Ocean eddies play crucial roles in climate and marine ecosystems. Still, small mesoscale eddies in the climate-sensitive and biologically unique Arctic Ocean remain poorly characterized and understood due to the coarse resolution of traditional gridded altimetry products and sparse in-situ observations. Here, we show that the Surface Water and Ocean Topography satellite mission overcomes these limitations through unprecedented two-dimensional high-resolution measurements of sea level anomalies. We demonstrate this wide-swath satellite altimetry’s capability to quantify previously unresolved eddy properties, revealing three persistent hotspots of mesoscale eddies in the southern Beaufort Sea that actively transport low-salinity, heat-retaining, and nutrient-enriched waters from the continental shelf to the interior basin. The observed eddies demonstrate their critical role in shelf-basin exchange while revealing biases in current high-resolution models. These findings advance our understanding of Arctic mesoscale processes and provide essential benchmarks for improving ocean models for this rapidly changing environment.