Atlantic Cold ‘Blob’ Worries Scientists, Could Disrupt Currents

This year was one of the hottest on record, but a cold blob of water in the North Atlantic Ocean has scientists baffled and worried. The blob may be the result of melting ice in Greenland, and it could indicate a slowdown of ocean currents in the north Atlantic. If that sounds familiar, it’s probably because the exact same thing happened in the 2004 film The Day After Tomorrow.

Nobody knows exactly what caused the cold blob in the North Atlantic, but scientists have some theories, and the implications are troubling.

atlantic cold blob
The Atlantic cold 'blob' is one of the few places in the world where temperatures are lower than normal.

Michael Mann of Penn State and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research spoke to the Washington Post on the subject of the cold blob.

According to Mann and Rahmnstorf, the cold blob, coupled with the record temperatures elsewhere this year, points toward a slowing down of something called the “meridional overturning circulation,” which is a fancy bunch of words that just means ocean currents in the Atlantic may be slowing down.

The way that the currents in the Atlantic work is that warm water travels north at the surface, reaches colder areas near the Arctic and Greenland, and cools down. As it becomes more dense, the cold water sinks, effectively pulling warm surface water northward to replace it. The cold water then travels south deep below the surface, and the process repeats.

One theory that seeks to explain the cold blob in the Atlantic has to do with abnormally warm temperatures this year, causing land ice in Greenland to melt. The newly melted ice flowed into the ocean, reducing the local concentration of salt water and making the ocean less dense in that area.

Since the cold water was no longer dense enough to descend due to the higher level of salinity in the water below it, less warm water was drawn north, and the cold blob was born.

That is just one theory, and not everyone agrees on it. Some scientists believe that natural variability in the currents of the North Atlantic could account for the appearance of the cold blob rather than lowered salinity due to melting ice.

While the events that have created the cold blob in the Atlantic are very similar to events portrayed in The Day After Tomorrow, scientists caution that the movie was not a true portrayal of the consequences of slower currents in the North Atlantic.

“The things that aren’t likely to result are just about anything that’s portrayed in the movie, The Day After Tomorrow, which is really a caricature of the science,” Michael Mann told the Washington Post.

climate anomalies
Some areas have been significantly hotter this year, while areas in the North Atlantic have been colder.

If the currents continue to slow, we could see slightly higher sea levels along the east cost. In fact, the Washington Post reports that when the currents slowed down between 2009 and 2010, the sea level along the east coast rose about four inches.

That pales in comparison to the “caricature of science” portrayed in The Day After Tomorrow, but the cold blob could have an effect on local marine life and weather throughout the Atlantic.

In fact, a warm blob in the Pacific had those exact same effects last year. According to Discovery, the warm blob was blamed for everything from sea lion die-offs to drought on the west coast.

According to CNN, 99 percent of the fresh water in the entire world is contained in Antarctic and Greenland ice sheets.

If ice in greenland continues to melt, that could mean a whole lot of fresh water being dumped into the North Atlantic and the currents being disrupted even further. Or this whole thing could just be another anomaly, like the slowdown that occurred in 2009-2010.

Do you think the Atlantic cold blob is something to worry about?

[Photo by Joe Raedle / Getty Images News, other images courtesy of NOAA]