Chapter 21 Section 1 Chapter 21 Section 1 Review Page 524Review Page 524

Ocean Surface Currents

1. Describe the force 1. Describe the force that drives most surface that drives most surface currents.currents.

• Uneven heating of Earth’s Uneven heating of Earth’s atmosphere produces wind. As atmosphere produces wind. As winds moves across the ocean winds moves across the ocean they transfer energy to the they transfer energy to the water creating surface currents.water creating surface currents.

2. Identify the winds 2. Identify the winds that affect the surface that affect the surface currents on either side currents on either side of the equator.of the equator.

• The trade wind belts, located The trade wind belts, located north and south of the equator north and south of the equator push surface currents west push surface currents west across all three oceans in the across all three oceans in the tropical latitudes.tropical latitudes.

3. Identify the winds that 3. Identify the winds that affect the surface affect the surface currents in the middle currents in the middle latitudes.latitudes.

• Prevailing Westerlies are located Prevailing Westerlies are located in the mid-latitudes and they in the mid-latitudes and they push ocean currents to the east.push ocean currents to the east.

4. Describe how density 4. Describe how density affects the flow of deep affects the flow of deep currents.currents.

• Denser water is “heavier” and Denser water is “heavier” and sinks below less dense water. sinks below less dense water. This ocean motion is the basis This ocean motion is the basis for deep-ocean currents.for deep-ocean currents.

5. List the factors that 5. List the factors that affect the density of affect the density of ocean water.ocean water.

• TemperatureTemperature

• SalinitySalinity

• TurbidityTurbidity

6. Describe how surface 6. Describe how surface currents would be currents would be affected if Earth did not affected if Earth did not rotate.rotate.

• Earth’s rotation causes the path Earth’s rotation causes the path surface currents to curve. If surface currents to curve. If Earth did not rotate, surface Earth did not rotate, surface currents would flow in straight currents would flow in straight paths until the ran into land.paths until the ran into land.

7. Explain how the 7. Explain how the distribution of solar distribution of solar energy around Earth energy around Earth affects ocean surface affects ocean surface currents.currents.

• Sunlight that shines on Earth Sunlight that shines on Earth adds thermal (heat) energy to adds thermal (heat) energy to air. Differences in the amount of air. Differences in the amount of solar radiation leads to uneven solar radiation leads to uneven heating of Earth’s surface. This heating of Earth’s surface. This uneven heating pattern creates uneven heating pattern creates winds, which drive surface winds, which drive surface currents.currents.

The End!!!!The End!!!!