Newly discovered Icelandic current could change climate picture

Terra Daily: 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....

Northern part of Denmark Strait showing the location of the newly discovered deep current in relation to the known existing pathway of dense water. (Graphic by Jack Cook, Woods Hole Oceanographic Institution)