The research project AXIS (An extended time series of deep overflow: how variable is the AMOC?) will now study this. The project brings together researchers from Denmark, the Faroe Islands and Norway and has just been launched.
Ocean currents with global significance
The North Atlantic plays a key role in the global climate system. When cold, heavy water masses flow down through the underwater passages between Greenland, Iceland, the Faroe Islands and Scotland, they drive the large ocean circulation AMOC, which transports warm water northwards. This mechanism helps ensure a mild climate in Northern Europe.
But how stable is the current? And how does it respond to climate change? These are the central questions that the AXIS project aims to answer.
The past as a key to the future
The researchers will analyse sediment cores from the seabed north of the Faroe Islands and in the Denmark Strait. Among other things, they will look at the grain size and composition of the sediments, which can reveal how strong the ocean currents have been over the past thousands of years. These geological data will be compared with instrumental measurements from recent decades. This will allow the researchers to create a long time series of how the ocean circulation has varied under different climatic conditions – including periods when it was warmer than today, e.g. during the previous interglacial period, Eem.
“We know that deep-water formation off the Faroe Islands plays a central role in the ocean circulation and thus in the climate. With AXIS, we can look back thousands of years and examine how the system responded during past climate changes. This gives us a unique opportunity to understand the changes we are seeing now,” says Project Leader Camilla S. Andresen, Professor at the Geological Survey of Denmark and Greenland (GEUS).
The Faroe Islands a key area
For the Faroe Islands, the project is particularly important.
“The Faroe Islands are located in the middle of this global system. For us, it is important to understand how the ocean currents around the islands have changed historically, and what this means for the future marine environment and climate in the region,” says Lis Mortensen from Jarðfeingi.
From Havstovan, Hjálmar Hátún adds:
“The project gives us the opportunity to put Faroese research into an international framework and at the same time contribute local knowledge that is crucial if we want to understand the whole picture.”
A combination of methods
One of the project’s strengths is the coupling of many different data sources: geological archives, contemporary measurements and climate models.
“This gives us the opportunity to extend the time series thousands of years back and study whether the variations we see today are part of a natural pattern – or a new phenomenon driven by climate change,” says Tine Rasmussen, Professor at the University of Tromsø.
International collaboration
The AXIS project has received DKR 3,597,718 from The Programme Committee for the Marine Research in the North Atlantic Ocean programme (MARiNAO).
The project is led by the Geological Survey of Denmark and Greenland (GEUS) in collaboration with the Geological Survey of the Faroe Islands, Jarðfeingi, the Faroese Marine Research Institute, Havstovan, and the University of Tromsø.
You can read more about the project here.