Decades-long Arctic rivers study reveals widespread changes

Research examining a 20-year record of water chemistry in the six largest Arctic rivers — the Ob', Yenisey, Lena and Kolyma in Russia, and the Mackenzie and Yukon in North America, which together capture two-thirds of the Arctic Ocean watershed area — finds that the rivers signal widespread effects of climate change in the Far North.

The results, published in Nature Geoscience, were made possible by the Arctic Great Rivers Observatory (ArcticGRO), which provides researchers with data about the chemistry of the largest Arctic rivers. These rivers transport huge quantities of water and materials to the Arctic Ocean and surrounding seas.

The project is supported by the U.S. National Science Foundation and is a component of NSF's Arctic Observing Network. ArcticGRO's work involves collaborators in the U.S., Canada and Russia.

"The chemistry of rivers provides information about the landscapes they drain, and thus we can assess climate change effects over vast areas through water chemistry at downstream locations," says Jim McClelland of the University of Chicago Marine Biological Laboratory. "This paper presents a comprehensive analysis of temporal [time] patterns in water chemistry of the major Arctic rivers, and offers insights into the effects of warming, permafrost thaw, vegetation changes and other climate impacts." 

Earlier research documented long-term increases in river water discharge to the Arctic Ocean, but at the time little was known about the chemical composition of these rivers.  Two decades later, chemistry data from ArcticGRO are showing that widespread changes are happening.

Roberto Delgado, a program director in NSF's Office of Polar Programs, says that "the findings underscore the importance of international collaborations and sustaining long-term observations to help detect and understand the drivers and consequences of environmental change across the Arctic."