Structure of the answer:
- Features of tropical cyclone
- Factors contributing in formation of cyclones
- Difference between tropical and extra tropical cyclones
Cyclone is an intense vortex or a whirl in the atmosphere with very strong winds circulating around it in anti-clockwise direction in the Northern Hemisphere and in clockwise direction in the Southern Hemisphere. For Ex- Cyclone Titli
Some of the special characteristics of tropical cyclones are as follows:
- Cyclones have intense low pressure areas and pressure increases outwards.
- They mainly originate mainly in zones between 5– 30 °C Norther & South of latitude.
- These originate over oceans in tropical areas & move to coastal areas.
- They have large destructive force caused by violent winds, heavy rainfall & storm surges.
- Tropical cyclones follow a parabolic path and its axis is parallel to the isobars.
Some of the necessary condition for the formation of tropical cyclones are as follows:
- Continuous supply of abundant warm and moist air.
- Sea temperature in lower latitudes should be around 27°C.
- The cyclones require presence of large Coriolis force to deflect winds blowing toward the low pressure centre.
- There must also be pre-existence of weak tropical disturbances.
- Further, there should be presence of anticyclonic circulation at the height of 9 to 15 km above the surface.
However, the tropical cyclones are different from temperate cyclones in following ways:
- Tropical cyclone is confined between 5-30° N-S of the equator, whereas temperate cyclone originate between 30 to 60° N-S of the equator.
- Coriolis force plays vital role in the origin of tropical cyclone, whereas for temperate cyclone frontogenesis is the driving force.
- Temperate cyclone covers large area as compared to tropical cyclone.
- Tropical cyclone generally originates over water surface but the temperate cyclone originates over mid-latitude land mass.
- Temperate cyclone generally moves eastward, while tropical cyclone moves from east to west.
- Cyclone’s eye is a typical feature in case of tropical cyclone, while temperate cyclone have no such concept.
Thus, as cyclones carries destructive force there is a need for timely dissemination of warning and increasing preparedness of disaster management authorities.