HR: 1330h
AN: SH42C-0548    [PDF]
TI: IPS investigation of CMEs in the solar wind
AU: * Tokumaru, M
EM: tokumaru@stelab.nagoya-u.ac.jp
AF: STE Lab., Nagoya Univ., 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Kojima, M
EM: kojima@stelab.nagoya-u.ac.jp
AF: STE Lab., Nagoya Univ., 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Fujiki, K
EM: fujiki@stelab.nagoya-u.ac.jp
AF: STE Lab., Nagoya Univ., 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Yamashita, M
EM: yamasita@stelab.nagoya-u.ac.jp
AF: STE Lab., Nagoya Univ., 3-13 Honohara, Toyokawa, 442-8507 Japan
AB: Interplanetary scintillation (IPS) measurements of natural radio sources act as a useful tool for clarifying global properties of solar wind plasma, particularly of the transient streams associated with coronal mass ejections, since they allow us to probe the solar wind at multiple points within a relatively short time. Taking this advantage, we have investigated the 3D structure and radial evolution of CMEs in the interplanetary medium from IPS measurements made with the 327 MHz four-station system of the Solar-Terrestrial Environment Laboratory (STEL), Nagoya University. In the present study, the model fitting analysis has been preformed to derive 3D properties of CMEs from IPS data. As a result, the majority of analyzed CME events is found to have a loop-shaped global structure with an anisotropic angular extent. The remainder of the CME events is found to be well explained by a bubble-shaped model with a nearly uniform angular extent. The elongated structure of CMEs tends to be oriented nearly parallel to the heliographic equator, although some of CME events show a large tilt to the equator. The radial variation of CME speed has been deduced for selected events by combining IPS data with coronagraph and in situ data. It is found that CMEs are decelerated significantly as they propagate through the solar wind. The interaction between CMEs and the ambient solar wind is considered to play an important role in forming the observed features (i.e. the 3D structure and deceleration) of CMEs.
DE: 2111 Ejecta, driver gases, and magnetic clouds
DE: 2139 Interplanetary shocks
DE: 2164 Solar wind plasma
DE: 7513 Coronal mass ejections
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting