Wavelet analysis of sunspot relative numbers

The time series of the monthly smoothed sunspot numbers in 1749-2000 is analyzed with the wavelet.The result shows that besides the known time-variation of the period about 11 years, other main periods of the sunspot numbers, such as the periods of about 100 years and so on,vary with time. We suggest that the time-variation of the main periods is the manifestation of the complex variation of sunspot numbers. It is significant to make a thorough study of the character and mechanism of the time-variation of the periods for proving prediction of sunspot numbers, especially for understanding the variation process of sunspot numbers.     

Long-term variations of solar activity

Using the Lomb-Scargle periodogram we analyzed two sunspot series: the one over the past 11000 years at the 10-year interval based upon the survey data of 14C concentration in tree-rings, recon- structed by Solanki et al.; and the sunspot number over the past 7000 years, derived from geomagnetic variations by Usoskin et al. We found the periods and quasi-periods in solar activity, such as about 225, 352, 441, 522 and 561 a, and near 1000 and 2000 a. An approach of wavelet transform was applied to check the two sunspot time series, with emphasis on investigating time-varying characteristics in the long-term fluctuations of solar activity. The results show that the lengths and amplitudes of the periods have changed with time, and large variations have taken place during some periods.     

Lons-term variations of solar activity

Using the Lomb-Scargle periodogram we analyzed two sunspot series： the one over the past 11000 years at the 10-year interval based upon the survey data of ^14C concentration in tree-rings, reconstructed by Solanki et al.; and the sunspot number over the past 7000 years, derived from geomagnetic variations by Usoskin et al. We found the periods and quasi-periods in solar activity, such as about 225, 352, 441,522 and 561 a, and near 1000 and 2000 a. An approach of wavelet transform was applied to check the two sunspot time series, with emphasis on investigating time-varying characteristics in the long-term fluctuations of solar activity. The results show that the lengths and amplitudes of the periods have changed with time, and large variations have taken place during some periods.     

Phase relationship between the relative sunspot number and solar 10.7 cm flux

A range of analysis approaches,namely continuous wavelet,cross wavelet,and wavelet coherence analyses,are employed to clarify the phase relationship between the smoothed monthly mean sunspot number and solar 10.7 cm flux(F10.7).Analysis shows that there is a region of high spectral power sitting across the Schwabe cycle belt,where the two time series are in phase.However,analysis of the cross-wavelet transform and wavelet coherence unveils asynchronous behavior featured with phase mixing in the high-frequency components of sunspot activity and solar F10.7,which may explain the different activity properties of the photosphere and corona on a short time scale.     

太阳黑子数与电离层TEC的相关性分析

为了研究电离层TEC与太阳黑子数在短周期上的相关关系,采用1997～2004年的太阳黑子数资料与同期厦门站的电离层TEC数据,利用小波功率谱分析的方法提取3个尺度的短周期,并利用小波相干谱的方法重点研究了两者在278 d周期上的相关性。研究表明：太阳黑子数和电离层TEC主要存在准27 d、准半年周期以及年周期等短周期,而且电离层TEC和太阳黑子在准27 d周期上有良好的相关性。位相计算表明,电离层TEC的变化滞后于太阳黑子数2～3 d。厦门地区TEC与太阳活动的相关性在夏季比其他季节更强,这对提高该地区电离层TEC预报精度有很大意义。     

1644-1911年云贵地区旱涝灾害的周期特征以及对太阳黑子活动的响应

为探究历史时期气候灾害特征及影响因子,建立了清代1644-1911年云贵地区的旱涝指数序列,采用滑动t检验和总体经验模态分解（EEMD）分析了清代云贵地区旱涝灾害的突变特征和多时间尺度周期性特征,研究表明：清代云贵地区旱涝指数整体较平稳,呈现先明显增加后减少,然后趋于平稳,清末又明显增加的趋势,旱涝指数序列具有多个跃变点,且具有显著的2.8 a和6.6 a年际周期,13.0 a和40.2 a的年代际周期.由旱涝灾害年次和年均县次比的空间分布图发现,其具有同旱同涝的空间分布特征.由于13.0 a的周期与太阳黑子相对数序列的周期接近,故采用交叉小波分析着重探究了太阳黑子活动对云贵地区旱涝变化的影响,发现云贵地区旱涝指数序列同太阳黑子相对数序列在3~6 a的时间尺度具有强凝聚性共振周期.     

