Additional measurements

The first measurement made by the floats, in addition to tracking ocean current velocities, was temperature (Pochapsky, 1963). This was followed by the customisation of some floats with angled fins. These fins meant that as water passed the float vertically, the float would rotate. This rotation was sensed by a magnetic compass and this was used to the study internal waves and upwelling through the measurement of vertical water velocities (Voorhis, 1968). Some floats were able to adjust their buoyancy, allowing them to measure vertical temperature gradients and the separation of density surfaces. This enabled scientists to study changes in stratification (Price, 1996; Rossby et al., 1994). Among these derivatives of the SOFAR and RAFOS floats were floats that could also measure electromagnetic fields (Sanford et al 1995).

Extensive use of both SOFAR and RAFOS floats was made primarily by research groups in the USA, France (Ollitrault,1994) and Germany (Zenk et al 1992).