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TRANSCRIPT
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Climate
Chapter 26
Modern Earth Science
26.1 Factors That Affect Climate
climate the average weather conditions in an area over a long period of time
Temperature Range: the difference between the
highest and lowest temperatures of a month Precipitation: The average amount of rainfall an
area can acquire over a year The climate of a region can also be affected by the
– Latitude of a region – Heat absorption and release – Topography – Winds – Ocean currents
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Latitude
Latitude is the distance from the equator. Latitude determines the amount of
solar energy received, and the prevailing winds of a region The higher the latitude of an area
is, the smaller the angle at which the sun’s rays hit Earth is and the smaller the amount of solar energy received by the area is.
Solar Energy
Because Earth’s axis is tilted, the angle at which the sun’s rays hit an area changes as Earth orbits the sun.
Equatorial regions: 12 hours day & night with steady high temperatures.
Polar regions: large variation of daylight hours, steady low temperatures.
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Wind Patterns
Latitude determines global winds
Winds affect humidity, precipitation, temperature, & cloud cover.
Different prevailing winds = different climate
Global winds also affected by ocean currents & major mountain ranges.
Heat Absorption & Release
specific heat the quantity of heat required to raise the temperature of 1 gram of a substance 1°C
Even if not in motion, water warms more
slowly than land does. Water also releases heat energy more
slowly than land does.
Heat Absorption & Release 2
Land heats faster than water and thus can reach higher temperatures in the same amount of time.
Waves, currents, and other movements continuously replace warm surface water with cooler water from the ocean depths.
In turn, the temperature of the land or ocean influences the amount of heat that the air above the land or ocean absorbs or releases.
The temperature of the air then affects the climate of the area.
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Ocean Currents
Water moves around the globe – LAND DOESN’T
The temperature of ocean currents that come in
contact with the air influences the amount of heat absorbed or released by the air.
The temperature of the air moving ONTO SHORE is affected by the temperature of the ocean/water it comes into contact with
Seasonal Winds
monsoon a seasonal wind that blows toward the land in the summer, bringing heavy rains, and that blows away from the land in the winter, bringing dry weather
Temperature differences between the land and the
oceans sometimes cause winds to shift seasonally in some regions.
Monsoon climates, such as that in southern Asia, are caused by heating and cooling of the northern Indian peninsula.
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Topography
Elevation The surface features of the land, or topography,
also influences climate.
The elevation, or height of landforms above sea level, produces distinct temperature changes.
Temperature generally decreases as elevation increases.
More Topography
Rain Shadows When a moving air mass encounters a mountain
range, the air mass rises, cools, and loses most of its moisture through precipitation.
As a result, the air that flows down the other side of the range is usually warm and dry. This effect is called a rain shadow.
One type of warm, dry wind that forms in this way is a foehn (FAYN), a dry wind that flows down the slopes of the Alps.
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26.2 Climate Zones
Climate Zones
3 Major Climate Zones – Polar Climate
– Middle-latitude Climate
– Tropical Climate
Tropical Climate
3 Tropical Climates – Desert
– Rain Forest
– Savanna
Rain Forest
Savanna
Desert
Tropical
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Polar Climate
2 Polar Climates – Subarctic
Severe winters & short summers
Canada
– Tundra No trees, very dry, cold
air with little precipitation
Northern Alaska
Tundra
Subarctic
Polar
Middle-Latitude Climate
5 Climates – Desert & Steppe
Eastern Montana
– Mediterranean Most of California
– Marine West-Coast Seattle
– Humid Sub-tropical Georgia
– Humid Continental Iowa
Humid Sub-tropical
Humid Continental
Marine West-Coast
Mediterranean
Desert & Steppe
Middle- Latitude
US: The Middle Latitude Climate
Marine West Coast Climate
Mediterranean
Middle Latitude Steppe
Middle Latitude Desert
Humid Continental
Humid Subtropical
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Tropical Rain Forest
Warm & humid
Near the equator (5 - 10° north & south)
Dense, rain-forest vegetation
Annual rainfall more than 250 cm
Yearly temp. range only about 3° C
Amazon River basin, parts of Central America & Southeast Asia
Tropical Desert
Tropical Savanna
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Polar Climates
Subarctic
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Tundra
Middle-Latitude Climates
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