Acceleration of the High Speed Solar Wind

Abstract

A theory is developed for the high speed solar wind based on a simple dissipation length characterization of wave heating of the coronal plasma close to the Sun. It is shown that solutions with the correct particle and energy fluxes and with a realistic magnetic field, match the requirements on the density at the base of the corona provided the dissipation length is relatively small (~ 0.25 – 0.5 solar radii). The significant features of these solutions are that the acceleration is rapid, with the sonic point at about 2 solar radii, and the maximum proton temperatures are high, namely 8−10 × 10⁶ K, in agreement with some recent observations. Such efficient dissipation requires any Alfvén waves responsible to have frequencies in the range 0.01 Hz - 10 kHz. This has implications for the nature of the plasma and energy source in the chromospheric network.