ANALYSIS OF SOLAR WIND PARAMETERS RELATED TOGEOMAGNETIC STORMS USING THE MULTIFRACTALDETRENDED FLUCTUATION ANALYSIS (MFDFA) METHOD

• Main Author: Husna, Miftahul
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/73566
• Institution: Institut Teknologi Bandung

<p align="justify">The nature and general pattern of fluctuations in 24 solar wind parameters are observed as a function of time. Samples of strong to extreme class geomagnetic storm events (Dst ? ?100 nT) of the 22nd to 24th solar cycles (October 1964 – September 1986) were selected as research objects. The Multifractal Detrended Fluctuation Analysis (MFDFA) method applied to solar wind parameters yields several related parameters such as Detrended Fluctuation Analysis (DFA) exponent, Hurst exponent H, fractal dimensions Df , h(q), ? (q), spectrum width w, and spectral graph skewness A. Of the 180 samples of storm events, the initial and recovery phases showed 58% and 54% dominated by persistent processes (0.51 ? ?DFA ? 0.99) and a main phase or peak 96% dominated by nonstationary processes (1.01 ? ?DFA ? 5.67). Fractal dimension of the obtained solar wind parameter < 2, which has an inversely proportional relationship with the exponent Hurst. Based on multifractal parameters: h(q); ? (q); spectrum width w; and skewness A, almost all parameters of the solar wind, the presence of multifractal properties. The characteristics of the initial phase and recovery phase in selected strong-class geomagnetic storm events show similar patterns or trends. This study confirms that the main phase of a solar storm is much more complex than the other 2 phases. Parameters such as the number of sunspots, f10.7 index, and, derived parameters (electric field) can be excluded in storm prediction. Samples of other class storm events (weak to moderate grade), as well as non-linearity chaotic system analysis on solar wind parameters, are needed for further research.