Subproton-scale cascades in solar wind turbulence: driven hybrid-kinetic simulations

Abstract

A long-lasting debate in space plasma physics concerns the nature of subproton-scale fluctuations in solar wind (SW) turbulence. Over the past decade, a series of theoretical and observational studies were presented in favor of either kinetic Alfvén wave (KAW) or whistler turbulence. Here, we investigate numerically the nature of the subproton-scale turbulent cascade for typical SW parameters by means of unprecedented high-resolution simulations of forced hybrid-kinetic turbulence in two real-space and three velocity-space dimensions. Our analysis suggests that small-scale turbulence in this model is dominated by KAWs at $\beta \gtrsim 1$ and by magnetosonic/whistler fluctuations at lower $\beta$. The spectral properties of the turbulence appear to be in good agreement with theoretical predictions. A tentative interpretation of this result in terms of relative changes in the damping rates of the different waves is also presented. Overall, the results raise interesting new questions about the properties and variability of subproton-scale turbulence in the SW, including its possible dependence on the plasma $\beta$, and call for detailed and extensive parametric explorations of driven kinetic turbulence in three dimensions.

6 pages, 4 figures, accepted for publication in The Astrophysical Journal Letters

References in corpus (9)

• Small Scale Energy Cascade of the Solar Wind Turbulence
• Radial Dependence of the Frequency Break Between Fluid and Kinetic Scales in the Solar Wind Fluctuations
• Multiscale nature of the dissipation range in gyrokinetic simulations of Alfvénic turbulence
• High-resolution hybrid simulations of kinetic plasma turbulence at proton scales
• Nature of the MHD and kinetic scale turbulence in the magnetosheath of Saturn: Cassini observations
• Spectral Features of Magnetic Fluctuations at Proton Scales from Fast to Slow Solar Wind
• Solar wind turbulence from MHD to sub-ion scales: high-resolution hybrid simulations
• Whistler Wave Cascade in Solar Wind Plasma
• Spectral breaks of Alfvenic turbulence in a collisionless plasma

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