LINEAR-MODELS OF STEADY-STATE, INCOMPRESSIBLE MAGNETIC RECONNECTION

The problem of linear, steady state reconnection in incompressible magnetic plasmas is addressed. A universal feature of all linear solutions is long current sheets contiguous with the equilibrium separatrices. Fast reconnection is associated with shear flow solutions that vary rapidly across the separatrices, over a scale length of order square-root eta where eta is the dimensionless plasma resistivity. These findings are shown to be consistent with dynamic shear flow solutions associated with disturbances of current-free X-point equilibria in open-flow topologies. The development of length scales of order square-root eta is also a signature of fast dissipation for small amplitude, arbitrarily compressible displacements in closed X-point equilibria. The impact of these findings on conventional steady state reconnection models is discussed.