Scientists have long struggled to predict the Atlantic Meridional Overturning Circulation (AMOC), a critical component of Earth’s thermal circuit. A new study has identified an underappreciated climate lever – the density of sinking water near Greenland – as a key driver of changes in the southern current.
Led by Petit, the research team found that it is not the strength of the North Atlantic current but rather the weight of cold water that sets the tempo for the AMOC. Heavier water drops faster, triggering midlatitude current shifts within a year. This discovery has significant implications for our understanding of climate regulation and the potential to predict major climate swings.
The study used OSNAP’s underwater moorings and roaming sensors to track how wind, pressure, and buoyancy influence ocean density and circulation strength. Changes in atmospheric pressure, driven by polar winds and weather shifts, alter sea surface conditions and indirectly affect the AMOC downstream.
Interestingly, midlatitude regions are not reacting directly to local forces but rather experiencing the effects of Arctic and subpolar processes that steer their ocean engine. This finding challenges the traditional view that deep ocean changes occur slowly. Instead, it reveals a climate machinery that can react with speed, precision, and force – driven by shifting density layers.
By monitoring subpolar density, scientists may be able to unlock smarter climate models, enabling predictions of major climate swings in advance, not just decades later, but seasons ahead.
Source: https://www.businesstoday.in/visualstories/news/who-controls-earths-heat-the-hidden-signal-that-powers-our-weather-shifts-238074-30-05-2025