Numerical Study of Magnetoacoustic Wave Interaction with Null Points: Plasma Beta Modulation in Solar Atmospheres

This investigation examines the interaction of magnetoacoustic pulses with a two-dimensional magnetic null point, explicitly accounting for variations in plasma β arising from spatial fluctuations in the magnetic field strength. The analysis employs the PLUTO code to solve the magnetohydrodynamic (MHD) equations, enabling a detailed exploration of nonlinear effects associated with plasma β modulation across distinct stratified layers. The results demonstrate temporal evolution in the system’s response, characterized by periodic fluctuations in amplitude and the emergence of pronounced peaks. These features indicate episodes of intensified coupling between the magnetoacoustic pulses and the magnetic topology. The observed variability in both amplitude and peak sharpness underscores the system’s inherent dynamism, with certain temporal phases exhibiting more vigorous interactions. Furthermore, the study reveals a correlation between plasma density alterations and radial velocity variations of the pulses, suggesting that these phenomena are closely tied to the redistribution of plasma β throughout the stratified magnetic environment.