MAGNETIC RECONNECTION - OBSERVATIONS ON OCTOBER 29, 1979, AND MODEL RESULTS

We discuss the structure of the reconnection layer as recorded by ISEE 2 during an outbound crossing of the dayside, northern magnetopause o n October 29, 1979. Besides a rotational discontinuity, this crossing shows slow mode shock structure. We interpret this event theoretically in terms of magnetic field line reconnection based on a pulse-like Pe tschek-type model, rather than in terms of steady state reconnection o n a moving magnetopause. Our model is generalized through the introduc tion of a space-and time-varying reconnection rate. Furthermore, the m agnetic fields and velocities on either side of the magnetopause curre nt sheet may have arbitrary strength and orientation with respect to e ach other; additionally, the densities on either side of the current s heet may be different in general. Using boundary/initial conditions fr om the spacecraft data, we calculate the temporal/spatial behavior of all reconnection-associated structures. In particular, having chosen a suitable trajectory through the magnetopause, we consider the tempora l behavior of the magnetic field and plasma parameters as these reconn ection-associated events pass by. The results reproduce the behavior o f the data reasonably well.