Oral Presentation

Intermittency and magnetic reconnections in interstellar and interplanetary turbulence

Author(s): Abraham C.-L. Chian University of Adelaide, Adelaide, SA 5005, Australia

Presenter: Abraham C.-L. Chian (University of Adelaide, Australia)

First, we discuss 3D numerical simulations of magnetorotational instability in turbulent accretion discs and identify on-off intermittency, similar to the long-term behaviour of sunspot and stellar cycles, whereby the magnetic field alternates randomly between periods of large- and small-amplitude variations resulting from amplitude-phase synchronization in multiscale interactions (Chian et al. Phys. Rev. Lett. 104, 254102, 2010; Miranda et al. MNRAS 448, 404, 2015). Next, we discuss observations of magnetic reconnections and genesis of intermittent magnetic turbulence at the boundary layers of coronal mass ejections (Chian and Munoz ApJL 733, L34, 2011; Chian et al. ApJ 832, 179, 2016). We obtain evidence of bifurcated current sheets, jets and counterstreaming Alfven waves associated with magnetic reconnections at the leading edge of a coronal mass ejection and at the interface region of two coronal mass ejections. The multifractal characteristics of Kolmogorov magnetic turbulence related to magnetic reconnections are studied by computing the kurtosis, phase coherence index, and scaling exponents. Finally, we discuss the relevance of our studies in the formation of stars and planets.