With the onset of the cold period, warnings begin to appear for both ice and black ice (sometimes it is called differently - “black ice”).
Ice- deposition of ice on any open surfaces, mainly on the windward side, as a result of freezing of drops of supercooled precipitation (rain, drizzle, freezing rain) falling at a negative temperature.
Ice is a very common occurrence in the cold half of the year. As a rule, this happens when the removal of warm humid air from the Atlantic or mediterranean sea. Approximately once every 10 years, it is intense, long-lasting and covers the entire region. The last time the ice reached the scale natural disaster in December 2010.
Most often observed in the warm front zone, where warm air displaces cold. Since warm air is lighter, it flows into the wedge of cold air, which causes an inverse vertical temperature distribution in the atmosphere. In the cloud layer, the temperature is higher than near the ground, and the difference can reach 10 degrees. For example, if the ground has -5, then it will be +5 in the cloud layer.
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As the front moves through a certain point, there is an increase in temperature, first in the cloud layer, then near the ground. At some point in time, the temperature in the cloud layer already becomes positive, while near the ground it still remains negative.
Precipitation, which initially falls in the form of snow, gradually turns into a rain phase. But since the earth remains minus, then when they come into contact with surfaces on it, they immediately freeze.
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It is important to note that the height of cloudiness in the warm front zone, as a rule, does not exceed 100–200 meters. Overcoming this distance, water drops do not have time to freeze.
When the thickness of the ice "shell" increases to 20 mm, the ice becomes dangerous phenomenon. Due to the increased weight load, tree branches break and wires break. For motorists and pedestrians, even light ice causes problems.
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In some cases, some of the droplets are still covered with a thin crust of ice, forming freezing rain. When it hits the ground, the “shell” breaks, and the water spreads and freezes. But in this case, the intensity of ice is much less than in the case of supercooled rain.
The duration of supercooled precipitation and, accordingly, the formation of ice is limited by the time of passage of the warm front and usually does not exceed several hours. But in some cases, in the zone of sedentary atmospheric front may last for several days. Most often, ice is observed at temperatures from 0 to -7 degrees, sometimes up to -16 degrees.
As the warm front passes, precipitation weakens. When the temperature passes through 0 to positive values, the ice is destroyed, ice crust melts gradually.
Ice should not be confused with sleet - saucers of ice on earth's surface, which are formed as a result of cooling. As a rule, the transition of temperature through 0 to negative values occurs after a thaw in winter or as a result of radiative air cooling at night during the transition period. Unlike ice, ice is local in nature and does not cause a natural disaster.
In winter, we listen to the weather forecast and often hear that sleet or ice is expected. No one ever thought about the fact that these are completely different phenomena. We will talk about this today in our article.
It is about her that radio stations report to warn vigilant motorists from accidents on the roads.
Black ice is nothing more than ice that can form on roadway, the roof of houses, sidewalks, soil and so on. The people have a second name "slippery road." It is formed on the surface of the earth due to a thaw or from rain during a sharp decrease atmospheric pressure(cooling).
Glaze occurs due to the melting of snow cover or ice due to sudden warming. Often occurs when temperatures change around 0 degrees Celsius. Black ice is also called snow and snow porridge (snow with water) compacted by the feet and tires of cars, as well as frozen puddles.
Therefore, when the media report on the upcoming black ice, it is necessary to carefully move along the streets, motorists need to be careful on the roads. It can continue for a long time until fresh snow covers the slippery road or a thaw occurs. Now it is clear what ice is.
A completely different phenomenon is also characteristic of the cold season, but does not last long. This is the accumulation of ice on exposed surfaces. It is formed from frozen drops after supercooled precipitation, only when low temperatures atmospheric pressure.
In simple words, this is the freezing of ice on tree branches, ground, wires, and so on, associated with the glaciation of precipitation that fell on a cold surface at sub-zero temperatures.
Thus, ice and sleet are two different concepts. They appear at air temperatures from 0 to -12 and from 0 to +3 degrees Celsius, respectively.
