What are cyclones?
The term cyclone refers to different types of storms, some mild and some extremely dangerous that wreaks havoc to nature and mankind. Although cyclones fall under the category of storms, it should, however, be noted that each type is different from the other based on the causes for their formation and so does their intensity differ. Location plays a very important role in determining the kind of storm that hits the shore. It is also integral to measuring the intensity of its effect on human life. For instance, if a cyclone has originated in the Atlantic Ocean it is referred to as a hurricane while those originating from the South Pacific and the Indian Ocean are called tropical cyclones.
Thus, if we are to define cyclones, they are “spinning storms that rotate around a low-pressure centre.”
How are cyclones formed?
The low-pressure area, also known as the eye of the spinning storm is responsible for the origination of a cyclone. Climatic and temperature differences below the low-pressure centre result in the cyclone to come about and revolve around the area.
In the process, the layer of warm air surrounding the region rises and later begins to cool. However, when cooled it should be noted that the cold air cannot hold as much moisture as the warm air, and this results in the formation of clouds with the condensing of air. Simultaneously, with the amount of water transforming into clouds increase, they eventually fall back as rain, and the cycle of the warm updraft and cool downdraft continues and eventually forms a storm cell. With the continuing of the process, this storm cell grows into a large thunderstorm cloud. It is this large thunderstorm cloud that ultimately takes the shape of different kinds of storms is it tropical cyclones, tornadoes or hurricanes.
However, this cannot happen unless the air in the cloud starts spinning horizontally.
Which are the different types of cyclones?
1. TROPICAL CYCLONES: Most of us might be familiar with the tropical cyclone as they are the most commonly occurring among the different types of cyclones. Hurricanes and typhoons are examples. While hurricanes normally hit the Atlantic and the Northeast Pacific, typhoons normally originate in the Northwest Pacific. Tropical cyclones are further divided based on their wind speeds. The greater the wind speed, the more dangerous is the intensity of the storm.
2. POLAR CYCLONES: These include cyclones the affect the polar regions of Greenland, Siberia and Antarctica. Unlike the tropical cyclones, the polar cyclones gain strength and intensity during the winter months. Since they occur in during the cold season and also because they strike areas that are in comparison minimally populated, polar cyclones pose very less danger and a threat to human and animal life.
3. MESOCYCLONE: A mesocyclone happens when a part of the thunderstorm cloud evolves to form a tornado. The term ‘meso’ means middle and hence it is an obvious answer to the kind of storms they cause- it is a mid-point between one type of storm and another. Therefore for a tornado to occur, a part of the thunderstorm cloud has to form a dangerous spinning cloud running along the ground, although one cannot really see this happening.
Given below is a list of some severe cyclones that have hit the shores of India:
1. NISHA (2008): Cyclone Nisha was the seventh tropical cyclone to have originated in the Bay of Bengal. The cyclone created mass destruction of land and life, killing over 180 people in Tamil Nadu alone. With heavy rain and massive floods, the damage caused by the cyclone is estimated to be about 3789 crores.
2. PHYAN (2009): Cyclone Phyan originated as a tropical turbulence in the Arabian Sea and later moved to wreak havoc in the south-west of Colombo, Sri Lanka on November 4th, 2009. The Joint Typhoon Warning Centre names it Phyan after he massive landfills caused the heavy storms. Even many coastal districts of Maharashtra were reported to have suffered massive damage to property and livelihood due to the cyclone.
3. JAL (2010): Hitting the shores of Thailand and Malaysia, Jal, derived from the Sanskrit word for water was the fourth severe cyclonic storm of the year. Torrential rains and heavy rainfall with extremely dangerous wind speeds caused massive floods and threatened the lives of over 80, 000 people. Many districts were under protection due to storm warnings and people from almost four districts of Andhra Pradesh were evacuated for fear of danger to life. The destruction caused by cyclone Jal was too much to recover that people in several districts across India still face difficulties of its aftermath.
4. THANE (2011): Cyclone Thane that originated in the North of Indian Ocean in 2011 is recorded as the strongest tropical cyclone that has ever hit India. The storm as very severe and affected almost all the states of India including Tamil Nadu and Andhra Pradesh that constitute the southern part of India. According to reports, it has been found that cyclone Thane resulted in the death of a minimum of 46 people in Tamil Nadu alone. Cuddalore and Puducherry were the worst affected areas.
5. NILAM (2012): Nilam of 2012 was one of the deadliest storms to affect India since the havoc caused by Cyclone Jal. It directly affected South India, especially Mahabalipuram creating not just storms with peak winds but also landfalls. The Marina Beach of Chennai faced a lot of destruction with strong winds pushing piles of sand ashore and seawater level was reported to have reached nearly 100 meters inland. Evacuation and 24*7 protection was given to people who resided in the neighbouring regions. Though human casualties were few, Cyclone Nilam caused economic losses of around 100 crores due to torrential rains.
6. PHAILIN (2013): Phailin which struck the coast of Odisha and Andhra in 2013 belong to the category 5 storm – the most powerful. The name is of Thai origin and it means Sapphire. In fact, this cyclone set record by prompting India’s biggest evacuation in 2013 – 5,50,000 people were moved to safer shelters from the coastline. Torrential rains and high intensity of wind speeds created massive damage to crops and claimed almost over 40 lives. Moreover, losses due to the cyclone were estimated to be around 420 crores!