The Origins of Hot Plasma in the Solar Corona

@article{DePontieu2011TheOO,
  title={The Origins of Hot Plasma in the Solar Corona},
  author={Bart De Pontieu and Scott W. McIntosh and Mats Carlsson and Viggo H. Hansteen and Theodore D. Tarbell and Paul Boerner and Juan Mart{\'i}nez-Sykora and Carolus J. Schrijver and Alan M. Title},
  journal={Science},
  year={2011},
  volume={331},
  pages={55 - 58}
}
The solar corona is heated by jets of plasma propelled upward from the region immediately above the Sun’s surface. The Sun's outer atmosphere, or corona, is heated to millions of degrees, considerably hotter than its surface or photosphere. Explanations for this enigma typically invoke the deposition in the corona of nonthermal energy generated by magnetoconvection. However, the coronal heating mechanism remains unknown. We used observations from the Solar Dynamics Observatory and the Hinode… 
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References

SHOWING 1-10 OF 72 REFERENCES
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 by
ON REDSHIFTS AND BLUESHIFTS IN THE TRANSITION REGION AND CORONA
Emission lines formed in the transition region (TR) of the Sun have long been known to show pervasive redshifts. Despite a variety of proposed explanations, these TR downflows (and the slight upflows
The Coronal Heating Mechanism as Identified by Full-Sun Visualizations
We constrain the properties of the mechanism(s) responsible for the bulk of the heating of the corona of the Sun by simulating, for the first time, the appearance of the entire solar corona. Starting
On Solving the Coronal Heating Problem
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
On the nature of dark extreme ultraviolet structures seen by SOHO/EIT and TRACE
Spectral lines in the extreme ultraviolet (EUV) observed on the Sun can originate either from the hot corona or the cooler chromosphere to corona transition region. In the present paper we
HIGH-SPEED TRANSITION REGION AND CORONAL UPFLOWS IN THE QUIET SUN
We study the line profiles of a range of transition region (TR) emission lines observed in typical quiet-Sun regions. In magnetic network regions, the Si iv 1402 Å, C iv 1548 Å, N v 1238 Å, O vi 1031
A FLUX-TUBE TECTONICS MODEL FOR SOLAR CORONAL HEATING DRIVEN BY THE MAGNETIC CARPET
We explore some of the consequences of the magnetic carpet for coronal heating. Observations show that most of the magnetic flux in the quiet Sun emerges as ephemeral regions and then quickly
A Tale of Two Spicules: The Impact of Spicules on the Magnetic Chromosphere
We use high-resolution observations of the Sun in Ca II H 3968 A from the Solar Optical Telescope on Hinode to show that there are at least two types of spicules that dominate the structure of the
Coronal Plasma Motions near Footpoints of Active Region Loops Revealed from Spectroscopic Observations with Hinode EIS
The solar active region 10938 has been observed from the disk center to the west limb with the Hinode EUV Imaging Spectrometer. In the disk-center observation, subsonic upflow motions of tens of km
The role of spicules in heating the solar atmosphere
From observations of downflowing material at transition region temperature, together with reasonable assumptions about the fate of spicules after they disappear from the view in the visual spectrum,
...
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