NDA » NDA Study Material » Geography » Pattern of Wind Direction in Cyclones and Anticyclones

Pattern of Wind Direction in Cyclones and Anticyclones

The atmosphere is not static because it’s made from air. Due to the earth’s rotation, the air is constantly moving where the direction of the wind is based on the surface temperature and pressure zones. As all these factors are quite varied, the entire atmosphere is divided into five wind zones. When the winds start to flow in different directions and the weather conditions change owing to temperature rise, the atmosphere is disturbed. 

Owing to this reason, depressions are formed over the earth’s surface, especially over the water bodies, because when air absorbs heat, it becomes lighter and rises. As a result, a low-pressure area is created, and the surrounding cold wind rushes to fill up the vacuum. It causes several types of storms, out of which the cyclones and anticyclones are more prevalent and disastrous. 

Cyclones- Cause, Wind Speed, Wind Direction, and More

A dramatic rise in the air’s temperature is observed in areas where the earth’s surface temperature is relatively high. As a result, it expands and rises upwards, creating a vacuum. As it grows, it starts to get cooled due to the increase in distance from the heat source. Owing to the cooling effect, the hot air forms clouds and precipitates. On the other hand, to fill in the vacuum over the low-pressure area, cool wind from the nearby regions rushes in. 

The incoming winds and the clouds together form a whirlwind that continues to rotate in the clockwise direction. This kind of storm is termed a cyclone. There are two types of cyclones- tropical and mid-latitude.

  1. In most cases, the mid-latitude cyclones are formed over the European and American continents due to the interaction of the cold polar winds and hot trade winds flowing from the equator. These cyclones are usually experienced in the winter season. 
  2. The tropical cyclones are formed over the equator and near about areas. These are also termed hurricanes and can be pretty disastrous. Due to the formation of multiple low-pressure zones over the water mass, the wind blowing over these areas gains a lot of power which is why hurricanes can be pretty dangerous. 

Wind Speed and Direction in Cyclones

The direction of the wind in cyclones is towards the core of the whirlwind of air and clouds because as the hot air rises, the cold air from the surroundings rushes in towards the centre. Usually, these cyclones gain power as long as they remain over the low pressure and high-temperature areas. Therefore, the wind speed usually stays close to 120 kilometres per hour. As the storm gains more power, the wind speed increases, and it spikes to a value of 240 kilometres per hour. Owing to this reason, the impact of a cyclone is disastrous. 

Features of the Cyclones

  • A cyclone constantly forms over warm water bodies with more than 27-degrees Celsius. 
  • The water body needs to maintain this high temperature till 50 metres depth. 
  • Between the height of 5000 and 16000 feet, the humidity should be at the standard level. 
  • It needs to be about 300 miles away from the equatorial region in the northern hemisphere, owing to the direction of the wind. 

Impact of Cyclones 

The impact of a cyclone is pretty dangerous as it usually starts moving towards the land as the low-pressure area starts shifting. As it attracts everything towards the core, the storm can suck in most things like plants, roofs, cars, and so on. 

Anticyclones- Cause, Wind Speed, Wind Direction, and More

Anticyclones are just the opposite of cyclones because these are formed over regions of high pressure. Since they do not contain any water vapour, no clouds are included, and no precipitation. When the earth’s surface temperature is within the standard level, the air does not get heated up, so it continues to stay in the same place. The hot air from the top comes to the surface, gets cooled down, and sinks.  

Cause of Anticyclones 

There are several causes of the anticyclones, namely: 

  1. An anticyclone is formed when the high-pressure areas develop over the northern latitudes. 
  2. In the inland areas, the temperature changes are always drastic. Therefore, during the winters, the temperature is pretty low, which causes the air to settle down and form the anticyclone.

Wind Speed and Direction in Anticyclones

When the anticyclone is formed, the direction of the wind changes and the air starts to move in the outward direction from the central portion of the whirlwind. Its speed will depend on a wide range but usually remains within 3 to 6 metres per second. 

Impact of Anticyclones

The impact of anticyclones is not known correctly due to the differences in the temperature, pressure belts, and wind belts. However, these storms threw everything away from the central vortex rather than the cyclones. 

Conclusion 

All the storms forming over different areas of the earth are somewhat interlinked because of the continuous changes in pressure, the direction of the wind, and temperature. This is why most meteorological departments make sure to study the prevailing conditions which can lead to the formation of these deadly storms, especially the cyclone and anticyclone. Over the years, several storms have wreaked havoc on different countries and islands worldwide. And with the greenhouse effect and global warming, there are high chances that future storms will be more frequent and disastrous.

faq

Frequently asked questions

Get answers to the most common queries related to the NDA Examination Preparation.

Is the cyclone and hurricane the same?

Ans : The hurricanes and tropical cyclones are termed the same. These form over the low-pressure areas, mainly above the water bodies and gain powe...Read full

What are the wind direction differences for anticyclone and cyclone?

Ans :During the cyclone, the direction of the wind is towards the low-pressure areas or the ...Read full