Acceleration of the solar wind as a result of the reconnection of open magnetic flux with coronal loops

Abstract

There are compelling observations of a clear anticorrelation between solar wind flow speed and coronal electron temperature, as determined from solar wind ionic charge states. A simple theory is presented which can account for these observations, including the functional form of the correlation: Solar wind flow speed squared varies essentially linearly as the inverse of the coronal electron temperature. In this theory, magnetic field lines in the corona that open into the heliosphere reconnect with coronal loops near their base. This process displaces the open field line and disturbs and imparts energy into the overlying corona, thereby determining the Poynting vector into the corona. This process releases mass from the loop into the corona and determines the mass flux of the solar wind. The Poynting vector and mass flux into the corona determine the final speed of the solar wind and yield a relationship that provides an excellent fit to observations. The reconnection of open field lines with coronal loops, and their subsequent displacements, also results in a diffusive transport of open field lines, which influences the configuration of the heliospheric magnetic field.