Do Now 4/28/14 1.Which of the following factors affects and/or helps create ocean currents? a) Wind b) Temperature c) Salinity (Salt) Levels d) Shorelines e) Tides (rise and fall of sea level because of tides) 2.Who discovered the 4 moons on Jupiter? 3.Describe the rock cycle.

Ocean Currents

What is a current? An Ocean Current is a directed, continuous movement of ocean water generated by various forces. Currents are caused by various factors (temperature, different salinity levels) and impact a lot of factors (climate and global economic trade)

Atlantic Slave Trade (16 th – 19 th Centuries)

Gulf Stream & other Atlantic Currents North Atlantic Gyre

Gulf Stream Map for Notes Africa Europe North America Charlotte

A Heat Map of the Ocean Currents

How temperature impacts ocean currents Heat moves from areas of more heat energy to areas with less heat energy (Think about convection currents). For currents, this means hotter water moves to areas where colder water is, and cold water moves to areas of warm water This means warm currents move from the Equator towards Polar regions (they go north and south)

Ocean water has formed layers according to density Low-density water occurs near the surface Higher-density water occurs below How does density affect the ocean?

Surface current = movements of water that flow horizontally in the upper part of the ocean’s surface – Develop from friction between the ocean and the wind that blows across its surface – global winds!

An increase in seawater density can be caused by a decrease in temperature or an increase in salinity Can also result from increased salinity of ocean water due to evaporation Subsurface Ocean Currents

a. The warmest layer of the ocean is the surface zone where water is mixed by waves and currents. b. The thermocline is the zone below the surface where rapid temperature change occurs. c. The coldest layer is the deep zone with temperatures of around 5 degrees Celsius.

Sun heats the water Warm water rises and moves North or South Cold water moves up to replace warm water Sun heats the water Summary – Write this down!

Rubber Ducks Lost at Sea

Look at the warm and cold fronts, what might the impact on the climate/ weather be?

Surface currents affect weather!!!

The Gulf Stream is known as a long-distance surface current that carries warm water from the southern tip of Florida along the eastern coast of the US. Currents in the Northern Hemisphere move clockwise (currents correspond to the wind circulation in each hemisphere), while currents in the Southern Hemisphere move counterclockwise

The Coriolis effect (the apparent shift in fluids or objects due to the rotation of the Earth) explains ocean current patterns curving in each hemisphere.

The movement of deep ocean currents to the surface is called upwelling. This occurs when deep cold currents are forced upward by the ocean floor bringing nutrient rich foodstuffs to the surface. This produces rich fishing grounds in areas where upwelling occurs. (Ex. Peru, Chile)

We’ll get into Climate later, but should Charlotte be a desert?

How does temperature affect density? 1.What are ocean currents? 2.Are temperature variations greater over land or water? 3.What causes ocean currents to occur? EXIT TICKET