Describe tropical cyclones, including their origin, patterns of movement, and the types of destruction caused by these atmospheric events. How are the number and frequency of cyclones related to latitude and season?

Question

What will be an ideal response?

Answer 1

Tropical cyclones are huge rotating masses of low pressure characterized by strong winds and torrential rain. They are the largest storm systems on Earth, though they are not associated with any fronts. What powers tropical storms is the latent heat of evaporation and condensation of water. A tropical cyclone begins as a low-pressure cell that breaks away from the equatorial low-pressure belt and grows as it picks up heat energy in the following manner. Surface winds feed moisture (in the form of water vapor) into the storm. When water evaporates, it stores tremendous amounts of heat in the form of latent heat of evaporation. When water vapor condenses into a liquid (in this case, clouds and rain), it releases this stored heat—latent heat of condensation—into the surrounding atmosphere, which causes the atmosphere to warm and the air to rise. This rising air causes surface pressure to decrease, drawing additional warm moist surface air into the storm. This air, as it rises and cools, condenses into clouds and releases even more energy, further powering the storm and continuously repeating itself as a feedback loop, each time intensifying the storm. These conditions are found during the late summer and early fall, when the tropical and subtropical oceans are at their maximum temperature. Even though hurricanes sometimes form outside hurricane season, the official Atlantic basin hurricane season is from June 1 to November 30 each year. These dates conventionally delimit the period when most tropical cyclones form in the Atlantic basin. When hurricanes are initiated in the low latitudes, they are affected by the trade winds and generally move from east to west across ocean basins. Hurricanes typically last from 5 to 10 days and sometimes migrate into the middle latitudes. Destruction from hurricanes is caused by high winds and flooding from intense rainfall. Storm surge causes the majority of a hurricane's coastal destruction. In fact, storm surge is responsible for 90% of the deaths associated with hurricanes. The majority of the world's tropical cyclones are formed in the waters north of the equator in the western Pacific Ocean. These storms, called typhoons, do enormous damage to coastal areas and islands in Southeast Asia.