FIGURE C.1 An example of a currently existing oceanographic float that provides measurements of conductivity, pressure, and temperature from which salinity and depth are calculated. Additional sensors include oxygen, nitrate, optical properties, and soon pH. New floats designed for operation underneath ice shelves would have a protective bonnet over the antenna.
SOURCE: Southampton Oceanography Centre.
Argo program (Figure C.1).1 Additional sensors that can be incorporated, separately from the Argo program, include oxygen, nitrate, fluorescence, velocity, and soon pH; the capability to profile to a much greater depth is under development. An emerging technology of importance for the sea-ice-covered Southern Ocean is the long-duration float, which is programmed to profile repeatedly in ice-covered oceans without transmitting data on each ascent. The float uses a collision avoidance algorithm to test for ice or open water above it, and data transmission occurs only when the float can surface through open water. The precedents for this approach are two previous studies in Antarctica’s Weddell Sea where an array of moored acoustic (RAFOS) sources