Chapter 10.3 – Distributing the Heat

1. Chapter 10.3 – Distributing the Heat (pages 388 – 396 in your text)

2. Every year, Calgary hosts a winter carnival where you can see really “cool” ice sculptures. During Calgary’s winter, ice sculptures are usually able to remain frozen. Meanwhile, only approximately 1000 km away, Vancouver’s winters are mild—too mild to maintain ice sculptures over weeks at a time.

3. How Oceans Distribute Heat • Water has a low albedo and absorbs more than 90% of the solar energy striking it. Because of water’s high specific heat capacity and large heats of vaporization and fusion, it takes a lot of energy to change its temperature or phase. the energy absorbed by water is distributed throughout great water depths due to waves, turbulence and ocean currents. • The Gulf Stream is a large surface current that starts in the Caribbean and follows the coastline of the United States and Canada. It ends up off the European coast, where it is called the North Atlantic Drift. This current helps to moderate the climates of western Europe.

5. El Niño and La Niña • El Niño is a disruption of the ocean-atmosphere system in the tropical Pacific that typically occurs every three to seven years. During an El Niño year, the wind direction over the South Pacific reverses and the winds flow eastward. The wind reversal causes an increase in the sea-surface temperature, causing heavy rains in South America and droughts in Asia and Australia. It is not known why the winds reverse directions. El Niño can affect weather patterns across 25% of the globe.

6. La Niña is the opposite of El Niño. La Niña is characterized by an increase in the strength of the normal patterns of westward moving winds. La Niña produces wetter than normal conditions in Australia and Asia. North America becomes warmer and drier than in non- La Niña years.

7. Answer the questions • Question 1. In the northern hemisphere, ocean currents that flow north tend to be warm currents and those that flow south tend to be cold currents. Give a reason for this.

8. Question 2. In which hemisphere do ocean currents flow clockwise? In which hemisphere do they flow counterclockwise? • Question 3. Name the regularly occurring disruption of ocean currents in the tropical Pacific that is linked to severe weather and climate events around the globe.

9. Patterns of Wind Movement • At the equator, warm air rises and loses its moisture. At 30◦, dry air descends; therefore, deserts occur at 30◦ latitude around the world. • Because the Earth is rotating on its axis, the trade winds move from the northwest to the west in the Northern hemisphere, and from southeast to the west in the Southern hemisphere. This is called the Coriolis effect. • The westerlies move from the west, towards the east. global wind patterns

10. Differences in atmospheric pressure in neighbouring regions on Earth’s surface lead to wind. • An area of low pressure occurs as warm air expands, becomes less dense, and rises from the surface. High pressure occurs as cold air contracts, becomes denser, and descends to the surface. This movement of air forms convection currents that circulate and distribute heat around the world.

11. Coriolis Effect • The Earth is constantly rotating and the atmosphere rotates with it at the same speed. Convection currents or any moving object tend to veer sideways from their original course due to Earth’s rotating eastward on its axis. This tendency is called the Coriolis effect. Coriolis effect

12. Jet Streams • Jet streams are currents of extremely fast-moving air about 10-15 km above Earth’s surface. Jet streams form at the boundaries of cold and warm air. Jet streams are usually larger in the winter when the temperature difference between cold and warm air masses is greatest. Intense winds within jet streams influence precipitation and thunderstorms.

13. Answer these questions • Question 4. In which direction does air move with regards to pressure areas? • Question 5. Why does an area of high pressure form where the air is cold? • Question 6. Earth’s rotation deflects airflow from a direct north-south direction. What is this deflection called?

14. Oceans and Mountains Influence Climate • Sea and land breezes form as a result of the vastly different specific heat capacities of water and land. Water heats and cools at a slower rate than land. This results in a temperature differential between the two bodies.

15. Sea Breeze (occurs during the day) • A – Sun’s rays warm the land faster than they warm the water • B – Warm air is less dense; warm air rises. • C – Air over the water is cooler; cool air is more dense and sinks. • D – Cool air flows towards land to replace the warm air that has risen

16. Land Breeze (occurs at night) • A – The sea loses heat more slowly than the land. The air over the sea is warmer. • B – Warm air over the sea rises. • C – Air over land is cooler; cool air is more denseand sinks. • D – Cool air flows towards the sea to replace the warm air that has risen.

17. Answer these questions • 1. Explain why different surfaces absorb different amounts of solar energy.

18. 2. Match the description in column A with the correct term in column B. Write the term in the line beside the description.

19. 3. Sketch a diagram of either a sea breeze or a land breeze. Include the following labels with your diagram: - “sea breeze” or “land breeze” - “daytime” or “nighttime” - “hot” - “cool” - “warmer air rising” - “cooler air sinking” - arrows showing direction of breeze.