By: Nicole Sassine, Cassandra Smith, and Carolina Szewczyk

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Katabatic
Mistral
Chinook
Winds
Sirocco
Dust Storms

• By Nicole Sassine, Cassandra Smith, and Carolina
  Szewczyk

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Table of Contents
Page 1 Winds Page 2 Wind Chill Page 3 Types of
Winds Page 7-9 Katabatic Winds Page 10-12
Chinook Page 13-19 Mistral Page 20- 25
Sirocco Page 26-29 Dust Storms
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Winds

• Wind is air in motion. The term is usually
  applied to the natural horizontal motion of the
  atmosphere. Winds are produced by differences in
  atmospheric pressure, which are primarily refer
  to differences in temperature. Variations in the
  distribution of pressure and temperature are
  caused largely by unequal distribution of heat
  from the sun, together with differences in the
  thermal properties of land and ocean surfaces.
  When the temperatures of nearby regions become
  unequal, the warmer air tends to rise and flow
  over the colder, heavier air. Winds initiated in
  this way are usually greatly modified by the
  earth's rotation.

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Wind Chill

• The feeling of temperature outdoors depends
  greatly on wind speed. Even slight winds give
  greater cooling effects than still air on any
  object. Weather forecasts in cold weather often
  give the wind chill equivalent temperature which
  takes into account extra cooling of the human
  body due to the wind. There is no accurate method
  of measuring this because it depends on the
  amount of your body exposed, clothing worn,
  humidity, sunshine and shelter.
• When low temperatures and moderate wind speeds
  are experienced together, this wind chill poses a
  severe hazard.

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Types of Winds

• In this presentation, we will be informing you
  on 5 different types of winds

1) Katabatic 2) Chinook 3) Mistral 4) Sirocco 5)
Dust Storms
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Katabatic Winds

• Katabatic wind is the term for downslope winds
  flowing from high elevations of mountains,
  plateaus, and hills down their slopes to the
  valleys or planes below. Katabatic winds exist in
  many parts of the World and there are many
  different names for katabatic winds depending
  where they are located and how they are formed.
  Warm, dry katabatic winds occur on the lee
  side of a mountain range situated in the path of
  a depression. Cold and usually dry katabatic
  winds result from the downslope gravity flow of
  cold, dense air. Most katabatic winds are more
  or less the result of air in contact when upper
  level ground is cooled by radiation, increases in
  density, and flows downhill and along the valley
  bottom. This effect is enhanced during winter
  over snow covered surfaces and after dry, clear
  nights. These types of winds can reach velocities
  of up to 4 meters per second.

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Katabatic Winds

• Katabatic winds dont occur in Windsor because
  there isnt enough big slopes to support them.
  They need a flat region of land to occur.

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Katabatic Winds
Strong Katabatic Winds can form where cold winds
rush downhill from an elevated plateau covered
with snow.
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Chinook

• Chinook winds are warm, dry, usually
  irregularly occurring katabatic winds, similar to
  Alpine foehn winds, that come down the eastern
  slopes of the Rocky Mountains into the plains of
  North America. These winds are caused by the air
  being stripped of its moisture due to
  precipitation, then releasing heat as it rises
  and cools, then warmed by increasing density as
  it descends. The wind is named after the Chinook
  people.

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Chinook

• Chinooks weather patterns cool at rates of
  .54C/100m for moist systems, and 1C/100m for
  dry systems. They usually begin with a sudden
  change in wind direction towards the west or
  southwest, and a rapid increase in wind speed.
  They occur along the eastern slopes of the
  Rockies. These winds are least likely to occur in
  places far away from water. There hasnt been any
  examples of Chinooks in our area because they
  only occur off the coast of Alberta.
• On January 11, 1983, the temperature in Calgary
  rose 30C (from -17C to 13C) in 4 hours, and on
  February 7, 1964, the temperature rose 28C
  (51F), and the humidity dropped by 43 percent.

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Chinook

• General Effects of Chinook Winds include
• ? Rapid. Large Temperature Changes Can Occur
• ? Snow may melt or evaporate through sublimation
• ? Loss of moisture due to significant drops in
  humidity.
• ? Rivers and Lakes may lose Ice at 2.5 Cm (1 In)
  per hour
• ? Strong, warm winds blow may carry sounds long
  distances  

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Mistral

• Mistral winds occur mostly in the winter and
  spring in the Gulf of Lion. It creates a cold,
  strong northwesterly wind along the coast,
  particularly from Marseille to Toulon, in
  southern France
• It is an example of a katabatic wind, which is
  caused by air that is cooled over the mountains
  by the presence of a high pressure system or
  radiative cooling. In Marseille, on about half
  of the days in the year the weather is
  characterized by the cold winds of the Mistral.
  These winds may affect the weather in North
  Africa, Sicily and Malta or throughout the
  Mediterranean, particularly when low pressure
  systems form in the Gulf of Genoa.

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Mistral

• Because the mistral wind is a Katabatic wind it
  needs a slope to flow along to pick up speed.
• In the winter the wind speeds can reach
  hurricane levels of over 100 knots making the
  mistral wind one of the most dangerous of all the
  Mediterranean winds.

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Mistral
This map shows where the Mistral winds are found
and where they move to.
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Sirocco

• Sirocco is a strong southerly to southeasterly
  wind in the Mediterranean that originates from
  the Sahara and similar North African regions. It
  is a warm, dry, tropical airmass that is pulled
  northward by low pressure cells moving eastward
  across the Mediterranean Sea. The hot, dry,
  continental air mixes with the cooler, wet air of
  the maritime cyclone, and the counter-clockwise
  circulation of the low propels the mixed air
  across the southern coasts of Europe.
• The Sirocco causes dusty, dry conditions along
  the northern coast of Africa, storms in the
  Mediterranean Sea, and cold, wet weather in
  Europe. The Sirocco's time period may be a half
  day or many days. Many people attribute health
  problems to the Sirocco either because of the
  heat and dust along the African coastal regions
  or the cool dampness in Europe. The dust within
  the Sirocco winds can degrade mechanical devices
  and invade homes.
• These winds with speeds of almost 100 km/h are
  most common during the autumn and the spring.
  They reaches a peak in March and in November,
  with a maximum speed of about 100 km/h (55 knots,
  hurricane-force).

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Sirocco in Libya
Sirocco winds brings dust and sand the sky is
red to brown and the visibility can lower to less
than 30 meters.
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Dust Storms
A dust storm is a incident common on the Great
Plains of North America, Arabia, in the Gobi
Desert of Mongolia, and the Sahara Desert of
northern Africa. Severe dust storms can reduce
visibility to zero, making travel impossible, and
can blow away valuable topsoil, while depositing
soil in places where it may not be wanted.
Drought and, of course, wind contribute to the
appearance of dust storms. The dust picked up in
such a storm can be carried thousands of
kilometers. Dust storms can often be observed
from satellite photos.
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Dust Storms

• Dust storms are also known to occur on a massive
  scale on the planet Mars. Storms on Mars last
  longer, and cover larger areas, than on Earth
  some of these storms cover the entire planet and
  last for hundreds of days.

A massive global dust storm raging on Mars in
2001.
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Dust Storms
Dust storm (1935) in Spearman, Texas.
Satellite photo of a Saharan dust cloud (2000)
over the Eastern Atlantic Ocean.
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THE END
Thank you for your time )