Compositional variations in magnetic clouds with ACE/SWICS

Magnetic Clouds (MCs) are a subgroup of Interplanetary Coronal Mass Ejections (ICMEs) showing a smooth rotation in their magnetic field vector and often enhanced magnetic field strength. From ICME studies a wide variety of compositional anomalies compared to normal solar wind is known (Richardson and Cane 2004). Enhanced iron charge states, enhanced O7/O6 ratios, and enhanced helium to proton ratios are common examples. From fitting the magnetic field inside a MC the trajectory of a spacecraft through the flux-rope MC can be reconstructed, allowing us to obtain spatially resolved compositional data. The considered MCs were observed from 2001 to 2007 using the magnetometer and the SWICS (Solar Wind Ion Composition Spectrometer) instrument onboard ACE (Advanced Composition Explorer). A total number of about 50 MCs were investigated, most of them were taken from the WIND list which ends in early 2006. We have completed the survey up to mid 2007 and also present the new MCs. The MCs were investigated for spatial heterogeneity with the aim to find trends for distinct compositional features.