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Title: What supplies the energy and momentum of the fast solar wind?
Plain: The fast solar wind leaves the Sun at about $7.5e7\,\mathrm{cm/s}$, and it is not settled whether waves in the magnetic field or bursts of magnetic reconnection push it to that speed.
Precise: Determine whether Alfven-wave turbulence, interchange reconnection at the base of coronal holes, or both supply the energy and momentum flux of the fast wind (speed $\sim 7e7\ \text{to}\ 8e7\,\mathrm{cm}/\mathrm{s}$), including the heating of protons and heavy ions above the electron temperature. Answer: the fraction of the energy flux supplied by each process, consistent with Parker Solar Probe and Solar Orbiter data inside and near the Alfven surface.
Settled by: Parker Solar Probe and Solar Orbiter measurements of wave energy flux and reconnection signatures inside the Alfven surface, connected to remote-sensed coronal-hole source regions, that close the energy budget.
Kind: phenomenon
Answer type: mechanism
References: (empty)
Literature status: open
Status note: 2021: Parker Solar Probe first crossed into sub-Alfvenic wind; since December 2024 it reaches 9.86 solar radii from the Sun's center.
Posed since: (empty)