Acceleration of the fast solar wind by reconnection

In order to verify the reconnection hypothesis of fast solar wind acceleration and to investigate the properties of reconnection in coronal holes we carried out computer simulations of the plasma dynamics in a polar coronal hole observed by SOHO on September 21, 1996. We start the simulation with the observed line-of-sight components of the photospheric magnetic fields and the derived photospheric plasma motion. The cross-field motion of the magnetized plasma causes currents flowing both parallel (force-free) and perpendicular to the magnetic field. We address the physics of current dissipation by applying threshold and dependence of finite resistivity on macroscopic plasma parameters according to the results of kinetic investigations of the collisionless dissipation. In particular we link the collisionless resistivity and the current carrier velocity as obtained by the MHD model. We obtain the structure and investigate the consequences of reconnection between low rising loops and funnel-shaped magnetic fields rooted in the supergranule boundary. The resulting reconnection heats the plasma at the funnel-loop interfaces and accelerates it to the necessary initial velocities starting from transition region heights. For the polar coronal hole we compared the results of our simulation with the observed signatures of heating and plasma acceleration.