Dawn-Dusk Asymmetry of Kelvin-Helmholtz Vortices Along the Kronian Magnetopause

Abstract

The Kelvin-Helmholtz instability (KHI) at the Kronian magnetopause is an important process resulting from the interaction between the magnetosphere and the solar wind. The Kronian magnetosphere is rotationally driven, thus dawn-dusk asymmetry has been observed in the KHI structures. However, analyses based on the Cassini data have yielded a discrepancy, with some studies indicating more KHI features on the duskside and others on the dawnside. To investigate the physical origin of the dawn-dusk asymmetry of the Kronian KHI, three-dimensional high-resolution global simulations of the Kronian magnetosphere have been developed. We found that KHI structures continuously develop in the prenoon sector and propagate toward both the dawn and dusk sides, exhibiting clear dawn-dusk asymmetry during their growth and propagation. Our study reveals the dawn-dusk asymmetric characteristics of KHI along Kronian magnetopause, including its growth and propagation, providing important insights into the interaction between rotation-driven magnetosphere and solar wind.