Thursday, March 26, 2015

Atlantic’s Overturning Circulation slows to Levels not Seen in More than 1,000 Years

Atlantic Ocean currents are known for fueling Gulf streams, influencing sea levels, affecting warm cities in continental Europe and North America and also to get nutrients to maintain marine ecosystems and fisheries.

But a new research has found flow of cold water from the melting Greenland ice sheet is reducing the ocean circulation to levels that have not been witnessed in more than 1,000 years.

The researchers have gathered data based on coral samples, ice cores and tree rings, so that they can track the decline of the Atlantic Ocean phenomenon. In the research published in the Nature Climate Change, observations and studies of sea-surface temperatures have bene done to come up with a new index.

The index would detail about the declining force of the Atlantic meridional overturning circulation (AMOC), considered to be one of the most important circulation systems of the planet. The index has unveiled about tha sharp slowdown between 1970 and 1990, which was detected as well.

Though it followed a partial recovery, it failed to strengthen the system enough to its vigorous state. If to go as per the researchers then increasing melt rates in Greenland, "might lead to further weakening of the AMOC within a decade or two, and possibly even more permanent shutdown" of important components of it, said the researchers.

Stephen Griffies, National Oceanic and Atmospheric Administration climate and ocean modeler, said that the findings are significant and consistent with the estimations made by computer climate models.

Griffies affirmed that it is expected that there will be more evidence to come for the slowdown of the circulation. It is considered that if the overturning circulation slows down more, the extreme sea-level events on the East Coast will become more frequent.

No comments:

Post a Comment