Typoons
Tropical cyclone, also called a typhoon or hurricane, is an intense circular storm that originates over warm tropical oceans and is characterized by low atmospheric pressure, high winds, and heavy rain.
Drawing energy from the sea surface and maintaining its strength as long as it remains over warm water, a tropical cyclone generates winds that exceed 119 km (74 miles) per hour.
In extreme cases winds may exceed 240 km (150 miles) per hour, and gusts may surpass 320 km (200 miles) per hour.
Typhoons start off as tropical thunderstorms.
The strong winds pull in moisture from the oceans, then the thunderstorms convert the moisture into heat.
The heat causes more air to flow to the center of the storm causing evaporation, all the heat and air flow toward the eye creating the typhoon
A characteristic feature of tropical cyclones is the eye, a central region of clear skies, warm temperatures, and low atmospheric pressure. Typically, atmospheric pressure at the surface of Earth is about 1,000 millibars.
At the center of a tropical cyclone, however, it is typically around 960 millibars, and in a very intense “super typhoon” of the western Pacific it may be as low as 880 millibars. In addition to low pressure at the center, there is also a rapid variation of pressure across the storm, with most of the variation occurring near the center.
This rapid variation results in a large pressure gradient force, which is responsible for the strong winds present in the eyewall. The most dangerous and destructive part of a tropical cyclone is the eyewall. Here winds are strongest, rainfall is heaviest, and deep convective clouds rise from close to Earth’s surface to a height of 15,000 meters (49,000 feet). As noted above, the high winds are driven by rapid changes in atmospheric pressure near the eye, which creates a large pressure gradient force.
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