On the Relationship between Circulation Patterns, the Southern Annular Mode, and Rainfall Variability in Western Cape

This study investigates circulation types (CTs) in Africa, south of the equator, that are related to wet and dry conditions Western Cape, statistical relationship between selected CTs Southern Annular Mode (SAM), changes frequency occurrence SAM under ssp585 scenario. Obliquely rotated principal component analysis applied sea level pressure (SLP) was used classify equator. Three were found have a high probability being associated with days four equally Cape. Generally, dry/wet feature southward/northward track mid-latitude cyclone, adjacent South Africa; anti-cyclonic/cyclonic relative vorticity, poleward/equatorward westerlies, Africa. One significantly variations SAM. Years an above-average index correlated below-average occurrences CT. The results suggest through dynamics CT, might control rainfall variability Under scenario, analyzed climate models indicated possible decrease aforementioned CT cyclonic activity mid-latitudes, increase enhanced SLP at mid-latitudes.