The Irminger Sea is strategically located to play a critical role in the oceans' global circulation and the Earth's climate. But it has resisted extensive exploration, because it is one of the windiest and roughest patches of ocean on the planet.
Scientists and crew aboard the research vessel Knorr faced winds ranging from 60 up to 100 knots and 30- to 40-foot tall waves on an expedition to the Irminger Sea in October 2007. (Photo by Kjetil V?ge, Woods Hole Oceanographic Institution)
Waves wash over Knorr's decks in the dark of night during one of several fierce storms encountered during the research cruise. (Photo by Dan Torres, Woods Hole Oceanographic Institution)
The North Atlantic Current carries warm, salty tropical surface waters northward and “becomes” the Norwegian Current. The currents surrender heat to the atmosphere, and prevailing winds help warm Europe in winter. As the waters give up their heat, they become colder, and therefore denser, and sink to the depths in the deep basins of the Norwegian, Greenland, and Iceland Seas north of the Denmark Strait. (Ruth Curry/Woods Hole Oceanographic Institution and Cecilie Mauritzen/Norwegian Meteorological Institute)
The Greenland-Scotland Ridge looms like a great undersea barrier, stretching from East Greenland to Iceland and the Faroe Islands, and across to Scotland. The Denmark Strait is a critical checkpoint through which cold, fresher waters from northern seas flow across the ridge into the the main body of the North Atlantic Ocean. (Illustration by E. Paul Oberlander, Woods Hole Oceanographic Institution)
Almost like a subsea waterfall, cold, dense waters flow southward over the Greenland-Scotland Ridge into the Irminger Sea and then underneath warmer, less dense waters. (Illustration by E. Paul Oberlander, Woods Hole Oceanographic Institution)
Bob Pickart, a physical oceanographer at WHOI, was chief scientist of the Irminger Sea expedition. As well as exploring waters flowing through the Denmark Strait into the Irminger Sea, he also investigated the East Greenland Current flowing into the strait from the north and searched for evidence of a newly conjectured deep, dense current, called the Northwest Icelandic Jet, flowing eastward along the northern border of Iceland.
To reveal the currents flowing and converging in the region, researchers stopped the ship every two miles to lower and retrieve a package of instruments called a “CTD," which measures seawater conductivity (a proxy for salinity) and temperature at various depths. Over the four-week cruise, crew and scientists did that 263 times. (Photo by Dan Torres, Woods Hole Oceanographic Institution)
The researchers also used a WHOI-developed instrument called a Moored Profiler, a stout plastic pod housing temperature and salinity sensors and a current meter, deployed on a mooring that remains in the ocean for a year. The Profiler chugs up and down a mooring line by means of a tiny traction motor; it can collect hundreds of measurements throughout the water column and throughout the year. (Photo by Rick Krishfield, Woods Hole Oceanographic Institution)
The Irminger Sea has another type of beauty when calm. Here the sun sets over an iceberg. (Photo by Nick M?ller)
Students from Seltjarnarnes Community in Iceland toured the WHOI-operated research vessel Knorr in early October 2008 before it departed for research in the Irminger Sea. The school was one of five from the U.S., Greenland, Iceland, and the United Kingdom that participated in an online expedition. During the voyage, students logged on to learn about oceanography and shipboard life by reading daily dispatches prepared in English and Greenlandic. Students also e-mailed questions to and received answers from scientists.
(Photo by Harpa Frimannsdottir)