Max-Planck-Institut für Sonnensystemforschung, Göttingen 37077, Germany.
Science. 2015 Mar 20;347(6228):1333-5. doi: 10.1126/science.1261470.
Sunspots and the plethora of other phenomena occurring in the course of the 11-year cycle of solar activity are a consequence of the emergence of magnetic flux at the solar surface. The observed orientations of bipolar sunspot groups imply that they originate from toroidal (azimuthally orientated) magnetic flux in the convective envelope of the Sun. We show that the net toroidal magnetic flux generated by differential rotation within a hemisphere of the convection zone is determined by the emerged magnetic flux at the solar surface and thus can be calculated from the observed magnetic field distribution. The main source of the toroidal flux is the roughly dipolar surface magnetic field at the polar caps, which peaks around the minima of the activity cycle.
太阳黑子和其他许多在太阳活动 11 年周期中发生的现象，是太阳表面出现磁通量的结果。观测到的双极黑子群的方向表明，它们起源于太阳对流包层中的环形（沿方位定向）磁通量。我们表明，通过对流区一个半球内的差异旋转产生的净环形磁场通量由太阳表面出现的磁通量决定，因此可以根据观测到的磁场分布来计算。环形通量的主要来源是极区的大致偶极子表面磁场，它在活动周期的极小值附近达到峰值。
