Cranmer, S. R. 2006, "Turbulent Origins of the Solar Wind," SHINE 2006 Workshop, Zermatt, Utah, July 31 - August 4, 2006 (Invited Talk). [Powerpoint viewgraphs (3.1 MB) are available.]

ABSTRACT:

The continually evolving convection below the solar photosphere gives rise to a wide spectrum of acoustic and magnetic fluctuations that propagate out into the heliosphere. In this talk I will review the various ways that waves, shocks, and turbulent eddies are expected to interact with the mean plasma conditions of the outer solar atmosphere. A major question, which I tentatively answer in the affirmative, is: Can the coronal heating and solar wind acceleration in open magnetic flux tubes be accomplished more or less entirely by wave dissipation and turbulent cascade? The importance of magnetohydrodynamic turbulence in the extended corona has been affirmed by the surprising measurements of the UVCS instrument on SOHO that heavy ions are heated to hundreds of times the temperatures of protons and electrons, indicating collisionless Alfven wave dissipation. Complete theoretical models are difficult to construct, though, because many of the proposed physical processes act on a multiplicity of spatial scales (from centimeters to solar radii) with feedback effects not yet well understood. Despite these difficulties, progress has been made toward the goal of producing models that predict the plasma properties everywhere above the solar surface using only lower boundary conditions at the photosphere.