ON THE SPATIAL DISTRIBUTION OF RAINFALL OVER SOUTH AFRICA

Summary

Using a 68 x 68 matrix of annual rainfall totals in which the rows are stations and the columns are years, principal components analysis has defined a set of uncorrelated rainfall fields over South Africa. The low-numbered principal components describe patterns over large groups of years that appear to be associated with the major forcing mechanisms for rainfall over the sub-continent. Higher numbered components are related to smaller groups of years and appear to describe phenomena of a more local nature. These results will lend themselves to further analyses in an attempt to relate spatial rainfall variations, both general and extreme such as droughts and floods, with those within the circulation of the atmosphere.