Core field acceleration pulse as a common cause of the 2003 and 2007 geomagnetic jerks
Core field acceleration pulse as a common cause of the 2003 and 2007 geomagnetic jerks
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DOI：
10.1029/2009gl042019
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发表时间：
2010-04-01
影响因子：
5.2
通讯作者：
Hulot, G.
中科院分区：
文献类型：
--
作者：
Chulliat, A.;Thebault, E.;Hulot, G.
利用天文台数据，我们报告了2007年地磁扰动的探测，我们将其与之前在卫星数据中注意到的地磁场二阶导数的跳跃联系起来。虽然不是全球范围的，但这种波动在南大西洋地区非常强烈。利用CHAOS-2模型，我们证明了这次和之前2003年的扰动都是由单个核心场加速脉冲在2006.0附近达到最大功率引起的。这个脉冲似乎同时发生在核心表面的几个区域，在那里它对应于主导的n = 5和6球谐模。几何衰减解释了为什么2003年和2007年的震动是局部的，而不是在地球表面完全同步的。我们的研究结果表明，这种地核场加速脉冲是从地核动力学的角度来研究的相关现象，而不是从弹跳本身来研究。引用本文：Chulliat， A.， E. Thebault，和G. Hulot(2010)，核心磁场加速脉冲作为2003年和2007年地磁震动的共同原因，《地球物理》。卷。生态学报，37,L07301, doi: 10.1029/2009GL042019。
Using observatory data, we report the detection of a geomagnetic jerk in 2007, which we relate to a jump in the second derivative of the geomagnetic field previously noted in satellite data. Although not of worldwide extent, this jerk is very intense in the South Atlantic region. Using the CHAOS-2 model, we show that both this jerk and the previous 2003 jerk are caused by a single core field acceleration pulse reaching its maximum power near 2006.0. This pulse seems to be simultaneously occurring in several regions of the core surface where it corresponds to dominant n = 5 and 6 spherical harmonic modes. Geometrical attenuation explains why the 2003 and 2007 jerks are local and not fully synchronized at the Earth's surface. Our results suggest that this core field acceleration pulse is the relevant phenomenon to be investigated from the point of view of core dynamics, rather than the jerks themselves. Citation: Chulliat, A., E. Thebault, and G. Hulot (2010), Core field acceleration pulse as a common cause of the 2003 and 2007 geomagnetic jerks, Geophys. Res. Lett., 37, L07301, doi: 10.1029/2009GL042019.