How many Pressure Belts are there around the Globe?

There are generally three pressure belts or zones around the globe: the low-pressure zone, the high-pressure zone, and the equatorial low-pressure trough.

The low-pressure zone is located near the equator and is known as the Intertropical Convergence Zone (ITCZ). Here, warm, moist air rises and cools, causing frequent rainfall and thunderstorms. The ITCZ moves north and south with the seasons, following the path of the sun.

The high-pressure zone, also known as the subtropical high, is located between 20 and 35 degrees latitude in both hemispheres. Here, cool, dry air sinks and creates stable, clear weather conditions.

The equatorial low-pressure trough is a region of low pressure located near the equator, where the trade winds from the Northern and Southern Hemispheres converge. This region experiences warm, humid conditions and is often characterized by thunderstorms and heavy rainfall.

In addition to these three primary pressure belts, there are also polar high-pressure zones located near the poles, where cold, dense air sinks and creates stable, dry conditions. However, these polar high-pressure zones are less pronounced and less consistent than the other three primary pressure belts.

PRESSURE

On the earth's surface, an air column applies weight in the form of pressure.

Atmospheric pressure, often known as air pressure, is the mass of the air column at a specific location and time. Atmospheric pressure is measured by a barometer. The force per unit area is used to measure atmospheric pressure. The millibar is the name of the measurement unit for pressure. The force of roughly one gramme per square centimetre is equal to one million

FACTORS CONTROLLING PRESSURE SYSTEM

The pressure differences that result in high and low-pressure systems have two primary causes: thermal and dynamic.

Thermal Elements

Heat causes air to expand, which lowers its density. Naturally, low-pressure results from this. Cooling, on the other hand, causes contraction. As a result, the density rises, and the pressure rises.

Examples of thermal lows and highs are the formation of equatorial lows and polar highs, respectively.

Dynamic Elements

In addition to temperature changes, dynamic controls resulting from pressure gradient forces and earth rotation can be used to explain how pressure belts form (Coriolis force).

The primary limit on how many cells a planet's atmosphere can divide into is imposed by the Coriolis deflection. For faster rotation, the Coriolis force is stronger. How many of them there are depends on the size of the planet, its rate of rotation, and to a lesser extent, the thickness of its atmosphere. Three cells make up the Earth's atmosphere. It is much greater for Jupiter because its day is just 12 hours long while having a diameter that is 12 times larger. Coriolis force is a powerful force

WORLD PRESSURE BELTS

1. Equatorial Belts of Low Pressure

This low-pressure belt covers the area from 0 to 5 degrees north and south of the Equator. Because of the sun's vertical rays, it is very hot here. The convection circulation causes the air to ascend and expand, which results in low pressure in this area. The doldrums are another name for this low-pressure belt since it is a region of total stillness with no breeze.

2. Belts of Subtropical High Pressure

Around 30° North and South of the equator is where the ascending equatorial air currents drop off. This is a high-pressure area as a result. It is also known as the Horse latitude. High to low-pressure winds are constantly present. Trade winds consequently blow.

3. Belts of circumpolar low pressure

Belts called circumpolar low-pressure stretch between 60 and 70 degrees in each hemisphere. In the Subtropical zone, the falling air is divided into two halves. The Equatorial Low-Pressure Belt is in the path of some wind.The Circumpolar Low-Pressure Belt receives the other half of the wind

.This zone is defined by the rising of warm subtropical air above arctic air travelling from the poles. Due to the rotation of the globe, the winds that surround the Polar region blow in the direction of the Equator.The centrifugal forces present here result in the creation of the Circumpolar Low-Pressure Belt, low-pressure belt. This region is renowned for its powerful storms in the winter.

4. Areas of High Polar Pressure

At the North and South Poles, temperatures are always extremely low between 70° and 90° North and South. Due to the cool falling air, there are high pressures from above the Poles. These high-pressure regions in the Arctic are known as the Polar Highs. These places are described as Permanent IceCaps.

SHIFTING OF PRESSURE BELTS

The pressure belts as detailed above would not exist if the earth were not inclined toward the sun. However, this is false because of the earth's 23 1/2° inclination towards the sun. This tendency causes significant changes in the temperature of the continents, oceans, and pressure conditions between January and July. In the Northern Hemisphere, January symbolizes the winter season and July, the summer season. In the Southern Hemisphere, the opposite is true. The pressure belts move 5° northward and 5° southward from their initial positions, respectively, when the sun shines vertically above on the Tropic of Cancer on June 21 and on the Tropic of Capricorn on December 22. Seasonal climate fluctuations are brought on by the movement of the pressure belts, particularly between latitudes 30° and 40° in both hemispheres. Due to the permanent belts' changing southward and northward with the sun's overhead position, this region has a Mediterranean-style climate. Westerlies dominate in the winter and bring rain. The dry Trade Winds that blow offshore in the summer are unable to bring rain to these areas. The pressure belts stay balanced in both hemispheres on March 21 and September 23, the Equinoxes, when the sun shines vertically over the Equator.

PRESSURE BELTS IN JULY

The thermal equator (belt of greatest temperature) is situated north of the geographical equator in the northern hemisphere during the summer due to the apparent northward shift of the sun. The pressure belts move a little bit north of where they are on average each year.

PRESSURE BELTS IN JANUARY

These circumstances are totally reversed during the winter, and the pressure belts move south of their yearly average positions. In the southern hemisphere, the situation is the opposite. However, because there is more water there, the amount of shift is lower there.

Similarly to this, the positioning of continents and seas has a significant impact on how pressure is distributed. In winter, when the continents are colder than the oceans, high-pressure centres are more likely to form; in summer, when they are substantially warmer, low-pressure centres are more likely to form. With the oceans, it is quite the opposite.