1. Scaling and Fractal Properties of the Horizontal Geomagnetic Field at the Tropical Stations of Langkawi and Davao in February 2007.
- Author
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Hamid, N. S. A., Gopir, G., Ismail, M., Misran, N., Usang, M. D., and Yumoto, K.
- Subjects
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GEOMAGNETISM , *SPACE environment , *GEOPHYSICS - Abstract
We investigate the scaling and fractal properties of the horizontal component of the geomagnetic field time series acquired by the Magnetic Data Acquisition System (MAGDAS) of the Space Environment Research Center (SERC) of Kyushu University in Japan. The data set covers the quiet period of geomagnetic activity in February 2007 at the near equatorial stations of Langkawi in Malaysia and Davao in the Philippines. These data were sampled every minute for 28 days giving a sample size of 40,320. The power spectra of the time series are obtained, showing dominant periodicities at 24, 12, 8 and 6 hours due to the effect of the sun on the geomagnetic field. The power spectra also indicate scaling with Hurst exponents of 0.50–0.77 in the period of 10 minutes to 6 hours. Then, rescaled range analysis and detrended fluctuation analysis are performed, producing similar ranges of Hurst exponents. Finally, these fractal methods are used to determine the Hurst exponents of similar sized data sets artificially generated by a fractional Brownian motion. The results of this study indicate that the horizontal geomagnetic field at these stations are fractal in nature and persistent. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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