ST/EST 4
Practice
The Atmosphere
1. What name is given to the layer of air that surrounds the Earth? ______
2. What two gases make up most of the atmosphere? ______and ______
3. Select the correct terms that are underlined in the statements below. Circle the correct term.
a) If air contains more particles, they collide more/less frequently and the pressure rises/falls.
b) Pressure is higher/lower at high altitudes because there are less/more air particles.
c) When air warms, the particles move more/less rapidly. The particles take up more/less space. This causes the density of the air to increase/decrease.
d) Cold air has a higher/lower density than warm air. Cold air therefore rises/descends.
4. What causes winds to blow?
______
5. The rotation of the Earth causes the air to move towards the right in the northern hemisphere. What is this phenomenon called? ______
6. a) What name is given to the wind that blows at about 10 000m at speeds of 300km/h?
______
b) In which direction does this wind blow in the northern hemisphere?
______
c) Should a pilot travelling from Kenya to Peru fly at an altitude of the subtropical Jet
Stream? Justify your response.
______
7. Identify the winds and convection cells in the diagram below.
8. Identify the temperature and humidity of each of the air masses below.
a) Polar continental: ______
b) Polar maritime: ______
c) Tropical continental: ______
d) Tropical maritime: ______
9. What name is given to the line where two air masses meet? ______
10. What symbol is used on weather maps to represent a cold front? ______
11. What symbol is used on weather maps to represent a warm front? ______
12. Louise is listening to the weather forecast with her friend Lucy.
TV host: “A warm front is heading toward our region and will remain over the area for
the whole week...”
Lucy, all excited, interrupts the forecast to say to Louise: “Great! Nice weather at last!
Do you want to go camping this week?”
Louise: “Wait. Let’s listen to the rest of the forecast first.”
Lucy does not understand why Louise does not share her enthusiasm about the weather forecast. Is Lucy right to think that the weather will be nice in the coming days? Explain your answer.
______
13. Out of concern for the environment, Sophie has chosen to leave her car at home two days a week and walk to the office instead of driving. Before leaving home, she listens to the radio. According to the weather report, a high-pressure area has appeared over the city where she lives.
a) What is the name of the weather system affecting the city? ______
b) Should Sophie think about taking an umbrella to work? Explain your answer.
______
______
14. Identify the following statements as true or false.
a) Depressions are caused by the rising of warm air. _____
b) An anticyclone is represented by the letter H on a weather map. _____
c) When air rises and falls, it turns because of the Coriolis Effect. _____
d) An anticyclone turns clockwise in the Northern Hemisphere. _____
e) A depression turns counter-clockwise in the Southern Hemisphere. _____
f) Depressions formed over oceans cause hurricanes. _____
15. Use a diagram to explain the greenhouse effect.
16. Why has the combustion of fossil fuels lead to global warming?
______
17. * What are the two principal contaminants which cause acid rain? ______and ______
18. * The ozone layer has been thinning because of the use of aerosol sprays.
a) What chemical compounds in the cans destroy the ozone molecules? ______
b) Researchers have linked this to an increase in skin cancer. Explain why they believe this could be true.
______
19. * What is smog? Why are the effects of smog worse when a high pressure area is over a city?
______
20. How can we use the wind to create energy?
______
21. How can we use the sun to create energy?
______
22. What are tides? How are they formed?
______
23. How can tides be used to create energy?
______