Ozone interesting facts. The importance of ozone for life on earth. Beneficial properties of ozone

MOSCOW, September 16 – RIA Novosti. International Day for the Preservation of the Ozone Layer, a thin “shield” that protects all life on Earth from the harmful ultraviolet radiation of the Sun, is celebrated on Monday, September 16 - on this day the famous Montreal Protocol was signed in 1987.

Under normal conditions, ozone, or O3, is a pale blue gas that turns into a dark blue liquid and then into blue-black crystals as it cools. In total, ozone in the planet's atmosphere accounts for about 0.6 parts per million by volume: this means, for example, that there is only 0.6 cubic centimeter of ozone in every cubic meter of the atmosphere. For comparison, carbon dioxide in the atmosphere is already about 400 parts per million - that is, more than two glasses for the same cubic meter of air.

In fact, such a small concentration of ozone can be called a blessing for the Earth: this gas, which forms the life-saving ozone layer at an altitude of 15-30 kilometers, is much less “noble” in the immediate vicinity of humans. According to the Russian classification, ozone belongs to the substances of the highest, first hazard class - it is a very strong oxidizing agent that is extremely toxic to humans.

RIA Novosti was helped to understand the different properties of complex ozone by Vadim Samoilovich, a senior researcher at the Laboratory of Catalysis and Gas Electrochemistry of the Faculty of Chemistry of Lomonosov Moscow State University.

Ozone shield

“This is a fairly well-studied gas, almost everything has been studied - everything never happens, but the main thing (is known) ... Ozone has many different applications. But don’t forget that, generally speaking, life arose thanks to the ozone layer - this is probably the main moment,” says Samoilovich.

In the stratosphere, ozone is formed from oxygen as a result of photochemical reactions - such reactions begin under the influence of solar radiation. There the ozone concentration is already higher - about 8 milliliters per cubic meter. The gas is destroyed when it “meets” with certain compounds, for example, atomic chlorine and bromine - these are the substances that are part of dangerous chlorofluorocarbons, better known as freons. Before the Montreal Protocol, they were used, among other things, in the refrigeration industry and as propellants in gas cartridges.

In 2012, when the Montreal Protocol celebrated its 25th anniversary, experts from the United Nations Environment Program (UNEP) named the protection of the ozone layer as one of only four key environmental issues in which humanity has made significant progress. At the same time, UNEP noted that the ozone content in the stratosphere had stopped declining since 1998, and, according to scientists’ forecasts, by 2050-2075 it could return to the levels recorded before 1980.

Ozone smog

30 kilometers from the Earth's surface, ozone "behaves" well, but in the troposphere, the surface layer, it turns out to be a dangerous pollutant. According to UNEP, the concentration of tropospheric ozone in the Northern Hemisphere has almost tripled over the past 100 years, which also makes it the third most important “anthropogenic” greenhouse gas.

Here, ozone is also not released into the atmosphere, but is formed under the influence of solar radiation in the air, which is already polluted with ozone “precursors” - nitrogen oxides, volatile hydrocarbons and some other compounds. In cities where ozone is one of the main components of smog, vehicle emissions are indirectly “to blame” for its appearance.

It's not just people and the climate that suffer from ground-level ozone. UNEP estimates that reducing tropospheric ozone concentrations could help preserve about 25 million tons of rice, wheat, soybeans and corn that are lost annually due to this gas, which is toxic to plants.

It is precisely because ground-level ozone is no longer so useful that experts from meteorological services and environmental monitoring constantly monitor its concentrations in the air of large cities, including Moscow.

Ozone is beneficial

“One of the very interesting properties of ozone is bactericidal. In terms of bactericidal activity, it is practically the first among all such substances, chlorine, manganese peroxide, chlorine oxide,” notes Vadim Samoilovich.

The same extreme nature of ozone, which makes it a very strong oxidizing agent, explains the applications of this gas. Ozone is used to sterilize and disinfect premises, clothing, tools and, of course, purify water - both drinking and industrial and even waste water.

In addition, the expert emphasizes, ozone in many countries is used as a substitute for chlorine in installations for bleaching cellulose.

