Observations of reconnection exhausts associated with large-scale current sheets within a complex ICME at 1 AU

During 26-27 November 2000 a complex interplanetary coronal mass ejection, composed of four flux ropes, was detected by Wind and ACE at 1 AU. We identify two Petschek-like exhaust events within the interiors of the second and third flux ropes, respectively. In the first event, Wind and ACE detected an exhaust at the same side from the reconnection site, which was associated with a large-scale bifurcated current sheet with a spatial width of similar to 10,000 ion inertial lengths and the magnetic shear was 155 degrees. In the second event, the two spacecraft observed the oppositely directed exhausts from a single reconnection X line. The exhausts were also related to a large-scale current sheet with a spatial width of similar to 3000 ion inertial lengths and a shear angle of about 135 degrees. The two exhaust events resulted from fast and quasi-stationary reconnection. The related current sheets were both flat on the scale of a few hundred Earth radii and located close to the centers of subflux ropes. The decrease of radial expansion speed of each flux rope might account for the formation of the two current sheets. Reconnections at the centers of flux ropes may change the entire topology of the flux ropes and may fragment them into smaller ones.