As a rule, the ice thickness reaches one or more centimeters. If the norm is exceeded, glaciation can cause great harm:
The ice crust builds up throughout the winter as supercooled drops fall. The resulting ice on houses, cars, trees can last up to several days. The growth occurs no more than sixty minutes, but it melts only during evaporation.
What they have in common is a danger to people. As for the differences, they are as follows: ice is formed from supercooled precipitation, and ice is nothing more than frozen water that has already formed on the surface of the earth from various sources.
For example, the earth's surface, a temporary thaw. Black ice is more common than ice. This is the difference between the two phenomena.
You need to follow the safety rules. Consider them:
Ice and ice are the same in meaning, but completely different in meaning. But for some reason, these concepts are always confused, and they say that one follows from the other. Consider what they actually mean, how they are similar and how they differ.
It is possible to observe the formation of a cloud when the air temperature is kept from zero to minus ten degrees. The thickness can reach from one or more centimeters, which creates additional weight and can lead to rupture of wires and breakage of tree branches, in some cases, to the fall of poles with electric lighting. It can also be dangerous to moving vehicles and people.
The location of ice may persist for several days, depending on the amount of chilled atmospheric precipitation or in the presence of fog.
Dangers that can be encountered in icy conditions:
Formed only on hard stone surface, most often on roads, sidewalks, paths or squares. It lasts for a long time until the frozen layer of water is covered with snow or melts by increasing the air temperature and warming the soil.
Ice problems:
The reason for the occurrence of icy conditions is not only melted snow, but also spilled water, snow covering the roadway or when fast moving vehicles, thanks to the tires of the wheels, a slurry of snow and mud is formed, which subsequently freezes.
It arises due to temperature difference. This phenomenon is very dangerous, both for people and for cars. But the invisible one is especially dangerous when the smooth plane of ice is covered with freshly fallen snow. In this case, the risk increases many times due to secrecy from our eyes.
Two ways to deal with the "slippery road":
| Contains a thick bark that covers the entire area. | Has a thin layer rare cases crust may become thicker than normal width) and covers a small area. |
| Covers any surface. | Ice appears, for example, on curbs, sidewalks and in places where water has frozen after a thaw. |
| Covers all vehicles, including exterior mirrors and windows. Because of this, poor visibility on the roadway. | Not all sections of the road may have a layer of ice, and therefore it is possible to drive 60 km / h from one part, and a frozen puddle from the other increases the chance of a vehicle skidding. |
| It is difficult for pedestrians to move, as they have to move on an icy road, which is very dangerous. | You need to be very careful and move calmly, without haste. Because, if it suddenly snowed, it is very difficult to consider where exactly it is worth taking a step so as not to get injured. |
| Special danger for wires as described above. | It causes great harm to crops, which leads to a “dead” crop, low productivity and, accordingly, high cost of food. |
| Lasts four to six days. It passes quickly, especially when the precipitation stops in the form of rain. | There is a long time, at least seven days. |
From time to time we hear the weather forecast for 1-2 days ahead. In this regard, in winter, we sometimes have to deal with such concepts as “icy ice” and “sleet”. Have you ever wondered what ice and sleet are? Many people believe that they are one and the same. Not! These are two completely different concepts! Do you know how to behave during icy and icy conditions, so as not to slip and not get serious injuries? Let's dot the "and" and figure out what's what.
The definition of this concept can be considered from both scientific and philistine points of view. FROM scientific point ice is the deposition of ice on certain exposed surfaces. This happens mainly from the windward side and by freezing drops of supercooled precipitation, for example, rain, and only at low air temperatures.
In simpler terms, ice is the formation of ice on trees, wires and the ground, directly related to the freezing of rain that has fallen on a cold surface at a negative air temperature. That's what ice is!
In principle, this is a fairly common occurrence in the winter. It is observed at air temperatures from 0 to -12 degrees Celsius and at plus values: from 0 to +3 degrees Celsius.
So, what is ice, we figured it out. But what is the frequency of its occurrence? As mentioned above, it occurs during the cold half-year and, as a rule, with the removal of warm, moist air from the Mediterranean Sea or the Atlantic.
