Analysis of Austral Summer and Winter Rainfall Variability in South Africa Using Ensemble Empirical Mode Decomposition

摘要

Rainfall exhibits nonlinear and non-stationary characteristic such that analysis done using linear methods are inconclusive. It is, therefore, necessary to understand the multi-scale variations of the rainfall. In this study, a comparison is done of two different regions which receive two distinct rainfall types. Northeastern to southwestern South Africa receives austral winter rainfall whilst the rest of the country receives austral summer rainfall. The multi-scale rainfall variability is done using data adaptive method, ensemble empirical mode decomposition. Changes of rainfall in both regions exhibited inter-annual and quasi-decadal oscillation. We found that there were distinctive spatial differences in the patterns.