Turbulence and whistlers in magnetic clouds observed by Solar Orbiter

Kinetic processes control the cross-scale energy transfer between large-scale dynamics and dissipation in the solar wind. Large-scale magnetic flux ropes, also known as magnetic clouds (MCs), inside interplanetary coronal mass ejections (ICMEs) have been shown to effectively drive magnetospheric disturbances, but little is known about the turbulence properties and wave-particle interactions inside the MCs.

Here, we study the properties of the turbulence inside MCs between 0.3-1 AU observed by Solar Orbiter. We find that the spectral index in the inertial range fits Kolmogorov’s power law, but in the high-frequency regime we find a spectral bump at the beginning of a steeper power law regime. This is likely due to the presence of a significant number of whistler waves inside the MCs.

We have developed an automated search algorithm to find and record the properties of whistler waves inside MCs observed by Solar Orbiter. We find that MCs contain a significant number of whistler wave events with high magnetic field wave power (>0.5 nT²), which we do not find in the ICME sheath regions. We study these waves and attempt to determine their generation mechanism. In order to explore possible relations between the turbulence and the presence of whistler waves, we also determine the mean energy transfer rate, the magnetic field intermittency and the turbulent properties of the MCs and compare with the sheaths.