14 DAY TRIAL // An international collaboration of researchers has recently confirmed the discovery of a new cold current in the North Atlantic. The flow, called the North Icelandic Jet (NIJ), was first found by two oceanographers from Iceland, who were also a part of the new team.
This finding has the potential to influence existing climate models, whose results depend to some extent on the way cold and warmer waters circulate through the critically-important North Atlantic.
NIJ was discovered by two investigators at great depths, off the northwestern coasts of Iceland, in the strait separating the island from Greenland. This circulation patterns may very well play a very important role in determining how the ocean responds to climate change.
According to the research team, the current contributes to the Denmark Strait Overflow Water (DSOW), which is in turn a current that is very important to the Atlantic Meridional Overturning Circulation (AMOC). The latter is one of the most important regulators of Earth's climate.
In the past, researchers determined that the primary source of water for the DSOW was the East Greenland Current (EGC), which is known to be a deep, overflow plume that feeds the lower limb of the AMOC, in the North Atlantic.
The reason why the Circulation is so important is because it carries warm water at high latitudes, where the heat warms the air. Winds then push the heated air over areas such as Europe, allowing the continent not to be overrun by glaciers all the way to the Mediterranean Sea.
After the water cools, it sinks to great depths and start moving towards the Equator again. The lower limb of the currents that make up the AMOC is fed from a variety of sources. The DSOW is one of the most important, and so the EGC was always known to be very important.
But what researchers did not know was that the EGC was not alone. Thanks to the new discoveries, they learned that NIJ also contributes to the DSOW, augmenting the effects of the East Greenland Current. The study appears in the August 21 online issue of the top journal Nature Geoscience
“Our data demonstrate that the NIJ indeed carries overflow water into Denmark Strait and is distinct from the East Greenland Current. The NIJ constitutes approximately half of the total overflow transport and nearly all of the densest component,” Robert Pickart explains.
“We present the first comprehensive measurements of the NIJ,” adds the Woods Hole Oceanographic Institution (WHOI) expert, who was also one of the coauthors on the new paper.
“These results implicate water mass transformation and exchange near Iceland as central contributors to the deep limb of the Atlantic Meridional Overturning Circulation, and raise new questions about how global ocean circulation will respond to future climate change,” Eric Itsweire adds.
The expert is a program director with the US National Science Foundation (NSF) Division of Ocean Sciences. The DOS funded this investigation, alongside the Research Council of Norway.