Energy release in the solar corona from spatially resolved magnetic braids

  title={Energy release in the solar corona from spatially resolved magnetic braids},
  author={Jonathan W. Cirtain and Leon Golub and Amy R. Winebarger and Bart De Pontieu and K. Kobayashi and R. L. Moore and Robert W. Walsh and Kelly E. Korreck and M. Weber and Patrick I. McCauley and Alan M. Title and S. Kuzin and Craig E. Deforest},
It is now apparent that there are at least two heating mechanisms in the Sun’s outer atmosphere, or corona. Wave heating may be the prevalent mechanism in quiet solar periods and may contribute to heating the corona to 1,500,000 K (refs 1, 2, 3). The active corona needs additional heating to reach 2,000,000–4,000,000 K; this heat has been theoretically proposed to come from the reconnection and unravelling of magnetic ‘braids’. Evidence favouring that process has been inferred, but has not been… 
Solar physics: Towards ever smaller length scales
High-resolution images obtained by a high-resolution camera on-board a sounding rocket reveal fine-scale braiding to a resolution of about 150 km in a coronal active region, and the images are consistent with energy production sufficient for the observed heating.
Observationally quantified reconnection providing a viable mechanism for active region coronal heating
It is reported that impulsive reconnection can give rise to an active region corona that is compatible with extreme-ultraviolet observations, and the heating power proportional to the velocity difference between magnetic footpoints and the photospheric plasma is calculated.
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How magnetic energy is injected and released in the solar corona, keeping it heated to several million degrees, remains elusive. Coronal heating generally increases with increasing magnetic field
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The outer atmosphere of the Sun is composed of plasma heated to temperatures well in excess of the visible surface. We investigate short cool and warm (<1 MK) loops seen in the core of an active
What can observations tell us about coronal heating?
  • J. Schmelz, A. Winebarger
  • Physics
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2015
The High Resolution Coronal Imager observed magnetic braids untwisting and reconnecting, dispersing enough energy to heat the surrounding plasma, and provides observational constraints that all viable coronal heating models will need to explain.
Confined pseudo-shocks as an energy source for the active solar corona
The Sun’s active corona requires an energy flux of ~103 W m−2 to compensate for radiative losses and to maintain its high temperature1. Plasma moves in the corona through magnetic loops2,3, which may
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Magnetic loops filled with hot plasma are the main building blocks of the solar corona. Usually they have lengths of the order of the barometric scale height in the corona that is 50 Mm. Previously
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One of the greatest challenges in solar physics is understanding the heating of the Sun’s corona. Most theories for coronal heating postulate that free energy in the form of magnetic twist/stress is
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We examine the turbulent relaxation of solar coronal loops containing non-trivial field line braiding. Such field line tangling in the corona has long been postulated in the context of coronal
Heliospheric magnetic field structures: Predictions & Implications
  • I. Roth
  • Physics
    Journal of Physics: Conference Series
  • 2018
The observational implication of braided solar magnetic fields opens a new venue for an interpretation of various solar and interplanetary phenomena. Direct imaging of the coronal fields at


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The Sun's corona is millions of degrees hotter than its 5000 K photosphere. This heating enigma is typically addressed by invoking the deposition at coronal heights of nonthermal energy generated by
The Origins of Hot Plasma in the Solar Corona
Observations from the Solar Dynamics Observatory and the Hinode solar physics mission are used to reveal a ubiquitous coronal mass supply in which chromospheric plasma in fountainlike jets or spicules is accelerated upward into the corona, with much of the plasma heated to temperatures between ~0.02 and 0.1 million kelvin.
Nature of the heating mechanism for the diffuse solar corona
The temperature of the Sun's outer atmosphere (the corona) exceeds that of the solar surface by about two orders of magnitude, but the nature of the coronal heating mechanisms has long been a
Magnetic Neutral Sheets in Evolving Fields - Part Two - Formation of the Solar Corona
It is shown in the previous paper that whenever twisted flux tubes are bundled together, they are subject to dynamical nonequilibrium and internal neutral point reconnection, causing rapid
Large-scale coronal heating by the small-scale magnetic field of the Sun
Magnetic fields play a crucial role in heating the outer atmospheres of the Sun and Sun-like stars, but the mechanisms by which magnetic energy in the photosphere is converted to thermal energy in
Self-Organized Braiding and the Structure of Coronal Loops
The Parker model for heating of the solar corona involves reconnection of braided magnetic flux elements. Much of this braiding is thought to occur at as yet unresolved scales, for example, braiding
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Estimates of the energy flux carried by these waves and comparisons with advanced radiative magnetohydrodynamic simulations indicate that such Alfvén waves are energetic enough to accelerate the solar wind and possibly to heat the quiet corona.
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The question of what heats the solar corona remains one of the most important problems in astrophysics. Finding a definitive solution involves a number of challenging steps, beginning with an
Braiding-induced Interchange Reconnection of the Magnetic Field and the Width of Solar Coronal Loops
The random walk of the footpoints of coronal loops in the rapidly evolving solar granulation is expected to cause braiding of the field, which in turn should lead to a multitude of coronal
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We present an ab initio approach to the solar coronal heating problem by modeling a small part of the solar corona in a computational box using a three-dimensional MHD code including realistic