A statistical study on Earth's magnetopause reconnection and association with solar wind parameters: POLAR/ACE observations

Magnetic reconnection at the Earth's dayside magnetopause has been an issue of great interest to understand solar wind-magnetosphere interaction. Using data from the Polar satellite we investigate 74 magnetic reconnection events observed at the Earth's dayside magnetopause based on a study done by Mozer (2005). We show that the distance from the expected location of the reconnection X-line to the satellite position for about 50% of the events is shorter than 2 Re. We also suggest that the current flowing along the X-line must be maximized at the reconnection line for shear angles for which the original Gonzalez and Mozer (1974) reconnection condition is not satisfied. As for the association of these events with solar wind parameters, we find that the magnitude of the angle between the reconnection X-line and the magnetospheric field has large associated values when the flow pressure and plasma beta values increase. Further, it is shown that the concentration of the reconnection events and the amplification of the magnetosheath with respect to the interplanetary magnetic field (IMF) are dependent on the angle between the Archimedean IMF direction and the GSM X-axis, and on the dipole tilt of the Earth's magnetic field and IMF Bx, respectively.