Argo Program

Argo is the international array of about 4,000 autonomous profiling floats that drift at depth, then cycle to the surface roughly every ten days, sampling temperature and salinity through the upper 2,000 m and relaying data by satellite. Since the early 2000s it has given the first near-global, year-round subsurface coverage, transforming ocean heat-content estimates. The biogeochemical (BGC-Argo) and Deep Argo extensions add chemistry and full-depth profiles.