To study synodic period and its subharmonics, we have utilized hourly average data of solar wind plasma field, geomagnetic index, and galactic cosmic ray intensity along with 5 min average data of selected solar wind field parameters during the recent minimum of Solar Cycle 24. Wavelet analyses of hourly average data reveal 28.1, 13.1, and 6.8 day of sigma in interplanetary magnetic field; 27.1, 13.1, and 9.0 day of plasma speed; 27.1, 13.6, 3.9, and 2.2 day of interplanetary electric field; 27.1, 13.6, 3.8, and 2.2 day of southward component of magnetic field; 26.2, 13.6, 8.6, and 3.0 day of geomagnetic Ap index; and 28.1, 11.0, 9.3, 7.0, and 1.6 day periods of galactic cosmic ray intensity. In addition to these prominent short‐term periods, we have significantly observed 6.6, 3.3, and 1.7 day periods of sigma in interplanetary magnetic field (σ_B); 5.6, 4.2, and 2.2 day of electric field (Ey) and 5.6, 3.3, and 2.4 day of southward component of magnetic field (Bz) in the 5 min average data. During the recent solar minimum, we have observed one solar rotational period and its second, third, fourth, fifth, sixth, seventh, eighth, tenth, eleventh, and twelfth subharmonics. The observed subharmonics of solar rotational period make the current solar minimum very special and noteworthy to study.

中文翻译：

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最小太阳周期24/25的太阳风等离子体场中的太阳旋转振荡及其次谐波，地磁和宇宙射线强度指示器

为了研究新约周期及其次谐波，我们利用了太阳风等离子体场，地磁指数和银河系宇宙射线强度的每小时平均数据，以及最近太阳周期24最小期间选定太阳风场参数的5分钟平均数据。小波每小时平均数据的分析揭示了星际磁场中sigma的28.1、13.1和6.8天；27.1、13.1和9.0天的血浆速度；27.1、13.6、3.9和2.2天的行星际电场；磁场向南分量的27.1、13.6、3.8和2.2天; 26.2、13.6、8.6和3.0天的地磁Ap指数; 和28.1、11.0、9.3、7.0和1.6天的银河宇宙射线强度。除了这些突出短期期间，我们已经观察到显著在星际磁场（西格玛6.6，3.3和1.7日时段σ_乙）; 平均5分钟数据中的5.6、4.2和2.2天电场（Ey）和5.6、3.3和2.4天磁场南分量（Bz）。在最近的太阳最低峰期间，我们观测到一个太阳旋转周期及其第二，第三，第四，第五，第六，第七，第八，第十，第十一和第十二次谐波。观测到的太阳旋转周期的次谐波使当前的太阳最小值变得非常特殊，值得研究。