Tornadoes are one of the most powerful and dynamic weather phenomena on Earth. How are they different from cyclones? Read here to learn more.
Tornadoes are known for their potential to cause significant destruction in a very short amount of time, including damage to structures, landscapes, and in severe cases, loss of life.
They are defined as violently rotating columns of air that are in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud.
Tornado Formation
These extreme storms typically form from severe thunderstorms. The most common environment for the development of tornadoes includes a combination of:
- Moisture in the lower atmosphere: Provides the fuel for thunderstorms.
- Instability: Warm, moist air near the surface overlaid by cooler, drier air aloft. This instability allows the warm air to rise swiftly.
- Wind shear: A change in wind speed and/or direction with height. This can create a horizontal spinning effect in the lower atmosphere that can be turned vertically by rising air within the thunderstorm, leading to the development of a tornado.
The precise mechanism often involves a complex interaction between a supercell (a long-lived thunderstorm with a deep, persistently rotating updraft) and the environment, leading to the formation of a tornado beneath the storm’s updraft.
Weather Conditions
- They are more likely to occur in conditions where warm, moist air is present near the surface with cooler, drier air above.
- This setup is commonly found in the central United States, particularly in an area known as “Tornado Alley,” during the spring and early summer when these conditions are most prevalent.
- However, these extreme storms can occur in a variety of weather conditions and have been observed on every continent except Antarctica.
Composition
- They are composed of air, water droplets, dust, and debris.
- The visible funnel is primarily made of water droplets formed from condensation, along with dust and debris picked up from the ground.
- The core of the storm is where the lowest pressure and highest wind speeds are found, and it’s here that the most significant damage occurs.
Impact
The impact of these extreme storms can range from minor damage to landscapes and structures to complete devastation, including loss of life.
The Enhanced Fujita Scale (EF Scale) is used in the United States to rate the intensity of tornadoes, based on the damage they cause, from EF0 (weakest) to EF5 (strongest).
- Structural Damage: They can destroy buildings, homes, bridges, and vehicles.
- Vegetation: They can uproot trees, destroy crops, and significantly alter landscapes.
- Economic: The economic impact can be profound, including the costs of rebuilding and the loss of businesses.
- Human: Beyond physical injuries and fatalities, tornadoes can have a lasting psychological impact on survivors and communities.
Tornado vs cyclone
Tornadoes and cyclones are both types of atmospheric storms, but they differ significantly in their scale, formation, and the destruction they can cause.
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Formation |
Key ingredients for formation include:
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Impact |
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Predictability |
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Why in the news?
On March 31, 2024, a deadly tornado struck the Mainaguri area of the Jalpaiguri district of West Bengal for 10 minutes killing five people and injuring over 100.
- In recent years, an increasing number of tornadoes have formed across India and caused destruction.
- A warming Bay of Bengal and land, along with anomalous wind patterns could be a reason behind this.
- IMD has warned of more tornadoes in northern Bengal in the future.
Tornado in India
These extreme storms are rare in India and have mostly been reported in the eastern states of West Bengal, Odisha and Jharkhand during the pre-monsoon period.
- But there is evidence of some of them having formed in northwest India as well.
- A research paper published by India Meteorological Department (IMD) scientists in 2016 provides different records for possible tornadoes in eastern India.
- The highest number was reported in a 1981 paper that documented 51 possible tornadoes across Bengal, out of which 18 killed 10 people or more.
- Twelve of these tornadoes occurred during 1838-1963 and 24 during 1968-81.
- The paper also recorded 15 tornadoes during 1903-2012 in northwest India.
- Twelve of these took place during 1976-2010, which means their frequency could have increased in later years. Most of these tornadoes occurred in March and a few in April.
- In India, there is no official monitoring of tornadoes.
Conclusion
Tornadoes are a testament to nature’s power, capable of causing significant destruction in a very short period.
Understanding their formation, the weather conditions under which they thrive, and their potential impacts is essential for preparedness and mitigation efforts, especially in regions where tornadoes are common.
Tornadoes are the most common in the United States, Argentina and Bangladesh.
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- Fronts: Types and significance
- Cyclones in the Arabian Sea: Why are they uncommon?
-Article by Swathi Satish
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