The global evolution of many, if not most, magnetized plasma systems where magnetic
reconnection is known or conjectured to play a critical role are well-described
by magnetohydrodynamic-based approximations of the plasma dynamics. This holds
true for most laboratory, solar, as well as astrophysical scale plasmas where the global
system sizes are much greater that the spatial scales on which the magnetic field topology
is allowed to change by breaking and reconnecting individual magnetic field lines.
This talk will focus on one of the most important questions in today’s magnetic reconnection
research: How do the small-scale mechanisms responsible for the field-line
reconnection and the associated local decoupling of the magnetic field from the plasma
fluid affect the macroscopic dynamics of the global system? What we know, what we think we know, and what we definitely don’t know will be highlighted by examining magnetic reconnection in a series of two- and three- dimensional MHD-based numerical models with different decoupling mechanisms.