Two Page Paper

A cyclone is an area of low atmospheric pressure, characterized by inward spiraling winds and rotate counter clockwise in the northern hemisphere and clockwise in the southern hemisphere of the Earth. Cold-core cyclones form due to the nearby presence of an upper level trough, which increases divergence over an area that induces upward motion and surface low pressure. Warm-core cyclones can have their initial start sue to nearby upper trough, but after formation of the initial disturbance, depend on a storm-relative upper level high to maintain or increase their strength. Cyclones can produce extremely strong winds, tornadoes, torrential rain, high waves, and storm surges. Also, heavy rains and storm surges can produce extensive flooding. When these things happen it is devastating on the human populations and also destroys homes, land, and forests. Cyclones can also be beneficial by relieving drought conditions and carry heat away from the tropics. Cyclones are predicted the same way hurricanes, typhoons, tropical storms, cyclonic storms, and tropical depression are because they are often mistaken for those. Warnings are issued because they can kill people and ruin land, also tornadoes and flooding occur during the process, which causes even more damage. There are different types of cyclones such as polar polar low, extratropical, subtropical, tropical, and mesoscale. Polar cyclones, also know as arctic cyclones, are vast areas of low pressure and usually spanning 1,000-2,000 kilometers. Polar low is a small-scaled, short-lived atmospheric low-pressure system and scale less than 1,000 km. Extratropical is a synoptic scale low-pressure weather system that has neither tropical nor polar characteristics. Subtropical is a cyclone that has the same characteristics of a tropical and extratropical cyclone’s. It can form in a wide band of latitude, from the equator to 50 degrees. Tropical cyclone is a storm system fueled by the heat released when moist air rises and the water vapor in it condenses. Mesoscale is a cyclonic vortex of air, between approximately 2 to 10 km diameter within a convective storm. Since cyclones produce from the water vapor, when the temperature changed in the ocean it is easier for them to produce. For example, when the ocean gets warmer tropical cyclones produce because the heat releases moister into the air. When cold and warm fronts cross the low and the wind ciculates around the low, a cyclone forms. Depending on the storm-relative upper level high depends if it maintains its strength or increases. The three parts of a cyclone are an eye, eyewall, and a rain band. An eye is a region of mostly calm weather that is in the center of the cyclone. It is typically 30-65 km or 20-40 miles in diameter. The cyclone's lowest barometric pressure occurs in the eye, and can be as much as 15 percent lower than the atmospheric pressure outside the storm. The eye is characterized by light winds and clear skies, surrounded on all sides by a towering, symmetric eyewall. The eyewall is a ring of towering thunderstorms where most of the severe weather occurs. Winds in an eyewall usually become greater than 115 mph. Cyclones reach a threshold of intensity, and the eyewall contracts, some of the outer rainbands may strengthen and turn into a ring of thunderstorms. An outer eyewall slowly moves inward and takes place of the inner eyewall because of needed moisture and angular momentum. Since the strongest winds are located in a cyclone's eyewall, the tropical cyclone usually weakens during this phase, as the inner wall is choked by the outer wall it eventually gets replaced by the outer eyewall, and the storm can re-intensify. A common mistake, especially in areas where hurricanes are uncommon, is for residents to go outside to inspect the damage while the eye passes over, thinking the storm is over. They are then caught completely by surprise by the violent winds in the opposite eyewall. Rain bands are bands of showers and thunderstorms that spiral cyclonically toward the storm center. High wind gusts and heavy downpours often occur in individual rainbands, with relatively calm weather between bands. Usually tornadoes form in the rain bands.

I got all this information at: http://en.wikipedia.org/wiki/Cyclone
and http://en.wikipedia.org/wiki/Eye_%28cyclone%29
and http://en.wikipedia.org/wiki/Tropical_cyclone




PHOTO: http://i13.photobucket.com/albums/a276/JessieMC1991/800px-Cyclone_Catarina_from_the_ISS.jpg
**Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004.**
LINK: http://en.wikipedia.org/wiki/Image:Cyclone_Catarina_from_the_ISS_on_March_26_2004.JPG


PHOTO: http://i13.photobucket.com/albums/a276/JessieMC1991/Hurricane_structure_graphic.jpg
**Structure of a tropical cyclone.**
LINK: http://en.wikipedia.org/wiki/Image:Hurricane_structure_graphic.jpg


PHOTO: http://i13.photobucket.com/albums/a276/JessieMC1991/UK-Cyclone.gif
**A fictitious synoptic chart of an extratropical cyclone affecting the UK. The blue arrows between isobars indicate the direction of the wind, while the "L" symbol denotes the centre of the "low".**
LINK: http://en.wikipedia.org/wiki/Image:UK-Cyclone.gif


PHOTO: http://i13.photobucket.com/albums/a276/JessieMC1991/Eye_structure.jpg
**A cross section diagram of a mature tropical cyclone, with arrows indicating air flow in and around the eye.**
LINK: http://en.wikipedia.org/wiki/Image:Eye_structure.jpg


PHOTO: http://i13.photobucket.com/albums/a276/JessieMC1991/HurricaneAndrewFLRADAR.png
**Typically, eyes are easy to spot using weather radar. This radar image of Hurricane Andrew clearly shows the eye over southern Florida.**
LINK: http://en.wikipedia.org/wiki/Image:HurricaneAndrewFLRADAR.png