Polarizations of coupling kinetic Alfvén and slow waves

Kinetic Alfvén waves (KAWs) are dispersive Alfvén waves with short perpendicular wavelengths and have been extensively applied to various energization phenomena of plasma particles. KAWs are coupled to slow magnetosonic waves in the case of a finite-β plasma. In this paper, the electromagnetic polarization states of the coupling KAWs and slow waves are investigated. The results show that the polarization states of these waves depend sensitively on the local plasma parameters such as the ion-electron temperature ratio (α=Ti/Te) and the plasma kinetic-magnetic pressure ratio (β=2μ0n(Ti+Te)/B2) as well as their perpendicular wavenumber (k⊥ρi). The polarization states of waves play an important and key role in wave-particle interactions and hence have a great interest of understanding the physics of particle energization phenomena by these waves.