C H A P T E R 3

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C H A P T E R 3

• The Earths Atmosphere and Climates

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I. GLOBAL ENERGY SYSTEMS
Weather and climate are affected by the suns
energy, air pressure, and the global circulation
system
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I. GLOBAL ENERGY SYSTEMS

• A. Temperature - measurement of the heat in
  Earths atmosphere

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A. Temperature

• The Greenhouse Effect
• process by which heat energy is trapped by the
  atmosphere, keeping Earth warm

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A. Temperature

• The negative Greenhouse effect (human-environment
  interaction)

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A. Temperature

• Most heat is lost to space at night and during
  the winter season

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A. Temperature

• The global energy exchange is a system that
  balances the temperature extremes between
  latitudes

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A. Temperature

• Atmospheric winds and ocean currents
• 1. Move excess heat from the tropics to the
  polar areas

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A. Temperature

• 2. move cold air and water from the polar areas
  to the tropics to be reheated

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B. Air pressure and wind

• The force exerted by air is called air pressure

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B. Air pressure and wind

• Air pressure creates the winds and ocean currents
  of the global energy exchange

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B. Air pressure and wind

• Low-pressure areas are formed when air is warmed,
  expands and becomes lighter, and rises

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B. Air pressure and wind

• Low-pressure areas often bring unstable weather
  conditions

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B. Air pressure and wind

• Cold air is dense, heavy, and tends to sink,
  causing high-pressure areas

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B. Air pressure and wind

• High-pressure areas generally cause clear, calm
  weather

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B. Air pressure and wind

• Wind is the horizontal motion of air between
  areas of different pressure

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B. Air pressure and wind

• There are four major air-pressure zones

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B. Air pressure and wind

• The Equatorial Low-Pressure Zone
• formed by heating of the sun at the equator,
  causes warm air to rise

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B. Air pressure and wind

• 2. At 30 north and south latitudes, warm air
  cools and sinks to the surface, causing the
  Subtropical High-Pressure Zone

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B. Air pressure and wind

• 3. At about 60 north and south latitudes, the
  Sub Polar Low-Pressure Zones are formed

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B. Air pressure and wind

• 4. At the N/S Poles, the sinking of very cold
  
• air forms the Polar High-Pressure Zone

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C. Global wind belts

• Prevailing winds of global wind belts blow from
  areas of high-pressure to areas of low-pressure

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C. Global wind belts

• Trade Winds blow from subtropical high-pressure
  zones toward equatorial low-pressure zone

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C. Global wind belts

• The doldrums are calm areas along the equator
  with no prevailing winds

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C. Global wind belts

• Westerlies dominate the middle latitudes and
  carry weather patterns from west to east

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C. Global wind belts

• Polar Winds are cold masses of air flowing out of
  the high-pressure zones of Arctic and Antarctic
  regions

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C. Global wind belts

• Fronts occur when winds with different
  temperatures and moisture meet - usually cause
  stormy weather

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C. Global wind belts

• Jet streams are prevailing winds in the upper
  atmosphere that move energy, storms, and major
  weather patterns

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D. Ocean circulation

• The oceans are the most important solar-energy
  collectors

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D. Ocean circulation

• Ocean currents are giant rivers of seawater
  flowing at the surface of the oceans

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D. Ocean circulation

• Ocean currents are one of the major ways heat is
  moved between the tropics and polar regions