The solar wind control of reconnection at the dayside magnetopause.

摘要

he solar wind control of reconnection is examined using both correlation analysis of geomagnetic activity and in situ observations at the magnetopause. The correlation of geomagnetic activity, as measured by the am index, reveals a dependence of reconnection on the direction of the interplanetary magnetic field, the solar wind magnetosonic Mach number, and the solar wind dynamic pressure. In situ observations of accelerated flows and the magnetic normal component at the magnetopause using the ISEE 1 and 2 spacecraft are correlated with solar wind and magnetosheath parameters. The magnitude of the magnetic normal component is found to increase as the solar wind magnetic field clock angle becomes southward. The occurrence of accelerated flows increases with increasing southward field as well. Accelerated flows are found to occur with greater probability when the magnetosheath beta is low. Accelerated flows occur most often near the subsolar point. The direction and location of accelerated flows indicate the merging line tilts according to the direction of the interplanetary magnetic field with an average length of