太阳活动峰年和谷年期间黑子群与耀斑的统计分析

基于NOAA/SWPC公布的太阳活动数据,我们选取第24太阳活动峰年附近的12个连续月份(2011年7月至2012年6月)和第23太阳活动周谷年附近的12个连续月份(2005年7月至2006年6月),统计了这两段时间中太阳黑子群和耀斑的活动规律,并根据时间、黑子群分布纬度、寿命和磁场类型等对峰年和谷年进行了详细分析和比较,主要结论如下所述.(1)黑子群数随时间的变化在峰年和谷年均比较随机,峰年期间黑子数比谷年增多1.5倍左右.耀斑爆发与黑子群活动具有良好的相关性,但峰年期间存在某个月份耀斑数很少的现象,而谷年期间存在某个月份耀斑数集中增多的现象.(2)无论峰年还是谷年,δ类型黑子群的耀斑产率(耀斑总数与黑子群总数之比)最大,但β型黑子群产生的耀斑爆发最多.耀斑产率与磁场类型有密切关系,但与其所处太阳活动周中的阶段无关.(3)黑子群和耀斑的纬度分布的南北不对称性,以X级耀斑最为显著.峰年较谷年的耀斑数增加主要集中在C级和M级.(4)耀斑产率同黑子群寿命具有良好的相关性,但黑子群的数目同它们的寿命之间没有明显的规律.     

A method to predict amplitude and date of maximum sunspot number

A method to predict the amplitude and date of the maximum sunspot number is introduced. The regression analysis of the relationship between the variation rate of monthly sunspot numbers in the initial stage of solar cycles and both of the maximum and the time-length of ascending period of the cycle showed that they are closely correlative. In general, the maximum will be larger and the ascending period will be shorter when the rate is larger. The rate of sunspot numbers in the initial 2 years of the 23rd cycle is thus analyzed based on these grounds and the maximum of the cycle is predicted. For the smoothed monthly sunspot numbers, the maximum will be about 139.2±18.8 and the time-length of ascending period will be about 3.31±0.42 years, that is to say, the maximum will appear around the spring of the year 2000. For the mean monthly ones, the maximum will be near 170.1±22.9 and the time-length of ascending period will be about 3.42±0.46 years, that is to say, the appearing date of the maximum will be later.     

用数字信号处理方法分析太阳黑子活动的周期性

太阳黑子数是描述太阳活动水平的主要指标,太阳活动直接影响人类健康和人类赖以生存的环境—地球;依据数字信号处理原理,采用多种处理方法,分析处理了1770-1869年的太阳黑子数年均值;得出了太阳黑子存在11-12年周期的结论.结果表明该方法对研究太阳活动规律乃至天体规律是有效的.     

Time-variation of the near 5-month period of sunspot numbers

The variation of the near 5-month period of sunspot numbers is discussed on the basis of the wavelet transform of the daily sunspot number series in the 14th—22nd solar cycles. The result shows that the period exists in every cycle and its energy density (amplitude) is comparatively large in the peak section of the cycle. In the distinct cycle, the length and intensity of the period is different, which means that the period varies with time. The near 25-day period is also analyzed and it is found to be timevariable and even not very stable in the peak section of the cycle. The variations of the two periods show that the near 5-month period should not be simply regarded as the multiples of the near 25-day period.     

太阳磁场磁性指数对东亚夏季风的影响

根据太阳黑子相对数建立了1850~2011年太阳磁场磁性指数序列,并分析了其变化规律与特征,应用SLP和NCEP/NCAR资料归一化得出相对应年代的东亚夏季风指数以及东亚地区的海陆温度变化趋势,基于Morlet小波分析法对太阳磁场磁性指数和东亚夏季风的相关性做了相应的分析,并在此基础上分析了太阳活动影响东亚夏季风的途径。结果表明:海陆温差的变化是太阳活动影响东亚夏季风的主要途径;从1972年开始东亚地区海陆温差大幅度减小,随之东亚夏季风也存在较大幅度的减弱并与太阳磁场磁性指数呈负相关;且太阳磁场磁性指数与东亚夏季风存在相同的22年和40年层次周期。     

Cross wavelet analysis of the relationship between total solar irradiance and sunspot number

Using the observational data of total solar irradiance (TSI) from 1976 to 2006, the evolution of total solar irradiance and the rela-tionship between TSI and sunspot number (SSN) have been analyzed with the wavelet technique. The results of the continuous wavelet transform (CWT) indicate that the TSI has multi-scale evolutionary characteristics. In the low frequency band, the TSI and SSN show similar variation with a significant and steady oscillation period from 8 to 11.4 a. While in the high frequency band, only around the maximum time of solar cycles, both the TSI and SSN present a significant intermittent oscillation period from 2 to 6 months. The results of the cross wavelet transform indicate that there is significant in-phase resonance oscillation between the TSI and SSN in 8–11.4 a band, where the variation of the SSN is 2 months ahead of that of TSI. Those results confirm the SSN as the primary cause for TSI’s periodic variation in the time scale of 8–11.4 a. However for the 2–6 month band, significant resonance periodicity is observed only within the maximum time of solar cycle, but the phase relationship between the TSI and SSN is unsteady. Finally, a reliable TSI monthly series from 1878 to 1975 is reconstructed and tested.     

