Why Tropical Cyclones Occur
By: Christine Lorraine
Tropical cyclones occur when a complex set of atmospheric conditions combine and advance to produce violent weather.
The generic term “tropical cyclone” encompasses hurricanes, typhoons, tropical storms, depressions and disturbances. These disruptive low-pressure weather systems that occur in moist tropical air have a measurable wind circulation and develop over subtropical and tropical bodies of water. They are prone to form in the Pacific Ocean, the Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico.
Every few days strong thunderstorms gather strength, and boom through the atmosphere above the water as tropical waves of low pressure travel with winds from the west. The low pressure draws moist air off of the surface of the sea, which causes winds to begin spiraling at the core of the low pressure.
When warm air gets close to the core it quickly rises, forming condensation that results in rain. At this point large forces of heat are released, causing winds to gain strength, and as a result, the storm becomes self-propelled. If a tropical cyclone progresses to hurricane strength, an eye will usually be created.
What’s the Difference, Cyclonically-Speaking?
Cyclones can develop in various parts of the world, but there is one uniquely identifiable characteristic which separates them from tropical cyclones. The tropical cyclone is a “warm core” system, which means it is warmer in the center than the winds raging around it. This “warm core” phenomenon occurs regardless of the height of the cyclonic storm.
Tropical Cyclone Umbrella
The term “tropical cyclone” covers any of the four stages of a hurricane’s life span: Tropical disturbance, tropical depression, tropical storm, hurricane.
* A tropical disturbance is defined as an isolated tropical cloud, shower or thunderstorm system which lasts for at least 24 hours. Another type of tropical disturbance is the occurrence of tropical waves, which are low-pressure forces that typically flow east to west.
* A tropical depression is created when a disturbance prompts winds to rotate around a low pressure center.
* A tropical storm is a powerful force, with winds raging between 39 to 73 miles-per-hour. When a tropical cyclone reaches this level, it is given a name by the National Hurricane Center.
* A hurricane is the most powerful form of tropical cyclone. Its destructive winds can range anywhere between 74 m.p.h. to well over 100 m.p.h. The severity of these storms is numerically categorized on a 1-to-5 scale based on damage potential, wind speed and barometric pressure.
The logical explanations as to why tropical cyclones occur were just presented, hopefully you enjoyed them. Of course, there is always more than one side to every stormy story. A purely speculative, non-scientific way to justify the constant existence of cyclones might be to ponder that, like her inhabitants, even Mother Earth needs to blow off some steam every now and then.
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Editor’s Note: This article was originally published on Feb. 11, 2011 at the now-defunct helium.com. This, and many of my other stories have since been plagiarized verbatim by the website actforlibraries.org. Although requests to remove have been sent, they have been ignored.