Numerical simulation to study solar wind turbulence and coronal heating

Abstract

The solar wind turbulence and coronal heating have been an open problem in solar physics in spite of newlinehaving proposed many theoretical models to explain it. Dispersive Alfvén wave (DAW) is one of the newlinemain candidate which is responsible for inhomogeneous heating of solar wind and coronal plasmas. In newlinethis thesis, we explore some of the magnetohydrodynamic and kinetic properties of nonlinear Alfvén newlinewaves in the context of solar wind, solar corona and the magnetospheric turbulence as well as the heating newlineof the plasma particles. It studies about the formation of coherent, filamentary Alfvénic structures, newlinetheir decay processes, their role in particle heating and acceleration, and their relevance for creating the newlinepower-law spectra of turbulence observed in solar wind and corona. The dynamical equations satisfied newlineby DAWs follow the form of modified nonlinear Schrödinger equation. The equations were numerically newlinesolved by pseudo-spectral method of simulation by taking Fast Fourier Transform and forward difference newlinemethod with predictor corrector scheme. By assuming an energy inputs in the form of pump waves newlinein the kinetic range or electron inertial range, the author studies numerically the evolution of these newlinewaves that lead to filamentary nonlinear structures, or to creation of spatio-temporal turbulence. The newlinemagnetic filaments of DAWs with high intensity are generated as the waves propagate along the direction newlineof magnetic field. The transverse modulation of Alfvén waves resulting in coherent structures formation newlinehas a significant effect on the evolution of the turbulent magnetic spectra and density fluctuations. newlineThe perpendicular characteristic scale of the magnetic coherent structurs is of the order of ion Larmor newlineradius for the kinetic Alfvén waves (KAWs) and it is of the order of electron skin depth for the inertial newlineAlfvén waves (IAWs). The applications of the dynamical models and numerical simulations of KAWs at newline1AU solar wind parameters and coronal loops, and IAWs at the coronal holes are also discussed. The newlinedynamical m