Global Detection and Regional Characterization of Anticyclonic Submesoscale Coherent Vortices using Argo Float Profiles.

Subsurface-intensified anticyclones are ubiquitous throughout the ocean, yet their role in large-scale ocean circulation of chemical tracers, heat, and salt is poorly understood. Contrasting with surface-intensified mesoscale eddies, these subsurface vortices can exhibit unusually long lifetimes owing to their propagation along isopycnals into the more quiescent ocean interior, away from stronger turbulent forces. These features, also known as submesoscale coherent vortices (SCVs), can advect origin waters several thousand kilometers over the course of months to years, providing a potentially important transport pathway that may be unresolved in low-resolution global climate models. Here, we take advantage of the global network of Argo floats to identify occurrences of SCVs which appear as Gaussian-shaped, weakly stratified cores of anomalously spicy (hot, salty) or minty (cold, fresh) homogeneous water masses. We develop a general algorithm to detect subsurface eddies that have propagated away from their source region and apply it to the Argo float array, resulting in roughly 3000 detections from 20+ years of observations. We spatially cluster detections into hot-spots of generation, allowing us to develop robust regional statistics in order to characterize the variability of their size, shape, and intensity.