Wind occurs because of horizontal and vertical differences (gradients) in atmospheric pressure. Accordingly, the distribution of winds is closely related to that of pressure. Near the Earth’s surface, winds generally flow around regions of relatively low and high pressure –cyclones and anticyclones respectively.
A cyclone is a large scale air mass that rotates around a strong center of lower atmospheric pressure. Cyclones are characterized by inward spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale. The cyclone blows in a counterclockwise direction north of the equator and in a clockwise direction to the south.
In a cyclone, air near the ground is pushed towards the low-pressure center of the cyclone and then rises upward, expanding and cooling as it moves. As it cools, the rising air becomes more humid, leading to cloudiness and high humidity within the cyclone.
Cyclonic winds move across nearly all regions of the Earth except the equatorial belt and are generally associated with rain or snow.
What You Need To Know About Cyclones
- It is a low pressure system with surroundings of high pressure.
- It blows anti-clockwise in the Northern Hemisphere.
- It blows clockwise in the Southern Hemisphere.
- It is associated with cloudy skies, heavy rainfall with stormy winds.
- It can cause great damage to lives and property if precautions are not taken.
- Winds converge at the eye (central low pressure) of the cyclone, wind moves in a spiral motion.
Anticyclone is any large wind system that rotates about a center of high atmospheric pressure, clockwise in the northern hemisphere and counterclockwise in the southern hemisphere. Its flow is the reverse of that of a cyclone.
Air at the center of an anticyclone is forced away from its area of high pressure and replaced by a downward blast of air from higher altitudes. The air compresses and heats up as it move downward, reducing its humidity and leading to fewer clouds within the anticyclone.
What You Need To Know About Ant-cyclones
- It is a high pressure system with surroundings of low pressure.
- It blows clockwise in the Northern Hemisphere.
- It blows anti-clockwise in the Southern Hemisphere.
- It is associated with clearer skies, mild winds and dry conditions.
- The weather is settled and pleasant.
- Winds diverge from the central high pressure to the surrounding low pressure.
Difference Between Cyclones And Anti-Cyclones In Tabular Form
|BASIS OF COMPARISON||CYCLONES||ANTICYCLONES|
|Description||It is a low pressure system with surroundings of high pressure.||It is a high pressure system with surroundings of low pressure.|
|Northern Hemisphere||It blows anti-clockwise in the Northern Hemisphere.||It blows clockwise in the Northern Hemisphere.|
|Southern Hemisphere||It blows clockwise in the Southern Hemisphere.||It blows anti-clockwise in the Southern Hemisphere.|
|Associated With||It is associated with cloudy skies, heavy rainfall with stormy winds.||It is associated with clearer skies, mild winds and dry conditions.|
|Effect||It can cause great damage to lives and property if precautions are not taken.||The weather is settled and pleasant.|
|Winds||Winds converge at the eye (central low pressure) of the cyclone, wind moves in a spiral motion.||Winds diverge from the central high pressure to the surrounding low pressure.|