Ekman transport and Ekman pumping are the two fundamental wind-driven mechanisms sustaining coastal upwelling in Eastern Boundary Upwelling Systems, yet their relative contributions along the Northern Humboldt Current System (NHCS) remain poorly constrained. Using three independent wind stress products (BLENDED, GEKCO2, and ORAS5) spanning 1992–2024, we quantify the seasonal and interannual partitioning between these mechanisms across two Regions of Interest (ROIs) selected to capture contrasting shelf geometries: a wide-shelf sector (8°–10°S) and a narrow-shelf sector (13°–15°S). Our results reveal that neither mechanism dominates uniformly: Ekman transport prevails during winter in both ROIs (~58% of the seasonal signal), while Ekman pumping becomes comparatively more important in the wide-shelf region during summer (~19–52% depending on the dataset), a pattern not mirrored in the narrow-shelf sector. This spatial asymmetry indicates that the relative weight of transport versus pumping is not fixed but shifts with latitude, shelf width, and season – a signature of the pronounced physiographic heterogeneity of the Humboldt Current System, where bathymetric and coastal-geometry variability locally modulates wind regimes and their oceanic response. We further show that this heterogeneity extends to the coupling between Ekman forcing and surface expressions (SST and chlorophyll-a), with correlations that differ in sign and strength between regions, and to the system's response during extreme events (the 2017 and 2023 coastal El Niño episodes and Cyclone Yaku), where transport and pumping anomalies diverged spatially rather than acting in unison. Together, these findings argue against treating the NHCS as dynamically homogeneous and underscore the need for regionally resolved upwelling indices that account for the differential roles of Ekman transport and pumping along the Peruvian coast. As a next step, we plan to refine the estimation of both mechanisms by incorporating their geostrophic component — the sea-level-balanced contribution to the total wind-driven transport — and to examine how changes in both processes relate to the offshore-to-coastal thermal gradient generated by warmer oceanic waters against colder upwelled waters, and its feedback with the wind field, which may help explain the stronger anomalies observed in the northern sector

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