Circles on the field and other formations. United States

Wind — flow of air, which quickly moves parallel to the earth's surface.

Wind is the result of uneven distribution of atmospheric pressure and is directed from areas of high pressure to the low pressure zone. Due to the continuous pressure changes in time and space speed and wind direction are constantly changing. With height wind speed varies with the decrease of the friction force.

Winds can affect the formation of the relief, causing Eolian deposits that form different kinds of soils (e.g., loess) or erosion.

It is believed that the phenomenon of "circles" has been known for about 400 years. All formations are known for this period, by origin can be divided into two types: natural and artificial.

Annually, researchers, journalists and witnesses encounter a lot of strange shapes in the fields. It's happening everywhere. Often the pattern has no apparent logic, but the skillful application of imagination it can be. As a rule, the cause of the formations is one or more natural factors.

Atmospheric vortex that occurs in cumulonimbus (thunderstorm) cloud and propagating down, often to the surface of the earth, in the form of a cloud sleeves or trunk diameter of tens to hundreds of meters. Tornadoes can appear in many shapes and sizes.