How is a tornado structured?
A tornado is a rapidly rotating column of air in contact with the ground surface and a source cloud (usually a thunderstorm cloud). Many complex atmospheric processes occur within a tornado, but here are its main characteristics and elements:
- Pillar of Air: This is the visible part of the tornado. It consists of water droplets, dust, and debris lifted by the vortex from the surface of the earth.
- Source Cloud: Most often, tornadoes form from beneath large thunderstorm clouds known as supercell thunderstorms. A separate portion of these clouds, called a mesocyclone, plays a key role in tornado formation.
- Funnel: This is the narrow, funnel-shaped part of the tornado that contacts the ground. It can vary in width, length, and visibility.
- Major Axis: Within a tornado, the central axis is usually an area of comparative calm compared to its outer regions.
- Rotational Winds: Winds rotating around the major axis provide the tornado with its destructive power. Wind speeds can reach 480 km/h or even more in the strongest tornadoes.
- Formation Mechanism: Although the exact mechanism of tornado formation is not fully understood, it is believed that they form when warm, moist air masses at lower levels of the atmosphere collide with cold, dry air masses at upper levels. This can create a vertical rotation that, under the right conditions, can come down to the ground in the form of a tornado.
- Path and Duration: Tornadoes can exist from a few seconds to over an hour. On the ground, they can travel from a few tens of metres to more than 100 km.
It is important to realise that although scientists have studied tornadoes for many years and know a lot about how they work, all aspects of this natural phenomenon are still not fully understood.