These characteristics provide valuable information for the evaluation of the climatic evolution, and the detection of variations in this evolution, either for natural mechanisms or by antropogenic impact, that suggests a climatic change.
A positive trend exists in the whole analyzed region. The spectral analysis presents significant periodicities between 3.4 and 7.5 years, that they show a possible linking with the ENSO phenomenon.
The used methodology responds to a hypothetical conception of the temporary series like that of a signal formed by aleatory components, with characteristics of white noise.
This extensive region shows a spatial-temporal similar behavior. The periodicities linked with ENSO are always present and the structures of the series are similar for the differents periods analyzed.