INBOUND WAVES IN THE SOLAR CORONA: A DIRECT INDICATOR OF ALFVÉN SURFACE LOCATION

@article{Deforest2014INBOUNDWI,
  title={INBOUND WAVES IN THE SOLAR CORONA: A DIRECT INDICATOR OF ALFV{\'E}N SURFACE LOCATION},
  author={Craig E. Deforest and Timothy A. Howard and D. J. Mccomas},
  journal={The Astrophysical Journal},
  year={2014},
  volume={787}
}
The tenuous supersonic solar wind that streams from the top of the corona passes through a natural boundary—the Alfvén surface—that marks the causal disconnection of individual packets of plasma and magnetic flux from the Sun itself. The Alfvén surface is the locus where the radial motion of the accelerating solar wind passes the radial Alfvén speed, and therefore any displacement of material cannot carry information back down into the corona. It is thus the natural outer boundary of the solar… 

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