OBSERVATION OF MAGNETIC RECONNECTION AT THE TURBULENT LEADING EDGE OF AN INTERPLANETARY CORONAL MASS EJECTION

Magnetic Cloud Boundary Layer (MCBL) is formed by the interaction between a magnetic cloud ejected by the Sun and the ambient solar wind, which may be linked to the outer loops of an Interplanetary Coronal Mass Ejection (ICME) and often display the properties of magnetic reconnection. We study the relation between current sheets, turbulence, and magnetic reconnection at the leading edge of an ICME intercepted by the four Cluster spacecraft in the solar wind, upstream of the Earth's bow shock, on 2005 January 21. We obtain the observational evidence of a fully-developed magnetic turbulence in the vicinity of two current sheets at the leading edge of ICME. Each current sheet shows the signatures of magnetic reconnections with oppositely propagating Alfven waves and jets. The current density of bifurcated current sheets is computed by the curlometer technique using multi-spacecraft data.