Pressure belts of the world

The physical features of the earth are astonishing as well as worth observing. One of the phenomena is the world pressure belt. It is one of the most interesting as well as fascinating geological features of the world. The world pressure belts are something related to the climatic and atmospheric changes taking place in the environment. 

When we take a closer look, the term already explains its meaning, i.e., “pressure belt” which means a barrier created in the different atmospheres of the world because of the pressure of different regions and the wind passing through them. 

What is a pressure belt?

Those regions on the surface of the earth, which are under the influence of the high-pressure cell or low-pressure cell are said to be the pressure belt of the world. 

Both the high-pressure cells and the low-pressure cells are arranged in such a pattern that they tend to be alternatives to each other. 

In simple words, the atmospheric pressure is inversely proportional to the temperature of the environment or the atmosphere. And therefore because of the uneven heating in the surfaces of the earth, in the equatorial region low pressure is developed while high pressure is on the Polar Regions. The belt created causes air to blow altogether in an area known as the intertropical convergence zone. 

How many world pressure belts are present on the earth?

Moving further towards the number of world pressure belts present, there are a total of seven in number. However, arranged alternatively for the regions of the southern hemisphere and the northern hemisphere. 

1. Equatorial low-pressure belt
2. Subtropical high-pressure belt present in Northern hemisphere
3. Sub-Tropical high-pressure belt present in Southern hemisphere
4. Sub-polar low-pressure belt present in Northern hemisphere
5. Sub-polar low-pressure belt present in Southern hemisphere
6. Polar high-pressure belt present in Northern hemisphere
7. Polar high-pressure belt present in the southern hemisphere. 

Of the seven pressure belts discussed above, six of them form the pairs with northern and southern hemispheres but the Equatorial low-pressure belt remains at the equator being an exception. The pressure belts present in the southern hemisphere are continuous while the pressure belts in the northern hemisphere are discontinued. 

Also, talking about their distribution from the equator towards the poles, they don’t have a definite pattern. The reason is the direction of the rotation of the earth and the humidity apart from temperature and atmospheric pressure. 

Based on the mode of genesis, the seven pressure belts are divided into two types: 

1. Thermally-induced pressure belts and
2. Dynamically induced pressure belts 

The Equatorial low-pressure belts and the polar high-pressure belts fall under the category of Thermally-induced pressure belts while the Subtropical high-pressure belts and the subpolar low-pressure belts are categorised as the Thermally-induced pressure belts. 

What is the subtropical high-pressure belt? 

The subtropical high-pressure belt lies between 25° to 35° latitudes in both hemispheres. The other name by which it is known is horse latitude. The characteristic features of this belt are high temperature and high pressure. The air blowing in this region is dry in comparison to the other belts. It is called the north subtropical high-pressure belt in the northern hemisphere and for the southern hemisphere, it is called the south sub subtropical high-pressure belt. 

Because of the earth’s rotation, the air coming from the equatorial region which gets diverted towards the poles enters this region after becoming cold and heavy. This phenomenon creates high pressure in the regions and hence forms the subtropical high-pressure belts. It is categorized under the dynamically induced pressure belt as it is formed because of the rotation of the earth. 

This process is known as the zone of wind divergence because of the wind blowing from this belt towards the equatorial low-pressure belt. It is also known as the anticyclone zone. 

Conclusion 

By now, we have already understood what a pressure belt is, how it is formed, what it does and how many types of the world pressure belt are there. Therefore, we now know that a pressure belt is formed because of the high-pressure cell and low-pressure cell in the atmosphere. They influence the geographic factors of the regions and divide the whole of the earth into two parts, i.eThermally-induced pressure belts and dynamically induced pressure belts. 

The subtropical high-pressure belt is also known as the horse latitude since it is the area of high pressure. They are formed at about 30° from the north and south of the equator. The air blowing in this region is quite dry in comparison to the other belts. The northern subtropical high-pressure belt and the southern subtropical high-pressure belts are known as the anticyclone zone.