Spatio-Temporal Trend of Past and Future Extreme Wave Climates in the Gulf of Guinea Driven by Climate Change

Abstract

This study assessed the extremes of wave conditions for past (1979–2005) and future (2026–2045 and 2081–2100) time slices in the Gulf of Guinea (GoG). The ensemble produced from eight General Circulation Models under different Representative Concentration Pathway (RCP) emission scenarios (RCP4.5 and RCP8.5) was subjected to linear regression analysis and Mann–Kendal test for their trends and significance, respectively. Results showed an increase in the extreme of significant wave height (Hs) and mean wave period (Tm) between 1979–2005, 2026–2045, and 2081–2100 with few exceptions. The average values of annual and seasonal Hs and Tm range from 1.26–1.62 m and 10.37 s–10.86 s, respectively, for 1979–2005. These Hs values are projected to increase by 0.1 m (0.05 m) to 1.72 m (1.67 m) and the Tm will increase by 0.29 s (0.24 s) to 11.15 s (11.10 s) by the end of the century (mid-century) time slices, respectively. The mean wave direction (Dm) (201.89°–206.27°) showed an anticlockwise shift (−29.2 × 10−3 degrees per year) for 1979–2005 which is projected to become more southwesterly with an increase up to 2.2° (0.5°) by end (mid) century in 2100 (2045), respectively. Future work will be on the impacts of changing wave on longshore sediment transport along the GoG.

Spatio-temporal assessment of the impacts of the trends in physical and biogeochemical parameters on the primary production of the Gulf of Guinea

“…The GoG region has a strong upwelling between the coast of Cote d'Ivoire and Benin Republic popularly referred to as the Central West African Upwelling [ [37] , [38] ]. This very productive coastal upwelling system peaks between July and September with minor upwelling seasons between December and March [ 39 , 40 ].…”

“…The seasonal analysis was done by separating the data into dry season months (winter) and rainy season months (summer). Winter was defined similar to those used in previous studies by Dahunsi et al [ 38 ] in the GoG as months from November to March. Summer starts from April to October which is the major rainy season for the GoG region.…”

Historical change and variability of spectral wind wave climate in the New York Bight

“…Wave climate analyses are typically performed based on trends and variabilities in integrated bulk wave parameters such as significant wave height, mean wave period and mean wave direction (El Safty & Marsooli, 2022; Marsooli et al, 2021; Menéndez et al, 2008; Young et al, 2012). Some studies aiming to investigate wave climate trends and variability rely solely on reanalysis data (Dodet et al, 2010) or satellite data (Izaguirre et al, 2011; Stopa, 2021), while others combine them with buoy (Jamous & Marsooli, 2023; Kumar et al, 2018; Loureiro & Cooper, 2018) or altimetry data (Hemer et al, 2010) to verify their findings. Previous wave climate studies have also investigated the relationships between the wave climate and climate indices.…”

Long-Term Evolution of Significant Wave Height in the Eastern Tropical Atlantic between 1940 and 2022 Using the ERA5 Dataset

“…For instance, Semedo et al (2011) [14] investigated the regional distribution of swell dominance in the Earth's oceans in terms of wavefield energy balance as well as the statistical relationships between the interannual variability in the wind-sea and swell wave heights observed over the Pacific, Atlantic, and Indian Oceans using the ERA-40 covering 45 years. Owing to improvements in the models, other studies, mainly using the ERA5 dataset, have focused on various oceanic regions and determined the wave climatology of these areas [14][15][16][17][18][19][20][21][22][23].…”