Their findings, published in the journal Nature Geoscience, provide new insight into the role that rivers play in the global carbon cycle — and how that role may change as the Arctic continues to warm.
The scientists studied the fate of river carbon in the Arctic Ocean by using a combination of field observations, laboratory experiments and computer modeling. They focused on the Laptev Sea, which receives large amounts of river water from the Lena River, one of the largest rivers in the world.
The researchers found that river carbon is transported into the Arctic Ocean in several different forms, including dissolved organic matter, particulate organic matter, and dissolved inorganic carbon.
Once in the ocean, river carbon can be used by phytoplankton as food, or it can be stored in the ocean floor sediments. The researchers found that the fate of river carbon in the Arctic Ocean is influenced by a number of factors, including the amount of river water that enters the ocean, the temperature of the ocean water, and the availability of sunlight.
The scientists also found that river carbon can be transported from the Arctic Ocean to the North Atlantic Ocean, where it can contribute to the build-up of atmospheric carbon dioxide.
The findings of this study have implications for understanding the global carbon cycle and how it may change in the future. As the Arctic continues to warm, the amount of river water that enters the Arctic Ocean is expected to increase, as will the temperature of the ocean water. These changes could lead to an increase in the amount of river carbon that is released into the atmosphere, contributing to climate change.
The study was funded by the National Science Foundation and the National Aeronautics and Space Administration.
