Global Weather Patterns: Ocean Currents8.10C: identify the role of oceans in the formation of

weather systems such as hurricanes

The Oceans

• The oceans have a stabilizing affect on the

Earth’s atmospheric temperatures

Let’s take a closer look:

There is a constant flow of water and air around the Earth that distributes heat. Without this heat distribution, the

difference between polar climates and equatorial climates would be much more extreme.

Types of Currents

•There are two kinds of ocean currents that distribute this heat: 1) deep ocean currents that are driven by

convection in the ocean that is influenced by ice melting from Antarctica 2) surface currents which are driven by

prevailing winds/convection in the atmosphere

Surface ocean currents are caused by the surface wind patterns.

The OceansWarmcurrents flow away from the equatorCold currents flow toward the equator from the poles

Convection Currents

Convection occurs because the oceanic waters heat up becoming less dense

This water moves above the cooler water, and gives off its heat to the surrounding environment

As it cools, it begins to sink, and the process begins again

Convection results in the continual circulation of ocean water on a global scale

Currents Animation

The OceansDeep ocean

currents are caused by differences in temperature and salinity (saltiness)These currents

help maintain Earth’s balance

Called the Conveyor Belt

Ocean Circulation

Cold water comes from the ice caps

When water is colder and saltier = denser

The Global Conveyor Belt

•Begins with the cold water near the North Pole and heads south between South America and Africa toward Antarctica, partly directed by the landmasses it encounters.

The Global Conveyor Belt

•In Antarctica, it gets recharged with more cold water and then splits in two directions -- one section heads to the Indian Ocean and the other to the Pacific Ocean.

The Global Conveyor Belt•As the two sections near the equator, they warm up and rise to the surface. When they can't go any farther, the two sections loop back to the South Atlantic Ocean and finally back to the North Atlantic Ocean, where the cycle starts again.

Finding Nemo (EAC)

https://www.youtube.com/watch?v=I-N_7cgwHmQ

Conveyor Belt Animation

Ocean Odyssey

The belt moves much more slowly than surface currents Scientists estimate

that it takes one section of the belt 1,000 years to complete one full circuit of the globe

Helps regulate temperatureTransports water around the

globeAllows for nutrient recyclingNutrients and carbon

dioxide from the bottom layers of the ocean are distributed through the upper layers enabling the growth of algae and seaweed that ultimately support all forms of life

Conveyor Belt

Overall effect of oceans:

• The vast amounts of heat in the oceans

stabilizes the temperature of Earth.

• The heat capacity of the ocean is much greater

than that of the atmosphere or the land.

• As a result, the ocean slowly warms in the

summer, keeping air cool, and it slowly cools in

winter, keeping the air warm.

• A coastal city like San Francisco has a small

range of temperature throughout the year, but a

mid-continental city like Fargo, ND has a very

wide range of temperatures.