Ch. 21 Climate

21.1 Factors That Affect Climate

Affect the 2 most important elements of climate Temperature & Precipitation

Latitude Elevation Topography Water Bodies Atmospheric Circulation Vegetation

Factors that Affect Climate

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

Latitude

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

Elevation

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

Topography

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?????

Water Bodies

Global winds influence climate bc they distribute heat & moisture around the Earth

HEAT BALANCE Warm air to the poles & cool air to

the equator

Atmospheric Circulation

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)

Vegetation

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?

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21.2 World Climates

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

The Koppen Climate Classification System

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

Humid Tropical Climates

Humid Tropical Climates

Wet Tropical

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

Tropical Wet & Dry

Bordering the wet tropics

Have temps. & total precipitation close to those in wet tropics, but this climate experiences times of low precipitation

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

Humid Mid-Latitude Climates

3 types: humid subtropical, marine west coast, & dry-summer subtropical

Humid subtropical – 25-40 degrees latitude on the Eastern side of the continent

Marine West Coast – 40-65 degrees latitude N & S

Dry-Summer Subtropical – 30-45 degrees latitude

Humid Mid – Latitude w/ Mild Winters

2 types: humid continental climates & subarctic climates

Continental landmasses strongly influence both climates

Absent in the Southern Hemisphere

Humid Mid-Latitude w/ Severe Winters

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

Dry 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

Polar 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

Highland Climates

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?

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