Mapping the Inflow and Exhaust Regions of a Kinking Magnetotail Reconnection Site using Data from Cluster

The inflow and exhaust regions of a moving magnetotail reconnection site is mapped using data from the four Cluster spacecraft. A kink structure in the dawn-dusk direction with a scale of a few ion skin depths is identified based on this mapping. At the start of the data collected on August 21, 2002 from 08:16:00 UT to 08:19:20 UT, Cluster 1, 2 and 3 are in the exhaust tailward of a reconnection site as indicated by tailward ion flow, negative Bz, and electrons characteristic of the reconnection exhaust. Cluster 4, north of the other spacecraft, remains in the inflow region for the duration of the data analyzed. As the reconnection site travels in the tailward direction, the electron distribution and magnetic field measurements indicate a decrease in thickness of the exhaust region. Cluster 1, 2, and 3 then cross the inflow region into the earthward exhaust region, which is documented through correlated Bz and Bx reversals, as well as the electron region transitions. A widening of the exhaust region is seen in the electron distribution measurements as the spacecraft travel deeper into the exhaust earthward of the reconnection site. The electron map and 3D nature of the spacecraft configuration enabled the identification of the kink structure.