ANALYSIS OF SOLAR WIND PARAMETERS RELATED TOGEOMAGNETIC STORMS USING THE MULTIFRACTALDETRENDED FLUCTUATION ANALYSIS (MFDFA) METHOD
<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 selec...
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| Format: | Theses |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/73566 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | <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.
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