Magnetic field topology and criticality in geotail dynamics: Relevance to substorm phenomena

Recent observations and analyses seem to suggest that certain dynamical fea tures of the Earth's magnetosphere could resemble the evolution of a comple x system near a forced and/or self-organized criticality (FSOC). Here, we r eview concepts dealing with the phenomenology of criticality and disorder s ystems in connection with magnetospheric processes. In more detail, we disc uss the importance of intermittency, turbulence and local topological disor der in the geomagnetic tail regions, that form a new paradigm for the under standing of the magnetotail dynamics.