Presented at the Global Ocean Salinity and the Water Cycle WorkshopMarine fronts are narrow boundaries that separate water masses of different properties. These fronts are caused by various forcings and believed to be an important component of the coupled ocean-atmosphere system, particularly in the tropical oceans. In this study, we use three years of sea surface salinity (SSS) observations from Aquarius satellite to investigate the spatial structure and temporal variability of six main frontal SSS features in the tropical Atlantic, their evolution between seasons and differences between individual years. Our results show that the strongest SSS fronts occur on edges of freshwater plumes from Amazon and Congo rivers. The patterns of the SSS gradients reveal a marked seasonal cycle, resulting in strong interaction between different fronts. Impacts of Aquarius SSS and Reynolds SST on variability of density gradients are also discussed. Insights into the dynamics of the fronts are obtained from analysis of vertical Argo profiles.