Thermohaline circulation This process transports and mixes the water of the oceans, moving heat, which influences regional and global climate patterns, and nutrients. Seawater density is determined by the temperature and salinity of a volume of seawater at a particular location. The difference in density between one location and another drives thermohaline circulation. (more) Atlantic Meridional Overturning Circulation ocean current system Ask the Chatbot a Question More Actions Share Share Share to social media Facebook X URL https://www.britannica.com/science/Atlantic-Meridional-Overturning-Circulation Feedback Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). Feedback Type Select a type (Required) Factual Correction Spelling/Grammar Correction Link Correction Additional Information Other Your Feedback Submit Feedback Thank you for your feedback Our editors will review what you’ve submitted and determine whether to revise the article.

　　External Websites Ask the Chatbot a Question Also known as: AMOC Written by Anna Dubey Anna Dubey is a freelance writer at Encyclopædia Britannica. Anna Dubey, John P. Rafferty John P. Rafferty writes about Earth processes and the environment. He serves currently as the editor of Earth and life sciences, covering climatology, geology, zoology, and other topics that relate to... John P. Rafferty•All Fact-checked by The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors. The Editors of Encyclopaedia Britannica Last Updated: Mar 11, 2025 • Article History Table of Contents Table of Contents Ask the Chatbot { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type" : "Question", "name" : " How does the Atlantic Meridional Overturning Circulation (AMOC) affect climate? ", "acceptedAnswer" : { "@type" : "Answer", "text" : "The AMOC influences global and regional temperature and precipitation patterns by regulating heat near Earthu2019s surface. The effect of this movement of heat is most pronounced in northwestern Europe, where the warm waters of the eastern North Atlantic help to warm the region more than the average of other areas at similar latitudes. Meanwhile, the prevailing westerly winds carry relatively warm air and the moisture it entrains deep into the continent." } } , { "@type" : "Question", "name" : " What factors contribute to the weakening of the AMOC? ", "acceptedAnswer" : { "@type" : "Answer", "text" : "The weakening of the AMOC is attributed to freshwater inputs from melting glaciers, especially in Greenland, and Earthu2019s natural climate variability. As global warming continues, Greenlandu2019s glaciers will continue to melt, adding increasing amounts of fresh water to the AMOC. The additional fresh water slows the circulation by reducing the salinity (and thus the density) of surface water, inhibiting its ability to sink, which weakens the mechanism that ultimately drives the current." } } , { "@type" : "Question", "name" : " What are the potential consequences of a weakened AMOC? ", "acceptedAnswer" : { "@type" : "Answer", "text" : "A weakened AMOC could lead to accentuated temperature differences between the Equator and the poles, a warming of the Southern Hemisphere, a cooling of Europe, changes in rain belts in southern Africa, altered Indian monsoon timing, accelerated melting of Antarcticau2019s ice sheets, and a reduction in the oceanu2019s ability to absorb atmospheric carbon." } } ] } Top Questions How does the Atlantic Meridional Overturning Circulation (AMOC) affect climate? The AMOC influences global and regional temperature and precipitation patterns by regulating heat near Earth’s surface. The effect of this movement of heat is most pronounced in northwestern Europe, where the warm waters of the eastern North Atlantic help to warm the region more than the average of other areas at similar latitudes. Meanwhile, the prevailing westerly winds carry relatively warm air and the moisture it entrains deep into the continent.

　　What factors contribute to the weakening of the AMOC? The weakening of the AMOC is attributed to freshwater inputs from melting glaciers, especially in Greenland, and Earth’s natural climate variability. As global warming continues, Greenland’s glaciers will continue to melt, adding increasing amounts of fresh water to the AMOC. The additional fresh water slows the circulation by reducing the salinity (and thus the density) of surface water, inhibiting its ability to sink, which weakens the mechanism that ultimately drives the current.

　　What are the potential consequences of a weakened AMOC? A weakened AMOC could lead to accentuated temperature differences between the Equator and the poles, a warming of the Southern Hemisphere, a cooling of Europe, changes in rain belts in southern Africa, altered Indian monsoon timing, accelerated melting of Antarctica’s ice sheets, and a reduction in the ocean’s ability to absorb atmospheric carbon.

　　Atlantic Meridional Overturning Circulation (AMOC), combination of surface and deep ocean currents in the Atlantic Ocean that conveys warm surface water northward and cold deep water southward while also circulating nutrients. It is the Atlantic component of thermohaline circulation, and, as such, it plays a substantial part in regulating heat near Earth’s surface, which affects global and regional temperature and precipitation patterns (see also climate). Mathematical models suggest that the AMOC has been undergoing a gradual decline in strength—which is attributed to decreases in salinity at the ocean’s surface due to increased inputs of fresh water—since the late 19th century, ...(100 of 938 words)

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