New evidence for ozone depletion in the upper stratosphere

We highlight one result of a time‐dependent analysis of reconnection at the terrestrial magnetopause, namely, that the Petschek‐type reconnection process is inevitably accompanied by the generation of surface waves. These waves propagate along the magnetopause at a speed which is generally different from that of the shocks and discontinuities bounding the region of heated and accelerated plasma, the so‐called outflow region of reconnected plasma. The surface waves play a central role in the reconnection process because it is through them that the perturbations of the magnetic field and velocity normal to the magnetopause are transmitted along the current sheet from the source region to the system at large. Since reconnection acts as a source of surface waves, the present general view that transient phenomena at the magnetopause are due either to surface waves (generated by, for example, variations in the solar wind) or to transient reconnection should be revised in the interests of a more unified treatment.