E-Print Archive

There are 3950 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
The Heating of the Solar Corona View all abstracts by submitter

Eric R Priest   Submitted: 2000-01-11 11:03

One of the paradigms about coronal heating has been the belief that the mean or summit temperature of a coronal loop is completely insensitive to the nature of the heating mechanisms. However, we point out that the temperature profile along a coronal loop is highly sensitive to the form of the heating. For example, when a steady-state heating is balanced by thermal conduction, a uniform heating function makes the heat flux a linear function of distance along the loop, while T7/2 increases quadratically from the coronal footpoints; when the heating is concentrated near the coronal base, the heat flux is small and the T7/2 profile is flat above the base; when the heat is focussed near the summit of a loop, the heat flux is constant and T7/2 is a linear function of distance below the summit. This realisation may act as an incentive to proponents of particular heating mechanisms to determine how the heat deposition varies spatially within coronal structures such as loops or arcades and to observers to deduce the temperature profiles with as low an error as possible. We therefore propose a new two-part approach to try and solve the coronal heating problem, namely first of all to use observed temperature profiles to deduce the form of the heating, and secondly to use that heating form to deduce the likely heating mechanism. In particular, we apply this philosophy to a preliminary analysis of Yohkoh observations of the large-scale solar corona. This gives strong evidence against heating concentrated near the loop base for such loops and suggests that heating uniformly distributed along the loop is slightly more likely than heating concentrated at the summit. The implication is that large-scale loops are heated in situ throughout their length, rather than being a steady response to low-lying heating near their feet or at their summits. Unless waves can be shown to produce a heating close enough to uniform, the evidence is therefore at present for these large loops more in favour of turbulent reconnection at many small randomly-distributed current sheets, which is likely to be able to do so. In addition, we address briefly the questions: why does the coronal intensity reduce by a factor of 100 from solar maximum to solar minimum; why is the temperature maximum in large-scale closed regions about 2.3 MK at an altitude 1.5 Rodot; and why are the corresponding values in coronal holes about 1.5 MK and 1.5 Rodot?

Authors: E. R. Priest, C. R. Foley, J. Heyvaerts, T.D. Arber$^{*}$, D. Mackay$^{*}$, J. L. Culhane$^{+}$ and L.W. Acton

Publication Status: Ap J (submitted)
Last Modified: 2000-01-11 11:03
Go to main E-Print page  Exact Solutions for Reconnective Magnetic Annihilation
  Aspects of 3D Magnetic Reconnection
  Edit Entry  Download Preprint  Submitter's Homepage Delete Entry 

Go to main E-Print pageGo to main E-Print page.
Previous AbstractPrevious Abstract.
Next AbstractNext Abstract.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
View All Abstracts By SubmitterView all abstracts by submitter.
Delete AbstractDelete abstract.

Latest Entries
Frequency rising sub-THz emission from solar flare ribbons
Particle acceleration in coalescent and squashed magnetic islands I. Test particle approach
Statistical Analysis of Torus and Kink Instabilities in Solar Eruptions
Solar Eruptions, Forbush Decreases and Geomagnetic Disturbances from Outstanding Active Region 12673
Coronal hard X-ray sources revisited
Manifestations of bright points observed in G-band and Ca II H by Hinode/SOT
Propagation of Leaky MHD Waves at Discontinuities with Tilted Magnetic Field
Time variations of the non-potential and volume-threading magnetic helicities
Advances in mean-field dynamo theory and applications to astrophysical turbulence
Reverse Current Model for Coronal Mass Ejection Cavity Formation
Predictions of DKIST/DL-NIRSP Observations for an Off-limb Kink-unstable Coronal Loop
Exploring the biases of a new method based on minimum variance for interplanetary magnetic clouds
The non-modal onset of the tearing instability
SpatioTemporal Evolution and North-South Asymmetry of Quasi-Biennial Oscillations in the Coronal Fe XIV Emission
Corotating Shock Waves and the Solar-Wind Source of Energetic Ion Abundances: Power Laws in A/Q
Coronal condensations caused by magnetic reconnection between solar coronal loops
Measurement of Vector Magnetic Field in a Flare kernel with a Spectropolarimetric Observation in He I 10830 A
The Relation Between Escape and Scattering Times of Energetic Particles in a Turbulent Magnetized Plasma: Application to Solar Flares
Implications of loop-top origin for microwave, hard X-ray, and low-energy gamma-ray emissions from behind the limb flares
Solar radio emission as a disturbance of aeronautical radionavigation

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey

© 2003 Solar Physics Group - Montana State University