Statistical evidence for the existence of Alfvénic turbulence in solar coronal loops

Jiajia Liu*, Scott W. Mcintosh, Ineke De Moortel, James Threlfall, Christian Bethge

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

Recent observations have demonstrated that waves capable of carrying large amounts of energy are ubiquitous throughout the solar corona. However, the question of how this wave energy is dissipated (on which timescales and length scales) and released into the plasma remains largely unanswered. Both analytic and numerical models have previously shown that Alfvénic turbulence may play a key role not only in the generation of the fast solar wind, but in the heating of coronal loops. In an effort to bridge the gap between theory and observations, we expand on a recent study by analyzing 37 clearly isolated coronal loops using data from the Coronal Multi-channel Polarimeter instrument.We observe Alfvénic perturbations with phase speeds which range from 250 to 750 km s-1 and periods from 140 to 270 s for the chosen loops. While excesses of high-frequency wave power are observed near the apex of some loops (tentatively supporting the onset of Alfvénic turbulence), we show that this excess depends on loop length and the wavelength of the observed oscillations. In deriving a proportional relationship between the loop length/wavelength ratio and the enhanced wave power at the loop apex, and from the analysis of the line widths associated with these loops, our findings are supportive of the existence of Alfvénic turbulence in coronal loops.

Original languageEnglish
Article number7
Number of pages10
JournalAstrophysical Journal
Volume797
Issue number1
Early online date18 Nov 2014
DOIs
Publication statusPublished - 18 Nov 2014
Externally publishedYes

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