Magnetic reconnection and plasma transport in the presence of plasma turbulence

Plasma turbulence can enhance the diffusion of both magnetic fields and plasmas. But, any theory must be consistent with their evolution equations having the mathematical form of advection-diffusion equations. Advection-diffusion equations have a remarkable feature. When the diffusion is extremely weak but non-zero, its magnitude makes only a small difference even when varied over sixteen orders of magnitude. This is true when the advective velocity is chaotic -- the exponential separation of neighboring streamlines -- as natural flows generally are. Even highly turbulent flows have in addition to eddies large-scale coherent flows, such as the Gulf Stream in the Atlantic, which dominates their transport effects on longest scales. Basic physics and easily understood mathematics place important constraints, which are explained.