Identification of Fractal Properties in Geomagnetic Data of Southeast Asian Region during Various Solar Activity Levels

Farhan Naufal Rifqi,Akimasa Yoshikawa,Nurul Shazana Abdul Hamid,A Babatunde Rabiu

doi:10.3390/universe7070248

Farhan Naufal Rifqi, Akimasa Yoshikawa + Show 2 more

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https://doi.org/10.3390/universe7070248

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Abstract

The fractal properties of geomagnetic northward component data (H-component) in the equatorial region during various phases of solar activity over Southeast Asia were investigated and then quantified using the parameter of the Hurst exponent (H). This study began with the identification of existence of spectral peaks and scaling properties in international quiet day H-component data which were measured during three levels of solar activity: low, intermediate, and high. Then, various cases of quiet and disturbed days during different solar activity levels were analyzed using the method that performed the best in the preceding part. In all the years analyzed, multifractal scaling and spectral peaks exist, signifying that the data have fractal properties and that there are external factors driving the fluctuations of geomagnetic activity other than solar activity. The analysis of various cases of quiet and disturbed days generally showed that quiet days had anti-persistence tendencies (H < 0.5) while disturbed days had persistence tendencies (H > 0.5)—generally a higher level of Hurst exponent compared to quiet days. As for long-term quiet day H-component data, it had a Hurst exponent value that was near H ≃ 0.50, while the long-term disturbed day H-component data showed higher values than that of the quiet day.

Highlights

The geomagnetic field of the Earth is an astonishing feat of nature as it protects us from the incoming forces from the Sun, such as charged particles in the solar wind [1,2] that may be the harbinger of catastrophe on earth, if the geomagnetic field were to never exist in the first place
Four methods were utilized for identifying fractal properties in this study—namely, the Power Spectrum Analysis (PSA), Rescaled Range Analysis (RRA), Detrended Fluctuation Analysis (DFA), and Robust Detrended Fluctuation Analysis (r-detrended fluctuation analysis (DFA))
We found that multifractal scaling exists in all of the data analyzed, signifying that the data exhibit fractal properties

Summary

Introduction

The geomagnetic field of the Earth is an astonishing feat of nature as it protects us from the incoming forces from the Sun, such as charged particles in the solar wind [1,2] that may be the harbinger of catastrophe on earth, if the geomagnetic field were to never exist in the first place. This so-called catastrophe is the geomagnetic storm; its occurrence of which can be attributed to the compression of the magnetosphere due to the solar wind [3]. The Hurst exponent was used extensively to quantify the fractal properties of the geomagnetic data

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