An international team led by Cambridge-based British Antarctic Survey is using airborne drones, marine robots, satellites and sensors to explore how a melting Greenland is affecting ocean currents, which could cause changes to weather in the UK and across Europe.
Their six-week expedition is designed to study how quickly the ice sheet’s rapidly-melting fjord glaciers are pushing the Atlantic Ocean towards a critical climate tipping point.
RRS SDA and Erebus in Greenland crop. Picture: BAS
The team, which travelled on the UK’s polar research ship RRS Sir David Attenborough, will use the data collected to improve predictions for the future of Greenland’s glaciers and their impact on the surrounding ocean as they melt.
The fieldwork is part of a five-year project called GIANT (Greenland Ice sheet to AtlaNtic Tipping points) which involves 17 partners, including seven international partners.
Dr Kelly Hogan, a marine geophysicist at British Antarctic Survey who is leading the GIANT research project, said: “We’re in a moment where our tools have finally caught up with our questions. With autonomous vehicles, advanced sensors, and powerful modelling – boosted by AI – we can explore glacier-ocean interactions in ways that were unimaginable just a few years ago.”
Vast quantities of freshwater are being added to the ocean by Greenland’s rapidly-melting ice and scientists are concerned it could affect a major Atlantic Ocean current system – the North Atlantic Subpolar Gyre.
It acts like a whirlpool of ocean currents, affecting the Atlantic Meridional Overturning Circulation (AMOC), which is described as the planet’s ocean conveyor belt as it moves heat and nutrients around the world.
RRS Sir David Attenborough in Greenland
The AMOC brings warm, salty water from the tropics to the north which is cooled by the cold, sub-Arctic air and sinks.
This pulls more water up from the south, driving a three-dimensional conveyor belt of water.
Scientists think fresh, cold meltwater from Greenland’s melting fjord glaciers could ‘cap’ the Subpolar Gyre, however, reducing the water beneath it from sinking.
This might slow the AMOC, seriously impacting the regional climate, including the UK – a major change that some estimates suggest could happen within decades.
The researchers have travelled to south-east Greenland to study tidewater glaciers near Kangerlussuaq Fjord. These glaciers flow through long, narrow fjords and end in towering ice cliffs of up to 100m. But frequent iceberg calving creates an ice mélange. This dense, slushy pack of sea ice and chunks of icebergs can act as a brake on the glacier and slow its flow into the ocean.
The debris clears in the summer, meaning calving rates increase and glaciers can retreat rapidly.
The scientists will use their floating laboratory to conduct detailed measurements of fjord depth and shape, as well as ocean temperature, salinity and currents. They will also launch autonomous vehicles to take samples in the hazardous region near the ice.
This will enable them to study fjord and glacier behaviour at all scales, from individual cracks in the ice to the flow of meltwater and icebergs into the North Atlantic.
RRS SDA in Greenland 2025. Picture: BAS
Meltstake – a first-of-its-kind instrument – will measure melting directly at the ice face. The sensor will be lowered by a remotely-operated boat and drill into the ice 100m below the surface to measure how water transfers heat to the ice.
Meanwhile, DriX – a surface skimming robot – will map the shape of the glacier under the water with a scanning sonar to track changes in melt rate on daily or even hourly timescales and collect data such as current strength and direction, temperature and saltiness
A family of robots – Gavia and EcoSubs – will use acoustic positioning technology to dive hundreds of metres below the surface as a team, collecting data from the glacial ice face.
These can get closer to the ice face than DriX, to map the submerged glacier front and collect data about the ocean.
And the UK’s most famous underwater robot – Boaty McBoatface – will be part of the fleet. The Autosub Long Range, developed by the National Oceanography Centre, will dive 1500m deep below the mélange to map its geometry and study how it impacts the surrounding ice and ocean as it melts.
Dr Pierre Dutrieux, an oceanographer at British Antarctic Survey, is leading the ocean robotics research on RRS Sir David Attenborough.
“If we want to understand how glaciers melt and fracture, we need to be where the action happens – where the glacial ice meets the ocean. We need these ocean robots to do this – the glacier front is so unpredictable and dangerous, because huge blocks of ice calve into the ocean with little warning,” he said.
“With the fleet of autonomous and remotely controlled instruments we have with us, some of the data we’ll be collecting will be the first of its kind. The DriX will give us a near-live feed of what is happening right at the glacier face – something we wouldn’t have thought possible even a few years ago.”
Gavia AUV in a Svalbard fjord in 2016. Picture: John Howe, SAMS
A small team of researchers will camp near the glacier itself to collect more data about how the ice is behaving. They will use an instrument called Adios, installed on the glacier, to measure its precise position and how fast it is moving. It will use radar to study internal ice layers, to track how the ice is moving and straining.
Small instruments called Geopebbles – GPS-enabled seismic sensors which record cracking and calving events – will also be deployed.
The huge amount of data, boosted by machine learning and AI, will feed into ice, ocean and climate models, helping us better understand how Greenland ice loss impacts global climate change.
The researchers also aim to develop a prototype Early Warning System to provide advance notice of rapid glacier change.
The work is funded by the Advanced Research + Invention Agency (ARIA), as part of their Forecasting Tipping Points programme.