Nonlinear evolution of 3D-inertial Alfvén wave and turbulent spectra in Auroral region

Abstract

In the present paper, we have investigated nonlinear interaction of three dimensional (3D) inertial Alfvén wave and perpendicularly propagating magnetosonic wave for low β-plasma (β m e /m i ). We have developed the set of dimensionless equations in the presence of ponderomotive nonlinearity due to 3D-inertial Alfvén wave in the dynamics of perpendicularly propagating magnetosonic wave. Stability analysis and numerical simulation has been carried out to study the effect of nonlinear coupling on the formation of localized structures and turbulent spectra, applicable to auroral region. The results reveal that the localized structures become more and more complex as the nonlinear interaction progresses. Further, we have studied the turbulent spectrum which follows spectral index (∼k −3.57 ) at smaller scales. Relevance of the obtained results has been shown with the observations received by various spacecrafts like FAST, Hawkeye and Heos 2.

Localization of 3D inertial Alfvén wave and generation of turbulence

“…In addition to that, demonstration of the turbulent spectrum has been simulated using pseudo-spectral method applicable to aurora. In Rinawa et al (2014), waves involved were 3D IAW and perpendicularly propagating magnetosonic wave and it was limited to study the filamentation and turbulent spectrum while in our present study authors have analyzed the interaction between 3D IAW and fast magnetosonic wave which is obliquely propagating. In addition to the filamentation and turbulent spectrum, density cavitation and parallel electric field variation have also been analyzed in the present work.…”