08-August-2005, 06:42 PM
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Established Member
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Join Date: Oct 2001
Location: USA
Posts: 311
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http://solar-center.stanford.edu/FAQ/Qsolwindcomp.html
The solar wind is a collection of streams of energetic particles that originate on the Sun. You can think of the particles of the solar wind as nothing less than the solar corona itself.[Noyes] This is because the distant corona expands outwards due to not enough restraining force from gravity, or from the pressure of the interstellar gas, to confine the distant corona. The solar wind escapes through the coronal holes at supersonic speeds. As the outer corona disperses, it must be replaced by gases welling up from below (lower corona).
The composition of the solar wind is a mixture of materials found in the solar plasma, composed of ionized hydrogen (electrons and protons) with an 8% component of helium (alpha particles) and trace amounts of heavy ions and atomic nuclei: C, N, O, Ne, Mg, Si, S, and Fe ripped apart by heating of the Sun's outer atmosphere, that is, the corona.
SOHO also identified traces of some elements for the first time such as P, Ti, Cr and Ni and an assortment of solar wind isotopes identified for the first time: Fe 54 and 56; Ni 58,60,62 [Galvin].
Note that although the solar wind is electrically balanced, the solar wind consists almost exclusively of charged particles (stripped away nuclei from atoms) and is an excellent electrical conductor. These electrically conducting particles is technically known as a plasma, so it may be misleading to think of the solar wind as like Earth "winds".
(Edit to emphasize point)
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