Climates and Ecosystems

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Chapter 2

• Climates and Ecosystems

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Weather and ClimateSection 1

• Weathertemporary condition in bottom layer of
  the atmosphere.
• Always changing.
• Climateweather patterns over a long period of
  time

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• Sun and solar energy
• a. Earths diameter is 8,000 miles
• b. Suns diameter is 865,000 miles, 100
  times larger
• c. Earths energy comes from solar rays
  weather, life.

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• Rotation, Revolution, and Tilt
• Earth tilts 23 ½º away from a perpendicular.
• Earth rotates around an axis.
• Axisimaginary line extending pole to pole.
• Rotateto spin.
• Important Parallels
• a. Equator--0º

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• b. Tropic of Cancer. 23 ½º N
• Farthest point north of equator that the
  sun shines overhead.
• c. Tropic of Capricorn 23 ½º S
• Farthest point south of equator that
  the sun shines overhead.
• Why? Tilt Angle.

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• d. Arctic and Antarctic Circles 66½º North
  and South. Periods of total daylight and
  darkness. Why? Tilt angle.
• e. Poles 90º NS
• Shape of Earthoblate ellipsoid
• a. Flattened at poles
• b. Bulging at the equator
• c. Caused by rotation

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• d. Equatorial diameter is 7927 miles
• Polar diameter is 7900 miles
• Movements of the earth.
• a. Rotation
• Spinning around its axis
• Caused by gravitational attraction of
  the sun direction is west to east

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• Effects of Rotation
• Centrifugal forcehigh tides on sides
  not facing the moon
• Coriolus forceall freely moving
  objects deflected to the right in northern
  hemisphere, left in southern.
• Velocity
• equator1000 to 1050 mph
• Ramsey700 to 750 mph
• poles0 mph

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• b. Revolution
• Movement of Earth around the sun
• Laws of Planetary Motion
• 1. Earth revolves around the sun in an
  elliptical orbit
• 2. Aphelionfarthest point
• July 4, 94.5 million miles
• 3. Perihelionclosest
• January 3, 91.5 million miles

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• Solstices
• December 21, sun directly overhead at Tropic of
  Capricorn. Winter
• June 21, directly over Tropic of Cancer. Summer.
• Equinoxequal day, equal night12 hrs.
• March 21 (vernal) and September 22 (autmunal).

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• The earth has systems in place that control and
  balance the climate to make it inhabitable.
• Suns rays are absorbed by the earths
  surfaceoceans and continents.
• Insolationamount of solar radiation received
  from the sun.
• Of the energy received from the sun
• 1. 37 reflected back into space by
  water
• and ice.
• 2. 20 absorbed back into space.
• 3. 43 absorbed into the earths
  surface.
• Ozone reflects ultraviolet rays why
  the sky is blue
• Heat energy created once solar rays are
  absorbed.

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• Temperaturemeasure of heat in the atmosphere
• Latitude
• 1. amount of solar energy varies from place to
  place.
• 2. cooler the further from the tropics
• 3. atmospheric winds move heat temperature,
  which creates a balance between the climates.
• Greenhouse Effect
• 1. trapping of heat by the atmosphere so we
  dont freeze at night.
• 2. heat slowly released into space at night.
• 3. greenhouse effect is natural while global
  warming in man made.

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• Air Pressure and Wind
• 1. Air pressuremeasurement of the force exerted
  by the air.
• 2. Air pressure creates wind and ocean currents
  because of the flow of air it creates.

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• 3. Low pressurewarm air rises and expands,
  creating unstable conditions.
• 4. High pressurecool air settles and contracts,
  creates clear weather.
• 5. Air always flows from high to low pressure

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• Global Wind Belts
• 1. winds named for the direction in which they
  originate.
• 2. balance temperatures.
• 3. prevailing windswinds that blow in the same
  direction.
• Trade Winds
• 1. 0-30? North and South of equator
• 2. Northeast and southeast trade winds
• 3. how explorers got to America
• Doldrums
• 1. 0-3? North and South of the equator
• 2. No wind, calm area.

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• Westerlies
• 1. 30 to 60? NS
• 2. dominate middle latitudes
• 3. carry our weather from west to east
• Polar Winds
• 1. 60-90? NS
• 2. Bring cold air to middle latitudes
• Fronttwo air masses meet with different
  temperatures and moisture. Create storms.
• Polar winds meet with westerlies

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• Jet Stream
• 1. high speed, westerly wind in the upper
  atmosphere.
• Boundaries of air masses.
• 2. moves energy, storms, major weather patterns.

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• Ocean Current
• 1. giant rivers in the ocean caused by earths
  rotation
• 2. brings warm water from tropics to poles, cool
  water from poles to
• tropics.
• 3. coastal areas have few temperature extremes.
• California Currentcold ocean current.

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• Water and the Atmosphere
• 1. Evaporationwater is changed from a liquid to
  a gas.
• Most water is evaporated from the ocean.
• 2. Humidityamount of water vapor in the air
• 3. Condensation
• a. water vapor changes from a gas to liquid
  droplets.
• b. air cools to the point it can no longer
  hold water.
• c. clouds, fog, dew.

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• 4. Precipitation
• a. condensed droplets become too large and
  fall.
• b. rain, snow, sleet, hail
• Storms
• 1. energy stored in water vapor in atmosphere is
  released.
• 2. low pressure
• 3. Thunderstorms
• a. convectional. Frontal, when cold and
  warm fronts meet
• b. orographicinfluenced by presence of a
  mountain

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• Tropical cyclone (Intense Low Pressure)
  
• a. Tropical disturbanceband of
  thunderstorms lasting 24hrs. over the ocean.
• b. Tropical depressionrotary circulation
  of air, winds up to 39mph.

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• Categories
• 1. weak 74-95
• 2. moderate 96-110
• 3. strong 111-130
• 4. very strong 131-155
• 5. devastating 156 plus
• e. other names
• hurricaneGulf of Mexico and Atlantic
• typhoonPacific
• cycloneIndian Ocean
• willy-willyAustralia

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• Elevation and Temperature
• 1. Altitude
• a. height above a given surface (sea-level)
• b. temperatures drop a s altitude increases
• 2. Orographic
• a. windward
• air forced to rise, and cools
• condensation, clouds form,
  precipitation
• receives moisture
• b. leeward
• air becomes warmer and drier as it
  moves down
• deserts
• rainshadow effect

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