Advancing Observations of Western Boundary Currents: Integrating Novel Technologies for a Coordinated Monitoring Approach

Western boundary currents (WBCs) play a crucial role in global ocean circulation, regulating climate, influencing weather patterns, driving marine ecosystems, and transporting heat, momentum, and biogeochemical properties across ocean basins. Despite their importance, their strong variability and deep structures make them challenging to observe. Here, we synthesize the physical properties of the five major subtropical WBCs and highlight the need for improved and sustained observations. We present dynamically driven priorities for observation, emphasizing novel and cost-effective methods. Advances in satellite altimetry, autonomous vehicles, and ship-based measurements have enhanced monitoring efforts, but gaps remain, particularly in subsurface observations and cross-system comparisons. Emerging technologies such as the fishing vessel observation network and uncrewed surface vehicles provide new opportunities for broad-scale, high-frequency data collection. Modified Argo float deployments (more frequent profiling) and repeat glider missions offer improved resolution of eddy structures and upper-ocean heat content estimates. We emphasize the need for consistent observational strategies across WBC systems to enable direct comparisons and improve predictive modeling. Integrating satellite data with in situ observations and high-resolution models is essential for refining estimates of WBC variability, heat transport, and climate-driven changes. A coordinated, multi-platform approach for observation and analysis is critical to understanding WBC dynamics and their long-term impacts on regional and global climate.