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Flashcards in Antartica and the Southern Ocean Deck (16)
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What is the Antarctic convergence zone?

A curve continuously encircling Antartica where cold northwards flowing Antarctic waters meet the relatively warmer waters of the sub-antarctic


How wide is the Antartica convergence zone?



What happens at the Antarctic convergent zone?

cold northward flowing water sinks beneath sub-antarctic waters w


What does the cold northward flowing water sinking beneath the sub-antarctic waters in the Antarctic convergent zone form?

Areas of mixing and upwelling currents which are very high in marine productivity, especially Krill


What does the Antarctic convergence zone separate?

Two distinct hydrological regions
Areas of distinct climate
Areas of distinctive wildlife


What is the ACC?

The only current which flows around the globe - 4x the size of the Gulf Stream


How does the ACC work?

The westerly winds blow from west to east around Antarctica pushing the surface layer of water with it


What does the westerly winds blowing from west to east around Antartica which push the surface layer of water with it cause?

Ekman spiral


What does the Ekman spiral do?

Push surface water to the left of the direction of the wind - northward force


Why does Ekman transport happen?

Because of the Coriolis effect


What does the force pushing the water to the left of the direction of wind in the ACC cause?

A difference in water pressure - pressure gradient - which pulls water back


What odes the pressure gradient and northward force do?

Balance each other out creating a geostrophic current


What does the geostrophic current do?

Flows at greater depths


Why does the ACC matter?

It takes deep water and brings it to the surface
Winds lead to breaking waves and bubbles which help to exchange gas and heat between the air and the sea


What is the ACC really important?

It allows the Southern ocean to exchange huge amounts of carbon and heat with the atmosphere


What is the summary of the ACC?

Mechanism by which deep, cold old water upwells and becomes exposed to the atmosphere for the first time - absorbing loads of CO2