Last updated October 10, 2018

Understanding Recent Eastern Horn of Africa Rainfall Variability and Change

  • Examines observations and sea surface temperature (SST)-forced simulations to study seasonal eastern Africa rainfall and its SST sensitivity from 1979–2012
  • Notes that the eastern Horn is drier than the rest of equatorial Africa, with two distinct wet seasons
  • Notes that whereas the October–December wet season has become wetter, the March–May season has become drier
  • Finds that the climatological rainfall in simulations driven by observed SSTs captures this bimodal regime
  • Identifies the most likely locations of SST forcing of precipitation trends in the model, and conceivably also in nature
  • Results indicate:
    • The October–December precipitation increase is mostly due to western Indian Ocean warming
    • October–December eastern Horn rain variability is strongly associated with El Niño–Southern Oscillation and Indian Ocean dipole phenomena on interannual scales, in both model and observations