A note on the precipitation anomalies in southern South America associated with ENSO variability in the Tropical Pacific

Summary

The precipitation variability over South America south of 20° S (SA20S) has been investigated at a decadal (DD) and non-DD time scales. The results suggest that the space-time particularities of the ENSO-related precipitation anomalous patterns depend on the time scales considered. The precipitation patterns in the SA20S associated with the non-DD episodes exhibit a space-time coherent characteristics during ONDJ (0)–JJAS (+1) period such that a prominent area of positive (negative) anomalies is observed in the central SA20S and displaced northeastward with the time for the non-DD El Niños (La Niñas). On the other hand, the precipitation anomalous patterns associated with the DD episodes feature more complex horizontal structures and larger anomalies than those of the non-decadal episodes. It is also worthwhile noting that the SA20S climate experiences the strongest and more extensive effects of the DD episode during the austral summer of the year following the onset of the DD episodes.