Unveiling the Global Characteristics of Turbulence in the Venusian Space Environment

Turbulence plays a crucial role in energy transfer from large to small scales in solar wind-Venus interaction. Observations have identified magnetic field fluctuations and turbulence in the Venusian space environment. However, due to limited observations and simulation resolutions, neither the global characteristics nor the driving mechanisms of turbulence are settled. In this study, we present the first three-dimensional configuration of turbulence at Venus using a high-resolution global magnetohydrodynamic (MHD) model, revealing fine structures of magnetic fields. We find that regions with spectral indices $\alpha$ near 5/3 or 3/2, indicative of MHD turbulence, are primarily located at the magnetospheric boundary layer, and the layer with $\alpha$ near 5/3 is wider in planes perpendicular to the interplanetary magnetic field. The turbulence is associated with the Kelvin–Helmholtz instability, resulting from the velocity shear between solar wind and the Venusian magnetosphere. These findings offer new insights into fundamental energy transfer processes at unmagnetized planets.