Long-Wavelength Turbulence and the Heating of the Solar Wind

Abstract

We propose a model of the solar wind in which the observed long-lived velocity streams are the source of long-wavelength turbulence, which in turn serves as an efficient and variable heat source for the solar plasma. The turbulence is characterized by the lack of an equilibrium subrange of wavenumbers, owing to the rapid damping of the waves by direct interaction with the thermal plasma. The model suggests that a-particles are heated more than protons (Ta `~~` 4T~) and predicts an effective end to turbulence and heating at a heliocentric radius of some 5-10 a.u. Both predictions agree with observations