Inflow of Atlantic water into the Arctic threatens Greenland's ice
Researchers have long assumed that northern Greenland, with its remote location and extensive ice cover, will be the last area to lose ice as global warming continues. Although North Greenland is a key area for Arctic ice research, there is very little field data, especially about how the ocean interacts with the ice, the land glaciers draining into the ocean, their floating parts and the surrounding sea ice.
Studying Atlantic water intrusion
Through advanced studies of seafloor sediments combined with glacial and ocean modelling, THAWING will map how the properties of intruding Atlantic water around northern Greenland have changed over several thousand years, and how these changes have affected the ice and ecosystems that depend on it.
Research area: Arctic cceanography and marine geology
Project: "Tracking the influence of Atlantic water on North Greenland: THAWING"
Main researcher: Helen Coxall, professor of marine micropalaeontology, the Department of geological sciences, Stockholm University
Grant: SEK 24,000,000 over five years
Atlantification of the Arctic
Atlantic water, which is a little warmer than typical Arctic Ocean water, arrives as a surface current, and then circumnavigates the entire Arctic Ocean as a deep layer before reaching northern Greenland. This is a natural flow that has been going on in some form for millions of years. But in the last 30 to 40 years, the flow has been undergoing a change called "Atlantification".
”"Atlantification" is used to describe the ongoing changes in the inflow of Atlantic water into the Arctic Ocean. So far, the effects are clearly visible around Svalbard and in the Barents Sea where Atlantic water is shallow. A clear sign is that the sea ice extent in this area is being pushed further and further north,” says Helen Coxall, professor of marine micropaleontology at the Department of geological sciences at Stockholm University.
Impact on the ecosystems
The Atlantic water layer that reaches northern Greenland flows at a depth of a few hundred meters. This is typically too deep to effect glaciers, but when it enters deep fjords, it comes into contact with the floating parts outlet glaciers causing melting of ice below the sea surface.
”The contact with increasingly warmer water has had a significant impact on the ecosystems in the fjords of Svalbard. There has also been a dramatic increase in the melting of sea ice from the glaciers that meet the sea,” says Helen Coxall.
New field studies
But what happens if the inflow of Atlantic water increases and the temperature rises, or if the currents end up closer to sea level? These are questions that the research group will now investigate.
”Will it cause similar changes along northern Greenland as can already be observed around Svalbard, where Altantification is evident?" Will the marine parts of the ice then retreat more rapidly? In our measurements we can already see the influence of Atlantic water on the ice in northern Greenland, and rising sea temperatures could destabilise the ocean and land ice cover in the region,” says Helen Coxall.
Recording the circulation
To find answers, the THAWING research project will conduct studies of seafloor bathymetry and fjord geometry, but also map the properties and distribution of Atlantic water around northern Greenland and western Svalbard.
”By also studying Svalbard, which has already been affected by changes in the properties of the Atlantic water, we are basically recording the start and end points of the circulation of the Atlantic water through the Arctic. Studies of the glacier systems in Svalbard also provide important insights into how corresponding changes in the ocean may affect the Greenland ice sheet,” says Helen Coxall.
Extensive material and data
The research is based on extensive collections of material and geophysical and oceanographic data collected during two previous expeditions with the icebreaker Oden, the expeditions Petermann 2015 and Ryder 2019, as well as the recently completed expedition North of Greenland 2024, which surveyed the Lincoln Sea and the completely unexplored Victoria Fjord, where the outlet glacier C.H. Ostenfeld empties, in the summer of 2024.
Contributes to better predictions
Using climate data from seafloor sediments, samples of the living under-ice ocean plankton, ocean circulation modelling and glacier modelling, among other things, the research team will contribute with more knowledge about the future of marine glaciers.
”This means we can make better predictions of future sea level rise associated with ice loss from the northern Greenland ice sheet”.
Last updated: October 18, 2024
Source: Communications Office