Ch 21.1 Factors that Affect Climate
Vocabulary
- Weather
- Climate
Objectives:
How do each of the following factors effect climate?
1. Latitude
As latitude increases, the average temperature decreases. See the figure 2 on page 589. The tropics are located between ______ degrees North and ______ degrees South. Why do the tropics have a higher average temperature than the Temperate zones located between ______ and ______ degrees North and South of the equator?
2. Elevation
As elevation increases, the average temperature decreases. Air temperature decreases with elevation by an average of about 6.5 degrees C every 1000 meters. If city A is 2,000 meters higher than city B, how much colder will city B be than city A?
Elevation also has an affect on precipitation. Use Figure 3 on page 589 to determine the affect.
The higher the elevation, the __________________ the precipitation.
3. Topography
Topographic features such as mountains play an important role in the amount of ____________ that falls over an area.
Click this link to see the average precipitation of Seattle, WA
Click this link to see the average precipitation of Spokane, WA
Click this link to see the location of Seattle and Spokane
How does the average rainfall compare between the two cities?
What do you notice about their locations?
Suggest a reason why the the two cities have different amounts of rainfall. Hint: See page 590
Click this link for a mini-lecture explaining a rain shadow. Use the “Light Saber Lecture” NOT the Magic School bus : )
4. Water Bodies
Link for average temperature and precipitation of Vancouver, BC
Link for average temperature and precipitation Winnipeg, Manitoba
http://weather.sg.msn.com/local.aspx?wealocations=wc:CAXX0547&q=Winnipeg%2c+CAN
Click this link to see the average temperature of Winnipeg, Manitoba Canada
Click this link to see the average temperature of Vancouver, British Columbia
Compare the June, July, and August temperatures of the two cities.
Compare the December, January, and February temperatures of the two cities.
The latitude if Vancouver is 49.2505° N and Winnipeg is 49.25° N. They are both at approximately the same elevation. Read page 50. Suggest a reason for the difference in temperature.
5. Atmospheric Circulation
Global winds are another factor that influences climate because they distribute heat and moisture around Earth.
Winds constantly move warm air toward the poles and cool air toward the equator. This helps to regulate Earth’s temperature.
Low pressure areas around the equator and middle latitudes lead to the formation of clouds that drop precipitation as rain or snow.
6. Vegetation
Vegetation patterns can affect both temperature and precipitation patterns in an area. Vegetation influences how much of the sun’s energy is absorbed and how quickly this energy is released. This affects temperature. During the process of transpiration, plants release water vapor from their leaves into the air.
Look at Figure 5 on page 591. Which area, A or B would receive more precipitation? Why?
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