Question

Why does tropical cyclone originate over the seas? In which part of the tropical cyclone do torrential rains and high-velocity winds blow and why?

Answer 1

Tropical cyclones originate over seas because warm and moist air from the ocean rises, creating a low-pressure area. This low-pressure area draws in more air. As the warm, moist air continues to rise and cool, it releases heat and forms clouds. The Coriolis force causes the wind to spiral, forming a cyclone. However, at the equator, the Coriolis force is zero, so the wind does not spiral. Instead, the low pressure gets filled instead of getting intensified. That is why tropical cyclones are not formed near the equator.

Torrential rain and high-velocity winds occur in the eyewall of the cyclone, not the eye. The eye is the calm center of the cyclone with subsiding air and clear skies. The eyewall surrounds the eye and is a region of strong spiraling upward movement of air reaching the tropopause. This is where the wind reaches maximum speed, sometimes up to 250 km/hr, and heavy rainfall occurs.

Outside the eyewall are rain bands, which consist of cumulus and cumulonimbus clouds. These clouds can bring rain to far outer areas of the cyclone. Because of these torrential rains, the winds coming from these regions carry moisture, leading to heavy rainfall on the eastern coast of India and the northeast coast of China.