English

Intermittency in Interplanetary Coronal Mass Ejections Observed by Parker Solar Probe and Solar Orbiter

Solar and Stellar Astrophysics 2025-07-08 v1 Plasma Physics Space Physics

Abstract

Intermittency has been studied extensively in the fast and slow solar winds but to a far lesser extent in interplanetary coronal mass ejections (ICMEs). While ICMEs are often characterized by their relatively smooth, large-scale magnetic flux rope structures, a spectrum of fluctuations is nonetheless present at smaller scales. We have examined kurtosis and its scaling exponents at magnetohydrodynamic inertial scales in 49 ICMEs observed between 0.25 and 1 au by Parker Solar Probe and Solar Orbiter, and compared the results to those obtained for the ICME sheath regions and ambient solar wind intervals. Kurtosis behaves similarly in all intervals studied and presents a universal behavior typical of intermittent time series. The ICMEs displayed a radially invariant level of intermittency, suggesting that they are relatively static, well-developed turbulent environments. In the sheath regions, the level of intermittency increased with distance, indicating that the turbulence is not yet fully developed at small heliocentric distances. In addition to intermittent fluctuations related to turbulence, the sheath regions may possess a population of non-turbulent structures that increase the absolute value of kurtosis.

Keywords

Cite

@article{arxiv.2505.22283,
  title  = {Intermittency in Interplanetary Coronal Mass Ejections Observed by Parker Solar Probe and Solar Orbiter},
  author = {Julia Ruohotie and Simon Good and Christian Möstl and Emilia Kilpua},
  journal= {arXiv preprint arXiv:2505.22283},
  year   = {2025}
}

Comments

12 pages, 5 figures; accepted for publication in the Astrophysical Journal Letters 2025 May 27

R2 v1 2026-07-01T02:46:13.658Z