The Gulf Stream, also called the Atlantic Meridional Overturning Circulation (AMOC), is operating at its weakest point in 1,600 years, according to new research. The deep-water circulation plays an important role in helping regulate climate around the globe; a disruption to it could have a major impact on Western Europe, the Eastern US, and the African Sahel.
The research comes from the Woods Hole Oceanographic Institution and University College London. According to it, the Gulf Stream hasn’t been running at its top strength since some time in the mid-1800s. However, the current is now at its weakest point in 1,600 years; this represents a 15-percent to 20-percent weakening in only 150 years.
Past models have underestimated the Gulf Stream’s weakening, but the reasons why aren’t clear. The team analyzed available data, including sediment records, to make their determination. Freshwater entering the North Atlantic is a key disruptor to the current by diluting the surface seawater, reducing its ability to deeply sink, which in turn slows down the entire circulation.
Warmer global temperatures can be blamed for the freshwater’s presence; as temps rise, Arctic ice melts and the freshwater pours into the ocean. According to the researchers, the weakening began around the end of the Little Ice Age, which was a cold period that ended in the mid-1800s.
As well, another recently published study on the same topic out of the Potsdam Institute for Climate Impact Research found that the weakening has picked up speed since the 1950s. That uptick can be attributed to global warming; as the planet heats up due to human activity, the Arctic ice melts more quickly and greater amounts of freshwater enter the North Atlantic, increasingly disrupting the circulation.
SOURCE: Science Daily