Saildrone, a seven-metre long, wind-powered unmanned surface vehicle (USV) is the first unmanned system to circumnavigate Antarctica. The vehicle, also called SD 1020, had climate-grade sensors installed, and had gathered data in previously unchartered waters, providing an additional insight into ocean and climate processes.
The mission lasted for 196 days and began from Southport in Bluff, New Zealand, on January 19, 2019. The vehicle returned back to where it started on August 3, after sailing over 22,000 km (13,670 miles) around Antarctica. During its journey, the USV experienced freezing temperatures, 15-meter (50-foot) waves, 130 km/h (80 mph) winds, and collisions with giant icebergs.
The Southern Ocean plays a crucial role in regulating heat and carbon for the planet; Yet, its remote location and inhospitable state, makes even big ships avoid the location. Nevertheless, the saildrone managed to not only survive the Southern Ocean winter but streamed back vital new data from previously unsampled territory.
In addition, the USV was equipped with an instrument developed by NOAA to measure carbon fluxes very precisely, and provided important new data on the rates of carbon uptake in the Southern Ocean.
Dr. Adrienne Sutton, an oceanographer with the NOAA Pacific Marine Environmental Laboratory (PMEL) Carbon Group commented that
There’s a lot left to be learned about the ocean’s uptake of CO2 emissions, especially in the Southern Ocean. Up until a few years ago, the Southern Ocean was understood to be a large CO2 sink.
Yet, Dr Sutton highlighted that with the help of the Saildrone, scientists found less of a CO2 sink than previously thought.
SD 1020 was equipped with the standard Saildrone sensor suite which collects a variety of variables from wind speed and direction to sea surface temperature, chlorophyll and salinity. SD 1020 also carried an ASVCO2 to measure atmospheric and dissolved pCO2 (carbon flux), dissolved oxygen, water temperature, and pH, as well as an ADCP to measure the speed and direction of ocean currents.
