6th Grade Earth Science Sutton Middle School Ocean Currents 6th Grade Earth Science Sutton Middle School

Land has a lower specific heat! Fill in the blanks! Land has a lower specific heat! Land heats up _______ than water, but it also cools off more __________. Oceans heat _______, hold heat well, and give off heat slowly. In winter, the ocean acts like a heater because it keeps the coastal climate ___________ In summer, the ocean acts like an _______________as cooler ocean air moves inland through convection currents. Land near the ocean is often _______ in winter and cooler in the________. 8

Land has a lower specific heat! Land heats up faster than water, but it also cools off more quickly. Oceans heat slowly, hold heat well, and give off heat slowly. In winter, the ocean acts like a heater to faster cooling land. In summer, the ocean acts like an air conditioner as cooler ocean air moves inland through convection currents. Land near the ocean is often warmer in winter and cooler in summer. 8

Mass movement or flow of ocean water River within the ocean Two types Ocean Currents Mass movement or flow of ocean water River within the ocean Two types Surface and 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

Controlled by three factors Global winds Coriolis Effect 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

Deep Currents Stream like movement of ocean water far below the surface Caused by Changes 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 make the average temperatures of climates more similar This is on a large scale Ocean air holds a lot of water vapor – so there is more rain at the coast Currents redistribute heat throughout the globe Example: Gulf Stream brings warm air into England, making it warmer

What is a surface current and what causes them? Question 1 What is a surface current and what causes them?

They are powered by wind Answer Surface currents move water horizontally – parallel to the Earth’s surface They are powered by wind

What is the Coriolis Effect? 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.