Tropical Cyclone, Hurricane, Storm Formation explained | Cyclone Biparjay in Arabian Sea, Gujarat

Tropical cyclones originate over oceans in tropical areas and coastal regions, specifically between the Tropic of Cancer and the Tropic of Capricorn. They are known by different names globally: 'cyclones' in the Indian Ocean, 'typhoons' in the Western Pacific/South China Sea, and 'willy-willies' near Western Australia, all referring to the same type of storm.

Tropical regions receive the most solar radiation due to direct and vertical sun rays, making them warm. As one moves towards the polar regions, the sun's rays become slanting and less effective in producing heat.

Wind movement is driven by differences in atmospheric pressure, blowing from high-pressure areas to low-pressure areas. Low pressure occurs when air is warm (over warm land or ocean), while high pressure occurs when air is cool (over cool land or ocean). Tropical regions are ideal for low-pressure formation, and polar regions for high pressure.

The Coriolis force, caused by the Earth's rotation, deflects moving objects (like air) to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This force is crucial for the global wind circulation patterns and the spinning of cyclones.

A cyclone forms around a central low-pressure area (the 'eye' of the storm) which attracts cool, high-pressure air from the surrounding areas. As this cool air rushes in, it warms, becomes moist, and rises, creating a continuous cycle. The Coriolis effect then causes this incoming air to spin: counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Tropical cyclones are sustained by a continuous supply of moisture from the ocean. They dissipate when they make 'landfall' because the moisture supply is cut off. The average diameter of a tropical cyclone varies, with those in the Bay of Bengal, Arabian Sea, and Indian Ocean being between 600 to 1200 kilometers, moving at 300 to 500 kilometers per day. Their circulation extends up to the troposphere (15,000-18,000 meters).

Warm, moist air rising in the atmosphere cools and becomes denser at higher altitudes, descending back towards the ground as subsiding warm air. This process intensifies the storm and expands its diameter. Tropical cyclones typically occur during periods of maximum solar radiation, usually from July to October in the Northern Hemisphere and December to March in the Southern Hemisphere.