Features of the Solar Active Cycles

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The Relation between the Amplitude and the Period of Solar Cycles

The maximum amplitudes of solar activity cycles are found to be well anti-correlated (r = -0.72) with the newly defined solar cycle lengths three cycles before (at lag -3) in 13-month running mean sunspot numbers during the past 190 years. This result could be used for predicting the maximum sunspot numbers. The amplitudes of Cycles 24 and 25 are estimated to be 149.5±27.6 and 144.3±27.6, respectively.     

The Prediction of Maximum Amplitudes of Solar Cycles and the Maximum Amplitude of Solar Cycle 24

We present a brief review of predictions of solar cycle maximum amplitude with a lead time of 2 years or more. It is pointed out that a precise prediction of the maximum amplitude with such a lead-time is still an open question despite progress made since the 1960s. A method of prediction using statistical characteristics of solar cycles is developed: the solar cycles are divided into two groups, a high rising velocity (HRV) group and a low rising velocity (LRV) group, depending on the rising velocity in the ascending phase for a given duration of the ascending phase. The amplitude of Solar Cycle 24 can be predicted after the start of the cycle using the formula derived in this paper. Now, about 5 years before the start of the cycle, we can make a preliminary prediction of 83.2-119.4 for its maximum amplitude.     

太阳总辐照的演化特征分析

太阳总辐照在23和24太阳活动周的显著周期分别为35 d和26 d,进而推断太阳的准旋转周期在23和24太阳活动周也分别为35 d和26 d.太阳总辐照在24周极小期的值可能与蒙德极小期的值相近.在一个太阳旋转周到几个月的时间尺度上,太阳黑子是引起太阳总辐照变化的主要原因,但不是唯一的原因;在几天到一个太阳旋转周的时间尺度上,太阳总辐照的变化与MgⅡ特征指数是不相关的.     

An Analysis of the Variation of Solar Activity

Using the method of Morlet wavelet transform, we analysed the sunspot relative numbers and obtained some meaningful results. The solar activity possesses the periods of 10.7a and 101a, and the period of 10.7a is very prominent. The variation of intensity of the solar activity exhibits certain stages. In 1950 there occurred abrupt changes of climate, and since then the solar activity has become more and more intense. It is predicted that it would be weaker for some time interval in the future.     

对太阳第21周最强烈活动区的分析

太阳第２１周实测到３９８６个活动区，以黑子面积、Ｘ射线耀斑指数、１０．７ｃｍ射电爆发及质子事件等四项指数，从中综合评估出ＡＲ３８０４、ＡＲ４４７４等１６个最强烈活动区。与２２周比较，两周都有在时空分布的相对集中性特征。但２１周集中在４个时段，不如２２周在２个时段集中；２１周出现的５个热点，只有南半球在经度８５°前后的热点，与２２周３个热点之一相似；２１周的整体活动水平略低，在Ｘ射线和质子事件两方面尤为显著低于２２周     

Size-Flux Relation in Solar Active Regions

We present a study of the relationship between integral area and corresponding total magnetic flux for solar active regions. It is shown that some of these relationships are satisfied to simple power laws. Fractal examination showed that some of these power laws can not be justified inside the simple models of stationary magnetic flux tube aggregation. All magnetic fluxes and corresponding areas were calculated using the data measured with the Solar Magnetic Field Telescope of the Huairou Solar Observing Station in Beijing.     

Statistical Characteristics of Sunspot Umbra Oscillations in the Ca Bandtwo

A group of successive evolutionary images of a sunspot were observed on 4th March 2014 at the Ca II H (396.85 nm) line by the telescope on board of the Hinode satellite. The calculated oscillation period of the sample point in the umbra is 149.75 s by using the Jurkevich (JK) method. A proper averaged value of the intensity profile is selected as the steady background radiation, then the distribution of the extreme values of oscillations in the umbra is analyzed by a statistical method. The results show that the valley values follow a normal distribution, while the peak values satisfy a partial normal distribution. The distribution of these extreme values indicates that the 3 min oscillation of the umbra may be caused by the propagation of a traveling wave with a period of about 5 min in the umbra. The variation of light intensity caused by the traveling wave may be proportional to the square of the displacement of the traveling wave, resulting in a 3 min period of the light intensity, which is one half of the period of traveling wave.     

太阳活动周期的小波分析

运用小波技术对太阳射电流量2800 MHz,太阳黑子数和太阳黑子面积数周期进行分析．其结果表明: (1)这3个系列的数据显示最显著的周期是10．69年,其他周期并不明显．(2)小波功率谱给出了全部时间-周期范围的功率谱变化,它显示了在某个周期处于某个时段的局部功率的变化,小波功率谱分析表明,小于1年的周期仅仅在太阳活动最大期附近比较明显．(3)太阳射电2800 MHz,太阳黑子数和太阳黑子面积数的几个周期(10．69年,5．11年, 155．5天)的小波功率谱比较相似,出现峰值的时间相同;曲线的起伏相似,周期越小,曲线起伏的频率越大．     

Prediction of the Beginning of Solar Activity Cycle 24 by the Similar Cycle Method

In this paper, the method of similar cycles is applied to predict the start time of the 24th cycle of solar activity and the sunspot numbers in the later part of the descending phase of cycle 23. According to the characteristic parameters and the morphological characters of the descending phase of cycle 23 and of cycles 9, 10, 11, 15, 17 and 20 (cycles selected as the similar cycles for the descending phase of cycle 23), the start time of cycle 24 is predicted to be in 2007 yr 5 ± 1m, the smoothed monthly mean spot number, 7.1 ± 2.6 and the length of the 23rd cycle, 11.1 yr. These results agree rather well with those stated in Refs.[11] & [12] as well as those of MSFC. Our work shows that the method of similar cycles can well be applied to the long-term prediction of solar activity.     

