Winds are horizontal streams of air. Types and character of winds

Winds are fast streams of air moving horizontally. They can be light and barely noticeable, but can be strong and powerful enough to destroy everything in their path. What is the nature of the wind? What is this - a "wind rose"? Let's find out.

The wind - what is this?

The wind exists not only on Earth. In the broadest sense, winds are streams of particles. They are present in space and on other planets and consist of a substance peculiar to a particular celestial body.

For example, on Neptune it is represented by hydrogen, helium, methane, ammonia and hydrogen sulphide. And the solar wind is represented by radiation streams that are emitted into outer space.

On our planet, winds are streams of air that move in a horizontal direction. They appear because of the uneven heating of the Earth's surface by the Sun. So, different pressure forms in different parts of the planet. The air begins to move from the area of high pressure to the area with a lower, hence the wind.

Winds are distinguished by strength and speed, scale, influence on nature. Some flows occur suddenly and last relatively briefly. Others are natural and appear only in a particular region and in a particular period. The graph, which shows the mode of air flow in a certain locality - is a wind rose.

Global Winds

Global or predominant air masses participate in the general circulation of the atmosphere. They blow, as a rule, in one direction and participate in the formation of climate on Earth. They include the trade winds, monsoons, the western temperate belt and the eastern winds of the polar regions.

The polar front and the subtropical ridge are peculiar borders. Here the air masses move, mainly, vertically. In the subtropics, they change direction every six months, coming from the temperate zone, then from the tropics.

Western winds blow within 35-65 latitude. In the Northern Hemisphere, they go from the south-west, in the Southern - from the north-west. They are strong in winter and very weak in summer. These streams of air affect the formation of powerful currents in the ocean, carrying warm waters of the tropics to the poles.

The eastern polar winds are not as strong and regular as the western ones. These are dry masses coming from the northeast in the Northern Hemisphere and the southeast in the South.

Trade winds and monsoons are characteristic of tropical regions. They blow year-round from the northeast (above the equator) and southeast (below the equator). Along the line of the equator there is a border of several hundred kilometers between them. Over the oceans they go without deviations, and near the land can change direction under the action of local conditions.

Monsoons are winds that change direction twice a year. In winter, they come from the land, bringing dryness and coolness, and in the summer - from the oceans, bringing moisture and precipitation. The most characteristic are monsoons for the tropics of Southeast Asia, but also reach the coastal regions of the Far East. In a weak form, they reach the south and east of the subtropical regions.

Local winds

Local or local winds are air masses that form within narrow areas. The most famous of them are: breeze, bora, fen, samum, mountain-valley winds, dry winds, mistral, marshmallow, etc. Sometimes they are offshoots of global currents that have acquired several other properties in a specific locality.

Breeze occurs on the coast of the sea, near lakes and large rivers. It changes twice a day, coming from the side of the reservoir in the daytime, and in the evening - from the land. Its speed rarely exceeds 5 m / s. It often occurs in the summer, in the middle latitudes and is clearly visible only on windless days.

Samum appears in deserts from excessive heating of air and lasts up to two hours. It is foreshadowed by the "singing of sand", after which a sharp storm and storm begins, carrying hot air and hot sand with dust.

Bora is a strong wind blowing with gusts. It occurs in places where the sea shore is surrounded by mountains. The wind appears from the outside of the mountains and, overcoming the obstacle, collapses on the coast with a powerful cold current. It lasts from one day to a week and can lead to storms and destruction.

Destructive winds

Some winds can have extraordinary power and strength. They turn settlements into debris, drown the ships in the ocean, raising waves. They are classified not by the terrain where they appear, but by strength and characteristic features.

Storms and storms are winds with a speed of 20-32.6 m / s (from 9 to 11 points). They periodically occur in different parts of the world during tornadoes, squalls and cyclones. Squalls are called a sharp increase in the speed and strength of the wind in a matter of minutes. The wind itself can last several hours and is accompanied by a dust storm and a thunderstorm.

Hurricanes and typhoons occur during tropical cyclones. They are stronger than storms and longer than squalls. In fact, these are the same phenomena, but in America the name "hurricane" is accepted, and in Asia - "typhoon". They are accompanied by downpours, waves. Such winds cause floods, destroy buildings, lift up heavy objects and root out trees.