Hurricanes
Of all of nature’s forces
that exist
hurricanes could be considered one of the most powerful of all these
forces
that can cause tremendous amounts of destruction is such a little amount
of
time. A hurricane is a powerful whirling storm of winds that measure
200-300
miles in diameter. Hurricanes are an area of low pressure that forms
over the
oceans in tropical regions in either the north Atlantic Ocean or
eastern north
Pacific Ocean. In the west Pacific Ocean hurricanes are
called typhoons, and in
the Indian Ocean they are called Cyclones. Hurricanes
develop from easterly
waves that over the oceans warm waters. These easterly
waves are long narrow
regions of low pressure that occur in ocean winds
called trade winds. The waves
may grow into a tropical depression, which are
winds from 1 to 31 miles per
hour. Then they can grow into a tropical storm,
which are winds from 32 to 73
miles per hour. These waves then turn into what
you call hurricanes and
hurricanes are winds greater than 74 miles per hour.
The winds swirl around a
portion of the storm called the eye. This is a calm
area in the center of the
storm. It is about 20 miles in diameter and has
little wind and clouds. The
storm clouds called that are around the eye of
the storm are called wall clouds.
Inside these wall clouds are where most
of the heaviest rains are and where the
strongest winds are. Outside of the
wall clouds are clouds called rain clouds.
They have winds and rain and
make up most of the diameter of the storm but
nothing as powerful as the wall
clouds. Hurricanes usually occur within the
months of June to November, most
occur in the month of September. Eight
Hurricanes occur a year on average
but as many as 15 have occurred in one years
time in the Atlantic Ocean. In
the Northern Hemisphere the winds of a Hurricane
move around the eye counter
clockwise due the gravitational pull from the North
Pole. In the Southern
Hemisphere the winds move around the eye clockwise. The
eye of the hurricane
travels over land at an average of 10 to 15 miles per hour.
The
atmospheric disturbance that causes hurricanes start approximately in
the
latitudes between 5-30 degrees on both sides of the equator. Hurricanes
start
moving towards land picking speed, strength, and size. They will then
drift away
from the equator as they reach temperate latitude where they are
called extra
tropical and travel over the land bring havoc and destruction to
all that they
pass over. The winds and the rains over the sea along with the
force of the sea
produce huge waves called a storm surge. These storm surges
cause lots of
flooding and damage to coastlines, especially if they happen at
high tide. The
storm weakens as it moves over land because hurricanes need
the warm sea to
supply energy to it through evaporation. Also the friction of
the storm over the
land causes the storm to slow down. Meteorologists of the
National Weather
Service keep a close watch over the Atlantic and Pacific
Oceans to see of there
are any storms brewing. They collect such information
as air pressure,
temperature, and wind speeds. By doing all this they will be
able to forecast
where and when a hurricane will begin, where it will travel,
and how strong it
is going to be. Meteorologists get information about
hurricanes by satellites,
airplanes and by radar. It is shocking to see the
amount of destruction from the
power of a hurricane that can be caused. To
put this in a better perspective: A
hurricane in one day averages 1.6 X 1013
kilowatt-hour, which is 8000 times more
than all the electrical power
generated in the United States in one day. This is
also equivalent to a daily
explosion of 500000 atomic bombs, the 20-kiloton
Nagasaki variety. This
is absolutely amazing to think about. Many people have
been trying to find
ways to slow down the speeds of hurricanes for the longest
time now. What is
needed is a small input that can make a large amount of
natural instability.
The first attempt was done with 91 kilograms of crushed dry
ice, and although
it is not known for certain scientists think that this did
effect the storm
because it changed direction which was not anticipated. The
Environmental
Science Services Administration and the US Navy conducted the
second attempt.
They dropped heavy doses of silver iodide by planes into the
wall clouds of
the storm. It was reported that after the first day of this
experiment the
winds decreased by 31% and by 15% on the second day. There is a
scale in
which hurricanes are rated on and that is the Saffir Simpson Scale. It
looks
like this: Category Wind Speed Severity Storm Surge 1 74mph-95mph weak
4-5
ft. 2 96mph-110 mph moderate 6-8 ft. 3 111mph-130mph strong 9-12 ft.
4
131mph-155mph very strong 13-18 ft. 5 * 155 mph devastating * 18 ft.
There have
been many hurricanes in the past but some of the most remembered
ones are
Hurricane Gilbert in 1988. This was the most powerful hurricane
ever recorded in
the Western Hemisphere. In 1989 there was Hurricane Hugo. In
1992 there was
Hurricane Andrew that hit the Florida region causing $22
billion in damage. And
then most recently, Hurricane Bonnie that hit in the
Carolinas, causing
tremendous damage and devastation. Hurricanes are an act
of nature and although
they are attempted to be controlled, they can’t really
ever be changed. This
is why nature is so amazing, making hurricanes, one of
nature’s most powerful
weapons, even more amazing.