The propagation of magnetosonic (MS) waves through plasmapause and density structures in the Earth’s magnetosphere has been previously studied by using full wave simulations. However, these studies have only investigated the reflection and transmission of MS waves by density structures, ignoring the wave damping or absorption because of the limitations of full wave simulations. In this paper, we performed one-dimensional particle-in-cell (PIC) simulations to study the damping of monochromatic MS waves with various wave normal angles and frequencies in the density structure with different height and width. Simulation results show that the MS waves are partially reflected and absorbed when they travel through a density structure. The reflectivity is higher when MS waves have a lower wave frequency and the density structure has a sharper density gradient. The absorption of MS waves is more pronounced within the density structure as opposed to other regions. Additionally, absorptivity increases with increasing height and width of the density structure and decreasing wave frequency. Besides, we observe that transmissivity is higher with lower height and higher wave frequency, but increases at first and then decreases with increasing width. Our study emphasizes the significance of absorption, even more important than reflection, in MS wave propagation, especially in a real-sized plasmapause.
 

magnetosonic wave,paticle-in-cell simulation,wave propagation,interactions with particles