Global ocean circulation appears to be slowing. NASA |
A recent study published in Nature outlines research by a team of Yale University and University of Southhampton scientists. The team found evidence that Arctic ice loss is potentially negatively impacting the planet's largest ocean circulation system. While scientists do have some analogs as to how this may impact the world, we will be largely in uncharted territory.
AMOC is one of the largest current systems in the Atlantic Ocean and the world. Generally speaking, it transports warm and salty water northward from the tropics to South and East of Greenland. This warm water cools to ambient water temperature then sinks as it is saltier and thus denser than the relatively more fresh surrounding water. The dense mass of water sinks to the base of the North Atlantic Ocean and is pushed south along the abyss of the Atlantic Ocean.
Schematic of the Atlantic meridional overturning circulation. Wikipedia |
Evidence is growing that the comparatively cold zone within the Northern Atlantic could be due to a slowdown of this global ocean water circulation. Hence, a slowdown in the planet's ability to transfer heat from the tropics to the northern latitudes. The cold zone could be due to melting of ice in the Arctic and Greenland. This would cause a cold fresh water cap over the North Atlantic, inhibiting sinking of salty tropical waters. This would in effect slow down the global circulation and hinder the transport of warm tropical waters north.
Measured trend in temperature variations from 1900 to 2012. NOAA |
This scenario of a collapse in AMOC and global ocean circulation is the premise for the movie "The Day After Tomorrow." As a disclaimer, the plot line in which much of New England and Western Europe gets plunged into an ice age is significantly over exaggerated and unrealistic on human time scales.
While geologists have studied events in the past similar to what appears to be happening today, scientists are largely unsure of what lies ahead.
Links
- Sinkhole Forms In Front Of Trump's Mar-a-Lago; Twitter Response Is Huge
- Arctic sea-ice decline weakens the Atlantic Meridional Overturning Circulation
- Humanity Has Officially Consumed More Than Earth Can Produce This Year
- Atlantic meridional overturning circulation
- Climate Model Suggests Collapse of Atlantic Circulation is Possible
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