3.1 Hydrodynamic characterization
The hydrodynamic characterization from the Equatorial Atlantic to the GoM was done by characterizing the transport routes and barriers using the cLCS and identifying the main current patterns using the SOMs. As the cLCS denotes areas of maximum attraction (warm colors in Figure 2, where red indicates the highest attraction strength of nearby water parcels), they can be used to identify the likely displacement of the released particles in the Lagrangian experiments, presented in section 3.2. From the cLCS results, we identified four regions of persistent trajectories in the study area: (i) near the coast of Brazil, Suriname, and the French Guiana coasts (associated with the Guiana Current (GC) and the North Brazil Current (NBC), (ii) the Lesser Antilles, (iii) the channel between Honduras and Jamaica, and (iv) the region from the Yucatan Channel to the Florida Peninsula (associated with the Loop Current (LC), the Florida Current (FC), and the Gulf Stream (GS)). Besides being related to the intensification of currents, these regions constitute paths that maximize the normal attraction of nearby trajectories. This implies that any floating, suspended material or, as in this case, numerical particles, are attracted by the cLCS and can flow along them without crossing strongly-attracting cLCS, thus acting as transport barriers (Duran et al., 2018; Gough et al., 2019; Gouveia et al., 2021). These persistent trajectories organize and characterize Lagrangian transport, where the cLCS are critical to interpreting the Lagrangian expression of surface currents driving the transport of drifting material.