NUK - logo
E-viri
Recenzirano Odprti dostop
  • Magnetic field topology for...
    Fuselier, S. A.; Petrinec, S. M.; Trattner, K. J.; Lavraud, B.

    Journal of geophysical research. Space physics, November 2014, Letnik: 119, Številka: 11
    Journal Article

    Ion observations from the Cluster spacecraft are used to investigate magnetopause reconnection for northward Interplanetary Magnetic Field (IMF) conditions. When the spacecraft cross the magnetopause and enter the magnetosphere at low latitudes, equatorward of the magnetospheric cusps, multiple ion populations of magnetosheath origin are almost always observed. The bulk flow velocities of these separate populations are consistent with their entry at high northern and southern latitudes. Furthermore, characteristics of the pitch angle distributions provide a means to estimate the entry point of the magnetosheath ions and the relative timing of the reconnections in opposite hemispheres. In the example presented, these entry points are poleward of both magnetospheric cusps, and the reconnections are separated by minutes. In a survey of magnetopause crossing events, most ion observations and associated electron observations are consistent with this dual‐lobe reconnection process as long as the reconnections are separated in time by several minutes. A small percentage of events are not consistent with this reconnection model and may indicate reconnection at other locations, such as equatorward of the cusp. Key Points Ion observations show that dual‐lobe reconnection occurs at the magnetopauseThis dual‐lobe reconnection is not simultaneous in both lobesThe reconnection produces characteristic ion distributions in the LLBL