Feb 21, 2000

ENSO and interannual rainfall variability in Uganda: implications for agricultural management

Phillips, Jennifer and McIntyre, Beverly
International Journal of Climatology
  • States that the El Niño–Southern Oscillation (ENSO) is correlated with the short rainy season (September–December) in East Africa
  • States that seasonal climate forecasts made on this basis are being disseminated in the hope that this information will be useful in regional or even local planning and resource management
  • Performs climate analysis at the sub-regional level with distinctions being made between unimodal (short season peak in August) and bimodal (short season peak in November) rainfall zone using monthly climate data from 1931 to 1960 at 33 sites
  • Shows that, averaging across all stations, Pacific Ocean NINO3 region sea-surface temperatures (SSTs) from July to September (JAS) are significantly correlated with both the concurrent August–September (AS) rainfall (r=−0.75) and the following November–December (ND) rainfall (r=0.57), but with opposite signs
  • Finds that when station data are separated into uni- and bimodal sites, it becomes clear that the importance of ENSO events is different in the two zones
  • Finds that in the unimodal zone, El Niño events are associated with a depression of the August peak in rainfall, but a lengthening of the season, potentially providing an opportunity for growing later-maturing crops
  • Results show that at bimodal sites, there is very little impact in August but November rainfall is enhanced in El Niño years and depressed in La Niña years