SIMULATIONS OF SOUTHERN AFRICAN CLIMATIC-CHANGE BY EARLY-GENERATION GENERAL-CIRCULATION MODELS

Early-generation equilibrium climate models display general agreement concerning possible changes in surface air temperature and mean sea le vel pressure for the Southern African region under doubled carbon diox ide conditions. There is consensus amongst the models considered that the entire region will become warmer and that tropical, subtropical an d mid-latitude circulation systems will weaken and shift southward. Co nsiderably less agreement exists concerning possible changes in precip itations. Encouragingly, though, the broad-scale features of predicted changes are in apparent agreement with the expected circulation chang es. Accordingly, northern tropical areas may be expected to become wet ter throughout the year. The summer rainfall region may experience wet ter summers while wetter summer and drier winter conditions are expect ed for the winter rainfall region of the SW Cape. However, caution mus t be exercised in the interpretation of simulated precipitation change s over the subcontinent due to the coarse spatial resolution and simpl istic parameterisation of precipitation mechanisms used in the models.