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Coronal Heating and the Magnetic Flux Content of the NetworkPreviously, from analysis of SOHO coronal images in combination with Kitt Peak magnetograms, we found that the quiet corona is the sum of two components: the large-scale corona and the coronal network. The large-scale corona consists of all coronal-temperature (T approximately 10(exp 6) K) structures larger than supergranules (greater than approximately 30,000 kilometers). The coronal network (1) consists of all coronal-temperature structures smaller than supergranules, (2) is rooted in and loosely traces the photospheric magnetic network, (3) has its brightest features seated on polarity dividing lines (neutral lines) in the network magnetic flux, and (4) produces only about 5% of the total coronal emission in quiet regions. The heating of the coronal network is apparently magnetic in origin. Here, from analysis of EIT coronal images of quiet regions in combination with magnetograms of the same quiet regions from SOHO/MDI and from Kitt Peak, we examine the other 95% of the quiet corona and its relation to the underlying magnetic network. We find: (1) Dividing the large-scale corona into its bright and dim halves divides the area into bright "continents" and dark "oceans" having spans of 2-4 supergranules. (2) These patterns are also present in the photospheric magnetograms: the network is stronger under the bright half and weaker under the dim half. (3) The radiation from the large-scale corona increases roughly as the cube root of the magnetic flux content of the underlying magnetic network. In contrast, the coronal radiation from an active region increases roughly linearly with the magnetic flux content of the active region. We assume, as is widely held, that nearly all of the large-scale corona is magnetically rooted in the network. Our results suggest that either the coronal heating in quiet regions has a large non-magnetic component, or, if the heating is predominantly produced via the magnetic field, the mechanism is significantly different than in active regions.
Document ID
20010039530
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Falconer, D. A.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Moore, R. L.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Porter, J. G.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Hathaway, D. H.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Rose, M. Franklin
Date Acquired
August 20, 2013
Publication Date
January 1, 2001
Subject Category
Solar Physics
Meeting Information
Meeting: American Geophysical Union Spring 2001 Meeting
Location: Boston, MA
Country: United States
Start Date: May 30, 2001
Sponsors: American Geophysical Union
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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