跳至主要内容

Solar Influences on the North Atlantic Oscillation by Wavelet-Based Multifractal Analysis

There is increasing interest in the relation between the solar activity and climate change. Regarding the solar activity, the fractal property of the sunspot number (SSN) has been studied by many previous works. In general, fractal properties have been observed in the time series of the dynamics of complex systems.

In this study, the authors examined the relationship among the solar activity, total ozone, and the North Atlantic Oscillation (NAO) from a viewpoint of multi-fractality and investigated the change of multifractal behavior of the SSN, F10.7 flux, geomagnetic aa, total ozone, NAO, the global temperature, and NH sea ice area indices by the multifractal analysis using the wavelet transform. For this purpose, they also illustrated the change of multifractality by plotting the τ-function and used the wavelet coherence.

The results showed that the solar activity related to the NAO, by observing the matching in monofractality or multifractality of these indices. When the SSN increased, the solar activity became stable and the NAO also became stable. When the SSN became maximum, the fractality of the SSN, F10.7 flux, geomagnetic aa, and NAO indices changed from multifractality to monofractality and those states became stable for most of the solar cycles. Also, an increase of a fluctuation was observed in a coupled chaotic system just before chaos synchronization. When the SSN became maximum, the fluctuations became large and multifractality became strong, and a change from multifractal to monofractal behavior was observed in the SSN, F10.7 flux, geomagnetic aa, and NAO indices. The strong interactions of the solar flux, geomagnetic activity, total ozone, and NAO occur in the SSN maximum. The strong interactions were inferred from the similarity of fractality changes and the wavelet coherence. The influence of the solar activity on the NAO was shown from a viewpoint of multi-fractality.

In short, these findings will contribute to the research on the effects of the solar activity on climate change.


Article by Fumio Maruyama, et al, from Japan.

Full access: http://suo.im/4LEOAK

评论

发表评论

此博客中的热门博文

Electron Spin and Proton Spin in the Hydrogen and Hydrogen-Like Atomic Systems

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52202#.VIj7tMnQrzE Author(s) Stanisław Olszewski * Affiliation(s) Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland . ABSTRACT The mechanical angular momentum and magnetic moment of the electron and proton spin have been calculated semiclassically with the aid of the uncertainty principle for energy and time. The spin effects of both kinds of the elementary particles can be expressed in terms of similar formulae. The quantization of the spin motion has been done on the basis of the old quantum theory. It gives a quantum number n = 1/2 as the index of the spin state acceptable for both the electron and proton ...
发表评论
阅读全文

Remarks on the Complexity of Signed k-Domination on Graphs

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53574#.VMnXsCzQrzE Author(s)    Chuan-Min Lee 1 , Cheng-Chien Lo 1 , Rui-Xin Ye 2 , Xun Xu 2 , Xiao-Han Shi 2 , Jia-Ying Li 2 Affiliation(s) 1 Department of Computer and Communication Engineering, Ming Chuan University, The First American University in Asia, Taoyuan, Taiwan, Chinese Taipei . 2 Department of Electronic Information Engineering, Fuzhou University, Fuzhou, China . ABSTRACT This paper is motivated by the concept of the signed k-domination problem and dedicated to the complexity of the problem on graphs. For any fixed nonnegative integer k, we show that the signed k-domination problem is NP-complete for doubly chordal graphs. For strongly chordal graphs and distance-hereditary graphs, we show that the signed k-domination problem can be solved in polynomial time. We also show that the problem is linear-time solvable for trees, interval graphs, and chord...
发表评论
阅读全文

A Review of Technical Requirements for High Penetration of Wind Power Systems

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52361#.VJN8VcCAM4 Author(s)    Yuan-Kang Wu 1 , Tung-Ching Lee 2 , Ting-Yen Hsieh 2 , Wei-Min Lin 2 Affiliation(s) 1 Department of Electrical Engineering, National Chung-Cheng University, Chiayi, Taiwan . 2 Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan . ABSTRACT Renewable portfolio targets have been established in many regions around the world. Regional targets such as 20% renewable energy by year 2020 are not uncommon. As the levels of wind power penetration increase, there are many power system impacts. This work investigated possible challenges and technic...
发表评论
阅读全文