Periodic Variations of Solar Corona Index during 1939–2020
Periodic Variations of Solar Corona Index during 1939–2020
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DOI：
10.3390/universe8070375
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发表时间：
2022-07
期刊：
影响因子：
2.9
通讯作者：
Rui Tang;Y. Fei;Chun Li;Wen Liu;X. Tian;Z. Wan
中科院分区：
文献类型：
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作者：
Rui Tang;Y. Fei;Chun Li;Wen Liu;X. Tian;Z. Wan
太阳磁指示器的周期性行为可能为理解太阳动态过程提供线索。结合Lomb-Scargle周期图，通过多锥同步压缩变换进行频率和时间的集中，研究了1939年1月1日至2020年8月31日期间修正日冕指数的周期变化。主要结果如下：（1）在太阳周期19至23期间，修正日冕指数的Schwabe循环运行，其长度在10.5之间变化。 和11-yr，长度平均值为10.67-yr，标准差为0.14-yr。 (2)里格型周期主要分布在120～200天范围内。此外，周期 18 至 24 期间的周期变化有些间歇性，周期 21 和 22 中的功率最高，而周期 23 和 24 中的功率要低得多。 (3) 对于旋转周期，时间变化表现出高度间歇性的模式，为不对称分布，其第 25、50 和 75 分位数分别为 26、27.8 和 31 天。 (4)还检测到其他中期周期，平均周期长度为8.07年、5.44年、3.42年、2.3年和1.01年。
Periodic behaviors of solar magnetic indicators might provide a clue for the understanding of solar dynamic processes. Combining with a Lomb–Scargle periodogram, the concentration of frequency and time via a multitapered synchrosqueezed transform is applied to investigate the periodic variations of modified coronal index for the time interval from 1 January 1939 to 31 August 2020. The main results are as follows: (1) During solar cycles 19 to 23, the Schwabe cycle of the modified coronal index is operating with its length variating between 10.5 and 11-yr, and the average value of length is 10.67-yr with standard deviation of 0.14-yr. (2) The Rieger-type periods are mainly distributed in a range from 120 to 200 days. In addition, the periods vary somewhat intermittently during cycles 18 to 24, which are operating with the highest power in cycles 21 and 22 while the power is much lower in cycles 23 and 24. (3) For rotation periods, the temporal variation exhibits a highly intermittent pattern as an asymmetrical distribution with its 25th, 50th, and 75th quantile of 26, 27.8, and 31-day, respectively. (4) Other mid-range periods are also detected with an average period length of 8.07, 5.44, 3.42, 2.3, and 1.01-yr.