Explained in a child-friendly way: How is wind created?

How is wind created is a question you may have asked yourself. Because wind does not only come up in coastal towns, but also in packed cities.

How is wind created?

How wind is created has a lot to do with pressure equalization. In order to understand how wind is created, you must first know that the air pressure that weighs on us and our surroundings under normal circumstances is ten tons per square meter. Experts measure this value in 1,013 hectopascals.

When the air heats up, the air pressure decreases because warm air always rises. Experts then speak of a so-called low-pressure area. You notice: The sun plays an important role in the development of wind! If it is cold or the air does not heat up so quickly, the cold air sinks and the air pressure increases. A so-called high pressure area develops.

Since pressure must always equalize, there is a pressure equalization between the high and low pressure areas.

create pressure equalization

A good example of this pressure equalization is the sea wind that blows from the sea to the coast in the morning. To do this, imagine two pillars of air: one on the water and one on land.

Now the sun rises and first warms the water and land. Since the land warms up faster than the water, the air there is automatically warmer – it rises, the air pressure decreases. At sea, on the other hand, the cold air still bobs up and down in the lower part of the “air column” – the air pressure is higher. So on land there is a low pressure area, on the other hand there is a high pressure area on the sea.

In order to create a pressure balance, the two pressure areas exchange warm for cold air. From land, the warm air travels to the top of the “air column” on the sea, while the cold air travels to the bottom of the “air column” on land. This movement of air creates wind. In the past, sailors liked to use the sea wind to enter the ports.

It’s not only windy on the coast

Of course, wind does not only arise on the coast, but also in cities, in the hot regions of the world, i.e. in the tropics and subtropics, and in the mountains.

How is wind generated in cities?

In cities, the pressure equalization takes place between the city center and the largely free surrounding area (meadows, fields, farmland). You may have noticed that the city is warmer than the country – especially late in the evening or at night. In addition to the sun, pollutants and other heat sources in the city also play a major role.

Because the air in the city heats up faster than in the country, a low-pressure area develops in the city, while a high-pressure area develops in the country. A pressure equalization takes place between the two areas and it winds.

Trade winds: how does wind develop in the tropics?

In the region along the equator, the sun is at its zenith, causing heated air to rise vertically and creating a low-pressure area. Since warm air can absorb water better than cold air, rain clouds form and regular, heavy showers and thunderstorms occur. Therefore, the rainforest is also located here.

After the rain, the air cools again and sinks to the north and south, creating high pressure areas on both the south and north sides (30° latitude) of the equator. These areas are called subtropical highs. They balance and the wind comes up, known as the trade wind. However, since it is still very warm in the region of the subtropical highs, the sinking air quickly heats up again, extracts moisture from the ground (deserts form) and migrates towards the equator again.

Foehn wind: how does wind develop in the mountains?

It’s windy in the mountains too. There, the pressure equalization works in a similar way to that between water and land, except that here it takes place between mountain and valley. A well-known wind from the mountains is the foehn wind, which is reminiscent of the dry, warm wind from the bathroom foehn, especially in summer.

As the air warms up on the windward side of the mountain, it rises and the air pressure decreases. But with the falling air pressure, the temperature of the air also cools down steadily. At a certain point, the air, which was initially able to absorb water, simply cannot hold the water any longer: it is raining in front of the mountain. The air that comes over the mountain is therefore cold and dry.

On the leeward side of the mountain, the cold, dry air is falling rapidly towards the ground, and it is precisely this movement of air, this fall wind, that we call foehn wind. Because sinking air automatically warms up again when it falls, the foehn wind usually arrives warm and dry.