Spatial and seasonal variability of mixed layer depth in the tropical Atlantic at 10 °W using 40 years of observation data Kouame, K.D. Kouassi, A.M. Trokourey, A. Toualy, E. N'guessan, B.K. /Brehmer, Patrice Ostrowski, M. The spatial and seasonal variability of the mixed layer depth (MLD) was studied using hydrological data from several databases collected over the period October 1973 to March 2017 at 10 °W between latitudes 2 °N and 10 °S in the Gulf of Guinea. The density threshold method with 0.03 kg m-3 criterion was used to calculate the MLD. In the equatorial band, the seasonal average MLD is 20 m whatever the season. At 6 °S and 10 °S, the MLD is relatively higher during the cold season. The MLD varies between 21 and 37 m at 6 °S, and the seasonal averages MLD are 21 and 40 m respectively during the hot and cold seasons. At 10 °S, during the hot season, the MLD varies between 28 and 52 m and the seasonal average is 39.5 m. During the cold season, the MLD varies between 45 and 55 m with a seasonal average of 49 m. 2021 text https://www.documentation.ird.fr/hor/fdi:010081936 fdi:010081936 Kouame K.D., Kouassi A.M., Trokourey A., Toualy E., N'guessan B.K., Brehmer Patrice, Ostrowski M.. Spatial and seasonal variability of mixed layer depth in the tropical Atlantic at 10 °W using 40 years of observation data. 2021, 158 (3), 207-217 FR ATLANTIQUE