“Chlorine (when reacting) with organic matter produces, respectively, an organochlorine, which is much more toxic than just chlorine. By and large, this (the appearance of toxic waste - ed.) can be avoided either by sharply reducing the concentration of chlorine, or simply eliminating it. One of the options — replacing chlorine with ozone,” explained Samoilovich.

Air can also be ozonized, and this also gives interesting results - for example, according to Samoilovich, in Ivanovo, specialists from the All-Russian Research Institute of Occupational Safety and Health and their colleagues conducted a whole series of studies during which “in spinning shops a certain amount of ozone was added to ordinary ventilation ducts.” As a result, the prevalence of respiratory diseases decreased, and labor productivity, on the contrary, increased. Ozonation of air in food warehouses can increase its safety, and there are also such experiences in other countries.

Ozone is toxic

The catch with using ozone is still the same - its toxicity. In Russia, the maximum permissible concentration (MPC) for ozone in atmospheric air is 0.16 milligrams per cubic meter, and in the air of the work area - 0.1 milligrams. Therefore, notes Samoilovich, the same ozonation requires constant monitoring, which greatly complicates the matter.

“This technique is still quite complex. Pour out a bucket of some kind of bactericide - it’s much simpler, pour it out and that’s it, but here you need to watch, there must be some kind of preparation,” says the scientist.

Ozone harms the human body slowly but seriously - with prolonged exposure to ozone-polluted air, the risk of cardiovascular and respiratory diseases increases. By reacting with cholesterol, it forms insoluble compounds, which leads to the development of atherosclerosis.

“At concentrations above the maximum permissible levels, headaches, irritation of mucous membranes, cough, dizziness, general fatigue, and decline in cardiac activity may occur. Toxic ground-level ozone leads to the appearance or exacerbation of respiratory diseases; children, the elderly, and asthmatics are at risk,” — noted on the website of the Central Aerological Observatory (CAO) of Roshydromet.

Ozone is explosive

Ozone is not only harmful to inhale, but matches should also be hidden away, because this gas is very explosive. Traditionally, the "threshold" for dangerous concentrations of ozone gas is 300-350 milliliters per liter of air, although some scientists are working with higher levels, Samoilovich says. But liquid ozone - that same blue liquid that darkens as it cools - explodes spontaneously.

This is what prevents the use of liquid ozone as an oxidizing agent in rocket fuel - such ideas appeared shortly after the beginning of the space age.

“Our laboratory at the university arose precisely on this idea. Each rocket fuel has its own calorific value in the reaction, that is, how much heat is released when it burns, and hence how powerful the rocket will be. So, it is known that the most powerful option is mix liquid hydrogen with liquid ozone... But there is one drawback. Liquid ozone explodes, and explodes spontaneously, that is, without any apparent reason,” says a representative of Moscow State University.

According to him, both Soviet and American laboratories spent “a huge amount of effort and time trying to make this somehow safe (an affair) - it turned out that it was impossible to do this.” Samoilovich recalls that once colleagues from the United States managed to obtain especially pure ozone, which “seemed to” not explode, “everyone was already hitting the kettledrums,” but then the entire plant exploded and work was stopped.

“We have had cases where, say, a flask with liquid ozone sits and stands, liquid nitrogen is poured into it, and then - either the nitrogen boiled away or something - you come, and half of the installation is missing, everything has been blown to dust. Why it exploded - who knows,” the scientist notes.

Who doesn’t remember how invigorating fresh air is after a thunderstorm! And what a pleasant smell there is after lightning strikes. And this scent cannot be confused with any other. It is associated with freshness. This smell is created by ozone, molecules of which are created when lightning passes through the atmosphere. Ozone owes its name to its special aroma. In the Greek language, popular in the past among scientists, this word means “fragrant.”

From a chemical point of view, ozone is a modification of ordinary oxygen. Due to its chemical properties, it is also called active oxygen. If the molecule of ordinary and familiar oxygen consists of two identical atoms (its formula is O2), then the ozone molecule contains three of the same atoms, and its formula is O3. The molecular weight of this gas is 1.5 times greater than that of oxygen, and is 48 (versus 32 for O2). Under standard or ordinary conditions (temperature and pressure), ozone spontaneously turns into oxygen, and this reaction occurs with the release of heat.

