MercoPress. South Atlantic News Agency

Scientists on board RRS Sir David Attenborough set to unlock Southern Ocean’s carbon secrets

Scientists are embarking on an ambitious 30-day scientific expedition on board RRS Sir David Attenborough

A team of scientists are embarking on an ambitious 30-day scientific expedition on board Falkland Islands flagged RRS Sir David Attenborough to investigate how carbon dioxide moves and transforms in the Southern Ocean. The ship heads to the Weddell Sea to begin the PICCOLO cruise this week, from Punta Arenas, Chile.

The scientists on board are hoping to learn more about the biological and chemical processes that draw carbon deep into the Southern Ocean.

As the carbon in the seawater rises to the surface near Antarctica, it interacts with the atmosphere, ice, and microscopic plants and animals, called phytoplankton and zooplankton, near the ocean surface, before descending to the ocean depths. By understanding more about this process, the researchers hope to improve models that make predictions about our future climate.

Researchers will make use of the latest technologies, such as autonomous submarines, gliders and floats, to observe these processes in places that, until now, have been inaccessible and unstudied, like under the sea ice.

The team will also drill holes in the sea ice to collect samples below it, as well as tagging seals with instruments which will continuously collect data about the ocean as they dive up and down through the water, sending data back to scientists in real-time via satellite communication.

Four researchers from British Antarctic Survey are on board, and will be investigating the key biological processes, such as how zooplankton transport carbon as they migrate between the ocean surface and its depths. The team will collect samples by using floating and moored platforms to catch tiny sinking particles – known as marine snow. They will also use nets to catch zooplankton at different depths to learn more about their movement through the water.

Dr Clara Manno, a marine ecologist at BAS and part of the PICCOLO project, says: “We’re focusing on the Western Weddell Sea to find out more about some of the key processes that control how much carbon the Southern Ocean is taking up.

Within this vast ocean, the Weddell Sea is considered a ‘trapdoor’ through which CO2 leaves the atmosphere and enters the deep ocean.”

PICCOLO is collecting first-of-its-kind, systematic, year-round measurements of the processes controlling the carbon cycle. Part of this involved anchoring a scientific mooring to the seabed last year, where it has been left over the winter to collect data. The team will collect this mooring as part of the cruise.

The observations and data from this project will be fed into earth system models, to help make future predictions about our climate more accurate.

The PICCOLO cruise will see the full capabilities of the RRS Sir David Attenborough put through their paces. Over the past couple of years, the ship has undergone numerous trials to get it science-ready, including the polar science trials last season.

British Antarctic Survey (BAS) operates the RRS Sir David Attenborough, which is owned by UKRI-NERC. It provides a platform for the UK polar community to do research in the Polar Regions.

The PICCOLO cruise is part of the NERC-funded RoSES research programme, which focuses on understanding of the tole the Southern Ocean plays in the wider earth system. The scientific evidence gained through this research will be used to inform decisions about international climate policy.