propagating obliquely in a homogeneous magnetic eld. Due to their dispersive nature kinetic Alfv en waves can evolve into soliton like structures which propagate at velocities of the order of the Alfv en velocity in a direction inclined to the magnetic eld. In the rst model we keep the plasma < m e =m i. Kinetic Alfv en solitons in this case can propagate at Mach numbers M > 1 or M < 1 as dilutions or as compressions of the plasma density. In the second model the plasma contains two electron components, a hot one and a cold one. We derive diierential equations for the plasma density and present examples of numerical solutions for the plasma density prooles. We nd that both dilutive and compressional solitons are uniquely determined by and the propagation velocity vector. Conditions are given for the existence of soliton solutions. Interactions between the hot and the cold electron component turn out to be signiicant for dilutions of the cold component.-We apply this kind of solitary density waves to solar intermediate drift radio bursts.