The geodynamo as a random walker: A view on reversal statistics
The geodynamo as a random walker: A view on reversal statistics
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作为随机游走者的地球发电机：反转统计的观点
DOI：
10.1029/2011jb008931
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发表时间：
2012
影响因子：
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通讯作者：
K. Fabian
中科院分区：
文献类型：
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作者：
V. Shcherbakov;K. Fabian
地磁极性间隔的持续时间序列通常被描述为具有时变反转率的非均匀泊松过程，反映了潜在地球动力过程的非平稳性。这一观点最近受到了挑战，在这里，我们表明，在平坦的电位起伏上发生的随机漫步的首次通过时间统计数据对地磁极性间隔的分布产生了更一致的解释。一种可能的物理解释表明，地球磁场极性时程的稳定性是由外核中统计独立、随机行为的发电机过程的总和控制的。随机漫步假说自然地包括了观测到的超长超时线的出现，它为当前布伦赫斯时线的总持续时间提供了一个新的、相当长的统计估计，预测未来30 Ka内地磁场反转的概率约为5%，我们生活在超过2 Ma的时线中的概率约为30%。
[1] The sequence of durations of the geomagnetic polarity intervals is often described in terms of a nonhomogenous Poisson process with time-dependent reversal rate, reflecting the nonstationarity of the underlying geodynamo process. This view has recently been challenged, and here we show that the first-passage time statistics of random walks taking place on a flat potential relief yields a much more consistent interpretation of the distribution of geomagnetic polarity intervals. A possible physical explanation suggests that the stability of a polarity chron of the Earth's magnetic field is controlled by a sum of statistically independent, randomly behaving, dynamo processes in the outer core. The random-walk hypothesis naturally includes the observed occurrences of very long superchrons, and it provides a new, considerably longer statistical estimate for the total duration of the present Brunhes chron predicting that the probability for a geomagnetic field reversal within the next 30 Ka is ≈5% and the probability that we live in a chron longer than 2 Ma is about 30%.