Solar wind flow past Venus and its implications for the occurrence of the Kelvin-Helmholtz instability

摘要

In this paper, the solar wind flow around Venus is modeled as a nondissipative fluid which obeys the ideal magnetohydrodynamic equations extended for mass loading processes. The mass loading parameter is calculated for four different cases, corresponding to solar minimum and maximum XUV flux and to nominal and low solar wind velocity. We get smooth profiles of the field and plasma parameters in the magnetosheath. Based on the results of this flow model, we investigate the occurrence of the Kelvin-Helmholtz (K-H) instability at the equatorial flanks of the ionopause of Venus. By comparing the instability growth time with the propagation time of the K-H wave, we find that the K-H instability can evolve at the ionopause for all four solar wind conditions.