In the earth's atmosphere there is an ozone layer located at an altitude of 20-30 km above surface level. In the lower part of the atmosphere, ozone occurs when high energies pass through the atmosphere - lightning strikes, powerful electrical discharges, and the operation of X-ray equipment.

The chemical activity of ozone is much higher than that of its isomer, molecular oxygen. It forms chemical bonds with a wide variety of substances much faster than molecular oxygen. Ozone is often used to fight bacteria - it kills them quickly. Therefore, it is used to disinfect drinking water or air.

Who discovered Ozone?

The discovery of ozone is the merit of the Dutch physicist Van Marum. He informed the scientific community about the discovery in 1785. More than half a century later, in 1850, its oxidizing ability was investigated, and the ability to form double molecular bonds when interacting with organic molecules was discovered. The practical application of these properties can often be found today in many industries.

Ozone is a very strong oxidizing agent. In addition, its disinfecting abilities are widely used. It has a detrimental effect on any microorganisms, including viruses. Species that are insensitive to the effects of chlorine compounds also die from ozone.

Ozone is also used instead of traditional chlorination for the preparation of drinking water. Its first use in this capacity was in 1898, in the city of San Maur in France. And the first industrial ozonation enterprise appeared in 1907, in the town of Bon Voyage. It processed up to 22,500 cubic meters of water from the Vazubi River per day, supplying it to Nice. In the Russian Empire, the first such station appeared in 1911 in St. Petersburg, and until 1916 this area of ​​water treatment was actively developing. A new round of such processing began in the 1980s, after the invention of compact, reliable, but most importantly, more economical ozonizers - devices for producing ozone on an industrial scale.

During the First World War, ozone was also used in medicine, as an antiseptic. Since 1935, experiments began on the use of ozone as a therapy for intestinal diseases. Rectal administration of gas has shown a beneficial effect in many peptic ulcers, colitis, hemorrhoids and the destruction of pathogenic intestinal microflora. Experiments were conducted on the use of ozone in surgery, in the treatment of tuberculosis, other lung diseases, herpes, numerous infectious and other diseases.

Today, ozone is becoming increasingly popular for killing germs in water, air and food, as this method produces unpleasant effects and unwanted odors.

In European countries and the USA today, the preparation of drinking water with the participation of ozone accounts for 95% of its total volume. Ozonation for the purification of industrial and domestic wastewater. The treatment removes traces of many hazardous substances: cyanide, petroleum processing residues, sulfur compounds, phenols and other hazardous wastes that can disrupt the ecological balance.

Atmospheric ozone, formed in the upper layers of the atmosphere, protects all living things from harsh ultraviolet radiation. Therefore, the thinning of this layer and the formation of “ozone holes” can have an extremely adverse effect on the entire animal and plant world, including humans.

MOSCOW, September 16 – RIA Novosti. International Day for the Preservation of the Ozone Layer, a thin “shield” that protects all life on Earth from the harmful ultraviolet radiation of the Sun, is celebrated on Monday, September 16 - on this day the famous Montreal Protocol was signed in 1987.

Under normal conditions, ozone, or O3, is a pale blue gas that turns into a dark blue liquid and then into blue-black crystals as it cools. In total, ozone in the planet's atmosphere accounts for about 0.6 parts per million by volume: this means, for example, that there is only 0.6 cubic centimeter of ozone in every cubic meter of the atmosphere. For comparison, carbon dioxide in the atmosphere is already about 400 parts per million - that is, more than two glasses for the same cubic meter of air.

In fact, such a small concentration of ozone can be called a blessing for the Earth: this gas, which forms the life-saving ozone layer at an altitude of 15-30 kilometers, is much less “noble” in the immediate vicinity of humans. According to the Russian classification, ozone belongs to the substances of the highest, first hazard class - it is a very strong oxidizing agent that is extremely toxic to humans.

RIA Novosti was helped to understand the different properties of complex ozone by Vadim Samoilovich, a senior researcher at the Laboratory of Catalysis and Gas Electrochemistry of the Faculty of Chemistry of Lomonosov Moscow State University.

