Turbulence and anomalous resistivity inside near-Earth magnetic clouds

We use in situ data from the Wind spacecraft (https://wind.nasa.gov/) to survey the amplitude of turbulent fluctuations in the proton density and total magnetic field inside a large sample of near-Earth magnetic clouds (MCs) associated with coronal mass ejections (CMEs) from the Sun. We find that the most probable value of the modulation index for proton density fluctuations (delta n(p)/n(p)) inside MCs ranges from 0.13 to 0.16, while the most probable values for the modulation index of the total magnetic field fluctuations (delta B/B) range from 0.04 to 0.05. We also find that the most probable value of the Mach number fluctuations (delta M) inside MCs is approximate to 0.1. The anomalous resistivity inside the near-Earth MCs arising from electron scattering due to turbulent magnetic field fluctuations exceeds the (commonly used) Spitzer resistivity by a factor of approximate to 500-1000. The enhanced Joule heating arising from this anomalous resistivity could impact our understanding of the energetics of CME propagation.