What Are Cyclones?
As per meteorology, a cyclone is considered as a large scale air mass that is rotating around a strong center of low atmospheric pressure. In simple words, a cyclone is a general term used to categorize a weather system in which winds seem to rotate inwardly to an area where the atmospheric pressure is low.
In large weather systems, the pattern of circulation is in an anticlockwise direction in the northern hemisphere whereas in the southern hemisphere it circulates in a clockwise direction. There are three types of cyclones: tropical cyclones, extratropical cyclones, and tornadoes. Let us briefly discuss each of these cyclones.
Types of Cyclones
A tropical cyclone is considered as a rotating low-pressure weather system with some organized thunderstorms but no fronts. They are generally formed over ocean waters that are warm.
Tropical cyclones that have maximum sustained surface winds of less than 39 mph are known as tropical depressions. In contrast, tropical cyclones that have maximum sustained surface winds of 39 mph or higher are known as tropical storms. When the maximum sustained surface wind of a storm reaches 74 mph, then they are called hurricanes or typhoons.
Extratropical cyclones are weather systems with a low-pressure which are formed outside the tropics as a response to the chronic instability of the westerly winds. This phenomenon takes place because this chronic instability depends on large horizontal temperature contrasts and concentrated regions of temperature change which are also known as fronts characterizing extratropical cyclones.
A tornado can be considered as a rapidly rotating column of air that is moving downward, being generated by a thunderstorm, to the ground. The tornadoes can be violent and can cause tremendous destruction with wind speeds reaching as high as 300 mph.
Tornadoes form in those regions of the atmosphere which have an abundance of warm and moist air near the surface with drier air at the top, and a possible change in wind speed and direction, with a height above the ground.
Destructions and Consequences of Cyclone
We all are aware of the fact that cyclones can cause large-scale devastation. The death toll is high in regions that are hit by the calamity. Cyclones become the reason for the destruction of houses, buildings, transportation, electricity, and the death of livestock. The living beings inhabiting the region which is hit by the calamity are the most affected ones.
The destruction caused by the cyclone depends on the intensity, location, and size of the cyclone. Cyclones affect different regions in a different way. Cyclones affect the forest region by uprooting the trees and affecting the canopies. The banks and embankments get eroded due to cyclones in coastal regions. In desert areas, the dunes lose their original shape and get reshaped due to the cyclones. Landslides occur in the mountainous region due to cyclones.
The hazards caused by a cyclone when it hits a region is divided into the following three parts.
Strong winds, heavy rains, and storms come under primary hazards. There is an abnormal rise in sea level near the coasts due to which low-lying areas that are present near the coastal regions get submerged causing the drowning of humans, destruction of livestock and their inhabitations, destroying vegetation and soil fertility. Strong winds can cause damage to houses, trees and communication systems, etc. Primary hazards cause huge loss of human life as well as property and live stocks.
Floods, fire, and freshwater flooding come under secondary hazards. Floods in the river are caused due to heavy rain which in turn causes submergence of the nearby inhabited regions. The floods also cause erosion of some fertile farming lands and destruction of many buildings as well as personal property. In forest regions, strong winds can cause forest fires which spread at an alarming rate due to the intensity of the wind. This can cause heavy damage to the forest and also to the wildlife. Many animals die due to these fires. This can also affect nearby regions with human habitats.
Tertiary hazards include diseases that are caused due to stagnant water, water poisoning, and a rise in the prices of goods and resources. Humans are the ones who are affected by the tertiary hazards. During these times people die due to a shortage of food. If not managed properly tertiary hazards can be terrifying than the primary and secondary hazards.
Through these hazards, students can get a clear idea of cyclones’ destructions and consequences.