Is the Hemispheric Asymmetry of Monthly Sunspot Area an Irregular Process with Long-Term Memory?
Is the Hemispheric Asymmetry of Monthly Sunspot Area an Irregular Process with Long-Term Memory?
复制标题
每月太阳黑子面积的半球不对称是一个具有长期记忆的不规则过程吗？
DOI：
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
B. B. Karak
中科院分区：
文献类型：
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作者：
R. Das;Aparup Ghosh;B. B. Karak
太阳黑子周期的半球不对称性是太阳的一个真实的特征。然而，它的起源仍然没有得到很好的理解。在这里，我们进行非线性时间序列分析的太阳黑子面积（和数量）的不对称性，以探索其动力学。通过测量黑子面积不对称性的关联维数，我们得出结论，在数据中不存在奇怪的吸引子。进一步计算Higuchi维数，我们得出结论，半球的不对称性在很大程度上是由随机噪声。然而，赫斯特指数的行为表明，时间序列并不完全由无记忆的随机噪声，而是有一个长期的持续性，它可以超过两个太阳周期。因此，我们的研究表明，太阳黑子周期的半球不对称性主要是由于太阳发电机中的一些不规则过程造成的。太阳活动周期不对称性的长期存在表明太阳磁场在对流区具有一定的记忆性。
The hemispheric asymmetry of the sunspot cycle is a real feature of the Sun. However, its origin is still not well understood. Here we perform nonlinear time series analysis of the sunspot area (and number) asymmetry to explore its dynamics. By measuring the correlation dimension of the sunspot area asymmetry, we conclude that there is no strange attractor in the data. Further computing Higuchi’s dimension, we conclude that the hemispheric asymmetry is largely governed by stochastic noise. However, the behaviour of Hurst exponent reveals that the time series is not completely determined by a memory-less stochastic noise, rather there is a long-term persistence, which can go beyond two solar cycles. Therefore, our study suggests that the hemispheric asymmetry of the sunspot cycle is predominantly originated due to some irregular process in the solar dynamo. The long-term persistence in the solar cycle asymmetry suggests that the solar magnetic field has some memory in the convection zone.