用物理神经网络研究太阳磁场非线性抑制效应,揭示强弱周期交替的机制。
Investigating Nonlinear Quenching Effects on Polar Field Buildup in the Sun Using Physics-Informed Neural Networks
- 引入物理约束神经网络求解太阳表面磁通输运方程,融合非线性抑制机制。
- 发现倾角抑制随扩散率增强而变强,纬度抑制主导对流主导情形,误差显著更低。
- 揭示了纬度与倾角抑制协同作用可自然解释太阳周期偶数奇数交替现象。
太阳发电机依赖于极向磁场通过非线性反馈机制(如倾角抑制TQ和纬度抑制LQ)的再生过程,这些机制决定太阳极区磁场积累及未来太阳周期的强度。本文采用物理信息神经网络(PINN)求解表面磁通输运(SFT)方程,将物理约束直接嵌入神经网络框架。通过系统调整输运参数,分离出TQ与LQ对极偶极子累积的相对贡献。以残余偶极矩为周期间放大诊断指标,发现TQ抑制随扩散率增加而增强,而LQ在对流主导区域占主导地位。ΔD_LQ/ΔD_TQ比值呈现与发电机有效性范围成反平方关系的平滑变化,优于以往经验拟合,精度更高、散点更少。结果还表明,无需显式衰减项,因训练过程已隐含物理一致性。相比传统1维SFT模型,PINN框架误差更低,更稳健地恢复非线性趋势。研究揭示,LQ与TQ的非线性相互作用可自然产生弱-强周期交替,为观测到的偶-奇周期调制提供物理解释。该工作展示了PINN在太阳周期预测中作为高精度、高效且物理一致工具的巨大潜力。
原文摘要 · Abstract (English)
The solar dynamo relies on the regeneration of the poloidal magnetic field through processes strongly modulated by nonlinear feedbacks such as tilt quenching (TQ) and latitude quenching (LQ). These mechanisms play a decisive role in regulating the buildup of the Sun's polar field and, in turn, the amplitude of future solar cycles. In this work, we employ Physics-Informed Neural Networks (PINN) to solve the surface flux transport (SFT) equation, embedding physical constraints directly into the neural network framework. By systematically varying transport parameters, we isolate the relative contributions of TQ and LQ to polar dipole buildup. We use the residual dipole moment as a diagnostic for cycle-to-cycle amplification and show that TQ suppression strengthens with increasing diffusivity, while LQ dominates in advection-dominated regimes. The ratio $ΔD_{\mathrm{LQ}}/ΔD_{\mathrm{TQ}}$ exhibits a smooth inverse-square dependence on the dynamo effectivity range, refining previous empirical fits with improved accuracy and reduced scatter. The results further reveal that the need for a decay term is not essential for PINN set-up due to the training process. Compared with the traditional 1D SFT model, the PINN framework achieves significantly lower error metrics and more robust recovery of nonlinear trends. Our results suggest that the nonlinear interplay between LQ and TQ can naturally produce alternations between weak and strong cycles, providing a physical explanation for the observed even-odd cycle modulation. These findings demonstrate the potential of PINN as an accurate, efficient, and physically consistent tool for solar cycle prediction.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。