22-Year periodicity in the solar differential rotation

Using the data on sunspot groups compiled during 1879–1975, we determined variations in the differential rotation coefficientsA andB during the solar cycle. The variation in the equatorial rotation rateA is found to be significant only in the odd numbered cycles, with an amplitude ∼ 0.01 μ rads^-1. There exists a good anticorrelation between the variations of the differential rotation rateB derived from the odd and even numbered cycles, suggesting existence of a ‘22-year’ periodicity inB. The amplitude of the variation ofB is ∼ 0.05 μ rad s^-1.     

江淮梅雨长期变化对太阳活动因子的响应分析

利用美国国家海洋大气局(NOAA)地球物理数据中心(NGDC)1954-2005年太阳黑子数资料,把太阳活动作为地球气候的外强迫因子,采用小波分析和交叉小波分析方法,研究了太阳黑子数与江淮梅雨特征量及西太平洋副热带高压指数的关系。结果表明:太阳活动与江淮梅雨的相关性存在南北差异,北部呈现正相关而南部呈现负相关,且正负相关性在时间序列上保持不变;江淮南部梅雨量与太阳黑子数有稳定的11年共振周期及0.5~1年的相位滞后;西太平洋副热带高压指数与太阳黑子数也有较好的相关关系,说明太阳活动影响地球气候可能存在太阳活动—西太平洋副热带高压—江淮梅雨这样一条过程链。     

中国西部及邻区百年尺度周期的地震活动及其和太阳活动之间的负相关性

利用小波变换分析中国西部及邻区1700年以来M≥7级和M-T图分析1700年以来M≥7.8级地震活动,除了得到和其他学者研究基本一致的几个十年尺度周期结果外,还得到百年左右尺度的地震活动周期结果,再与太阳黑子活动进行比较,发现地震活动与太阳黑子数在百年左右尺度周期上具有负相关性,地震高活动时段对应太阳黑子低值时段.此外...     

Geomorphic and climatic change over the past 12,900 yr at Swiftcurrent Lake, Glacier National Park, Montana, USA

Glaciated alpine landscapes are sensitive to changes in climate. Shifts in temperature and precipitation can cause significant changes to glacier size and terminus position, the production and delivery of organic mass, and in the hydrologic energy related to the transport of water and sediment through proglacial environments. A sediment core representing a 12,900-yr record collected from Swiftcurrent Lake, located on the eastern side of Glacier National Park, Montana, was analyzed to assess variability in Holocene and latest Pleistocene environment. The spectral signature of total organic carbon content (%TOC) since ~ 7.6 ka matches that of solar forcing over 70-500 yr timescales. Periodic inputs of dolomite to the lake reflect an increased footprint of Grinnell Glacier, and occur during periods when sediment sinks are reduced, glacial erosion is increased, and hydrologic energy is increased. Grain size, carbon/nitrogen (C/N) ratios, and %TOC broadly define the termination of the Younger Dryas chronozone at Swiftcurrent Lake, as well as major Holocene climate transitions. Variability in core parameters is linked to other records of temperature and aridity in the northern Rocky Mountains over the late Pleistocene and Holocene.     

太阳黑子本影振荡的周期测量

本影振荡是出现在太阳黑子内的一种常见现象,精确测定它们的振荡周期对于理解黑子的结构和演化有着重要意义。应用快速傅里叶变换方法对空间望远镜HINODE在2007年5月1日观测的活动区AR10953内的黑子本影数据进行了细致的分析,结果发现在该活动区本影内存在一种典型的3 min振荡,其振荡周期约为154 s。     

菲律宾Ms≥7级地震活动规律及未来趋势

通过可公度信息提取方法、蝴蝶结构图、震中时空迁移特征分析近50年菲律宾Ms≥7级中、浅源地震,发现2013、2014年Ms≥7级地震信号强,2014年最强;22年地震主周期明显,其中可划出活跃期与平静期;2012年为菲律宾新地震周期及活跃期的开始;菲律宾Ms≥7级地震震中时空交替迁移规律明显,未来震中向西北部迁移.菲律宾Ms≥7级地震与太阳黑子活动22年双周期关系密切,多发生在太阳黑子活动偶数周期极大年附近及其下降段.目前,太阳黑子活动处于第24周期极大年附近,2013～2014年Ms≥7级地震发生的可能性很大,与可公度分析结果一致.     

