Fast Winds Accelerate Rapidly

Fast Winds Accelerate Rapidly

. The fast solar wind accelerates to its high velocity very close to the Sun, within at least 10 solar radii. Interferometric observations of interplanetary radio scintillations are marked with circles and squares. The vertical bar on each data point is the 90 percent confidence limit, and the horizontal bar indicates the distance range over which the scintillation estimate is averaged. The upper and lower bounds of the Ulysses measurements are plotted as horizontal dotted lines, and the mean Ulysses fast-wind speed is marked with an arrow at 100 solar radii. The flow speed from a wave-assisted acceleration model is plotted as a dashed line, and the apparent scintillation velocity calculated from this model is plotted as a heavy solid line. The point nearest the Sun is estimated from Spartan-201 coronagraph measurements.

Copyright 2010, Professor Kenneth R. Lang, Tufts University