Tropical cyclones are like giant engines that use warm, moist air as fuel. That is why they form only over warm ocean waters near the equator. The warm, moist air over the ocean rises upward from near the surface. Because this air moves up and away from the surface, there is less air left near the surface.

Why do cyclones occur?

Cyclone is system of winds rotating inwards at a high speed with the area of low pressure in the middle. ... When warm, moist air over the ocean rises upward from near the surface, a cyclone is formed. When the air rises up and away from the ocean surface, it creates an area of lower air pressure below.

Where do cyclones usually occur?

Cyclones are called hurricanes in the Atlantic and eastern Pacific, typhoons in Southeast Asia, and cyclones in the Indian Ocean and western Pacific around Australia.