Modelling Spatial Pattern of Sea Surface Variability and Projection and Its Influence on Rainfall Dynamics in the Gulf of Guinea.

The ocean plays an important role in the earth’s climate system as it’s a major source of moisture and heat fluxes with the atmosphere and therefore its warming has considerable impact on the lower atmospheric circulation and precipitation intensities. West Africa and the Gulf of Guinea (GOG) has been characterized by high rainfall variability leading to severe floods and droughts in the coastal and Sahel regions with severe impacts on human and socio-economic activities. In view of the above, this study was conducted to examine spatial pattern, variability, projection of SST and its influence on rainfall dynamics over the Gulf of Guinea, The study employed a combination of geospatial, statistical and climate models in the analysis of decal, seasonal variability of SST on annual and seasonal rainfall in the Guinean cost while the CMIP 6 models was used for SST projection from 2030-2100. SST and rainfall data of 52 years (1970-2020) at 2^o×2^o resolution was obtained from the Columbia Climate School International Research Institute (IRI) at 12 locations along the GOG specifically between Latitudes10^ON, 3^ON, 1^ON, 1^OS, 3^OS. 5^OS and Longitude10^oW, 8^OW,6^OW, 4^OW, 2^OW, 0⁰, 2^oE, 6⁰E and 5^oE. The outcome of the various analysis that between 1970-2022, SST increased at 0.5^o 2010-2020 was the warmest decade in the GOG, anomalously low SST was observed in the months of June, July and August as well September, October and November due to the influence of coastal upwelling. In terms of Rainfall variability, 2010-2020 recorded the highest amount of 2.716.5-3.390.1mm in the study period while 2022 was 2.647.2-3.29.8mm. Seasonal rainfall analysis revealed that June July August recorded the highest rainfall of 601.6-751.9 followed by September, October and November 31.4-362.⁶and December January and February the lowest with 94.3-117.7. The SST and rainfall anomaly analysis indicates that Abijan, Accra, Freetown, and Lagos showed positive teleconnection of SST and rainfall while Conakry, Douala and Lome were negative implying that other parameters might for be responsible for the observed rainfall trend. The HadGEM3-GC31-HM(MOHC) model proved reliable and performed better in the SST projection from 2030-2090 as SST was projected to be 34.8^oC. The study is a further contribution to the understanding of West Africa climate prediction and the management of climate risk related disasters.