Space Physics Seminar winter-2014

Plasma transport in the plasma sheet and auroral oval is known to involve a significant amount of transient fast flows that are longitudinally localized and occur in various magnetic conditions. Recently, those fast flow channels are found to play a crucial role in triggering substorm auroral onset, whose pre-onset sequence has been in strong debate in the community for decades. Not only substorm onset, but many other phenomena such as steady magnetospheric convections (SMCs) and Pi2 pulsations are also identified to involve fast flow channels. On the other hand, these findings led to many interesting questions in broader aspects of the magnetosphere-ionosphere coupling: (1) How are plasma sheet flow channels triggered? Is there any precursor on open field lines? (2) What is the mechanism of the substorm onset instability? And (3) how do flow channels affect the inner magnetosphere? This talk will address those issues by using the growing capability of ground-based auroral and radar observations as well as conjugate satellite observations.