Large-scale Control of Kinetic Dissipation in the Solar Wind

作者：Vech Daniel^*; Klein Kristopher G; Kasper Justin C

来源：Astrophysical Journal Letters, 2018, 863(1): L4.

DOI：10.3847/2041-8213/aad329

• magnetohydrodynamics (MHD)
• plasmas
• solar wind
• turbulence
• waves

In this Letter, we study the connection between the large-scale dynamics of the turbulence cascade and particle heating on kinetic scales. We find that the inertial range turbulence amplitude (delta B-i; measured in the range of 0.01-0.1 Hz) is a simple and effective proxy to identify the onset of significant ion heating, and when it is combined with beta(parallel to P), it characterizes the energy partitioning between protons and electrons (T-p/T-e); proton temperature anisotropy (T-perpendicular to/T-parallel to); and scalar proton temperature (Tp) in a way that is consistent with previous predictions. For a fixed delta B-i, the ratio of linear to nonlinear timescales is strongly correlated with the scalar proton temperature in agreement with Matthaeus et al., though for solar wind intervals with delta(parallel to p)> 1, some discrepancies are found. For a fixed beta(parallel to p), an increase of the turbulence amplitude leads to higher T-p/T-e ratios, which is consistent with the models of Chandran et al. and Wu et al. We discuss the implications of these findings for our understanding of plasma turbulence.

• 出版日期2018-8-10