Professor Laurie Monville

Hello, Jonathan.

It all comes down to the energy we receive from the sun, which is much higher at the low latitude, which is the equator, than at the high latitude.

So for example, Greenland and Antarctica, if you wish.

And so since we receive more energy in those low latitudes, the Earth tries to redistribute this energy.

And so we redistribute this energy either through the atmosphere or through the ocean.

The rotation of the earth comes into play into where those currents exactly are from.

But what is important is that we try to get this energy from the low latitude into the high latitude.

And most of these come into what we call western boundary current.

So in Australia, an important one would be the East Australian current that brings energy from the low latitude towards us here in New South Wales, for example.

So it brings warm water, which kind of warms the atmosphere.

Yeah, in all oceans.

So here we have the East Australian Current.

In the North Pacific, we have the Corotio Current.

And the one that we are really interested in today in the North Atlantic is the Gulf Stream and its extension, the North Atlantic Drift.

what we have in the North Atlantic, but also in the Southern Ocean, are formation of deep waters.

Okay, so if we go back into the Atlantic, we have the Gulf Stream that bring warm and salty waters from the Caribbean Sea into the North Atlantic.

When those warm water travel northward,

they lose their heat to the atmosphere.

So that's why Western Europe has a relatively mild climate.

So when you have those very dense water, they're probably denser than the underlying water, therefore they sink.