We studied temporal variation of the differential rotation and poleward meridional circulation during solar cycle 24 using the magnetic element feature tracking technique. We used line-of-sight magnetograms obtained using the helioseismic and magnetic imager aboard the Solar Dynamics Observatory from May 01, 2010 to March 26, 2020 (for almost the entire period of solar cycle 24, Carrington rotation from 2096 to 2229) and tracked the magnetic element features every 1 h. We also estimated the differential rotation and poleward meridional flow velocity profiles. The observed profiles are consistent with those of previous studies on different cycles. Typical properties resulting from torsional oscillations can also be observed from solar cycle 24. The amplitude of the variation was approximately ±10 m s $$^{-1}$$ - 1 . Interestingly, we found that the average meridional flow observed in solar cycle 24 is faster than that observed in solar cycle 23. In particular, during the declining phase of the cycle, the meridional flow of the middle latitude is accelerated from 10 to 17 m s $$^{-1}$$ - 1 , which is almost half of the meridional flow itself. The faster meridional flow in solar cycle 24 might be the result of the weakest cycle during the last 100 years.

中文翻译：

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太阳活动周期中太阳微分旋转和子午流的太阳周期相关变化 24

我们使用磁元素特征跟踪技术研究了太阳活动周期 24 期间微分旋转和极向子午环流的时间变化。我们使用了从 2010 年 5 月 1 日到 2020 年 3 月 26 日（几乎在整个太阳活动周期 24 期间，卡林顿自转从 2096 年到 2229 年）使用太阳动力学天文台上的日震和磁成像仪获得的视线磁力图，并进行了跟踪磁性元件每 1 小时显示一次。我们还估计了差分旋转和极向子午流速度分布。观察到的曲线与先前对不同周期的研究一致。从太阳周期 24 也可以观察到由扭转振荡引起的典型特性。变化的幅度约为 ±10 ms $$^{-1}$$ - 1 。有趣的是，我们发现在太阳活动周期 24 观测到的平均子午流比在太阳活动周期 23 观测到的要快。特别是在周期的下降阶段，中纬度的子午流从 10 ms 加速到 17 ms $$^ {-1}$$ - 1 ，几乎是子午流本身的一半。太阳活动周期 24 中更快的子午流可能是过去 100 年来最弱周期的结果。