why is Antarctica colder than the Artic even though they’re both poles
In: Planetary Science
The Atlantic ocean is dominated by an overturning circulation in which warm water flows northward, cools off, and flows southward. The heat delivered to the North Atlantic is about 20% as much as delivered by the sun! This heat then spreads out and warms the Northern Hemisphere.
Around Antarctica there is a band of open latitudes where the water is at least 2000m deep. Winds at these latitudes push water in the same direction as the earth is spinning. This makes the water drift away from the earth’s axis of spin (in other words to the north) in the same way that if you spin a lasso faster it spreads out more. The cold water from the North Atlantic then upwells in this region, gets freshened and then warmed and completes the circuit.
This pattern appears to date from about 40 million years ago, when Antarctica separated from South America although the exact point in time when these dynamics started to hold is debated.
Once you start building up an ice sheet on Antarctica, the top of that ice sheet gets colder as well.
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