High winds affect ocean circulation in North Atlantic, says study

December 20, 2012 in Earth / Earth Sciences

(Phys.org)—Gale-force winds that whip around the Greenland coast are driving ocean circulation, confirms a new study on the cover of the Nov. 30 issue of Geophysical Research Letters.

The study, led by U of T Mississauga professor Kent Moore, shows that a new diagnostic tool reveals the formation of high-speed winds in the northern Atlantic and their effect on waters, deep sea currents and sea ice behaviour.

"We now have a more complete understanding of the complexity of the climate system," says Moore, a professor in the Department of Chemical and Physical Sciences. "This new diagnostic shows us how the shape of coastline can impact winds, and how the winds in turn drive oceanic events."

Moore began with an examination of Cape Farewell, on the southernmost tip of Greenland. The windiest oceanic site in the world, Cape Farewell experiences gale force winds called "tip jets" for one-sixth of the time during the winter.

With the new diagnostic, a , Moore separated out gale force wind observations by wind direction and re-analyzed from 1979 to 2012. It confirmed previous hypotheses that tip jets are caused by the sudden and steep elevation of Greenland's coast. Winds hitting the coast are forced to go around the land instead of over, causing wind acceleration (known as the Bernoulli effect, which also results in lift on an ).

"The diagnostic is quite simple but provides a more comprehensive view of how these winds develop and makes a real difference in how we study these winds," says Moore. He discovered three additional regions where strong winds are driven by the steep – along the northeastern and southwestern coasts of Greenland and on Iceland's southeast coast.


"These winds play a vital role in the thermohaline, or large-scale ocean, circulation which is a very important part of the ," says Moore. "The winds are what cause the return flow for the Gulf Stream, and are an example of how the atmosphere drives ocean circulations."


"We showed these tip jets form in several areas around Greenland, and in all these regions they play a crucial role in oceanic events," says Moore. "The diagnostic allows us to unify many questions relating to the land, the atmosphere and the ocean."

Provided by University of Toronto Mississauga

"High winds affect ocean circulation in North Atlantic, says study" December 20, 2012 http://phys.org/news/2012-12-high-affect-ocean-circulation-north.html