This work seeks through the intermediary of the eigendecomposition filtering and reconstructing technique the signal time series of Southern Oscillation Index (SOI) and analyze possible cycles that can be observed in this SOI time series. The technique of decomposition was very consistent and can show possible trends in cycles in time series of SOI. The final result is featuring a composition of components that operate in the formation of SOI signal variability, the first component is featuring approximately 1.33, 2.66, 3.58, 4.83 years and decadal time period, larger scales and periods, matching a variance approximately of 70% of the signal of the SOI time series. In addition to the influence of solar activity cyclThis work seeks through the intermediary of the eigendecomposition filtering and reconstructing technique the signal time series of Southern Oscillation Index (SOI) and analyze possible cycles that can be observed in this SOI time series. The technique of decomposition was very consistent and can show possible trends in cycles in time series of SOI. The final result is featuring a composition of components that operate in the formation of SOI signal variability, the first component is featuring approximately 1.33, 2.66, 3.58, 4.83 years and decadal time period, larger scales and periods, matching a variance approximately of 70% of the signal of the SOI time series. In addition to the influence of solar activity cycles, associated with its sunspots number, the variability observed from 20 to 27 years may be related to the interaction between Pacific Decadal Oscillation (PDO) and Southern Oscillation Index (SOI). The understanding of the dynamics that control the decadal variability in the Pacific Ocean and its interactions with climate change on a global scale. These results can be correlated to the atmospheric dynamics behavior characteristics and predominance in northeastern Brazil, and it has importance affecting activities in Rocket Launch Centre in Alcântara. Keywords: Time-series analysis, Eigendecomposition filtering andes, associated with its sunspots number, the variability observed from 20 to 27 years may be related to the interaction between Pacific Decadal Oscillation (PDO) and Southern Oscillation Index (SOI). The understanding of the dynamics that control the decadal variability in the Pacific Ocean and its interactions with climate change on a global scale. These results can be correlated to the atmospheric dynamics behavior characteristics and predominance in northeastern Brazil, and it has importance affecting activities in Rocket Launch Centre in Alcântara.This work seeks through the intermediary of the eigendecomposition filtering and reconstructing technique the signal time series of Southern Oscillation Index (SOI) and analyze possible cycles that can be observed in this SOI time series. The technique of decomposition was very consistent and can show possible trends in cycles in time series of SOI. The final result is featuring a composition of components that operate in the formation of SOI signal variability, the first component is featuring approximately 1.33, 2.66, 3.58, 4.83 years and decadal time period, larger scales and periods, matching a variance approximately of 70% of the signal of the SOI time series. In addition to the influence of solar activity cycles, associated with its sunspots number, the variability observed from 20 to 27 years may be related to the interaction between Pacific Decadal Oscillation (PDO) and Southern Oscillation Index (SOI). The understanding of the dynamics that control the decadal variability in the Pacific Ocean and its interactions with climate change on a global scale. These results can be correlated to the atmospheric dynamics behavior characteristics and predominance in northeastern Brazil, and it has importance affecting activities in Rocket Launch Centre in Alcântara.
