Interannual variability of south-eastern African summer rainfall. Part 1: Relationships with air-sea interaction processes

Abstract

This paper investigates the role that air-sea interaction processes may play in interaction variability of south-eastern African summer rainfall. The principal spatial modes of south-eastern African summer rainfall are first identified using principal component analysis. Four modes are retained. The most important mode of variability is found to represent rainfall variability over most of the domain, particularly in the regions to the south. The influence of ENSO (as measured by the SOI) on summer rainfall is investigated in detail for different SOI leads. The relationship is such that during the summer following the onset of an ENSO event, south-eastern Africa tends to experience dry condit..