For many years, scientists were confounded by an unusual region of the ocean just south of Greenland that behaved differently than the rest of the planet. While ocean temperatures worldwide have steadily increased, this area, referred to as the Atlantic Warming Hole, has experienced a cooling of nearly half a degree Fahrenheit over the past century. Now, researchers suggest they may have unraveled the mystery.
Contrary to its designation, this area is anything but warm. It is, in fact, a cold region in the North Atlantic where temperatures have declined even as the rest of the ocean warms. Such a deviation has significant consequences, particularly for climate predictions. The primary inquiry, however, concerns what could potentially lead to this cooling in a rapidly warming environment.
Based on new research released in Communications Earth and Environment, the explanation is found in the deceleration of a significant system of ocean currents known as the Atlantic Meridional Overturning Circulation, or AMOC. This system transports warm water from the tropics northward, where it cools, sinks, and then flows back south. It serves as one of the main influences on the planet’s climate.
When the AMOC experiences a slowdown, it alters this heat distribution. A reduced amount of warm water reaches the North Atlantic, resulting in surface cooling. The researchers discovered that only climate models that accounted for this slowdown were able to reproduce the temperature patterns observed in the Atlantic Warming Hole.
To arrive at this finding, scientists examined over a century’s worth of temperature data, which act as indirect measures of the ocean’s current strength. They also employed numerous computer models to simulate how various alterations would impact ocean temperatures. Only those incorporating a weakened AMOC corresponded with the detected cooling trend.
Gaining insight into the Atlantic Warming Hole is crucial since this cold region impacts rainfall and wind patterns throughout Europe and can disrupt marine ecosystems. Furthermore, as the AMOC continues to decelerate, some scientists caution about wider disruptions to weather and climate systems.
