Interplanetary Coronal Mass Ejections between 0.3 and 30 AU: Multi-spacecraft Observations and Model Comparison
作者单位：Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology 37-655 Cambridge MA 02139 USA
会议名称：《第十一届全国日地空间物理学术讨论会》
会议日期：2005年
学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学]
摘 要：正Using observations from multiple spacecraft such as Helios, PVO, ACE, Ulysses and Voyager 2 which are distributed throughout the heliosphere, we identify and characterize interplanetary coronal mass ejections （ICMEs） between 0.3 and 30 AU. An abnormally low proton temperature is used as the primary identification signature of ICMEs. The occurrence rate of ICMEs approximately follows the solar activity cycle. Statistically, the average radial width of ICMEs increases with distance up to about 15 AU, with a radial expansion speed of the order of the Alfven speed. The expansion features of the average temperature, density, and magnetic field magnitude of ICMEs are also studied. We employ a one-dimensional MHD numerical code to model the propagation of ICMEs to try to understand the observations. The model results reproduce the basic expansion characteristics of ICMEs.