Linkages between the Indian Ocean Dipole and East African Seasonal Rainfall Anomalies

Abstract

This study was designed to understand the nature of the relationship between the Indian Ocean Dipole (IOD) index and seasonal rainfall in East Africa using statistical approaches. The statistical methods used in this study include correlation, regression and composite analyses. Results from the analyses suggested that the pattern in Sea Surface Temperature (SST) anomalies manifested during the IOD events have strong signals on the regional climate system during the October to December rainfall season. The study has demonstrated that some of the extreme rainfall conditions over East Africa were associated with positive and negative IOD phases. The linkages were strong during El Niño/La Niña years. Such information will help to improve monitoring, prediction and early warning of extreme rainfall events over east Africa to reduce the vulnerability of the society of the region to negative impacts of extreme rainfall events that are common in the region.