Effect of Morphological Asymmetry between Leading and Following Sunspots on the Prediction of Solar Cycle Activity
Effect of Morphological Asymmetry between Leading and Following Sunspots on the Prediction of Solar Cycle Activity
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DOI：
10.3847/1538-4357/ab3b04
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发表时间：
2019-08
期刊：
影响因子：
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通讯作者：
H. Iijima;Hideyuki Hotta;S. Imada
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文献类型：
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作者：
H. Iijima;Hideyuki Hotta;S. Imada
前导和后继太阳黑子的形态不对称是太阳表面的一个众所周知的特征。在表面磁场大规模演化的背景下，不对称性被认为仅具有可忽略不计的影响。利用表面通量输运（SFT）模型，我们表明前导和跟随太阳黑子的形态不对称性对太阳表面大尺度磁场的演化具有重大影响。通过评估每个双极磁区（BMR）的形态不对称性的影响，我们观察到，在 BMR 模型中引入不对称性显着降低了对极地磁场的贡献，特别是对于大型和高纬度的 BMR。强烈不对称的 BMR 甚至可以逆转规则的极地场形成。基于观测到的太阳黑子记录的 SFT 模拟表明，形态不对称的引入使观测到的轴向偶极子强度的均方根差异减小了 30%~40%。这些结果表明，前导和跟随太阳黑子的形态不对称性对太阳周期预测有显着影响。
The morphological asymmetry of leading and following sunspots is a well-known characteristic of the solar surface. In the context of the large-scale evolution of the surface magnetic field, the asymmetry has been assumed to have only a negligible effect. Using the surface flux transport (SFT) model, we show that the morphological asymmetry of leading and following sunspots has a significant impact on the evolution of the large-scale magnetic field on the solar surface. By evaluating the effect of the morphological asymmetry of each bipolar magnetic region (BMR), we observe that the introduction of asymmetry to the BMR model significantly reduces the contribution to the polar magnetic field, especially for large and high-latitude BMRs. Strongly asymmetric BMRs can even reverse regular polar field formation. The SFT simulations based on the observed sunspot record show that the introduction of morphological asymmetry reduces the root-mean-square difference from the observed axial dipole strength by 30%–40%. These results indicate that the morphological asymmetry of leading and following sunspots has a significant effect on the solar cycle prediction.