Forecasters note that about once every 10 years ice is quite intense and prolonged, covering the entire region. According to the Russian Hydrometeorological Center, last time this phenomenon reached the proportions of a natural disaster and occurred in 2010.
The thickness of the frozen ice, as a rule, does not have any gigantic dimensions. Usually it fluctuates within 1 centimeter and slightly higher. But if this thickness exceeds the aforementioned level, then this can lead to serious consequences. Here is some of them:
In winter, ice usually grows during the entire time when supercooled precipitation falls on the earth from space. Ice deposited on the ground, trees, cars, roofs of houses can remain for many days. Its growth usually lasts no more than an hour, but the destruction occurs rather slowly and almost always due to the evaporation of ice.
What is ice? This is the most common ice that occurs on the earth's surface (on roads, roofs of houses) as a result of freezing of water after a thaw or rain during a sudden drop in air temperature (cooling). The second name of this natural phenomenon is "slippery road".
In a word, ice is formed by melting snow (or ice) during a sharp warming. This phenomenon occurs quite often when the air temperature fluctuates around 0 degrees Celsius. That's what ice is!
As noted above, both of these concepts have nothing in common with each other, but they are equally dangerous for humans. With data natural phenomena there is a rather serious threat to the life and health of people, especially motorists.
Once again, we note the difference between them: ice is a fallout of supercooled precipitation, and ice is frozen water that has already covered the earth, for example, came from its surface or from other sources, formed as a result of a short-term thaw. In addition, ice is a rare occurrence compared to black ice.
Listen carefully to the weather forecast. If weather forecasters report ice or black ice, you need to act.
Temperature fluctuations and not even freezing rain, but, as weather forecasters called it, “supercooled”. Drops freeze instantly, in contact with any surface. As a result, shells on cars, slippery roads and sidewalks, accidents, queues in emergency rooms.
So slippery that any movement - "Fell, woke up!"The main thing is not to break anything. Today, the Internet is filled with stories about how a simple trip to the store over and over again turned into a story from the category of “stay alive”.
“I pushed off the subway and drove off. Slower than the bus, but also nothing”, “There is ice on the street. The dream that all men will be at my feet is starting to come true: while I went to the store, I helped two to get up, and even lay next to one!” say the pedestrians.
Residents of the Central Federal District obviously did not expect this from the weather. A rare anomaly covered cities and towns last night. Strong wind with sleet, fog. And as a result - frost. She appeared all over the place at night. The utilities did their best. But it seems that in the fight with the weather this time the forces were not equal. The ice on the roads grew faster than the reagents worked.
For motorists, the usual trip turned into a test strip this morning. To begin with, to get the car out of the ice shell, and then to stay on the road when the tracks turned into a skating rink. However, it was hardly easier for pedestrians.
“A lot of people fell, especially when they crossed the roads. Those yellow curbs, they're very slippery. There's a lot of ice there. It is impossible to walk on them”, “I reached the subway - I crossed myself. I took a bus from the metro to work and there I was already taking small, small steps,” say the pedestrians.
In anticipation women's day The queues have tripled. But not for flowers - at emergency rooms. Fractures, bruises, sprains - all stories, like a blueprint.
“Yesterday it was plus, and minus at night, it rained with snow yesterday, hail. And it seems to be frozen, and that's it, sleet all around, ”says the injured Nina Klyuchnikova.
Ice appeared not only on the roads. Here are the electric trains - icy wires sparkle. Dozens of flights have been canceled and delayed at airports. By lunchtime, the capital is like in milk. But, according to meteorologists, this is not the worst option. The most acute situation with the weather and ice may develop in the Ivanovo, Yaroslavl and Vladimir regions.
Today's footage from Nizhny Novgorod - as a confirmation. City center, zero grip.
Freezing again tonight. Therefore, getting on a slippery road, everyone decides for himself how to prolong such an unexpected spring obstacle. Someone takes out already packed skates from the mezzanine, and for someone the March “cats” have become a salvation.
“There is such a point, they stick into the ice and do not let you slip,” says Margarita Lavanskaya.
