This study intents to contribute to the understanding of inter-annual, inter-decadal and multidecadal variations in the climate of southern Africa. Thus, main features of climate and circulation variability in southern Africa are identified, described and discussed including interactions with sea surface temperatures (SST). A 98 year record of gridded data covering Africa south of the equator was used to document the spatial patterns of climate variability and long-term changes during the 20th century.

The data used in this study are the monthly Global Sea-Ice and Sea-Surface Temperature (GISST2.3b), the Kaplan SST anomalies, the Global Mean Sea Level Pressure (GMSLP2.1f) and gridded temperature and precipitation data, obtained from the Climatic Research Unit (Norwich). Additional proxy data from coral reefs are used to confirm the SST data.

The major modes of SST, SLP, temperature and precipitation variability have been derived by principal component analyses with Varimax rotation. The resulting time coefficients of the PCAs have been further analysed by canonical correlation analysis in order to investigate the influence of the Atlantic and Indian Oceans on the climate of southern Africa. Associations between SSTs and southern African rainfall are evident and are discussed in terms of recent climate change. Trend analyses confirm the well known warming with strongest temperature increase in the central interior of southern Africa and the region of Angola. Precipitation, however, does not show any significant trend pattern.

Special emphasis has been put on discussions of recent climate change in terms of internal and external forcing factors. Statistical links between solar activity and southern African climate could be substantiated by correlation and time series analyses. Solar-climatic relationships are difficult to proof, but highly significant correlations of surface air temperature and solar activity variations do suggest a physical link between sun and climate. Thus, increasing surface air temperatures may partly be due to increasing solar activity. Further investigations will try to detect cumulative effects of volcanic eruptions on southern African climate by using different volcanic indices.