Ozone shield

“This is a fairly well-studied gas, almost everything has been studied - everything never happens, but the main thing (is known) ... Ozone has many different applications. But don’t forget that, generally speaking, life arose thanks to the ozone layer - this is probably the main moment,” says Samoilovich.

In the stratosphere, ozone is formed from oxygen as a result of photochemical reactions - such reactions begin under the influence of solar radiation. There the ozone concentration is already higher - about 8 milliliters per cubic meter. The gas is destroyed when it “meets” with certain compounds, for example, atomic chlorine and bromine - these are the substances that are part of dangerous chlorofluorocarbons, better known as freons. Before the Montreal Protocol, they were used, among other things, in the refrigeration industry and as propellants in gas cartridges.

In 2012, when the Montreal Protocol celebrated its 25th anniversary, experts from the United Nations Environment Program (UNEP) named the protection of the ozone layer as one of only four key environmental issues in which humanity has made significant progress. At the same time, UNEP noted that the ozone content in the stratosphere had stopped declining since 1998, and, according to scientists’ forecasts, by 2050-2075 it could return to the levels recorded before 1980.

Ozone smog

30 kilometers from the Earth's surface, ozone "behaves" well, but in the troposphere, the surface layer, it turns out to be a dangerous pollutant. According to UNEP, the concentration of tropospheric ozone in the Northern Hemisphere has almost tripled over the past 100 years, which also makes it the third most important “anthropogenic” greenhouse gas.

Here, ozone is also not released into the atmosphere, but is formed under the influence of solar radiation in the air, which is already polluted with ozone “precursors” - nitrogen oxides, volatile hydrocarbons and some other compounds. In cities where ozone is one of the main components of smog, vehicle emissions are indirectly “to blame” for its appearance.

It's not just people and the climate that suffer from ground-level ozone. UNEP estimates that reducing tropospheric ozone concentrations could help preserve about 25 million tons of rice, wheat, soybeans and corn that are lost annually due to this gas, which is toxic to plants.

It is precisely because ground-level ozone is no longer so useful that experts from meteorological services and environmental monitoring constantly monitor its concentrations in the air of large cities, including Moscow.

Ozone is beneficial

“One of the very interesting properties of ozone is bactericidal. In terms of bactericidal activity, it is practically the first among all such substances, chlorine, manganese peroxide, chlorine oxide,” notes Vadim Samoilovich.

The same extreme nature of ozone, which makes it a very strong oxidizing agent, explains the applications of this gas. Ozone is used to sterilize and disinfect premises, clothing, tools and, of course, purify water - both drinking and industrial and even waste water.

In addition, the expert emphasizes, ozone in many countries is used as a substitute for chlorine in installations for bleaching cellulose.

“Chlorine (when reacting) with organic matter produces, respectively, an organochlorine, which is much more toxic than just chlorine. By and large, this (the appearance of toxic waste - ed.) can be avoided either by sharply reducing the concentration of chlorine, or simply eliminating it. One of the options — replacing chlorine with ozone,” explained Samoilovich.

Air can also be ozonized, and this also gives interesting results - for example, according to Samoilovich, in Ivanovo, specialists from the All-Russian Research Institute of Occupational Safety and Health and their colleagues conducted a whole series of studies during which “in spinning shops a certain amount of ozone was added to ordinary ventilation ducts.” As a result, the prevalence of respiratory diseases decreased, and labor productivity, on the contrary, increased. Ozonation of air in food warehouses can increase its safety, and there are also such experiences in other countries.

Ozone is toxic

The catch with using ozone is still the same - its toxicity. In Russia, the maximum permissible concentration (MPC) for ozone in atmospheric air is 0.16 milligrams per cubic meter, and in the air of the work area - 0.1 milligrams. Therefore, notes Samoilovich, the same ozonation requires constant monitoring, which greatly complicates the matter.

“This technique is still quite complex. Pour out a bucket of some kind of bactericide - it’s much simpler, pour it out and that’s it, but here you need to watch, there must be some kind of preparation,” says the scientist.

