Artículos de revistas
Geomagnetic disturbances analysis using discrete wavelets
Geomagnetic disturbances analysis using discrete wavelets
Autor
Zossi de Artigas, M.
Fernandez de Campra, P.
Zotto, E. M.
Institución
Resumen
Para estudiar periodicidades y tendencia en tormentas geomagnéticas se aplicó la transformada wavelet discreta, usando la función Daubechies. De entre una variedad de técnicas disponibles para analizar variabilidad, el análisis wavelets ha surgido en la última década como una herramienta estadística útil para este propósito. En el presente análisis se usó el número de tormentas geomagnéticas desde 1957 al 2004. El análisis wavelets se aplicó a tormentas con diferentes intensidades. Para identificar tormentas geomagnéticas se usó el índice ecuatorial Dst. La tendencia durante el período analizado no es uniforme, con mínimos alrededor de los años 1965 y 2000, y un máximo alrededor de 1990. Se han detectado diferentes periodicidades. Su comportamiento no es regular a lo largo del período analizado. Se discuten posibles causas para la variabilidad observada. To assess long-term trends and periodicities in geomagnetic storms, the discrete wavelet transform, using the Daubechies function, was applied. Among a variety of techniques, which are available for analyzing variability, wavelet analysis has emerged in the last decade as a useful statistical tool for this purpose. The number of geomagnetic storms from 1957 to 2004 was used for the present analysis. The wavelet analysis has been applied to storms with different intensities. For identify geomagnetic storms, the equatorial index, Dst, has been used. The long-term trend during the analyzed period is not a uniform, with minimum around the years 1965 and 2000, and a maximum around 1990. Different periodicities have been detected. Their behavior is not regular along the analyzed period, they have different intensity values. Possible causes for the observed variability are discussed.
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