Natural selection in the corona
Article Abstract:
Jack Scudder's 1992 explanation of the observed temperature differences between the sun's photosphere and corona exploits the concept of a velocity filter and the lack of thermodynamic equilibrium in the photosphere. If the photosphere is not in thermodynamic equilibrium, gravity may function as a velocity filter that keeps slower molecules closer to the surface and results in the escape of higher temperature plasma. Scudder's work on the solar wind and collisionless shocks led to an understanding of how non-equilibrium distributions develop. This was the key making the velocity filter concept explanatory.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
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Three-dimensional image of the solar corona from white-light observations of the 1991 eclipse
Article Abstract:
The three-dimensional structure of the Sun's corona may be deduced from images taken by the Multi-station International Coronal Experiment during the total solar eclipse of Jul 1991. Separated by an interval of three hours, two white-light images of the eclipse yield a stereoscopic view of the corona. On this time scale, the corona is found to undergo semi-rigid rotation. The structure of the corona's jets and streamers is described, and their equations of motion given.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1992
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Kilometer-scale structure in the sun's corona
Article Abstract:
Some features of the density fluctuations in the sun's corona and in the solar wind are very difficult to establish. Two such characteristics are the sudden rise in anisotropy of the fluctuations near the sun and the break in the power-law spectrum that details the density irregularities. It is proposed that these properties reflect a shift from tiny ray-like structures in the corona rotating with the sun to chaotic density fluctuations convecting with the solar wind.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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