Deformation of ICMEs/MCs along their path

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• 作者：A. Lynnyk^a ; J. Š ; afrá ; nková ; ^a ; ^{jana.safrankova@mff.cuni.cz"" rel=""nofollow} ; Z. Ně ; meč ; ek^a ; J.D. Richardson^b
• 关键词：Interplanetary coronal mass ejection ; Magnetic clouds ; Solar wind ; Interplanetary magnetic fields ; Flux ropes ; Expansion
• 刊名：Planetary and Space Science
• 出版年：2011
• 出版时间：July 2011
• 年：2011
• 卷：59
• 期：9
• 页码：840-847
• 全文大小：498 K

文摘

Interplanetary coronal mass ejections (ICMEs) and their subset, magnetic clouds (MCs), are important manifestations of solar activity which have substantial impact on the geomagnetic field. We re-analyze events already identified in Wind and Voyager 2 data and estimate changes of their geometry along the path from the Sun. The analysis is based on the thickness of the sheath between a shock and a particular ICME or MC which is proportional to the apparent curvature radius of ICMEs/MCs. We have found that this apparent radius of curvature increases with the Mach number and this effect is attributed to the larger deformation of the fast ICME/MC. Further, the relative sheath thickness that is proportional to the flux rope oblateness decreases with the magnetic field intensity inside the ICME/MC and increases with the heliospheric distance.