Flow-through magnetic reconnection -: art. no. 1626

[1] This note reports properties of a little-studied but possibly common mode of magnetic reconnection-"flow-through reconnection'' or "FTR''-characterized by plasma flowing at high speed right through a stationary reconnection site. FTR is readily identified in global MHD simulations by the following diagnostic properties, which affect slab-like portions (tongues) of the magnetopause, usually at high latitudes and along the flanks. 1. A magnetic null point lies near the downwind extreme of an FTR tongue. 2. Elsewhere within the tongue the magnetic field is also weak. 3. Electric current density is strong. 4. "J-dot-E'' dissipation is strong. 5. Most remarkable, the electric field is antiparallel to and stronger than -V x B, the motional electric field. This last property implies that plasma and magnetic field flow in opposite directions-plasma downwind, magnetic field upwind. Here we discuss FTR for strictly northward interplanetary magnetic field, which manifests FTR properties in idealized geometry.