January 4, 2017 Yale University ScienceDaily See full article here
One of the world’s largest ocean circulation systems may not be as stable as today’s weather models predict, according to a new study. In fact, changes in the Atlantic Meridional Overturning Circulation — the same deep-water ocean current featured in the movie ‘The Day After Tomorrow’ — could occur quite abruptly, in geologic terms, the study says.
- …AMOC is responsible for carrying oceanic heat northward in the Atlantic Ocean. It consists of a lower limb of denser, colder water that flows south, and an upper limb of warm, salty water that flows north. The system is a major factor for regional climate change, affecting the Atlantic rim countries, especially those in Europe.
“In current models, AMOC is systematically biased to be in a stable regime,” Liu said. “A bias-corrected model predicts a future AMOC collapse with prominent cooling over the northern North Atlantic and neighboring areas. This has enormous implications for regional and global climate change.“…
A collapse of the AMOC system, in Liu’s model, would cool the Northern Atlantic Ocean, cause a spreading of Arctic sea ice, and move tropical Atlantic rain belts farther south. …the researchers said a significant weather change could happen quickly in the next few centuries…..
Wei Liu, Shang-Ping Xie, Zhengyu Liu and Jiang Zhu. Overlooked possibility of a collapsed Atlantic Meridional Overturning Circulation in warming climate. Science Advances, 2017 DOI: 10.1126/sciadv.1601666