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从欧斯特德和马格萨特卫星数据推断出地力发电机的小规模结构
Gauthier Hulot1, Céline Eymin, Benoît Langlais
1Département de Géomagnétisme et Paléomagnétisme, CNRS UMR 7577, Institut de Physique du Globe de Paris, 4 Place Jussieu, B89, Tour 24, 75252 Paris cedex 05, France. gh@ipgp.jussieu.fr
Nature
|April 12, 2002
概括
地球的地磁力发电机从其液态外核产生磁场. 最近的卫星数据揭示了核心表面的变化,显示了不同的流动模式,这可能解释了古磁场观测和逆转前的地磁场状态.
科学领域:
- 地质物理学 地质物理学
- 地球科学 地球科学 地球科学
- 动力机理论 动力机理论
背景情况:
- 地球液态外核中的地力发电机产生了地球的磁场.
- 这个电场对于保护地球免受有害的太阳辐射至关重要.
- 了解核心动态是解释表面磁场变化的关键.
研究的目的:
- 用卫星数据分析过去20年的磁场变化.
- 识别和解释变化到以前无法访问的长度尺度.
- 了解地力学摩的行为及其与古磁学的关系.
主要方法:
- 利用了来自欧斯特德和马格萨特卫星的数据.
- 在20年的时间里分析了磁场变化.
- 计算了核心表面流动模式,以解释观察到的磁场变化.
主要成果:
- 在极地度和南非以下确定了显著的磁场变化.
- 在太平洋下方观察到最小的变化.
- 计算了核心表面流动模式,其中包括向西流动,极地,以及不对称的环结构.
结论:
- 计算的流量模式类似于数值动力马模拟,但显示纵向不对称.
- 这种不对称状态可能解释了古磁场中持续存在的模式.
- 地力发电机可能在逆转极性之前在这种不对称状态下运行.
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