And it’s a source of water vapor to the atmosphere.
So we’ll walk through some of those things that the ocean does as part of
the climate system and how the ocean moderates our weather and climate.
I'll also talk a little bit about how the ocean is important for humans.
Okay, so the climate system on Earth gets its energy from the sun.
And the sun's energy strikes the Earth differently at different latitudes.
In the tropics, at low latitudes, the sun's energy is coming in directly, and
so it's very intense on any given area of land.
At higher latitudes, that same amount of sun's energy is spread out.
Because instead of striking directly on the surface of the Earth,
it's striking the top of a sphere, and so that energy gets spread out more.
So the high latitudes on the Earth receive less energy
per unit area than the low latitudes.
And if that energy didn't get moved around,
we would have much hotter tropics and much colder poles than we do.
It's the moving of that energy around the Earth system that creates weather and
climate for us.
The ocean plays a really important role in that.
So here's what ocean temperatures look like on the surface of the Earth.
We've got warmer temperatures across the low latitudes here, and
we've colder temperatures at the higher latitudes.
But again, the ocean is moving that heat around to minimize that difference,
believe it or not.
[LAUGH] This is a animation of a current that does that moving around for us.
So it's an animation of the Gulf Stream in the North Atlantic.
But I should point out that every ocean basin has its own current that
does the same things that I'm going to describe here from the North Atlantic.
So what we're seeing is this current moves from areas
of warm water in the southern part, in low latitudes.
And it moves that heat in a complicated, meandering path into the North Atlantic.
And this Gulf Stream is one of the strongest currents on the planet.
And one of the strongest currents, for
sure the strongest current in the North Atlantic surface.
Okay, so as it moves that heat northward, it warms the ocean there.
Also over the warm parts of the ocean in all the ocean basins,
we have a lot of evaporation of water.
That evaporation of water is really important for climate and
weather on the planet.
The ocean is a fundamental part of the global hydrologic cycle.
By evaporating water from the ocean surface, that moisture is carried inland
by weather systems and precipitated out as rain or snow.
Ad that's what allows us to have plants on the surface of the land,
to grow food, and to inhabit the land surface.
So the ocean's a really important part of the hydrological cycle as well.