Time‐independent and time‐dependent behaviour of high‐latitude flux bundles at the core‐mantle boundary
Time‐independent and time‐dependent behaviour of high‐latitude flux bundles at the core‐mantle boundary
复制标题
核幔边界高纬度通量束的时间无关和时间相关行为
DOI：
10.1029/2001gl014543
复制
发表时间：
2002
影响因子：
5.2
通讯作者：
J. Bloxham
中科院分区：
文献类型：
--
作者：
J. Bloxham
使用一个数值发电机模型，我们研究了在过去300年中在地磁场中观察到的准静态高纬度通量束，以及可能在更长的时间内，是否是热核幔相互作用的结果。我们这样做的基础上，在最低地幔地震不均匀性的主导模式的核心-地幔边界的横向热通量的变化。我们发现，时间平均场的通量束排列与过去几百年中观察到的相似。然而，磁场是与时间相关的，磁通束的这种排列并不是磁场在任何时候的特征。
Using a numerical dynamo model, we examine whether quasi‐stationary high latitude flux bundles which are observed in the geomagnetic field over the last 300 years, and possibly over much longer time periods, result from thermal core‐mantle interactions. We do so by imposing lateral heat flux variations at the core‐mantle boundary based upon the dominant pattern of seismic heterogeneity in the lowermost mantle. We find that the time‐averaged field then has a similar arrangement of flux bundles to that observed during the last few hundred years. However, the field is time‐dependent, and this arrangement of flux bundles is not a feature of the field at all times.