Kinetic Alfven wave; Filamentation; Ponderomotive force; Solar winds; Corona; Turbulence
The nonlinear equation for the propagation of kinetic Alfven waves has been derived in two-dimensions using the two-fluid model of the plasma. By taking into proper account of the nonlinear electron heating and ponderomotive force driven nonlinearity modification in the background density, the kinetic Alfven wave equation has been derived. The solution of this model equation has been obtained by using analytical and numerical methods to find out the amplitude of the kinetic Alfven wave at a particular distance. The relevance of these investigations has been discussed for the solar wind plasmas and coronal heating. It is seen that the kinetic Alfven wave breaks up into filamentary structures (hot spots) with very high intense magnetic energy. These filaments are separated from each other by a distance of the order of 1 AU in the case of solar winds while it is of the order of 0.6 AU in the case of coronal heating. The effect of these hot spots on other parametric processes which take place in the solar wind plasma and Alfven wave turbulence is also proposed. In the case of the solar corona, rough estimates for additional heating have been made by assuming that the energy of the kinetic Alfven wave is dumped to particles by wave particle interaction. Self-consistent models based on excited wave number spectra of kinetic Alfven waves, calculating the velocity space diffusion coefficient and using this in the Fokker Planck equation is also suggested for coronal heating. The impact of these studies on the Alfven wave turbulence spectrum, space weather and related experimental observation has been pointed out.