Q. What is a twister? Why are the majority of twisters observed in areas around the Gulf of Mexico?
UPSC Mains 2024 GS1 Paper
Model Answer:
Twister
A twister, commonly known as a tornado, is a violently rotating column of air extending from a thunderstorm to the ground. These powerful weather phenomena are characterized by their funnel-shaped cloud and can cause widespread destruction due to their intense wind speeds, which can exceed 300 mph in extreme cases.
The formation of twisters involves the following key elements:
• Warm, moist air near the ground
• Cool, dry air aloft
• Wind shear (change in wind direction and speed with height)
• Instability in the atmosphere
When these conditions converge, they create an environment conducive to tornado formation, typically within supercell thunderstorms.
The majority of twisters are observed in areas around the Gulf of Mexico, particularly in a region of the United States known as “Tornado Alley.” This concentration can be attributed to several geographical and meteorological factors:
1. Unique air mass interactions: The Gulf of Mexico provides a source of warm, moist air that collides with cool, dry air from Canada. This interaction creates the instability necessary for tornado formation.
2. Flat terrain: The Great Plains region, extending from the Gulf to Canada, offers little topographical resistance to air movement. This allows the uninterrupted flow of contrasting air masses, facilitating the development of severe thunderstorms and tornadoes.
3. Jet stream patterns: The positioning of the jet stream in this region, especially during spring and early summer, enhances wind shear and atmospheric instability, further promoting tornado development.
4. Dryline formation: A boundary between moist and dry air masses, known as the dryline, frequently forms in this region. The dryline acts as a focal point for thunderstorm and subsequent tornado formation.
5. Mesoscale convective systems: Large, organized thunderstorm complexes that frequently develop in this area can spawn multiple tornadoes.
The combination of these factors creates an environment uniquely suited for twister formation, making the Gulf of Mexico region, particularly the southern United States, the most tornado-prone area in the world.
