Ocean Currents 6 th Grade Earth Science Sutton

Ocean Currents 6 th Grade Earth Science Sutton Middle School

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 8 cooler in the____.

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

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

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

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.