This laboratory demonstration shows a key process that maintains a large-scale but slow circulation in the Atlantic Ocean that is an important part of how Earth’s climate works. Near the equator warming of the surface ocean by the strong sunlight produces a layer of warm, low-density surface water that starts to spread northwards (in the real ocean this northward movement is helped by the average winds). In the far north of the Atlantic, the surface water cools and becomes more dense. This dense water sinks to great depth and begins to move southward. Eventually you see a large-scale overturning circulation that takes warm, low-density water northward at the surface and cold, dense water southward near the bottom. The formation of cold water at the surface in the North Atlantic is important to our climate. Cold water absorbs CO2 from the atmosphere, and when the water sinks it takes that CO2 with it thus removing CO2 from the atmosphere and storing it in the deep Atlantic. The storage is temporary - for the time that the overturning circulation takes to take the dense water southward and eventually reintroduce it to the sea surface. This takes several centuries, so this process has been helping us by removing and storing some of the CO2 w have been emitting into the atmosphere since the start of the industrial revolution.
Негізгі бет Ғылым және технология The Atlantic Meridional Overturning
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