The Collapse of an Atlantic Ocean Current Would Ripple Across The World, Says Studyhttps://www.sciencealert.com/the-collapse-of-an-atlantic-ocean-current-would-ripple-across-the-world-says-study?fs=e&;s=cl#l4h7yfy4gse0j9taenuIn our study, we used a comprehensive global model to examine what Earth's climate would look like under such a collapse.
We switched the Atlantic overturning off by applying a massive meltwater anomaly to the North Atlantic, and then compared this to an equivalent run with no meltwater applied.
Our focus was to look beyond the well-known regional impacts around Europe and North America, and to check how Earth's climate would change in remote locations, as far south as Antarctica.
The first thing the model simulations revealed was that without the Atlantic overturning, a massive pile up of heat builds up just south of the Equator.
This excess of tropical Atlantic heat pushes more warm moist air into the upper troposphere (around 10 kilometers into the atmosphere), causing dry air to descend over the east Pacific.
The descending air then strengthens trade winds, which pushes warm water toward the Indonesian seas. And this helps put the tropical Pacific into a La Niña-like state.
Australians may think of La Niña summers as cool and wet. But under the long-term warming trend of climate change, their worst impacts will be flooding rain, especially over the east.
We also show an Atlantic overturning shutdown would be felt as far south as Antarctica. Rising warm air over the West Pacific would trigger wind changes that propagate south to Antarctica. This would deepen the atmospheric low-pressure system over the Amundsen Sea, which sits off west Antarctica.
This low-pressure system is known to influence ice sheet and ice shelf melt, as well as ocean circulation and sea-ice extent as far west as the Ross Sea.
Interbasin and interhemispheric impacts of a collapsed Atlantic Overturning Circulation | Nature Climate Changehttps://www.nature.com/articles/s41558-022-01380-y