Temporal and spatial variation of rainfall anomalies in Africa south of latitude 22° during the period of meteorological record

Annual rainfall anomalies over Africa south of 22° are shown to have exhibited a striking degree of organisation in both time and space during the period of meteorological record. Since the beginning of the twentieth century eight regularly alternating wet and dry spells of nine to ten years duration are shown to have occurred in association with a widespread quasi 20-year rainfall oscillation; before the turn of the century at least three spells occurred and more may have. For each wet or dry spell the spatial variation of rainfall over southern Africa is presented.Visiting from the University of the Witwatersrand, Johannesburg.