Abstract:
This study investigates the contribution of Atlantic Ocean to the seasonal rainfall over Benin
using Singular Value Decomposition (SVD) and correlation. The rainfall over the country is
mainly unimodal, experienced in the months of June to September (JJAS). The SVD analysis on
the anomalous JJAS rainfall and anomalous Sea Surface Temperature (SST) in the Atlantic
Ocean reveals two dominant coupled modes. The first couple mode that dominates the
covariability between the anomalous rainfall and the SST reveals positive covariability
between anomalous rainfall in central Benin and anomalous SST in central Atlantic. The
second couple mode that dominates the covariability between the anomalous rainfall and
the SST reveals positive covariability between anomalous SST in central Atlantic and
anomalous rainfall in northern Benin to be negative and to be positive to anomalous rainfall
in the southern Benin. Generally, the correlation between rainfall over Benin and sea surface
temperature over Atlantic Ocean is high and positive. Analysis shows that the years 1988,
1989, 2003, 2007 and 2008, were wet while the years 1982, 1983, 1984, 1986 were dry. The
moist southwesterly air dominated the country during wet years. The country was
characterized by dry northeasterly air during the dry years. Close observation of the evolution
of sea surface temperature over Atlantic Ocean and wind flow over Benin is recommended, in
the seasonal forecasting and updating of the forecast.
