Why hoarfrost is formed

Why hoarfrost is formed

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The nature of a midland of Russia is generous, but does not impose to people of bright and rich colors and is by no means not so fabulous and colourful as, for example, the nature of tropics. Like the true aristocrat she chooses pale gold of the autumn woods and silver gloss of winter plains, an izumrudnost of the spring spilling greens and diamond blueness of transparent springs for the dresses. And surprising properties of the, apparently, simplest and habitual things. For example, hoarfrost – one more, but not the only thing, magic property of the most usual water.

Water "is guilty" of everything

Water – the most amazing and the most valuable of gifts which the creator in the unearthly generosity awarded Earth. In passing, together with it people were granted also beauty. Properties of water are surprising – at Earth it is present at three aggregate states at once and many millennia strike with the metamorphoses. For example, winter – snow, a frost, it is white and is monotonous. But one morning having gone outside, you fade with delight – hoarfrost to what it is beautiful!

What is hoarfrost and as it is formed

As a matter of fact, hoarfrost is thinnest ice kristallik, a kind of a firm atmospheric precipitation. Surprisingly, but these pieces of ice at a different temperature have the different form. At a temperature below -15 °C – needle, at a moderate frost – lamellar, at temperatures below 0 °C – a form of a six-sided prism.

As scientists speak, hoarfrost arises in the course of a desublimation. Desublimation – process at which any substance passes from gaseous into a firm state, passing intermediate, i.e. liquid. Sublimation is the return process. But how it is possible? Water vapor is present at air always. The maintenance of their subjects is more considerable, than air temperature is higher. At contact with objects colder, than he, water vapor is condensed and drops out in the form of dew if temperature of a surface of these objects is above 0th °C or in the form of hoarfrost or hoarfrost if they have negative temperature. Hoarfrost often arises late fall, at the still clear nights and accumulates on horizontal surfaces – benches, roofs of houses, the earth, a grass – heat conductivity of which is small and temperature is lower than ambient temperature. At contact with them, water vapor very quickly is cooled and turns into small ice crystals. On rough surfaces the crystallization happens quicker. The small wind very promotes this process as brings all new and new air masses containing water vapor. Strong wind opposite, interferes with formation of hoarfrost.

What is hoarfrost and what it differs from hoarfrost in

Hoarfrost and hoarfrost – for most of people they are absolutely equivalent. Scientists, however, divide these two states. Process of formation of hoarfrost is more difficult, than process of formation of hoarfrost, and not up to the end is still studied and clear. Hoarfrost is also formed in the course of a desublimation. But it is besieged generally on thin long objects – wires, branches of trees and bushes – from the windward side at a temperature below -15 °C and a light breeze. Hoarfrost is never formed on thin objects. One more necessary condition of formation of hoarfrost – fog or a haze, i.e. a large amount of water vapor in air. At very low temperatures – it is below -30 °C – existence of the last condition is not obligatory though process of formation of hoarfrost all the same takes place at the expense of the water vapor which is contained in air. So, strictly speaking, the most part of that winter beauty which people call hoarfrost actually is hoarfrost. And however, whether everything is equal?

Author: «MirrorInfo» Dream Team

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