Newly Discovered Icelandic Current Could Change Climate Picture
National Science Foundation
Current called North Icelandic Jet contributes to key component of ocean circulation
If you'd like to cool off fast in hot summer weather, take a dip in a newly discovered ocean current called the North Icelandic Jet (NIJ).
You'd need to be far, far below the sea's surface near Iceland, however, to reach it.
Scientists have confirmed the presence of the NIJ, a deep-ocean circulation system off Iceland. It could significantly influence the ocean's response to climate change.
The NIJ contributes to a key component of the Atlantic Meridional Overturning Circulation (AMOC), critically important for regulating Earth's climate.
As part of the planet's reciprocal relationship between ocean circulation and climate, the AMOC transports warm surface water to high latitudes where the water warms the air, then cools, sinks and returns toward the equator as a deep flow.
Crucial to this warm-to-cold oceanographic choreography is the Denmark Strait Overflow Water (DSOW), the largest of the deep, overflow plumes that feed the lower limb of the AMOC and return the dense water south through gaps in the Greenland-Scotland Ridge.
For years it has been thought that the primary source of the Denmark Overflow was a current adjacent to Greenland known as the East Greenland Current.
However, this view was recently called into question by two oceanographers from Iceland who discovered a deep current flowing southward along the continental slope of Iceland.
They named the current the North Icelandic Jet and hypothesized that it formed a significant part of the overflow water.
Now, in a paper published in the August 21st online issue of the journal Nature Geoscience, the team of researchers--including the two Icelanders who discovered the current--has confirmed that the Icelandic Jet is not only a major contributor to the DSOW but "is the primary source of the densest overflow water."
"We present the first comprehensive measurements of the NIJ," said Robert Pickart of the Woods Hole Oceanographic Instititution in Massachusetts, one of the co-authors of the paper.
"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."
The researchers used a numerical model to hypothesize where and how the NIJ is formed.
"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," said Eric Itsweire, program director in the U.S. National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the research.
"We've identified a new paradigm," Pickart said, likely a new, overturning loop of warm to cold water.
The results, Pickart says, have "important ramifications" for ocean circulation's impact on climate.
National Science Foundation
Current called North Icelandic Jet contributes to key component of ocean circulation
If you'd like to cool off fast in hot summer weather, take a dip in a newly discovered ocean current called the North Icelandic Jet (NIJ).
You'd need to be far, far below the sea's surface near Iceland, however, to reach it.
Scientists have confirmed the presence of the NIJ, a deep-ocean circulation system off Iceland. It could significantly influence the ocean's response to climate change.
The NIJ contributes to a key component of the Atlantic Meridional Overturning Circulation (AMOC), critically important for regulating Earth's climate.
As part of the planet's reciprocal relationship between ocean circulation and climate, the AMOC transports warm surface water to high latitudes where the water warms the air, then cools, sinks and returns toward the equator as a deep flow.
Crucial to this warm-to-cold oceanographic choreography is the Denmark Strait Overflow Water (DSOW), the largest of the deep, overflow plumes that feed the lower limb of the AMOC and return the dense water south through gaps in the Greenland-Scotland Ridge.
For years it has been thought that the primary source of the Denmark Overflow was a current adjacent to Greenland known as the East Greenland Current.
However, this view was recently called into question by two oceanographers from Iceland who discovered a deep current flowing southward along the continental slope of Iceland.
They named the current the North Icelandic Jet and hypothesized that it formed a significant part of the overflow water.
Now, in a paper published in the August 21st online issue of the journal Nature Geoscience, the team of researchers--including the two Icelanders who discovered the current--has confirmed that the Icelandic Jet is not only a major contributor to the DSOW but "is the primary source of the densest overflow water."
"We present the first comprehensive measurements of the NIJ," said Robert Pickart of the Woods Hole Oceanographic Instititution in Massachusetts, one of the co-authors of the paper.
"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."
The researchers used a numerical model to hypothesize where and how the NIJ is formed.
"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," said Eric Itsweire, program director in the U.S. National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the research.
"We've identified a new paradigm," Pickart said, likely a new, overturning loop of warm to cold water.
The results, Pickart says, have "important ramifications" for ocean circulation's impact on climate.
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