The Interannual Variability of the Onset of the Maize Growing Season over South Africa and Zimbabwe

• DOI: 10.1175/jcli3423.1
• Publication Date: 2005-09-30T18:09:20Z
• Authors: M. A. Tadross; B. C. Hewitson; M. T. Usman
• Keywords: Geopotential height; Teleconnection

Abstract Subsistence farmers within southern Africa have identified the onset of maize growing season as an important seasonal characteristic, advance knowledge which would aid preparations for planting rain-fed maize. Onset over South and Zimbabwe is calculated using rainfall data from Climate Prediction Center (CPC) Merged Analysis Precipitation (CMAP) Computing Water Research (CCWR). The two datasets present similar estimates mean, standard deviation, trend common period (1979–97) Africa. During this period, has been tending to occur later in season, particular coastal regions Limpopo valley. However, CCWR (1950–97) indicate that part long-term (decadal) variability. Characteristic patterns associated with late early are estimated a self-organizing map (SOM). Late heavier subcontinent. When Zimbabwe, there increased frequency more intense northeast Madagascar during preceding August. Accompanying these events positive 500-hPa geopotential height anomalies southeast continent. Similar also frequently onset. study indicates variability partly forced by synoptic conditions, successful use general circulation models estimate will depend on their simulation zonally asymmetric component westerly circulation.