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Ocean Currents. Ocean Currents. Mass movement or flow of ocean water River within the ocean Two types Surface and Density (Deep). Surface Currents. Link Horizontal, stream-like movements of water that occur at or near the surface of the ocean Can reach depths of several hundred meters
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Ocean Currents • Mass movement or flow of ocean water • River within the ocean • Two types • Surface and Density (Deep)
Surface Currents Link • Horizontal, stream-like movements of water that occur at or near the surface of the ocean • Can reach depths of several hundred meters • Example: Gyres
Surface Currents • Controlled by three factors • Global winds • Coriolis Effect • Continental Deflections
Surface Currents • Global Winds • Cause surface currents to flow in the direction the wind is blowing • EX: Jet Stream • Coriolis Effect Link • The apparent curving of moving objects due to the Earth’s rotation
Surface Currents • Coriolis Effect • Northern Hemisphere = clockwise • Southern Hemisphere = counter clockwise • Continental Deflections • Shape of continents change the direction of current flow
Density Currents • Stream like movement of ocean water far below the surface • Caused by • Differences in density • Change in temperature • Change in salinity
What Effects Deep Currents? • Change in temperature • Decreasing the temperature of water increases density • Change in salinity • Increasing the salinity of water increases density
Currents and Climate • Warm water currents • Bring warm water to colder regions
Currents and Climate • Cold water currents • Bring cold water to warmer regions
Why are Ocean Currents Important? • They affect weather on a local scale and climate on a global scale. • Evaporation enables rains to fall dependent upon currents. • Currents redistribute heat throughout the globe • Example: Gulf Stream brings warm air into England, making it warmer
Question 1 • What is a surface current and what causes them?
Answer • Surface currents move water horizontally – parallel to the Earth’s surface • They are powered by wind
Question 2 • What is the Coriolis Effect?
Answer • The Coriolis effect is the shifting of winds and surface currents caused by Earth’s rotation.
Question 3 • What is upwelling?
Answer • Upwelling is a vertical circulation in the ocean that brings deep, cold water to the ocean surface.