A New Method to Determine Epochs of Solar Cycle Extrema

A weighted average method is proposed to determine the epochs of solar cycle extrema and hence the solar cycle lengths. Comparing to the previous methods, this method has the advantage that the extremum epochs are easily and uniquely determined.     

A Running Average Method for Predicting the Size and Length of a Solar Cycle

The running correlation coefficient between the solar cycle amplitudes and the max-max cycle lengths at a given cycle lag is found to vary roughly in a cyclical wave with the cycle number, based on the smoothed monthly mean Group sunspot numbers available since 1610. A running average method is proposed to predict the size and length of a solar cycle by the use of the varying trend of the coefficients. It is found that, when a condition (that the correlation becomes stronger) is satisfied, the mean prediction error (16.1) is much smaller than when the condition is not satisfied (38.7). This result can be explained by the fact that the prediction must fall on the regression line and increase the strength of the correlation. The method itself can also indicate whether the prediction is reasonable or not. To obtain a reasonable prediction, it is more important to search.for a running correlation coefficient whose varying trend satisfies the proposed condition, and the result does not depend so much on the size of the correlation coefficient. As an application, the peak sunspot number of cycle 24 is estimated as 140.4±15.7, and the peak as May 2012± 11 months.     

Three Super Active Regions in the Descending Phase of Solar Cycle 23

We analyze the magnetic configurations of three super active regions, NOAA 10484, 10486 and 10488, observed by the Huairou Multi-Channel Solar Telescope (MCST) from 2003 October 18 to November 4. Many energetic phenomena, such as flares (including a X-28 flare) and coronal mass ejections (CMEs), occurred during this period. We think that strong shear and fast emergence of magnetic flux are the main causes of these events. The question is also of great interest why these dramatic eruptions occurred so close together in the descending phase of the solar cycle.     

A Study of the Periodic Variations of Solar Magnetic Fields During Maxima and Minima of Solar Activity

By using the solar magnetic ?eld data of Wilcox Observatory from 1975 to 2010, the short-time periodicities of solar mean magnetic ?elds during solar maximum and minimum years are analyzed. The results reveal that the solar magnetic ?elds mainly exhibit the approximate periods of 9 d, 13 d, and 27 d. During maximal solar activity the period about 27 d is most conspicuous, while during minimal solar activity the most evident period is approximately 13.5 d (except the solar minimum in the years 1984-1986). These results imply that solar active regions exhibit evidently different distributions in the periods of maxima and minima of solar activity.     

2003年10月22日太阳活动区AR0484内日浪事件的研究

利用色球Hα、TRACE／WL、SOHO／EITEuV单色像观测资料及SOHO／MDI光球磁场观测资料，对2003年10月22日太阳活动区AR0484内发生的日浪事件进行了研究．发现：(1)在Ha线心观测上，日浪包含有亮、暗2个分量，这2个分量先后出现而且并不共空间．日浪的亮分量与UV和EUV波段上观测到的喷发具有较好的同时性和共空间性．(2)日浪喷发物质沿着EUV环运动。(3)在光球层，日浪足根处的黑子和磁场有明显的变化．这些观测结果支持日浪的磁重联模型。     

太阳活动的不对称性研究

从三方面概述了太阳活动不对称的进展;不对称性的特征及其演化行为、周期性和可能的解释。太阳活动的南北半球及东西半球人发布是不均匀的,且在南北半球上分布不对称;但目前仍无法确定东西半球分布不对称。在众多的解释太阳活动不对称的理论中,没有一种理论被广泛接受。对将来开展太阳活动不对称性研究工作提出了一些看法。     

Verification of a Similar Cycle Prediction for the Ascending and Peak Phases of Solar Cycle 23

Reviews of long-term predictions of solar cycles have shown that a precise prediction with a lead time of 2 years or more of a solar cycle remains an unsolved problem. We used a simple method, the method of similar cycles, to make long-term predictions of not only the maximum amplitude but also the smoothed monthly mean sunspot number for every month of Solar Cycle 23. We verify and compare our prediction with the latest available observational results.     

The Effect of Solar Activity on the Annual Precipitation in the Beijing Area

Using continuous wavelet transform, we examine the relationship between solar activity and the annual precipitation in the Beijing area. The results indicate that the annual precipitation is closely related to the variation of sunspot numbers, and that solar activity probably plays an important role in influencing the precipitation on land.     

太阳光球磁通量南北不对称性研究

运用统计方法系统研究了1978-2002年太阳光球磁通量南北不对称性变化特征，发现其与太阳活动周有关．不对称值在太阳活动极小年要明显高于太阳活动极大年，并且磁通量变化总是由上升段的北半球占优逐渐过渡到下降段的南半球占优．另外运用小波变换方法详细讨论了这种不对称性变化可能存在的周期信息．