Circulation Cells

Mr. Silva

Ag Earth Science

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Air Circulation Cells Preview

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Hadley Air Circulation Cells

• Circulation of hot air near the equator• Air is heated, rises and spreads north and

south toward subtropics.• Subtropic air replaces hot tropical

air...process starts again

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Hadley Air Circulation Cells

• high humidity• high clouds• heavy rains/precipitation• No winter!!! • Temperature change greater from day to

night than from season to season.

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Ferrel Air Circulation Cells

• Ferrel cells develop between 30* and 60* north and south latitudes.

• Great seasonal fluctuation of temperature.

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Ferrel Air Circulation Cells

• Distinct winter season• Usually has broadleaf deciduous and

evergreen coniferous forest

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Polar Air Circulation Cells

• Icy-cold, dry, dense air descends from the troposphere

• Meets warmer air at mid latitudes and then returns to the poles cooling and sinking

• Sinking air suppresses precipitation, thus polar regions are deserts

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Polar Air Circulation Cells

• Low temperatures• severe winters• small amounts of precipitation• Two biomes:

– tundra– taiga

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Air Circulation Cells Review

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Hurricanes, Cyclones, and Tornadoes, Oh My!

• Hurricanes are the most severe weather phenomenon on the planet...cyclonic circulation of air, thunderstorms, and rain

• Tornadoes are swirling masses of air with wind speeds of 300mph that happen over land.

• Cyclones are larger than tornadoes, happen over water and last several days.

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Tornadoes

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Hadley Air Circulation Cells

• Circulation of hot air near the equator• Air is heated, rises and spreads north and

south toward subtropics.• Subtropic air replaces hot tropical

air...process starts again• Hadley cells characterized by high

humidity, high clouds, and heavy rains• No winter!!! Temperature change greater

from day to night than from season to season.

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Coriolis Effect

• Uneven heating of the Earth’s surface– caused by the Earth’s axis, rotation, and

revolution around the sun.

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