The Source Region for Continuous Magnetic Reconnection at the Earth Magnetopause

Abstract:

Magnetic reconnection at the Earth’s magnetopause is the mechanism by which magnetic fields in different regions change topology to create open magnetic field lines that allow energy, mass and momentum to flow into the magnetosphere. One of the open questions in understanding this process is whether reconnection at the magnetopause is an intrinsically intermittent or continuous process. While intermittent or pulsed reconnection turns on and off, continuous reconnection might have a variable reconnection rates but never ceases. Observational evidence for pulsed reconnection include flux transfer events (FTE), poleward moving auroral forms or steps in the ion dispersion signatures seen in the magnetospheric cusps. However, cusp observations observed by the Polar and Cluster satellites also exhibit single dispersion signatures which have previously been interpreted as either continuous reconnection or the occurrence of a single brief reconnection pulse. This study investigates a Polar data base with single cusp dispersions to ascertain whether these dispersions are consistent with continuous magnetic reconnection, and if so, to determine the magnetopause location of the reconnection region.