AbstractBased on 18 years of satellite altimetry data and temperature/salinity (θ/S) profiles from Argo floats, we analyze the isopycnal θ/S anomalies (θ'/S') within newborn eddies in the tropical Atlantic Ocean (TAO). Our results show that on density‐coordinates, both anticyclonic eddies (AEs) and cyclonic eddies (CEs) can exhibit positive, negative, or nonsignificant θ'/S'. Almost half of the sampled eddies do not have significant θ'/S' at their generation site. The other half exhibits significant positive or negative θ', up to ±0.5°C typically. More than 70% of them have a subsurface signature. Refined analyses of the vertical structure of new‐born eddies in three selected subregions show the dominance of cold (warm) subsurface AEs (CEs) likely due to isopycnal advection of large‐scale potential vorticity (PV) and θ. PV is a key parameter to analyze eddy generation and dynamics. Isopycnal advection, friction or diapycnal mixing can be involved in the generation of PV anomalies from which vortices can then emerge. However, it is difficult to evaluate PV at mesoscale. In this study, we propose to combine θ'/S' and PV anomalies to analyze which process could be involved in its transformation in the ocean. We argue that eddies created by diapycnal mixing or isopycnal advection of water‐masses are associated with PV anomalies and significant θ'/S'. In contrast, a frictional forcing also creates PV anomalies but without modifying θ/S. Even though our results remain qualitative, the proposed diagnostics can be of interest to validate realistic models and then use them to analyze the PV anomaly sources.