UK ocean robots exploring depths of the Labrador Sea

The year-long experiment, led by scientists from the UK's National Oceanography Centre (NOC) in Southampton, is part of the ReBELS project (Resolving Biological Carbon Export in the Labrador Sea).

The project is investigating the biological carbon pump, a key ocean process that helps remove carbon dioxide from the atmosphere and store it in the deep sea.

Without this process, atmospheric CO₂ would be 50 per cent higher.

Dr Louis Clement, ReBELS co-investigator (Image: Supplied) The project uses a combination of moored sensors, drifting profiling floats, and autonomous underwater vehicles to understand how carbon-rich particles sink through the water column and how physical ocean processes might enhance carbon storage in this remote region.

A key innovation in the project is the FluxCAM, a novel marine snow camera system designed to measure the sinking speeds of different-sized particles to reduce uncertainties in how much carbon the ocean absorbs from the atmosphere.

Two FluxCAMs were installed on a deep-sea mooring in the Labrador Sea last year, along with a specially programmed drifting profiling float.

They have now been joined by autonomous underwater gliders, which will measure ocean properties and carbon flux for five to six months.

Deployment underway (Image: Alexander Cerra) Dr Filipa Carvalho, project lead at NOC, said: "The biological carbon pump plays a crucial role in regulating Earth's climate.

"Microscopic marine plants, known as phytoplankton, absorb carbon dioxide from the atmosphere and convert it into organic material.

"This material is then consumed by marine organisms, with remnants eventually sinking as 'marine snow'—tiny carbon-rich particles that settle in the deep ocean, where the carbon can be stored for centuries.

"However, the rate at which these particles sink and how much carbon is ultimately locked away remain uncertain.

"The ReBELS project is using cutting-edge technology to answer these questions."

The ReBELS float has been programmed to carry out more frequent and varied depth profiles than standard floats and is also equipped with advanced sensors, including an optical sediment trap.

One of the gliders will stay near the mooring, while another one will follow a drifting profiling float, capturing detailed, high-resolution data on particle movement, ocean circulation, and biological activity.