TY - JOUR T1 - Eastern Tropical Atlantic Mixed Layer Depth: Assessment of Methods from In Situ Profiles in the Gulf of Guinea from Coastal to High Sea A1 - N’guessan,Benjamin Kouadio A1 - Kouassi,Aka Marcel A1 - Trokourey,Albert A1 - Toualy,Elisée A1 - Kanga,Desiré Kouamé A1 - Brehmer,Patrice AD - Centre de Recherches Océanologiques (CRO), Abidjan, Côte d’Ivoire AD - UFR SSMT, Université Felix Houphouët-Boigny, Laboratoire de Chimie-Physique, Abidjan, Côte d’Ivoire AD - UFR SSMT, Université Felix Houphouët-Boigny, Laboratoire de Physique de l’Atmosphère et de Mécanique des Fluides (LAPA-MF), Abidjan, Côte d’Ivoire AD - IRD, Univ Brest, CNRS, Ifremer, Lemar, Délégation Régionale IRD Oues, tPlouzané, France UR - https://doi.org/10.1007/s41208-019-00179-7 DO - 10.1007/s41208-019-00179-7 KW - Mixed layer depth KW - Gulf of Guinea KW - Atlantic Ocean KW - Density KW - Temperature N2 - To assess the eastern Atlantic tropical mixed layer depth (MLD) at 4°W in the Gulf of Guinea, water temperature and density profiles from over five hundred historical observational Conductivity – Temperature - Depth (CTD) data were used. These data, obtained from key oceanographic survey databases covering 60 years (1956 to 2016) were used for a numerical and visual determination of the MLD. The numerical approach consists of the use of the algorithms of three methods; while the visual estimation of the MLD were made on both temperature and density profiles. The numerical approaches were evaluated by comparing their results on the determination of tropical MLD with those of the visual inspections by means of statistical and graphical analysis in order to determine the most suitable method for the determination of MLD in the study area. Our results show that the Boyer Montegut density threshold method (potential density) with the constant criterion Δσ = 0.03 kg.m−3 and a reference depth of ten meters is the most appropriate for determining the MLD in the Gulf of Guinea regardless the season. However, in the situation where only temperature profiles are available it is advisable to estimate MLD using the Lorbacher curvative method. Y1 - 2020/04 PB - Springer Science and Business Media LLC JF - Thalassas SN - 0212-5919 VL - 36 IS - 1 SP - 201 EP - 212 ID - 71115 ER -