2 Data and Methods
Our study uses daily sea-surface velocity data from a 25-year climatology (1994-2018) based on the HYbrid Coordinate Ocean Model (HYCOM) reanalysis, encompassing from the Equatorial Atlantic Ocean to the coast of North Carolina, USA, including the Gulf of Mexico, as delimited by coordinates -100oW to -20oW and -7oS to 35oN (Figure 1 and Figure S1 in Supplementary Information). To gain a deeper understanding of the primary current pathways and transport barriers, we computed climatological Lagrangian Coherent Structures (cLCS) and identified the main current patterns using Self-Organized Maps (SOMs). The cLCS provided insights into the transport barriers and primary current pathways, while the SOMs allowed us to efficiently characterize the system by synthesizing spatial and temporal variability into limited current patterns. To further identify transport routes, the effect of wind, and the probability of particle arrival in the CS region, we conducted Lagrangian experiments under three different scenarios: (i) currents without additional wind, (ii) currents with an additional 1% of wind, and (iii) currents with an additional 2% of wind. For each scenario, we integrated trajectories using time-dependent velocities from a HYCOM climatology, wind climatology, and SOMs patterns. We further illustrate the implications of our findings by analyzing a case study for the YP. Our approach allowed us to understand the region’s ocean currents system, characteristics, and response to varying wind conditions in Lagrangian terms. Following is a description of the data and methods employed in the study.