Oceanography Ocean Currents Chapter 24.1 and 24.2

There are 2 types of ocean currents Surface Currents Density Currents ( currents under the surface)

Surface Currents Wind is the driving force behind surface currents **This should look REALLY familiar! Click here to see how wind and surface currents are related!

Layers of the Ocean SURFACE CURRENTS Mixed Layer (2%) Temp Change Deep waters Density Currents

Surface Currents In the Northern Hemisphere, travel clockwise In the Southern Hemisphere, travel counterclockwise Like winds, this is due to the Coriolis Effect

Turn to page 533!

Global Surface Currents p.532

Warm Ocean Currents Travel __________ the equator. This transfers ______ from the _________to the _______ Example: Creates the Sargasso Sea AWAY FROM ENERGY EQUATOR POLES GULF STREAM

CANARY CURRENT (AFRICA) Cold Ocean Currents CANARY CURRENT (AFRICA) CALIFORNIA CURRENT

Cold Ocean Currents Travel __________ the equator. Example: TOWARDS California Current: travels down the WEST side of the U.S. Canary Current: travels down the WEST side of AFRICA

El Nino vs. Normal Conditions ~ Normal Conditions:

El Nino vs. Normal Conditions ~ El Nino:

Subsurface Currents The driving force behind a subsurface current is _________________. They are also known as ____________________________. If water becomes denser it will ___________. If it becomes less dense it will ___________. density density currents sink rise

Global Conveyor Belt

What are the ways (liquid)water becomes denser? Cooling – molecules closer together Evaporation – leaves salt behind Freezing – leaves salt behind

Antarctic Bottom Water is created at the poles where freezing and cooling increase the salinity and the density of the water.

Mediterranean Sea (p538) This density current is caused by evaporation instead of freezing and cooling. Close to 30° latitude = Dry Air

Upwelling As wind drives water away from the coast, deep cold waters replace it This brings CO2 to the surface for phytoplankton to feed on Click the picture to see the animation!

Global Conveyor Belt

Ocean Temperature Mixed Layer Thermocline Deep Water Wind and waves mix heat evenly Absorbs almost all of the sun’s light Maximum depth usually 100 meters Thermocline Area where temperature drops rapidly Maximum depth usually 1000 meters Deep Water Very cold water moving from poles to equator Most dense water Found beneath other ocean water in almost all ocean locations