Evidence for Vortex Shedding in the Sun's Hot Corona

Abstract

Vortex shedding is an oscillating flow that is commonly observed in fluids due to the presence of a blunt body in a flowing medium. Numerical simulations have shown that the phenomenon of vortex shedding could also develop in the magnetohydrodynamic (MHD) domain. The dimensionless Strouhal number, the ratio of the blunt body diameter to the product of the period of vortex shedding and the speed of a flowing medium, is a robust indicator for vortex shedding, and, generally of the order of 0.2 for a wide range of Reynolds number. Using an observation from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, we report a wavelike or oscillating plasma flow propagating upward against the Sun's gravitational force. A newly formed shrinking loop in the post-flare region possibly generates the oscillation of the upflow in the wake of the hot and dense loop through vortex shedding. The computed Strouhal number is consistent with the prediction from previous MHD simulations. Our observation suggests the possibility of vortex shedding in the solar corona.

6 pages, Published in PRL, Ref: T. Samanta, H. Tian, and V. M. Nakariakov, Phys. Rev. Lett. 123, 035102 (2019)

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Cited by in corpus (8)

• Kink oscillations of coronal loops
• Decayless oscillations in solar coronal bright points
• Plasma Heating Induced by Tadpole-Like Downflows in the Flaring Solar Corona
• Transverse loop oscillations via vortex shedding: a self oscillating process
• Current-sheet Oscillations Caused by Kelvin-Helmholtz Instability at the Loop Top of Solar Flares
• Finite memory time and anisotropy effects for initial magnetic energy growth in random flow of conducting media
• Statistical Investigation of the Kinematic and Thermal Properties of Supra-arcade Downflows Observed During a Solar Flare
• Statistical Investigation of the Widths of Supra-arcade Downflows Observed During a Solar Flare