Ozone harms the human body slowly but seriously - with prolonged exposure to ozone-polluted air, the risk of cardiovascular and respiratory diseases increases. By reacting with cholesterol, it forms insoluble compounds, which leads to the development of atherosclerosis.

“At concentrations above the maximum permissible levels, headaches, irritation of mucous membranes, cough, dizziness, general fatigue, and decline in cardiac activity may occur. Toxic ground-level ozone leads to the appearance or exacerbation of respiratory diseases; children, the elderly, and asthmatics are at risk,” — noted on the website of the Central Aerological Observatory (CAO) of Roshydromet.

Ozone is explosive

Ozone is not only harmful to inhale, but matches should also be hidden away, because this gas is very explosive. Traditionally, the "threshold" for dangerous concentrations of ozone gas is 300-350 milliliters per liter of air, although some scientists are working with higher levels, Samoilovich says. But liquid ozone - that same blue liquid that darkens as it cools - explodes spontaneously.

This is what prevents the use of liquid ozone as an oxidizing agent in rocket fuel - such ideas appeared shortly after the beginning of the space age.

“Our laboratory at the university arose precisely on this idea. Each rocket fuel has its own calorific value in the reaction, that is, how much heat is released when it burns, and hence how powerful the rocket will be. So, it is known that the most powerful option is mix liquid hydrogen with liquid ozone... But there is one drawback. Liquid ozone explodes, and explodes spontaneously, that is, without any apparent reason,” says a representative of Moscow State University.

According to him, both Soviet and American laboratories spent “a huge amount of effort and time trying to make this somehow safe (an affair) - it turned out that it was impossible to do this.” Samoilovich recalls that once colleagues from the United States managed to obtain especially pure ozone, which “seemed to” not explode, “everyone was already hitting the kettledrums,” but then the entire plant exploded and work was stopped.

“We have had cases where, say, a flask with liquid ozone sits and stands, liquid nitrogen is poured into it, and then - either the nitrogen boiled away or something - you come, and half of the installation is missing, everything has been blown to dust. Why it exploded - who knows,” the scientist notes.

Ozone is a word of Greek origin, which means “fragrant”. What is ozone? At its core, ozone O3 is a blue gas with a characteristic odor that is associated with the smell of air after a thunderstorm. It is especially felt near sources of electric current.

History of ozone discovery by scientists

What is ozone? How was it discovered? In 1785, the Dutch physicist Martin van Marum conducted several experiments aimed at studying the effect of electric current on oxygen. Based on their results, the scientist investigated the appearance of specific “electric matter.” Continuing to work in this direction, in 1850 he was able to determine the ability of ozone to interact with organic compounds and its property as an oxidizing agent.

The disinfecting properties of ozone were first used in 1898 in France. In the town of Bon Voyage, a plant was built that disinfected and disinfected water from the Vazyubi River. In Russia, the first ozonation plant was launched in St. Petersburg in 1911.

Ozone was widely used during the First World War as an antiseptic. The ozone-oxygen mixture was used to treat intestinal diseases, pneumonia, hepatitis and was practiced for infectious lesions after surgery. Particularly active in ozonation began in 1980, the impetus for this was the appearance on the market of reliable and energy-saving. Currently, about 95% of water in the USA and throughout Europe is purified with the help of ozone.

Ozone generation technology

What is ozone? How is it formed? In its natural environment, ozone is found in the Earth's atmosphere at an altitude of 25 km. Essentially, it is a gas that is formed as a result of ultraviolet radiation from the Sun. On the surface it forms a layer 19-35 km thick, which protects the Earth from solar radiation. According to the interpretation of chemists, ozone is active oxygen (a combination of three oxygen atoms). In the gaseous state it is blue, in the liquid state it has an indigo tint, and in the solid state it is dark blue crystals. O3 is its molecular formula.

What is the harm of ozone? It belongs to the highest hazard class - it is a very poisonous gas, the toxicity of which is equal to the category of chemical warfare agents. The reason for its appearance is electrical discharges in the atmosphere (3O2 = 2O3). In nature, you can feel it after strong flashes of lightning. