Southern oscillation and South African rainfall

An unresolved problem in South African climatology is the extent of the control of the Southern Oscillation, a major mode of Southern Hemisphere atmosphere-ocean interaction and variation, on South African rainfall. Present evidence indicates that rainfall over much of South Africa fluctuates with the phase of the oscillation, but no conclusive evidence had been obtained to confirm the link. Rainfall along the east coast may not be similarly associated with the oscillation. This paper presents statistical evidence to demonstrate that interseasonal differences in South African rainfall are related in part to the phases of the Southern Oscillation. Variations in the association between the Southern Oscillation and rainfall, both spatially across the country and temporally through the year, are also considered.