Paradigm transition in cosmic plasma physics, magnetic reconnection and the generation of field-aligned current

The traditional theories of field-aligned current (FAC) generation, magnetic reconnection and mass, momentum and energy transfer within the magnetosphere were built on the basis of a convection picture and describe mainly large-scale, quasi-steady state phenomena occurring in a passive plasma region. However, these theories have not been able to account for many of the detailed observations that have been made in recent years. These incomplete, but widely accepted, theoretical models have led to numerous misleading or controversial issues in magneto-spheric physics in the past few decades. In this paper, we point out that MHD wave propagation, in particular, wave packet dynamics, plays an important role for phenomena occurring in the active plasma region, such as FAC generation and reconnection. The topological approach, using the concept of helicity, is used to describe the structure of MHD wave packets. The theories of FAC generation as well as the concept of reconnection need to be revised under wave packet dynamics. The MHD wave packet paradigm gives a major change in our approach to cosmic plasma physics. The rich and varied implications of wave packet dynamics exceed those given by either the u-B paradigm or the E-J paradigm. This paradigm transition will bridge the gap between cosmic plasma physics and modem physics.