Localization of finite frequency inertial Alfven wave and turbulent spectrum in low beta plasmas

In the present paper, we have investigated non-linear interaction of inertial Alfven wave with ion acoustic wave, for low beta-plasma (beta << m(e)/m(i)) where beta is the thermal to magnetic pressure ratio. We have developed the dynamical equation of inertial Alfven wave by considering the finite frequency as well as finite ion temperature correction. The dynamical equation of ion acoustic wave, propagating at an angle with respect to the background magnetic field, in the presence of ponderomotive nonlinearity due to inertial Alfven wave is also derived. Numerical simulation has been carried out to study the effect of nonlinear coupling between these waves which results in the formation of localized structures and turbulent spectrum, applicable to auroral region. The result reveals that the localized structures become complex and intense in nature (quasi-steady state). Further, we have studied the turbulent spectrum which follows spectral index (similar to k(-4.46)) at smaller scales. Relevance of the obtained results has been shown with the observations reported by various spacecrafts like Hawkeye and HEOS-2 (Highly Eccentric Orbiting Satellite-2).