Atlantic Sea Surface Temperatures and Rainfall Variability in Ghana

Abstract

Monthly rainfall between 1926 and 1985 from 17 synoptic stations in Ghana were averaged over four major zones of the country. Anomalies from the rainfall series were correlated with sea surface temperature (SST) anomalies in the Atlantic Ocean. Significant positive correlations were observed between rainfall and SST for the period July to September in the eastern equatorial Atlantic. Correlations of rainfall with SSTs in closest proximity to the country are between 0.62 and 0.75 in magnitude and are significant at the 1% level. Significant lag correlations between the SSTs in May to July and rainfall in July to September were also observed, offering the possibility of forecasting rainfalls. Ghana is just south of the Sahel but the sign of the Ghana rainfall-SST relationship is opposite to that of the Sabel seasonal (July-September) rainfall-SST relationship.