Forecasting the Time Series of Sunspot Numbers

Forecasting the solar cycle is of great importance for weather prediction and environmental monitoring, and also constitutes a difficult scientific benchmark in nonlinear dynamical modeling. This paper describes the identification of a model and its use in the forecasting the time series comprised of Wolf’s sunspot numbers. A key feature of this procedure is that the original time series is first transformed into a symmetrical space where the dynamics of the solar dynamo are unfolded in a better way, thus improving the model. The nonlinear model obtained is parsimonious and has both deterministic and stochastic parts. Monte Carlo simulation of the whole model produces very consistent results with the deterministic part of the model but allows for the determination of confidence bands. The obtained model was used to predict cycles 24 and 25, although the forecast of the latter is seen as a crude approximation, given the long prediction horizon required. As for the 24th cycle, two estimates were obtained with peaks of 65±16 and of 87±13 units of sunspot numbers. The simulated results suggest that the 24th cycle will be shorter and less active than the preceding one.     

太阳黑子相对数最强周期的小波分析

利用小波变换,分析了1749年以来每个太阳活动周太阳黑子相对数的最强周期以及第1～22太阳活动周的最强周期. 分析结果表明,在第5和第6个太阳活动周,太阳黑子相对数最强的周期分别为64.67年和69.31年;在第13～15太阳活动周,太阳黑子相对数的最强周期分别为98.02年,105.06年和105.06年. 在第1～22太阳活动周中,太阳黑子相对数最强的周期是128个月,约10.67年,其他太阳活动周的最强周期介于9.29～11.43年之间. 本文最后给出了128个月周期的幅度随时间的变化.     

华南强震相关背景的一些环境因子初探

研究了华南强震与太阳黑子、月相、地球自转和宇宙线GLE事件的关系,发现华南强震在太阳黑子活动周期中分布很不均衡,主要分布在峰段和谷段,这两段占76％,其中谷段占40～50％;由月相分布表明．阴历月份的初四和初十前后,是强震易发生时段,较之其它时段高3倍;此外．文中还给出华南强震与地球自转日长变化,宇宙线CLE事件等相关分析的初步结果。     

How useful is the Waldmeier effect for prediction of a sunspot cycle?

Waldmeier effect [Waldmeier M., 1955. Ergebnisse und Probleme der Sonnenforschung. Second Ed., Leipzig, p. 154] states that the rise-time of a cycle depends upon a single parameter, namely the sunspot number Rz(max) at the maximum. Strong cycles have a steeper rise, while moderate cycles rise more slowly. In this paper, using the past data for sunspot cycles 1–23, these aspects are re-examined. It was noticed that the inverse relationship between Rz(max) and rise-time is discernable only when average patterns obtained by superposition of several cycles (separately for strong and weak cycles) are compared. In individual cycles, considerable deviations from the average patterns can occur (several tens of units of Rz and several months of rise-time). For a study of the relationship of Rz(max) with features in the early part of a cycle, the features chosen were Ro (i.e., Rz(min)) and Rz values Ra, Rb, and Rc, 12, 24 and 36 months, respectively, later than Ro (only 12-monthly running means were used). Ro had a moderate correlation (<0.6) with Rz(max), but Ra, Rb, Rc had better correlations. For hindsight predictions for cycles 18–23, the predictions for cycle 19 was grossly erroneous (observed value almost double of the predicted value). For other cycles, the errors were within 25%. For cycle 24, the Rz monthly values up to March 2008 give 12-month running means centered in June, July, August, September 2007 as 7.6, 6.5, 5.8, 6.1. Thus, though we cannot be absolutely sure yet that Rz(min) for cycle 24 has occurred, a tentative, provisional prediction using Rz(min) (i.e., Ro) as 5.8 is Rz(max)=113±19, i.e., in the range 94–132. This is an upper limit, as Ro value may reduce further in coming months, but most probably not very much. For Ro=5.0, the prediction would be Rz(max)= 109±17, while in the extreme hypothetical case of Ro=0.0, the prediction would be Rz(max)=79±14.