Name _____________________________________________________________ Period ______________________
Unit 4, Lesson 3 – Influences of Weather Study Guide (86)
Define: Include in your answer the temperature or humidity and where each air mass comes from.
1. Tropical air mass– warm air mass from the equator
2. Polar air mass- cold air mass form the poles
3. Maritime air mass – moist air mass form the oceans
4. Continental air mass – dry air mass from Mexico or Canada
Using the diagram above describe each air mass.
A–
cold, moist
D - warm, moist
B–
cold, dry
E – warm, dry
C-
cold, moist
F – warm, moist
Directions: Define, draw, use arrows to show the movement of air, and what weather comes before and after the front
5. Cold front – when cold air pushes warm air up, preceding the front is stormy weather (heavy rain or snow), after
it passes by there is cold and dry air (see pg. 185 for a diagram) cumulus clouds formed
6. Warm front – when warm air rises over the cold air, preceding the front is drizzly rain and after if passes by
there is warm, humid air and clear weather (see pg. 185 for a diagram) stratus clouds form
9. Stationary front - when not enough wind for either the cold air mass or the warm air mass to move, can cause
many days of unchanging weather, usually clear
10. What does density have to do with fronts? –cold air is denser and will push the warm air up because it is less
dense
11. Fill in the chart.
Low pressure
High pressure
rising
sinking
Counter -clockwise
clockwise
cloudy
C;ear
Air is rising or sinking?
Winds movement
counter -clockwise or clockwise?
Weather associated with the
pressure system
cloudy or clear?
12. Water cycle – the continuous movement of water between the atmosphere, the land, the oceans and living
things.
13. Condensation – occurs when water vapor cools and changes form a gas to a liquid
14. Evaporation – occurs when liquid water changes into water vapor
15. Humidity – the amount of moisture in the air
16. Barometer – an instrument used to measure air pressure
17. When the barometer is falling what weather could occur? Low pressure means cloudy weather
18. When the barometer is rising what weather could occur? High pressure means clear skies
19. Where do cold water currents come from? ____equator________________ What affect do they have on the
coastal regions they flow by? Cool the coastal areas
20. Where do warm water currents come from? ______poles______________ What affect do they have on the
coastal regions they flow by? Warm the coastal areas
21. Infrared radiation – radiation from the sun that we feel as heat
22. Ultraviolet radiation – radiation from the sun than kills living cells, causes cancer and sunburn
23. Precipitation - occurs when rain, snow, sleet, hail or freezing ran fall from the clouds onto Earth’s surface