A revision to the flux-transport dynamo model for the solar sunspot cycle is proposed and is demonstrated by using the axisymmetric kinematic simulations. The flux-transport dynamo has succeeded to explain the general cyclic behaviors of the sunspots. It has been known, however, that previous models failed to avoid the strong polar surface field and the strong toroidal field at the base in the high latitude, both of which are not consistent with observations. We propose a new regime of the flux-transport dynamo model by assuming an additional intense diffusivity profile near the surface. The surface poloidal field generated by the α effect is transported down to the base of the convection zone not by the meridional flow but by the surface diffusion mainly in the mid-latitude. With a moderate α quenching, this prevents the concentration of the polar surface field and the amplification of the toroidal field at the high latitude. The condition to obtain the proper magnetic field strength near the pole is ηsurf/u 02 × 109 cm, where ηsurf and u 0 are the surface diffusivity and the meridional flow speed, respectively. We also do some parameter studies to ensure the importance of the surface strong diffusivity. In addition, the dependence of the cycle period on free parameters, the speed of meridional flow and the surface diffusivity, is investigated.
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机译：提出了对太阳黑子周期通量发电机模型的修正，并通过轴对称运动学模拟进行了论证。磁通量传递发电机已经成功地解释了黑子的一般循环行为。然而，已知的是，先前的模型未能避免在高纬度地区的强极性表面场和强环形场，这两者均与观测结果不一致。通过在表面附近假设一个额外的强扩散率分布，我们提出了一种通量传递发电机模型的新机制。由α效应产生的表面极向场不是通过子午流而是通过主要在中纬度的表面扩散向下传递到对流区的底部。通过适度的α淬灭，可以防止极性表面场集中和在高纬度时环形场的放大。在磁极附近获得适当磁场强度的条件是ηsurf/ u 0> 2×109 cm，其中ηsurf和u 0分别是表面扩散率和子午流速。我们还进行了一些参数研究，以确保表面强扩散性的重要性。此外，研究了循环周期对自由参数，子午流速度和表面扩散率的依赖性。
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