Scientists study flow of glacial meltwater into oceans
A research team measures meltwater runoff from the ice sheet margin in Greenland during summer 2013. Photo: Thomas Mote/UGA
Scientists have observed a significant increase in the melting of glacial land ice on Greenland, spurring concerns about global sea level rise.
A research team led by the University of Georgia (UGA) and including a Georgia Tech scientist has discovered the fate of much of the fresh water that pours into the surrounding oceans as the Greenland ice sheet melts every summer. The findings were published in the journal Nature Geoscience.
“Understanding the fate of meltwater is important, because research has shown that it can carry a variety of nutrients, which may impact biological production in the ocean,” said Renato Castelao, co-author of the study and associate professor of marine sciences at UGA.
The researchers created a simulation that tracks meltwater runoff under a variety of atmospheric conditions, and they were surprised to discover that most of the meltwater found off the west coast of Greenland actually originated from ice on the east coast. The meltwater is largely deposited into the Labrador Sea, an arm of the Atlantic between Canada’s Labrador Peninsula and the east coast of Greenland.
Annalisa Bracco, a professor in Georgia Tech’s School of Earth and Atmospheric Sciences, says the Labrador Sea is a basin of key climate relevance because it’s one of the few places in the world where “deep water” is formed in the ocean through convection.
“In winter, water can mix to depths of 2,000 meters (6,000 ft.) and feed deep ocean currents,” she said. “If the surface stratification of the ocean changes — because so much melted water reaches the central Labrador Sea — convection will be halted, which creates dangerous consequences for the global climate.” — James Hataway, University of Georgia