Long-term variations of solar activity  

作　　者：YIN ZhiQiang MA LiHua HAN YanBen HAN YongGang 

机构地区：[1]National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China [2]Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Science Bulletin》2007年第20期2737-2741,共5页

基　　金：Supported by the National Natural Science Foundation of China (Grant No. 10373017)

摘　　要：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.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.

关 键 词：太阳活跃性 太阳黑子 光谱分析 光波传播 

分 类 号：P182[天文地球—天文学]