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August 24, 2016 23:11

Why does it snow?

Snow - is a form of precipitation that consists of many small ice crystals.It is the heavy precipitation that falls to the ground.By the way, this form of rainfall is considered one of the essential attributes of winter.Of course, there are times when the air temperature is low, but there is no snow at all, but in most cases, under similar circumstances, he certainly falls and lies throughout the winter or with small breaks.

In our country there is snow in most parts of the Russian Federation, however, in different places, he falls at different times.For example, in Chukotka and Yakutia it falls at the end of September or early October, and can lie around until June.In Moscow, the first snowflakes can be seen as early as the middle of October and the first snow in November and appears completely coming off no earlier than March and April.In the southern areas cover lasts very long, usually no more than two to three weeks.

With regard to warm regions of our planet, such as the UAE, there is no snow

at all, and even in winter, daytime temperatures rarely fall below 20-25 ° C.Yet even in such regions can be observed icy rain, though it happens rarely, usually not more than once every few decades.

Why is snowing?

To understand this, it is necessary to describe the formation of the crystal itself.Thus, snow is formed when tiny water droplets in the clouds are attracted to the dust particles and freeze.First ice crystals formed are extremely small size - less than 0.1 millimeters in diameter.However, as they begin to fall down as a result the rise to condensation of moisture from the air.Around the same time, they become familiar six-pointed crystal forms.Interestingly, due to the structure of water molecules formed between the beams snowflakes form only two angles - 60 and 120 degrees.It should also be noted that the crystal water is in the form of a regular hexagon, on top of which was later deposited new crystals, and it occurs continuously, which is why snowflakes have a variety of forms.

believed that to find two identical snowflakes impossible and it seems to be true.Kenneth Liebrecht, the owner of the largest collection of snowflakes, assures us that even simple snowflakes that are formed at low humidity, outwardly look the same, but at the molecular level are still large differences.By the way, they have a white color, which is associated with a prisoner in their air.Light of different frequencies reflected from the surfaces of the crystal and the air, and then scattered.As snowflakes on more than 90 percent consist of air, their low density, as well as the rate of fall - at least one kilometer per hour.

As for the big snowflakes, it found in the distant 1887 in one of Montana, USA cities.Its diameter is about 38 centimeters, and the weight - a few grams.Her photo was published in a local newspaper.

Crunching snow

As is known, if the pressure on the snow, for example, leg, it will emit a sound like a creaking or crunching.We encounter him often enough, for example, when walking down the street in the winter, skiing and so on.It is worth noting the fact that the characteristic creaking we hear only when the ambient temperature is not higher than -5 ° C.What are the causes of this sound?

To date, there are two:

  • Friction crystals against each other at a pressure
  • Breaking crystals

Scientists believe that the most correct cause of the phenomenon is the second.By the way, that sound in the old days it was decided to assess the weather outside.However, if the temperature rises above -5 ° C, then there is a slight thawing of snow, which is why snowflakes are beginning to publish quite a creak.And the faster the heat comes, the less a person hears a distinctive crunch.Why?Because the crystals at a pressure virtually unbreakable and even more melting.Because of that released water wets them and snowflakes slide on the wetted surface.By the way, do not forget that the sound is also influenced by their shape and size.

What is the use?

Snow, oddly enough, is used for the construction.Thus, it is made igloo - winter dwelling Eskimos.It is a small (usually 3 meters in diameter), a dome-shaped building height of two meters, which is based on ice or snow blocks.In order that would have occurred carbon dioxide surplus the outflow and inflow of oxygen, the entrance is usually done below floor level.Windows rarely do - lack of light that penetrates the ice cubes.

The interior often shrouded with animal skins, is sometimes the same thing to make with the walls.For heating use bowls-zhirniki slightly podplavlyayutsya because of what the housing wall but do not melt because the excess heat comes out.That is why the inside is formed is a normal human body temperature.

At first glance it is easy to build a needle, although it is not so, in what could see many travelers.The secret lies in the special form of plates.Now construction is often taught in preparation for the ski trip - just in case