Mountains

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Mountains

• SPI 0507.8.2 Explain how mountains affect weather
  and climate.

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Three Ways

• In this PowerPoint you are going to study three
  ways mountains affect climate.
• Elevation
• Rain Shadows
• Mountain and Valley Breezes

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• How Mountains Affect Weather Climate
• Number 1 - Elevation

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• Have you ever noticed as you are driving into
  Mountain City from Bristol or Johnson City that
  the temperatures get cooler?

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Johnson County

• How many times have you seen snow on the top of
  Snake Mountain when there was none in Mountain
  City?

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• The reason for this is the elevation.
• Mountain City has the highest elevation of any
  city in Tennessee at 2350 feet above sea level.
  The highest point in Johnson County is Snake
  Mountain at an elevation of 5574 feet above sea
  level.

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Elevation

• The higher the elevation, the lower the
  temperature becomes.
• The rate at which the temperature drops is known
  as the lapse rate. On average, the lapse rate is
  3.6 degrees per 1,000 feet.

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Elevation Differences

• With Snake Mountain over 2000 feet higher in
  elevation than Mountain City, the temperature on
  top of Snake Mountain could easily be 7 degrees
  cooler.

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• How Mountains Affect Weather Climate
• Number 2 - Rain Shadows

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Rain Shadows

• Mountains greatly affect the climate. They act as
  barriers blocking rain and wind.

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• One side of the mountain may have a very
  different climate from the other side. In some
  cases mountains create a shadow. This is where
  rain does not fall. Deserts can form in the rain
  shadow regions.

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Animations

• http//www.mhhe.com/biosci/genbio/tlw3/eBridge/Chp
  29/animations/ch29/rain_shadow_formation.swf
• http//bio1100b.nicerweb.com/med/Vid/Discover2e/ch
  39a04_RainShadow.swf
• http//www.uky.edu/AS/Geology/howell/goodies/elear
  ning/module07swf.swf
• http//www.mrphome.net/mrp/rainshadow.swf

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Example Rain Shadow

• Death Valley in the United States is behind the
  Pacific Coast Ranges of California and the Sierra
  Nevada range.

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(No Transcript)
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BrainPop

• http//www.brainpop.com/science/earthsystem/mounta
  ins/

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• How Mountains Affect Weather Climate
• Number 3
• Mountain Breezes and Valley Breezes

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Mountain Breeze Valley Breeze

• Mountain and valley breezes are very similar to
  land and sea breezes.
• Remember Air pressures try to equalize
  themselves through wind. High pressures move
  toward low pressures.

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• During the day the surface of the mountain heats
  the air high up in the atmosphere quicker than
  the valley floor can. This creates a low pressure
  area near the top of the mountain. Wind moves
  from the valley where the air pressure is high to
  equalize this pressure.

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Day Valley Breeze

• When the wind moves from the valley to the top of
  the mountain, this is called a valley breeze.

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• During the night the mountain tops cool more
  quickly than the air in the valleys. This creates
  a high pressure area at the mountain top where
  the air becomes more densely packed.

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• The wind changes direction and moves from the
  mountain top to the valley floor to equalize this
  high pressure.

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Mountain Breeze Valley Breeze

• Most of the time we see valley breezes during the
  day, as winds blow from the valley up towards the
  mountains. During the night we see mountain
  breezes, as winds travel from the mountains, down
  towards the valleys.

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Animation

• http//www.bborucki.com/wind.swf