Turbulence and chaotic structure generated by nonlinear kinetic Alfvén waves near magnetic null points in solar corona

Abstract

In the dynamic and complex environment of the solar corona, the interaction between kinetic Alfvén waves (KAWs) and magnetic null points might play a significant role in understanding various plasma processes. Recognizing the potential role of reconnection in coronal heating, our study aims to delve into how different types of null points affect KAW dynamics and ultimately contribute to heating. We investigate the behavior of nonlinear KAWs near the more frequently occurring components-null point with a mean magnetic field in the solar corona. The nonlinearity is attributed to the ponderomotive effects due to density perturbations. We used a three-dimensional model equation that describes the dynamics of KAWs in the presence of components-null point. Numerical methods are employed to solve the model equation for solar coronal parameters. Our simulations reveal that the nonlinear interaction between KAWs and magnetic null points can lead to the generation and amplification of turbulent and chaotic structures. This formation of localized structures, progressively exhibit more chaotic behavior over time, which may efficiently contribute to energy transfer. The power spectrum analysis of these turbulent structures shows a steeper spectrum with a pronounced cascade. Turbulence implies the presence of localized plasma heating, particle acceleration, and magnetic reconnection. These phenomena have significant implications for understanding the energy transport, particle dynamics, and magnetic topology in the solar corona. We also address nonlinearity’s role in promoting turbulence. This research offers insights into the dynamics of nonlinear KAWs near null points in the solar corona, suggesting their potential role in energy transfer and current sheet formation.