Potential evidence for the onset of alfvénic turbulence in trans-equatorial coronal loops
This study investigates Coronal Multi-channel Polarimeter Doppler-shift observations of a large, off-limb, trans-equatorial loop system observed on 2012 April 10-11. Doppler-shift oscillations with a broad range of frequencies are found to propagate along the loop with a speed of about 500 km s-1. The power spectrum of perturbations travelling up from both loop footpoints is remarkably symmetric, probably due to the almost perfect north-south alignment of the loop system. Compared to the power spectrum at the footpoints of the loop, the Fourier power at the apex appears to be higher in the high-frequency part of the spectrum than expected from theoretical models. We suggest this excess high-frequency power could be tentative evidence for the onset of a cascade of the low-to-mid frequency waves into (Alfvénic) turbulence.
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http://n2t.net/ark:/85065/d7x06803
eng
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publication
2016-01-01T00:00:00Z
publication
2014-02-20T00:00:00Z
An edited version of this article was published by the Institute of Physics on behalf of the American Astronomical Society. Copyright 2014 the American Astronomical Society.
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