today

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today

• Hurricanes
• Beginning of a video
• the video will be at the library (Hurricane
  Katrina the storm that drowned a city) on
  reserve in media services

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READ for Wednesday

• first two pages of ch. 8
• sec. 8.2 Tropical cyclones
• p. 246 (Hurricanes)
• go on-line and watch
• http//learners.gsfc.nasa.gov/mediaviewer/birth_hu
  rr/

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Clickers, of course (youre here and so you get
credit)
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Hurricanes (tropical cyclones)

• A hurricane is a type of tropical cyclone
  low-pressure system that forms in the tropics
• Accompanied by thunderstorms
• Hurricane is used in the northern Pacific and
  Atlantic Oceans
• Names of Atlantic hurricanes are rotated on 6-yr
  basis

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A joke when I was a kid

• Why dont hurricanes ever have boys names?

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A joke when I was a kid

• Why dont hurricanes ever have boys names?
• Have you ever heard of a himicane?
• (Boys and girls names used since 1979)
• Other ocean basins have names generally more
  applicable to the cultures of people who live
  there

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Some 2005 statistics

• 28 named storms (21 in 1933)
• 15 hurricanes (12 in 1969)
• 4 major hurricanes hit the US (3 in 2004 and
  other years)
• 7 tropical storms before Aug. 1 (5 in 1977)

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And some hurricane facts

• Generally 300 miles (500 km) wide
• The eye at the center is generally 20-40 miles
  across (30-65 km)
• Hurricane-force winds stretch outwards from the
  center of the storm anywhere from 25 to 150 miles
  (40 - 240 km)
• The right side of the storm is more dangerous

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How do hurricanes form?

• Need
• warm seawater
• warm air
• weak winds
• Coriolis effect

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stages

• Tropical disturbance
• Tropical depression
• Tropical storm
• Hurricane

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Tropical depression disorganized group of
thunderstorms
http//ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hurr/
stages/td.rxml
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If your last name starts with H - P, please put
your name on a piece of paper, together with the
name of the person next to you, and answer this

• What happens to the warm rising air in the center
  of a growing tropical storm (and why) ?

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Tropical storm (Katrina, Aug. 30, 2005)
http//www.nnvl.noaa.gov/hurseas2005/Katrina1315z-
050830-1kg12.jpg
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(No Transcript)
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Eye and eyewall of the hurricane

• Winds cant get in to the core
• Air sinks in the core
• Strongest winds
• in the system in
• the eyewall

NASA photo
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How do hurricanes die?

• need warm water to replenish system
• need warmth
• need water
• need weak wind

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Why is damage greater on the right side of a
hurricane?
20 mph
100 mph