标题： 太阳次表层纬向流动在分布式剪切巴克利-莱顿发电机中的最小作用 显示英文标题

标题： Minimal Roles of Solar Subsurface Meridional Flow in the distributed-shear Babcock-Leighton Dynamo

摘要： 地下的经向流动长期以来被认为是在驱动太阳周期中的关键因素。 具体而言，急流层中的赤道返回流动被广泛认为是形成太阳黑子蝴蝶图的根源，并在通量传输发电机（FTD）模型框架内决定太阳周期的长度。 我们的目标是研究地下的经向流动是否也在最近发展的分布剪切Babcock-Leighton（BL）发电机模型中起重要作用，该模型在对流层内运行，而不是在急流层内。 在分布剪切BL发电机模型中应用了各种经向流动配置，包括一个深层单细胞、一个浅层单细胞和双细胞，以探索驱动蝴蝶图和周期变化的机制。 在分布剪切BL发电机中，地下的经向流动起着最小的作用。 即使存在双细胞经向流动，也可以生成类似太阳的蝴蝶图。 该图是由时间依赖和纬度依赖的环向磁场再生产生的，由纬度依赖的纬度差旋转和表面磁场演化所控制。 周期长度由负责极区磁场生成的表面通量源和传输过程决定，这对应于BL型发电机中的$\alpha$-效应。 周期长度可能对地下的流动幅度表现出不同的依赖性。 分布剪切BL发电机与FTD模型有根本的不同，因为它不依赖于地下的通量传输。 这种区别使分布剪切BL发电机更接近原始的BL发电机和传统的$\alpha\Omega$发电机。 尽管在我们的分布剪切BL发电机中地下的经向流动起着微不足道的作用，但极向表面流动是必不可少的。 显示英文摘要

摘要： The subsurface meridional flow has long been recognized as a critical factor in driving the solar cycle. Specifically, the equatorward return flow in the tachocline is widely believed to be responsible for the formation of the sunspot butterfly diagram and determine the solar cycle period within the framework of flux transport dynamo (FTD) models. We aim to investigate whether the subsurface meridional flow also plays a significant role in the recently developed distributed-shear Babcock-Leighton (BL) dynamo model, which operates within the convection zone, rather than the tachocline. Various meridional flow configurations, including a deep single cell, a shallow single cell, and double cells, are applied in the distributed-shear BL dynamo model to explore the mechanisms driving the butterfly diagram and variations in the cycle period. Subsurface meridional flow plays a minimal role in the distributed-shear BL dynamo. A solar-like butterfly diagram can be generated even with a double-cell meridional flow. The diagram arises from the time- and latitude-dependent regeneration of the toroidal field, governed by latitude-dependent latitudinal differential rotation and the evolution of surface magnetic fields. The cycle period is determined by the surface flux source and transport process responsible for polar field generation, which corresponds to the $\alpha$-effect in the BL-type dynamo. The cycle period may exhibit varying dependence on the amplitude of the subsurface flow. The distributed-shear BL dynamo differs fundamentally from the FTD models, as it does not rely on the subsurface flux transport. This distinction aligns the distributed-shear BL dynamo more closely with the original BL dynamo and the conventional $\alpha\Omega$ dynamo. Although the subsurface meridional flow plays a negligible role in our distributed-shear BL dynamo, the poleward surface flow is essential.