The system of winds that rotate clockwise in the Southern Hemisphere and anti-clockwise in the Northern Hemisphere around a centre that has low pressure: cyclones. Cyclones can be classified into two types – Tropical Cyclones and mid-latitude cyclones. Winter storms are generally generated by the Mid-latitude Cyclones whereas hurricanes are generated by the tropical cyclones. The winds of cyclones move nearly around all the parts of the Earth. The winds that have a flow opposite to cyclones are known as anticyclones. These cyclones rotate around the high-pressure centre. Bad weather and violent storms usually accompany cyclones.
Cyclones
The word cyclone is derived from Cyclos which is a Greek word that means the coil of a snake. The name was given by Henry Peddington because the tropical storms of the Arabian Sea and Bay of Bengal used to appear like coiled serpents. These are the rapid circulation of air in the inward direction around a low-pressure area. The circulation of air in the Northern Hemisphere is anticlockwise, whereas the circulation of air is clockwise in the Southern Hemisphere. There are two types of cyclones: Middle Latitude Cyclones and Tropical Cyclones.
Types of Cyclones in India
Types of Cyclones in India can be classified on the following basis which is formulated by IMD; the Indian Meteorological Department. The IMD classifies the different types of cyclones in the Arabian Sea and the Bay of Bengal on their capacity to damage. Let us look into a table for a brief idea about the classification of Cyclones.
Types of Disturbances | Wind Speed (Km/h) | Speed in Knots |
Low Pressure | <31 | <17 |
Depression | 31-49 | 17-27 |
Deep Depression | 49-61 | 27-33 |
Cyclonic Storm | 61-88 | 33-47 |
Severe Cyclonic Storm | 88-117 | 47-63 |
Super Cyclone | >221 | >120 |
Henceforth cyclones can be classified into 5 more categories according to the speed of the wind in which the air flows around the centre.
Types of Cyclones | Wind Speed (Km/h) | Capacity to damage | |
01 | 120-150 | Least | |
02 | 150-180 | Balanced/Not extreme | |
03 | 180-210 | Huge/Vast | |
04 | 210-250 | Utmost/Severe | |
05 | >= 250 | Disastrous |
These were the types of cyclones in India. India is one of the regions which is severely affected by cyclones in the world. India is currently exposed to a total of 10% of the world’s cyclones due to the vast coastline of 8041 kilometres. The majority of cyclones initially rise in the Bay of Bengal and hit the eastern coast of India. On average, there can be around 5 to 6 cyclones in a year out of which 2-3 can be severe.
Effects of Cyclones
The majority of cyclones which hit India are generated over the Bay of Bengal and therefore hit the Eastern coast of India. 80% of the cyclones in India are formed over the Bay of Bengal whereas 20% of the cyclones form over the Arabian Sea. Heavy rain, tornadoes, large storm surges and strong winds are all effects of cyclones in India. The destruction that a cyclone can cause depends upon the size, location and intensity of the hurricane or storm. They can change the landscape near the coastal areas and even remove forest canopies. Once the cyclone passes the devastation does not end, but the tail of the storm continues to ravage the surrounding areas. Approximately 2 million people have died globally due to storms.
Conclusion
A system of winds that rotate in a particular direction either clockwise in the Southern Hemisphere or anticlockwise in the Northern Hemisphere. Cyclones can be classified into two types: Tropical Cyclones and mid-latitude cyclones. The winds of mid-to-high intensity cyclones are felt all around the world. The winds that have a flow opposite to cyclones are known as anticyclones. 80% of the cyclones in India are formed over the Bay of Bengal and the other 20% form over the Arabian Sea. India is one of the regions severely affected by cyclones in the world. India is currently exposed to a total of 10% of the world’s cyclones due to the vast coastline stretching to over 8040 kilometres.