A new scenario with two subranges in the inertial regime of solar wind turbulenceShow others and affiliations
2025 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 697, article id A187Article in journal (Refereed) Published
Abstract [en]
Context. The solar wind provides a natural laboratory for plasma turbulence. The core problem is the energy cascade process in the inertial range, which has been a fundamental long-standing question. Much effort has been put into theoretical models to explain the observational features in the solar wind. However, there are still many questions that remain unanswered. Aims. Here, we report the observational evidence for the existence of two subranges in the inertial regime of the solar wind turbulence and show the scaling features for each subranges. Methods. We performed multi-order structure function analyses for one high-latitude fast solar wind interval at 1.48 au measured by Ulysses and one slow but Alfvénic solar wind at 0.17 au measured by the Parker Solar Probe (PSP). We also conducted statistical analyses on 103 fast solar wind intervals observed by Wind. Results. We identify the existence of two subranges in the inertial range according to the distinct scaling features of the magnetic field. The multi-order scaling indices versus the order for the two subranges demonstrates a clear disparity, with the second-order scaling index being 1/2 in the larger-scale subrange 1 and 2/3 in the smaller-scale subrange 2. Both subranges display apparent but different anisotropies. The velocity exhibits similar features as the magnetic field. The PSP interval shows that subrange 1 follows Yaglom scaling law, while subrange 2 does not. The Ulysses interval shows that the intermittency abruptly grows to a maximum 5% of the interval from subrange 1 to subrange 2. Conclusions. Based on the observational features, we propose a new scenario that the inertial regime of the solar wind turbulence consists of two subranges. The observational evolution of the scaling as the solar wind expands may be a consequence of observing different subranges at different radial distances.
Place, publisher, year, edition, pages
EDP Sciences , 2025. Vol. 697, article id A187
Keywords [en]
Solar wind, Sun: heliosphere, Sun: magnetic fields
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:kth:diva-364012DOI: 10.1051/0004-6361/202553848ISI: 001490583400016Scopus ID: 2-s2.0-105005657838OAI: oai:DiVA.org:kth-364012DiVA, id: diva2:1962849
Note
QC 20250603
2025-06-022025-06-022025-07-03Bibliographically approved