伽利略卫星观测磁异常及其解释  

Magnetic anomalies obserred by Galilean satellites and interpretations

作　　者：焦立果 匡伟佳 马石庄 

机构地区：[1]中科院研究生院计算地球动力学实验室,北京100049 [2]美国宇航局Goddard空间飞行中心,greenbeltmd20771

出　　处：《地球物理学进展》2010年第4期1259-1272,共14页Progress in Geophysics

基　　金：国家自然科学基金(40328006);NASA的MFRP和ESIP基金联合资助

摘　　要：伽利略飞船在木星四颗最大的卫星附近探测到了显著的磁异常.尽管磁异常不同,但是都来自于卫星内部和周围环境的磁流体动力学过程,例如冰下海洋的电磁感应,卫星的轨道运动与外部等离子体的相互作用等等.本文总结了每颗卫星的观测磁异常以及现有解释.我们也提出了磁异常来源的新的可能解释机制:磁异常可能部分来自卫星冰下导电海水或者流体核的磁对流.对该机制的研究有助于进一步理解所观测到的磁异常,也可能提供对卫星内部物理的磁约束.Galileo mission measured significant magnetic anomalies near four biggest Jovian moons. Though they are different from each other, these anomalies are produced mainly by magnetobydrodynamic processes within the satellites and in the surrounding environment, e.g. magnetic induction in the subsurface oceans, perturbations of satellite orbital motions to the surrounding plasma. In this paper we summarize the observed anomalies and existing interpretations for each moon. We also propose a new possible mechanism on the origin of the anomalies： they may arise in part from magneto-convection in electrically conducting subsurface oceans or fluid cores of the moons. Investigation of this mechanism could help further understanding the observed magnetic anomalies, and provide possible magnetic constraints on the physics of the moons＇ interior.

关 键 词：伽利略卫星 磁场 磁流体动力学 冰下海洋 

分 类 号：P318[天文地球—固体地球物理学] P35[天文地球—地球物理学]