New current that transports water to major ‘waterfall’ discovered in deep ocean
The high-seas ferry MS Norröna, cited in the Nature Communications paper, measures upper ocean currents with an ADCP (acoustic Doppler current profiler) installed in its hull as it makes a weekly roundtrip between Denmark, the Faroe Islands and Iceland.
Credit: Erik Christensen – Own work, CC BY-SA 3.0, commons.wikimedia.org/w/index.php?curid=45707529
An international team discovered a previously unrecognized ocean current that transports water to one of the world’s largest “waterfalls” in the North Atlantic Ocean: the Faroe Bank Channel Overflow into the deep North Atlantic. While investigating the pathways that water takes to feed this major waterfall, the research team identified a surprising path of the cold and dense water flowing at depth, which led to the discovery of this new ocean current.
“This new oceancurrent and the path it takes toward the Faroe Bank Channel are exciting findings,” said Léon Chafik, the lead author of the paper published in Nature Communications and a research scientist at Stockholm University, Sweden.
“The two discoveries reported here, in one of the best studied areas of the world ocean, is a stark reminder that we still have much to learn about the Nordic Seas,” said co-author Thomas Rossby, emeritus professor at the URI Graduate School of Oceanography. “This is crucial given the absolutely fundamental role they play in the major glacial-interglacial climate swings.”
Previous studies dealing with this deep flow have long assumed that these cold waters, which flow along the northern slope of the Faroes, turn directly into the Faroe-Shetland Channel (the region the water flows through before reaching the Faroe Bank Channel). Instead, Chafik and the paper’s co-authors show that there exists another path into the Faroe-Shetland Channel. They show that water can take a longer path all the way to the continental margin outside Norway before turning south heading toward this major waterfall. “Revealing this newly identified path from available observations was not a straightforward process and took us a good deal of time to piece together” said Chafik.
The researchers also found this new path depends on prevailing wind conditions. “It seems that the atmospheric circulation plays a major role in orchestrating the identified flow regimes,” added Chafik.