Australia’s national science agency CSIRO has sent out a fleet of unmanned surface vehicles (USVs) out of Hobart as part of a mission monitoring the Southern Ocean to better understand how much carbon dioxide from the atmosphere is absorbed by the ocean surface.
The USVs, made by US-based unmanned systems specialist Saildrone, will be deployed every quarter over five years to circumnavigate Antarctica, operating through the challenging conditions of the Southern Ocean.
The Saildrone USVs are autonomous mobile research platforms powered by wind and solar energy. They will operate in remote waters for months at a time, recording data in real time to better understand ocean carbon sinks.
The project is part of an international collaboration between CSIRO, the National Oceanic and Atmospheric Administration (NOAA), South Africa’s Southern Ocean Carbon-Climate Observatory, Columbia University, the University of Washington, and Schmidt Sciences, through the Virtual Institute for the Carbon Cycle program, and Saildrone, to capture data on ocean carbon sinks.
CSIRO said ocean sinks store about a third of CO₂ absorbed from the atmosphere each year, with the Southern Ocean accounting for 40 per cent of global ocean CO₂ uptake, but more information is needed to better estimate how much CO₂ is absorbed.
CSIRO’s Dr Elizabeth Shadwick said this project is the first multi-year campaign to deploy USVs in the Southern Ocean specifically to acquire data in seasons and regions where ship traffic is limited.
“The Southern Ocean is central to the uptake and storage of CO₂ from human emissions,” Dr Shadwick said. “The Saildrone USVs are expected to travel around 22,000 kilometres for each deployment, giving us unprecedented coverage of regions that we can’t get to with research vessels or commercial ships. This will help fill critical gaps on how much carbon is being absorbed by the Southern Ocean, and what influences it.”
Dr Adrienne Sutton from NOAA said using a range of innovative technologies, like USVs, will enable scientists to capture data on what is driving CO₂ variability.
"The Southern Ocean is one of Earth's harshest environments and notoriously difficult to observe,” Dr Sutton said. “This project brings together new tools to overcome this challenge and tackle long-standing questions about the ocean's carbon sink.
“We will have a fleet of four Saildrone [USVs] operating at different points around the Southern Ocean. As a USV completes a circumnavigation of Antarctica, it will come back into Hobart where sensors will be replaced and the USV will be redeployed to start another circumnavigation. This pattern will continue for the duration of the five-year project.”
Professor Galen McKinley from Columbia University said instead of sailing pre-set routes, the USVs could conduct targeted data collection.
“We will be able to make adjustments over the course of the five-year mission to target data collection in the regions that are most needed to better understand the ocean carbon sink. We will also apply advanced, model- and AI observing tools to investigate carbon cycling in the Southern Ocean.”