How does air flow on earth?

The trees around us are often dancing with the wind.

Not just the trees, but everything around the world comes in contact with the air around it.

This air is often causing shifts in the way things are placed, sometimes even destruction based on how intense the wind might be.

Does the real question lie in how this air around us flows?

What is air?

Air refers to the Earth's atmosphere.

Air is said to be the mix of multiple gases and many minute tiny dust particles.

It is the clear gas in which all living things exist. We use the air around us to live and breathe.

It has an indefinite shape and volume and cannot be held in one’s hands.

Yet, it has mass and weight, because it is a kind of matter.

The reason behind the motion

Even with all the disruptions on this planet, such as weather fronts and storms, there seems to be a consistent pattern in how the air moves around in the planet’s atmosphere.

This consistent pattern is called atmospheric circulation.

It is caused because the Sun heats the Earth more at the equator than at the poles.

This is also affected by the spin or rotation of the planet in itself.

In the tropics, especially near the equator, warm air tends to rise above.

When it reaches a height of around 10-15 km or 6-9 miles above the

Earth’s surface it starts to flow away from the equator and towards the poles.

Air that initially rose from the north of the equator flows back north.

Air that rose from the south of the equator flow back to the south. 

This air eventually cools down and it drops back to the ground. As this flows back to the ground, it drops back to the ground again and starts to turn warm again.

The now warmed air starts rushing up again, and this process keeps repeating itself in a loop all the time.

This pattern is also known as convection.

The scientific definition of convection is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in the transfer of heat.

This convection keeps repeating itself on a global scale.

Other than on a large and global scale, it also happens on a small scale within individual storms.

Yet, we must account for another factor that is crucial in establishing how air flows on this planet.

As the Earth is constantly spinning, the air that moves north and south from the equator also ends up turning with the rotation of Earth itself.

Air going north turns to the right.

Air traveling south turns to the left.

The magnitude of the power of Earth's spin around its axis that leads to turning the flow of air is called the Coriolis Effect.

In a hypothetical situation where the Earth did not have any sort of rotation, there would be one large convection cell between the equator and the North Pole and one large convection cell between the equator and the South Pole.

As this is not true in the case of our planet, this convection gets divided into three cells north of the equator and three south of the equator.

To summarise the whole process we can say that:

The primary cause of airflow is the existence of air.

Air behaves fluidly, meaning particles naturally flow from areas of higher pressure to those where the pressure is lower.

Atmospheric air pressure is directly related to altitude, temperature, and composition.

Due to all these changes in temperatures and pressures, air flows in the way we experience it.