How Blows the Wind?

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How Blows the Wind?

• Charlsie Allen, NBCT
• OKAGE Teaching Consultant

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Purpose

• To locate and identify wind patterns of the
  world
• to describe their effect on the environment and
• To identify and describe how humans have adapted
  life to these wind patterns.

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PASS

• 7th Grade
• Standard 3.1 Recognize regional climatic patterns
  prevailing winds.
• Standard 5.0 The student will examine the
  interactions of humans and their environment.
• Standard 5.2 Evaluate the effects of human
  adaptation to the natural environmentdesertificat
  ion.

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A Legend

• The Ancient Greeks used to think that wind was
  the Earth breathing in and out. We now know that
  it is just

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• air on the move.

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Global Wind Patterns

• Air moves between different areas around the
  world.
• Air moves at different heights in the atmosphere.
  
•  

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Global Wind Patterns

• Colder air from the poles tends to sink and move
  towards the equator closer to the surface of the
  Earth.
• Warm air from the equator rises and moves towards
  the poles high in the atmosphere because it is
  lighter.  

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Coriolis Effect

• Causes distinct pattern of winds around the
  world.
• In the northern hemisphere, winds blow to the
  right.
• In the southern hemisphere, winds blow to the
  left.

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Major Wind Patterns

• Westerlies
• Trade winds
• Roaring Forties
• The Doldrums

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Wind Patterns

• Wind patterns occur all over the world and these
  patterns have names given by local residents.

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Chinook Winds

• Location
• North America

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Chinook Winds

• Source of wind
• Cold arctic winds from northern Canada.

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Chinook Wind
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Chinook Winds

• Effects on environment
• Colder than usual winters throughout the United
  States

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Chinook Winds

• Impact on Humans
• Colder winters cause higher heating bills.
• Cattle are lost in harsh winters
• Businesses lose money during bad winters.

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El Niño and La Niña

• Location
• Pacific Ocean

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El Niño and La Niña

• Source of wind
• Winds blowing East to West across the Pacific
  weaken and change course.
• The large warm air mass near Australia begins to
  move east toward South America.

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El Niño and La Niña
La Niña
El Niño
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El Niño and La Niña

• Incidence
• In the past, every 4 to 5 years
• Recently, more often

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El Niño and La Niña

• Effects on environment
• Severe storms in North and South America.
• Drought in Australia
• Polar jet stream moved north.
• Eastern United States has warmer winter.

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El Niño and La Niña

• Effects (continued)
• The Pacific jet stream moves further south than
  usual.
• Fierce storms hit Californias coast which
  usually has mild, sunny weather.

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El Niño and La Niña

• Impact on Humans
• Thousands of deaths
• Billions of dollars lost around the world

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Monsoons

• Location
• South Asia

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Monsoons

• Source of wind
• Summer Wet Monsoons begin in the Indian Ocean
  between India and Africa.
• Winds move northeast across India toward the
  Himalayas.

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Monsoons

• Incidence
• Regularly each year
• Summer Monsoon May to September
• Winter Monsoon October to April

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Monsoons

• Effects on environment
• Before the summer Monsoon rains, land mass heats
  to 120 F.
• Winter Monsoons bring cool land, mild
  temperatures, low humidity.

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Monsoons

• Impact on Humans
• Monsoons are key to farming success.
• Seeds planted before Monsoon develop roots before
  the rains come.

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Monsoons

• Impact on Humans (continued)
• If Monsoons are late, young plants die, and
  famine follows.
• If Monsoons are early or too severe, young plants
  wash away, and famine follows.

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Mistral

• Location
• Rhone Valley, France

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Mistral

• Source of Wind
• Cold, north-westerly wind that blows down the
  Rhone valley.

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Mistral

• Incidence
• 100 days a year

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Mistral

• Effect on environment
• Winds blow 40 to 80 mph
• 100 days per year
• Trees grown permanently bent

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Mistral

• Impact on Humans
• Homes have windows only on the southeast side for
  protection from the cold, dry wind that blows
  through the Rhone Valley.

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Sirocco

• Location
• Wind blows from North Africa to Italy.

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Sirocco

• Source of wind
• Over north Africa, winds become hot and dry and
  blow toward Italy
• Sirocco is a hot, dust-and-sand-laden wind
  especially common in summer blowing from Algeria
  northward.

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Sirocco Wind
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Sirocco Winds
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Sirocco

• Incidence
• Spring and Summer

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Sirocco

• Effect on environment
• Supports the Mediterranean Climate with sunny,
  mild summers.
• Cool moist fall and winter replaces Sirocco.

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Sirocco

• Impact on Humans Italy
• Encourages rain
• Climate allows Italian farmers to grow crops

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Sirocco

• Extension
• What might happen to farmers if the Sirocco wind
  blew all year long?
• How might the climate of Italy be affected if
  there were no Sirocco wind?

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Sirocco

• Impact on Humans Algeria
• Soil erosion from overgrazing
• Other poor farming practices
• Desertification
• Inadequate supplies of potable water

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Harmattan

• Location
• South of Sahara
• West coast of Africa
• Algeria, Guinea, Guinea-Bissau

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Harmattan

• Source of Wind
• Dry, dusty wind which blows south from the Sahara
  in winter.
• Brings dust storms and very dry air.

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Harmattan

• Incidence
• Blows in winter

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Harmattan

• Effect on environment
• Generally hot and humid
• Monsoonal-type rainy season (June to November)
  with southwesterly winds
• Dry season (December to May) with northeasterly
  Harmattan winds

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Harmattan

• Impact on humans
• Hot, dry, dusty Harmattan haze may reduce
  visibility during dry season
• Inadequate supplies of potable water
• Desertification

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Discussion Questions

• Extension
• Is there a connection between the Sirocco and the
  Harmattan?
• Both begin in the Sahara
• Sorocco blows north in summer
• Harmattan blows south in winter

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Other Named Winds

• The Levante
• an easterly Mediterranean wind
• bringing mild, moist air to Gibraltar and the
  mainland of Spain and Africa.

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Other Named Winds

• The Pampero
• a very cold south westerly wind in Argentina
• formed in the middle of the continent
• blowing across the Pampas grasslands.

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Resources

• http//www.rcn27.dial.pipex.com/cloudsrus/activiti
  es.html Games and activities on weather, winds,
  and climate.
• http//www.rcn27.dial.pipex.com/cloudsrus/wind.htm
  l Definitions of winds and wind patterns.
• http//www.rcn27.dial.pipex.com/cloudsrus/features
  .html Weather and climate patterns.
• http//www.cia.gov/cia/publications/factbook/geos/
  gv.html Facts and maps on most countries of the
  world.