Data Sources and Analysis

Daily rainfall records for the various sites were obtained from the Meteorological Services Department, Accra, Ghana while the OND SSTs (1960 to 2000) were downloaded from the International Research Institute for Climate Prediction website. The rainfall years were sorted into three ENSO phases namely El Niño, La Niña and neutral years according to Japan Meteorological Agency (JMA). Rainfall records for seven out of the nine sites namely: Axim, Accra, Ada, Akuse, Kumasi, Yendi and Wa covered the period 1961 to 1990. This period involved eight La Niña and El Niño events each and fourteen neutral events; Kpandu (1964 to 1990) also involved eight La Niña and El Niño events each and eleven neutral years while Akatsi (1976 to 2000 excluding 1991) involved five La Niña, seven El Niño and twelve neutral events.

For each site the seasonal rainfall for each year was sorted according to the ENSO phase. For sites within the south of Ghana, only the major season was considered. Using Box and Whisker plots (not shown) the median rainfall was determined for each ENSO phase. Thereafter, the seasonal rainfall at each site was correlated with the OND Niño 3 SST anomalies.

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