Warm Up  Name 2 processes that drive ocean currents.

Ocean Currents

Movement of Ocean Water  Oceans are always in constant movement caused by:  Variations in Density  Wind

Specific Heat of Water  Water has a high specific heat (4.184 J/g*C)  It takes a lot of energy to heat up water and cool it down

Density Currents  Density Currents-Ocean Currents that move due to differences in density  Global Conveyor Belt

Ocean Currents  Upwelling Currents – Occur when wind moves seawater at the surface and new water from below replaces it

Critical Thinking #1  How might upwelling currents be beneficial to life in the ocean? Explain.

Coriolis Effect  Coriolis Effect-The rotation of the Earth results in wind blowing in a circular motion  Wind blows to the right in the Northern Hemisphere  Wind blows to the left in the Southern Hemisphere

Gyres  Gyres are large circular current systems that flow from north to south and are caused by the Coriolis Effect  5 major gyres:  2 in the Pacific Ocean  2 in the Atlantic Ocean  1 in the Indian Ocean

Surface Currents  Surface Currents are currents that affect the upper most portions of the surface  Surface Currents that flow towards the equator generally bring cold water  Surface Currents that flow away from the equator generally bring warm water

Ocean Currents  Deep Currents – Move slowly beneath surface, primarily caused by differing water densities

Critical Thinking #2  What processes might cause changes in density that form deep ocean currents?

Climate Impact  Coastal Areas: Have a high amount of water vapor in the air.  Summer will be cooler  Winters will be warmer

Climate Impact  In cities located further from the coast there is less water vapor in the air  Summers will be very hot  Winters will be very cold

Tides  Tides – Daily changes in the level of the ocean surface  2 high tides and 2 low tides each day  caused by gravitational pull of primarily the moon, but also the sun

High Tides and Low Tides  High (Flood) Tides – Occur on side of Earth facing and opposite the moon, due to both gravity facing and centrifugal force opposite Low (Ebb) Tides – Occur on sides halfway between the moon

Spring Tides and Neap Tides  Neap Tides = Small tidal range, when moon and sun are perpendicular Spring Tides = Highest and lowest tides, when moon and sun align

Critical Thinking #3  Why are spring tides stronger than neap tides? Explain.