Improving the Quality and Accessibility of Current Profile Measurements in the Southern Ocean

Like most modern oceanographic research vessels, RVIB Nathaniel B. Palmer and ARSV Laurence M. Gould are equipped with acoustic Doppler current profilers (ADCPs) for measuring the structure of ocean currents over a range of several hundred meters below the hull, both on station and while underway. It takes more than the ADCP itself, however, to yield good current measurements. The end result depends on how and where the sonar is installed; on the quality of ancillary information including position, heading, and, for some sonars, speed of sound at the transducer; on the data acquisition and processing techniques; and on ambient conditions of weather, ice, noise, and the availability of acoustic scatterers in the water (Firing and Hummon, 2010). In addition, the value of the measurements depends not only on their accuracy but also on their accessibility to scientific users both in near real time at sea and as a final product ashore.