Source-to-sink carbon transfer using carbonate system parameters, oxygen, and radium isotopes
What is the motivation?
The Arctic is warming three times faster than the global average, causing Greenland’s ice sheet to melt rapidly. This adds freshwater and carbon to fjords, raising sea levels, lowering sea surface salinity, and accelerating the carbon cycle. Understanding these changes is crucial to predict how Arctic environments will evolve.
Why does it matter?
Arctic waters are highly sensitive to ocean acidification because cold, fresh meltwater absorbs more CO₂ than warmer, saltier waters. Retreating glaciers and increased freshwater flow alter fjord circulation and chemistry, potentially threatening coastal ecosystems and their productivity. Studying physical, chemical, and biological interactions in these areas is vital to anticipate changes in these fragile environments and to inform global climate and ecosystem models.
© Bruno Lansard
Project Focus
CARAMBAR investigates carbon sources and sinks along Greenland’s fjords and examines how Arctic warming affects them. The project tracks freshwater from rivers, glaciers, and sea ice using oxygen isotopes, while radium isotopes reveal water mixing rates. Sediment cores quantify carbon storage on the seafloor. This approach connects the land-sea continuum, linking glacier melt, water movement, and carbon cycling in rapidly changing Arctic fjords.
How will it be done?
Seawater pH, alkalinity, and dissolved carbon will be measured on board. Carbon isotopes determine whether carbon originates from the atmosphere, land, or ocean and reveal its reactivity. Oxygen isotopes identify freshwater sources, while radium isotopes track water mixing rates. Both inorganic and organic, dissolved and particulate carbon forms will be analyzed to quantify carbon flow and storage in fjord waters and sediments.
© Bruno Lansard
What will be collected?
Samples include seawater from the surface to the seafloor, meltwater from glaciers, lakes, rivers, and sea ice, as well as sediment cores and porewater. Sediment cores will be sectioned to measure sedimentation rates using natural and artificial radionuclides, providing insight into carbon sequestration over time.
Members and partners
- Principal Investigator:
- Bruno Lansard, Laboratory for Climate and Environmental Sciences, Université Paris-Saclay, France
- Other participants:
- Pieter Van Beek, Laboratory of Space Geophysical and Oceanographic Studies, Toulouse Université 3, Toulouse, France
- Swan Schluk, Laboratory for Climate and Environmental Sciences, Université Paris-Saclay, France
- Claire Waelbroeck, Laboratoire d’Océanographie et du Climat : Expérimentations et Approches Numériques, Université Sorbonne, Paris, France
- Partners:
- Mathieu Ardyna, University of Laval, Québec City, Canada
- Jean-Éric Tremblay, University of Laval, Québec City, Canada
- Philippe Archambault, University of Laval, Québec City, Canada
- Gwénaëlle Chaillou, Université du Québec à Rimouski, Rimouski, Canada
- Ludovic Pascal, Université du Québec à Rimouski, Rimouski, Canada
- Mathilde Jutras, Université du Québec à Rimouski, Rimouski, Canada
- Lisa Bröder, Department of Earth and Planetary Sciences, ETH Zurich, Zurich, Switzerland
- Margot White, Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, Canada