Argo Beyond 2020: Towards a global, full-depth multidisciplinary array

Starting in 2000, Argo reached global coverage in 2007 and has sustained a globally distributed array of ~ 3000 profiling floats for almost two decades. This Argo array delivers ocean temperature and salinity profiles from the sea surface to 2000 dbar roughly 300km apart every 10 days in realtime. Just as the present Argo array originated from an opportunistic mix of developments in both technology and data management, a new step-change in global ocean observing is now possible. Advances in platform and sensor technologies presents a new opportunity to (i) improve Argo’s global reach and value beyond the original design, (ii) extend Argo to span the full ocean depth, (iii) add biogeochemical sensors for improved understanding of oceanic cycles of carbon, nutrients, and ecosystems – all within the context of a comprehensive Argo data system. Each of these enhancements are evolving along a path from experimental deployments to regional pilot arrays to global implementation.The ultimate objective is to implement a fully global, top-to-bottom, dynamically complete, and multidisciplinary Argo Program that will integrate seamlessly with satellite and with other in situ elements of the Global Ocean Observing System. The integrated system will deliver enhanced operational reanalysis and forecasting capability, and assessment of the state and variability of the climate system with respect to physical, biogeochemical, and ecosystems parameters. It will enable basic research of unprecedented breadth and magnitude, and a wealth of ocean-education and outreach opportunities.