Ion fractionation and mixing processes in the turbosphere and the solar wind formation region: Scaling approach

The kinetic theory of the ion distribution function formation in the plasma is briefly considered. Models are discussed of the individual particle and collective behavior. Governing dimensionless parameters are presented for numerous collisional and collisionless regimes of the ion generation, separation and mixing in the solar atmosphere. Global steady state and local non-stationary processes are shown to be interrelated in a complicated manner possibly leading to the observed diversity in composition variations of the solar wind. The strongest composition variations are produced at the shocks, but the mixing prevails in the sense that protons remain the dominant component even under these extreme conditions. The dynamical balance between the mixing and fractionation depends on many space-time scales simultaneously present in the plasma and electromagnetic fields, which explains the lack of simple universal classifications and poor understanding of the laminar or turbulent processes of the ion composition formation. For example, it is not clear if the persistent difference between the composition of the quasi-stationary slow and fast solar wind streams could be related mainly to the vertical stratification or to the horizontal inhomogeneity of the solar corona and dynamical processes in holes and streamers