1. Ocean Currents

2. Surface Currents
Surface currents generally occur from 0 to about 400 meters (some are deeper)
Deep currents are those whose upper portions remain below the ocean surface
3 major factors that set ocean currents in motion
Wind
Changes in sea level
Variations in water density

3. Wind
Wind transfers energy through friction on the water’s surface as it blows over the water
Causes both surface currents and waves
A water current will develop if wind blows in the same direction.
When wind stops friction will cause the energy from the wind to spread

4. Changes in water density
Changes in sea Level
This is driven by pressure gradient force
Sea level does change
It is an average of low and high tide
When the level drops, the current carries water out
Similar to changes in sea level
Causes a difference in weight and therefore pressure
Results in pressure gradient
Current flow is below the surface

5. Gyre Large ocean currents that run into land
It is caused by a combination of the coriolis effects the different atmospheric cells
There are 5 major gyre
One in each major ocean basin