The mysterious weaknesses of the Atlantic currents

From his scientific name The rotation of the atlantic meridian inversionor AMOC in English, it means ” Knot We owe the warm waters of the Gulf Stream rising to the north, to the surface of the ocean, and the colder, saltier Arctic waters, which descend to the south, below the surface. The perturbation of this phenomenon has long been referred to as one of the dangers of global warming: if the ocean current slowed down too much, or even stopped, this would disturb meteorologists on both sides of the North Atlantic, part of it getting colder and the other warmer – in addition to changing precipitation, accelerating rising water levels and reducing the ability of the oceans to absorb carbon dioxide.

Such disruption is inevitable as Arctic waters become warmer and melting ice brings more fresh water to the region. The problem is that experts cannot reach a consensus on the point of no return. It is clear that a significant portion of AMOC fluctuations are normal, and even this “weakest point in 1000 years” is still in the “average variables”, summarizes study Posted on April 25 in The nature of climate change. But more record falls are expected, considering that data has been piling up for 20 years to show that the tide is slowing. how much distance and speed, Impossible to say so we know What part of this slowdown It is the result of a natural cycle and any part is the result of human action. research The publication in 2018 put this latest slowdown in the context of a “weaker” stream for 150 years.

The new research is based on data collected by international networks of devices built across the Atlantic for 20 years, and on measurements collected since at least 1900. In line with what climate models predict – that is, it corresponds to what we are entitled to expect when we look for the “fingerprint” of human action on these ocean currents. But still not saying How much does this footprint weigh, and how fast it weighs.