Figure 10.14 ARGO floats are widely used by the oceanographic community to measure deeper currents at a depth of 1 km in the ocean, and to profile temperature and salinity as a function of depth between 2 km and the surface. To ascend, the hydraulic pump moves oil from an internal reservoir to an external bladder, reducing the drifter’s density. To descend, the latching valve is opened to allow oil to flow back into the internal reservoir. The antenna is mounted to the end cap. Sensors measure temperature and salinity on ascent. From the ARGO Project.