In situ measurements of Alfvenic waves in the interplanetary coronal mass ejections

As for the present situation of coronal mass ejection (CME) triggering models, the distributions of Alfven waves in flux ropes are different from model to model, and thus examining those distributions in interplanetary coronal mass ejection (ICME) is an effective way to connect ICME observations with these theoretical models of CME triggering. However, previous observations of Alfv\'{e}nic fluctuations in ICMEs were rare with locations ranging from 0.3 AU to 0.68 AU only, which is usually explained as rapid dissipation of those remnant waves. Here we present a preliminary statistical study of Alfven waves in magnetic clouds (MC) near 1 AU, \textit{in situ} detected by WIND. The Alfven waves, slow waves, as well as the power spectral densities of magnetic fluctuation in the MC, are identified and compare with those modes in ambient solar wind. The results will also be helpful for studies of CME theories and ICME thermodynamics.