1. Ch. 21 Climate

2. 21.1 Factors That Affect Climate

3. Factors that Affect Climate
Affect the 2 most important elements of climate
Temperature & Precipitation
Latitude
Elevation
Topography
Water Bodies
Atmospheric Circulation
Vegetation

4. Latitude Distance N or S of the equator
As latitude increases, the intensity of solar energy decrease
The sun’s rays are most intense in the tropics why…bc the region is at a right angle to the sun
Tropical Zones
Temperate Zones
Polar Zones

5. Elevation Height above sea level Air temp. decreases w/ elevation
The higher the elevation is, the colder the climate is
Elevation also determines how much precipitation an area gets

6. Topography
Topographic features such as mountains play an important role in the amount of precipitation that falls over an area.
Rain Shadows – the dry area on the leeward side of the mountain

7. Water Bodies
Large bodies of water such as lakes & oceans have an important effect on the temp. of an area bc the temp. of the water body influences the temp. of the air above it
Think back to last unit…how does land heat & cool differently than water?????

8. Atmospheric Circulation
Global winds influence climate bc they distribute heat & moisture around the Earth
HEAT BALANCE
Warm air to the poles & cool air to the equator

9. Vegetation
Certain types of plants only can grow in particular climates
Vegetation can affect both temp. & precipitation patterns in a particular area
Vegetation influences how much of the sun’s energy is absorbed & how fast this energy is released (affects temp.)
Transpiration (influences precipitation)

10. REVIEW REVIEW REVIEW How does latitude affect climate?
How does elevation affect climate?
How does a mountain range affect climate?
How do bodies of water affect climate?
What effect do global winds have on climate?
Describe how vegetation affects climate?

11. 21.2 World Climates

12. The Koppen Climate Classification System
Uses mean monthly & annual values of temp. and precipitation to classify climates
Classifies it into climate regions
5 principle groups: humid tropical, dry climates, humid mid-latitude, polar climates, & highland climates

13. Humid Tropical Climates
Climates without winters
Every month has a mean temp. above 18 oC
Amt. of precipitation exceeds 200 cm
2 types of humid tropical climates:
Wet Tropical
Tropical Wet & Dry

14. Humid Tropical Climates
Wet Tropical
Tropical Wet & Dry
Tropical Rainforest
High temps. & a lot of precipitation
Sun’s rays are always high
Winds blow over causing the warm, humid unstable air to rise cool and condense and then fall as precipitation
Bordering the wet tropics
Have temps. & total precipitation close to those in wet tropics, but this climate experiences times of low precipitation

16. Humid Mid-Latitude Climates
Include climates with mild winters & severe winters
Climates with mild winters have an avg. temp. in the coldest month that is below 18 oC but above -3 oC
Severe winters have an avg. temp. in the coldest month that is below -3 oC

17. Humid Mid – Latitude w/ Mild Winters
3 types: humid subtropical, marine west coast, & dry-summer subtropical
Humid subtropical – degrees latitude on the Eastern side of the continent
Marine West Coast – degrees latitude N & S
Dry-Summer Subtropical – degrees latitude

18. Humid Mid-Latitude w/ Severe Winters
2 types: humid continental climates & subarctic climates
Continental landmasses strongly influence both climates
Absent in the Southern Hemisphere

19. Dry Climates
Yearly precipitation is not as great as the potential loss of water by evaporation
Evaporation is dependent on temperature
2 types of dry climates: arid or desert & semi-arid or steppe
Result of global distribution of air pressure and winds

20. Polar Climates Mean temp. of the warmest month is below 10 oC
Very little precipitation
Evaporation rates are also low
2 types: Tundra Climate & Ice Cap Climate
Tundra is a treeless region most in N. Hemisphere
Ice Cap Climate does not have a single monthly mean above 0 oC & has little vegetation & permanent ice and snow

21. Highland Climates
Localized (much different from climates in surrounding areas)
Vary from place to place
In general they are cooler & wetter than nearby areas at lower elevations

22. REVIEW REVIEW REVIEW
Describe the Koppen climate classification system.
How do highland climates compare with nearby lowlands?
Can tundra climates exist at low latitudes? Why or why not?