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 William 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… Expand
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. Expand
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. Expand
What can observations tell us about coronal heating?
  • J. Schmelz, A. Winebarger
  • Physics, Medicine
  • 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. Expand
New Evidence that Magnetoconvection Drives Solar-Stellar Coronal Heating
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 fieldExpand
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 mayExpand
Miniature loops in the solar corona
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. PreviouslyExpand
The Role of Magnetic Helicity in Coronal Heating.
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 isExpand
Observable Signatures of Energy Release in Braided Coronal Loops
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 coronalExpand
3D magnetic field configuration of small-scale reconnection events in the solar plasma atmosphere
The outer solar atmosphere, i.e., the corona and the chromosphere, is replete with small energy-release events, which are accompanied by transient brightening and jet-like ejections. These events areExpand
The Duration of Energy Deposition on Unresolved Flaring Loops in the Solar Corona
Solar flares form and release energy across a large number of magnetic loops. The global parameters of flares, such as the total energy released, duration, physical size, etc., are routinelyExpand


Observing the Roots of Solar Coronal Heating—in the Chromosphere
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 byExpand
Magnetic tornadoes as energy channels into the solar corona
The imprints of these chromospheric swirls in the transition region and low corona are identified as observational signatures of rapidly rotating magnetic structures, which resemble super-tornadoes under solar conditions and provide an alternative mechanism for channelling energy from the lower into the upper solar atmosphere. Expand
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. Expand
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 aExpand
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 rapidExpand
Coronal Currents, Magnetic Fields, and Heating in a Solar Active Region
We compare microwave images of a solar active region with state-of-the-art fully nonlinear force-free extrapolations of the photospheric fields in order to study the link between coronal currents andExpand
Alfvénic waves with sufficient energy to power the quiet solar corona and fast solar wind
Observations of the transition region of the chromosphere and the corona are reported that reveal how Alfvénic motions permeate the dynamic and finely structured outer solar atmosphere. Expand
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 inExpand
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, braidingExpand
Chromospheric Alfvénic Waves Strong Enough to Power the Solar Wind
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. Expand