Hurricanes: The Greatest Storms on Earth
Introduction
Few things in nature can compare to the destructive force of a hurricane. Called the greatest storm on Earth, a hurricane is capable of annihilating coastal areas with sustained winds of 155 mph or higher and intense areas of rainfall and a storm surge. In fact, during its life cycle a hurricane can expend as much energy as 10,000 nuclear bombs!
The term hurricane is derived from Huracan, a god of evil recognized by the Tainos, an ancient aborigines Central American tribe. In other parts of the world, hurricanes are known by different names. In the western Pacific and China Sea area, hurricanes are known as typhoons, from the Cantonese tai-fung, meaning great wind. In Bangladesh, Pakistan, India, and Australia, they are known as cyclones, and finally, in the Philippines, they are known as baguios. Hurricane Formation and Decay
Hurricanes form over tropical waters (between 8° and 20° latitude) in areas of high humidity, light winds, and warm sea surface temperatures (typically 26.5°C [80°F] or greater). These conditions usually prevail in the summer and early fall months of the tropical North Atlantic and North Pacific Oceans and for this reason, hurricane "season" in the northern hemisphere runs from June through November.
The first sign of hurricane genesis (development) is the appearance of a cluster of thunderstorms over the tropical oceans, called a tropical disturbance. Tropical disturbances most commonly form in one of three different ways, all of which involve the convergence of surface winds. Near the equator, the easterly trade winds converge (come together) to trigger numerous thunderstorms in a region called the Intertropical Convergence Zone (ITCZ). Occasionally, a cluster of thunderstorms will break away from the ITCZ and become better organized. Another mechanism is the convergence of air that occurs along a mid-latitude frontal boundary that has made its way into the Gulf of Mexico or off the East Coast of Florida. The last mechanism is the easterly wave, a tropical disturbance that travels from east to west in the region of the tropical easterlies. Converging winds on the east side of the easterly wave trigger the development of thunderstorms.