论文标题
在太阳能最小值期间子午血浆流动驱动的弱磁循环持续存在的证据
Evidence of persistence of weak magnetic cycles driven by meridional plasma flows during solar grand minima phases
论文作者
论文摘要
长期的黑子观测和太阳活动的重建表明，太阳有时会滑入称为太阳大小的静态阶段，这种动力学尚不清楚。我们使用通量传输发电机模型，在平均场和Babcock-Leighton Poloidal场源项中具有随机波动，以模拟太阳周期的可变性。我们的长期模拟检测到太阳大最小发作期间极地田地的逐渐衰变。尽管常规的主动区域出现停止，损害了Babcock-Leighton机制，但在平均场$α$效应的最小阶段中，磁性弱较弱。令人惊讶的是，在这些阶段期间，周期性极地幅度调制持续存在。对模拟极通量时间序列的光谱分析表明，11年周期变得不那么突出，而在大小最小发作中，高频周期和周期大约22年。对长期太阳能开放通量观测的分析似乎与这一发现一致。通过数值实验，我们证明了极小最小值发作中极性场和主要频率中周期性振幅调制的持久性受到子午等离子体流动的速度控制 - 这似乎是时钟。
Long-term sunspot observations and solar activity reconstructions reveal that the Sun occasionally slips into quiescent phases known as solar grand minima, the dynamics during which is not well understood. We use a flux transport dynamo model with stochastic fluctuations in the mean-field and Babcock-Leighton poloidal field source terms to simulate solar cycle variability. Our long-term simulations detect a gradual decay of the polar field during solar grand minima episodes. Although regular active region emergence stops, compromising the Babcock-Leighton mechanism, weak magnetic activity continues during minima phases sustained by a mean-field $α$-effect; surprisingly, periodic polar field amplitude modulation persist during these phases. A spectral analysis of the simulated polar flux time series shows that the 11-year cycle becomes less prominent while high frequency periods and periods around 22 years manifest during grand minima episodes. Analysis of long-term solar open flux observations appears to be consistent with this finding. Through numerical experimentation we demonstrate that the persistence of periodic amplitude modulation in the polar field and the dominant frequencies during grand minima episodes are governed by the speed of the meridional plasma flow -- which appears to act as a clock.