酒泉市肃州区近55a的气候变化特征、突变与周期分析

利用1951-2005年酒泉市肃州区气象观测站平均气温和降水量资料,运用多年趋势线、5a滑动趋势线、Mann-Kendall突变检验、滑动t检验和小波分析等方法对肃州区气候变化的主要特征、突变特点和周期特征进行分析.结果表明:近55a来,肃州区年平均气温呈明显上升趋势,年降水量呈微弱减少趋势.年平均气温和年平均降水量均有明显的突变,前者突变年份在1992年,后者突变年份较多,以1995年最显著.Morlel小波及其功率谱分析表明,年平均气温和年平均降水量的变化周期具有多尺度、多层次和多分辨的特性结构.其中,年平均气温存在21a和7.14 a(P≤0.16)的优势周期,年降水量存在21a,10.87a,9.09a和6.41a(P≤0.1)的显著周期,且中长期优势周期一致,中短周期不同.     

煤和瓦斯突出与太阳黑子活动的关系

本文在对鱼田堡煤矿和白皎煤矿历年突出资料进行统计和处理的基础上，研究了煤和瓦斯突出与太阳黑子活动的关系。发现煤和瓦斯突出年分布具有周期性，并与太阳黑子活动周期有关，讨论了太阳黑子活动影响煤和瓦斯突出的机理，最后就如何利用太阳，黑子活动周期预防煤和瓦斯突出提出了方法和建议。     

Has the maximum of Solar Cycle 23 appeared?

In this note, we define firstly a compositive parameter as an index describing the level of solar activity in a solar cycle. The parameter is derived from a combination of the smoothed monthly mean sunspot number with the fluctuation of the associated monthly mean sunspot numbers to the smoothed one. Then, a method is developed for estimating the time of the appearance of a solar maximum based on the conception of similar cycles. An application of the method to the 23rd solar cycle shows that the maximum of the cycle should have appeared in the period from April to August 2000, and the descending phase of Cycle 23 has come.     

BL Lac天体OJ 287的光学光变周期研究

从大量文献中收集了BL Blac天体OJ 287光学V波段30多年的观测数据,分析了光变周期。用两种不同的方法分析周期光变(功率谱方法及小波分析法),发现其光变曲线中存在7.06年和13.5年的周期,预期2020年秋将再次爆发。     

New evidence for possible impact of solar activity on long-term fluctuation of the earth rotation

The long-term fluctuation of the Schwabe period (LSP) of sunspots number (SSN) has been found to have high correlation with the variation of the length-of-day (LOD) in low frequency by using the data of smoothed monthly mean SSN during 1818–1999 and the method of wavelet transform. Analyses indicate that the maximum correlation coefficient between the series of LSP and LOD during 1892–1997 is about 0.9, with a time lag of about 5 years for the LOD related to the LSP. Though the maximum correlation coefficients between the LSP and the other two LOD series (1818–1997) reduce to about 0.4, they remain over the thresholds of 95% confidence level. This suggests new evidence for possible impact of solar activity on the long-term fluctuation of the earth rotation.     

太阳黑子活动对滇中地区气候演变特征的影响

对云南昆明地区近４０ａ的气温及降水资料和太阳黑子相对数资料进行了初步的分析与研究,结果显示：云南滇中地区气候演变与太阳活动准１１ａ振荡和准２ａ振荡之间有一定的联系。     

应用数据挖掘技术的短期太阳耀斑预报模型

为了进一步探讨太阳耀斑与太阳黑子参量的关系,本文采集了大规模的活动区黑子数据,统计其与耀斑发生的产率关系,应用得到的拟和公式对原始数据计算得到规范化后的数据集.在此基础上使用数据挖掘技术对黑子耀斑数据建立决策树模型和建立分类规则,具体描述了黑子数据和太阳耀斑之间的相关性.最后应用这两种技术对活动区未来48h是否爆发耀斑给出了预报,预报结果具有较高的准确率和较低的虚报率.     

太阳活动对天气气候的影响

太阳活动强紫外线、X射线等短波射线强,对高层大气的影响强,对对流层大气影响不大,对天气和气候的作用微小;而太阳活动强时可见光、红外光等长波辐射减弱,对地球热辐射减少,使大气环流减慢。反之太阳活动弱时,使大气环流加快,两者从而使洋流发生改变,大气环流和洋流的改变,对短期天气影响不立即显现,而对于气候则显示出来。