Question

how are cyclones formed ?

Answer 1

•  Tropical cyclones form only over warm ocean waters near the equator.
• To form a cyclone, warm, moist air over the ocean rises upward from             near the surface. As this air moves up and away from the ocean surface, it   leaves is less air near the surface. So basically as the warm air rises, it   causes an area of lower air pressure below.
• Air from surrounding areas with higher air pressure pushes in to the low     pressure area. Then this new “cool” air becomes warm and moist and rises,   too. And the cycle continues…
•         As the warmed, moist air rises and cools the water in the air forms clouds. The whole system of clouds and wind spins and grows, fed by the ocean’s heat and water evaporating from the ocean surface.
•         As the storm system rotates faster and faster, an eye forms in the centre. It is very calm and clear in the eye, with very low air pressure. Higher pressure air from above flows down into the eye.

When the winds in the rotating storm reach 39 mph (63 kmph), the storm is called a “tropical storm”. And when the wind speeds reach 74 mph (119 kmph), the storm is officially a “tropical cyclone” or hurricane. Tropical cyclones usually weaken when they hit land, because they are no longer being “fed” by the energy from the warm ocean waters. However, they often move far inland, dumping many centimeters of rain and causing lots of wind damage before they die out completely.


The green arrows show where warm air is rising. The red arrows indicate where cool air is sinking.(refer the file)

Answer 2

Answer:

The moist air over the seas and oceans gets heated by sunrays. The warm air containing water vapour rises upwards and forms a low pressure region. The moist warm air gets cooler as it goes higher. As a result, water vapour starts condensing. During condensation, heat is released and the air around it gets warm. This warm air rises upwards, creating a low pressure region.

Cooler air rushes to fill the space created by the rising warm air. This cycle of events continues till a very low-pressure system with very high speed winds revolving around it is formed. This is how a cyclone is formed.