We have used very high-cadence (sub-minute) observations of the solar mean magnetic field (SMMF) from the Birmingham Solar Oscillations Network (BiSON) to investigate the morphology of the SMMF. The observations span a period from 1992 to 2012, and the high-cadence observations allowed the exploration of the power spectrum up to frequencies in the mHz range. The power spectrum contains several broad peaks from a rotationally modulated (RM) component, whose linewidths allowed us to measure, for the first time, the lifetime of the RM source. There is an additional broadband, background component in the power spectrum which we have shown is an artefact of power aliasing due to the low fill of the data. The sidereal rotation period of the RM component was measured as 25.23 ± 0.11 d and suggests that the signal is sensitive to a time-averaged latitude of ∼12°. We have also shown the RM lifetime to be 139.6 ± 18.5 d. This provides evidence to suggest that the RM component of the SMMF is connected to magnetic flux concentrations (MFCs) and active regions (ARs) of magnetic flux, based both on its lifetime and location on the solar disc.

中文翻译：

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太阳平均磁场内的寿命和旋转

我们使用来自伯明翰太阳振荡网络 (BiSON) 的太阳平均磁场 (SMMF) 的非常高频率（亚分钟）观测来研究 SMMF 的形态。观测时间跨度为 1992 年至 2012 年，高频率观测允许探索高达 mHz 范围内频率的功率谱。功率谱包含来自旋转调制 (RM) 组件的几个宽峰，其线宽允许我们首次测量 RM 源的寿命。功率谱中还有一个额外的宽带背景分量，我们已经证明这是由于数据填充量低而导致的功率混叠伪影。RM 分量的恒星自转周期测量为 25.23 ± 0。11 d，表明信号对~12°的时间平均纬度敏感。我们还显示 RM 寿命为 139.6 ± 18.5 d。这提供了证据表明 SMMF 的 RM 分量与磁通量浓度 (MFC) 和磁通量的有效区域 (AR) 相关，这取决于其寿命和在太阳盘上的位置。