Transcript Hurricanes-Slideshowx

What is a storm?
Air is heated up creating low pressure
 Air rises
 Cools and condenses
 Air from high pressure move to low
pressure
 This air rises, “fueling” the storm
 Winds push the storm out to sea
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What is a hurricane
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storm system
low pressure center
surrounding thunderstorms.
Hurricanes strengthen over oceans
What they are called depends on their
location of formation.
 Hurricane in the Atlantic ocean
 Tropical cyclone in the Pacific and Indian
oceans
 Typhoon in the Northwest Pacific ocean
 Willy Willies in Australia
How they form
Begins with a thunderstorm blown out to
sea.
 Then it must have:
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 1. ocean waters must be warm to put heat
and moisture into the overlying atmosphere
 2. moisture from sea water evaporation must
combine with that heat and energy
 3. a wind pattern
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hurricane takes in air from surrounding
areas this new air replaces the lost old air
die out over land masses
destructive force lie in their storm surges.
also have some destructive force in their
winds and rains.
The hurricanes spin counter clockwise in
the Northern Hemisphere and clockwise in
the Southern Hemisphere*
 *Due to coriolis effect, when rising it reverses
 *Winds become slower toward the poles theory
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http://www.youtube.com/watch?v=kjd9Fa1
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How we measure hurricanes
Saffir–Simpson Hurricane Scale
Category
A hurricane is measured using
the Saffir-Simpson scale
 We measure their intensity
through their wind speed and
storm surge height.
Wind speed
Storm surge
mph
(km/h)
(kn)
ft.
(m)
Five
≥ 157
(≥ 252
(≥ 137)
> 18
(> 5.5)
Four
130–156
(209–251)
(113–136)
13–18
(4.0–5.5)
Three
111–129
(178–208)
(96–112)
9–12
(2.7–3.7)
Two
96–110
(154–177)
(83–95)
6–8
(1.8–2.4)
One
74–95
(118–153)
(64–82)
4–5
(1.2–1.5)
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 A storm surge is the rise of water
that is associated with an
incoming storm.
Additional classifications
Tropical
storm
Tropical
depression
39–73
(63–117)
(35–63)
0–3
(0–0.9)
0–38
(0–62)
(0–34)
0
(0)
Their anatomy
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Eye- low-pressure, center of
the hurricane
Eye wall- area around the
eye, includes the most violent
storms
Rain Bands- thunderstorm
bands that circulate out from
the eye
Coriolis effect- natural
phenomenon that causes
winds to veer right in the
northern hemisphere and left
in the southern due to spin
Rain shields- completely solid
or nearly solid areas of rain
that are heavier the closer to
the eye
Random facts
After god Huracan
 Can release power up to the amount of
a couple of Atomic bombs
 Hurricane season during summer
 Naming
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Originally only phonetic names
Then only women
Changed to alternate
Used to be named after saints
Their effect on waters
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Aquatic environments
 Cause sediment erosion removing many
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habitats/homes
Salt water intrusion killing many freshwater fish
Flood waters filled with many industrial products
that poison organisms
Fisheries can be totally destroyed by winds
Effect on coastal ocean is the scraping of the
bottom due to large waves
Little effect on open ocean due to tidal flow
Normally can rebound in 3 years
Their effect on land
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Terrestrial environments
 Wetlands destroyed the most due to the
erosion or shift of barrier islands
 Mangrove forests destroyed by winds,
destroying many animal’s habitats
 Sea grass beds, which are for feeding and
nesting are often destroyed
 Also causes massive damage to human
structures
Examples
Bhola cyclone- 1970 in Bangladesh killed
300,000 to 500,000 though only Cat. 3
 Galveston hurricane- 1900 in Galveston,
TX killed 6,000 cost 500 million dollars,
destroyed 3,600 Cat. 4
 Hurricane Katrina- Cat. 5, 1,833 killed,
costliest hurricane in U.S. history 108
billion dollars
http://www.youtube.com/watch?v=s76Qn7b
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Detection/Prevention
Aircrafts- fly near the hurricane to collect
information
 Ships- measure the heat of the sea
around the storm also collect
information.
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Satellites- take pictures showing the
direction and speed of the storm also
measure temperature and rainfall in and
estimate its strength and course.
Detection/Prevention
 Doppler
radar- show location and
intensity of precipitation and the wind
motions
Levee prevent the floods from coming
 Reinforcing buildings help with strong
winds
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Questions
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If I was on the southern coast of Brazil in
fall should I be worried about being hit by a
hurricane?
Where are the most violent storms?
How do hurricane’s destroy ocean life in
the coastal waters?
What is the name of the scale we use to
measure hurricanes?
Overview:
http://www.youtube.com/watch?v=75qAgSu
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