A. Verdini et al 2009 ApJ 700 L39 doi:10.1088/0004-637X/700/1/L39
A. Verdini1, M. Velli2,3 and E. Buchlin4
Show affiliationsWe study the formation and evolution of a turbulent spectrum of Alfvén waves driven by reflection off the solar wind density gradients, starting from the coronal base up to 17 solar radii, well beyond the Alfvénic critical point. The background solar wind is assigned and two-dimensional shell models are used to describe nonlinear interactions. We find that the turbulent spectra are influenced by the nature of the reflected waves. Close to the base, these give rise to a flatter and steeper spectrum for the outgoing and reflected waves, respectively. At higher heliocentric distance both spectra evolve toward an asymptotic Kolmogorov spectrum. The turbulent dissipation is found to account for at least half of the heating required to sustain the background imposed solar wind and its shape is found to be determined by the reflection-determined turbulent heating below 1.5 solar radii. Therefore, reflection and reflection-driven turbulence are shown to play a key role in the acceleration of the fast solar wind and origin of the turbulent spectrum found at 0.3 AU in the heliosphere.
96.60.Vg Particle emission, solar wind
95.30.Qd Magnetohydrodynamics and plasmas
Issue 1 (2009 July 20)
Received 2009 March 17, accepted for publication 2009 May 15
Published 2009 July 2
A. Verdini et al 2009 ApJ 700 L39
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