ATLANTIC MERIDIONAL OVERTURNING CIRCULATION (AMOC)

NEWS: Atlantic Meridional Overturning Circulation (AMOC) is Weakening: Study

Atlantic Meridional Overturning Circulation (AMOC)

• System of ocean currents that circulates water within the Atlantic Ocean, bringing warm water north and cold water south.
• Circulation is driven by differences in temperature + salinityà create differences in water density, a process known as thermohaline circulation.
• AMOCà brings warm, salty water from the Gulf of Mexico to the north Atlantic, keeping temperatures in western Europe milder than in Canada or Russia.
• The dense water then cools and sinks, moving south on the seafloor along the western Atlantic.
• It eventually rises again through upwelling, warms up, and restarts the cycle.
• Part of the large “global conveyor belt,” it circulates water, heat, and nutrients throughout the Atlantic Ocean.

AMOC Collapsing

• Climate Change induced Freshwater influxàGreenland’s melting ice sheet has added ~5,000 km³ of freshwater into the subpolar North Atlantic Ocean.
• Freshwater reduces the ocean’s salinity and density, which slows sinking of water, resulting in weakening AMOC.

Potential implications of collapse of AMOC

• Extreme Cooling of Europe, leading to severe winters and agricultural failure.
• May turn the Southern Ocean from a carbon sink into a sourceàadditional global warming.
• A collapse would shift the tropical rain belt southward, potentially causing: Droughts in the Sahel (Africa) and parts of South Asia.
• Disruption of Monsoons in India