New Evidence for Magnetic Reconnection in the Tail of Interplanetary Magnetic Cloud

We analyse the WIND data of an interplanetary magnetic cloud (MC) on 2 November 2001, and find new evidences for magnetic reconnection in the tail of this MC. In the MC tail, the largely dip and the large change of the orientation of the magnetic field occurred simultaneously, Δθ approx 45°, and ΔФ changed from 90° to 320°. Correspondingly, the number density of ions increased, and the superthermal electrons were heated and accelerated, however its number density decreased. Meanwhile, inverse jets and Hall term were observed. The pitch-angle distributions of the electrons with lower energy and higher energy showed strong turbulence and bi-direction flow, respectively. The plasma wave activity enhanced near the electron plasma frequency, f_pe and 2f_pe. These important physical characteristics are new evidences for magnetic reconnection existing in interplanetary space.