Seasonal Variations in Temperature and Salinity in the Gulf of Guinea

Abstract

A simple linear regression model was used to determine variations in temperature and salinity profile in the coastal waters of Ghana in Gulf of Guinea (GOG) from four surveys, two from each hydrographic season conducted between 2000 and 2002. The model estimated an average sea surface temperature (SST) of 27.13°C for thermocline season and 22.52°C for upwelling season. The average sea surface salinity (SSS) estimated by the model for the thermocline season was 35.24‰ and the upwelling season was 35.56‰. A seasonal sea surface temperature (SST) variability of 4.61°C was observed in the GOG. This revealed that that seasonal SST variability in the Gulf of Guinea (GOG) has reduced. The changes in temperature and salinity with unit change in depth did not show any clear pattern between thermocline and upwelling seasons. Temperatures showed higher level of correlation with changes in depth than salinity. The range of temperature within the 80-metre water column was higher in the upwelling season than the thermocline season. The range of salinity however did not show any clear pattern between the thermocline and upwelling seasons. There were no significant differences in temperature and salinity between the two upwelling seasons. There were however significant differences in temperature and salinity between the two thermocline seasons. The reduction in seasonal variability of SST in the GOG has implications for marine life in the region;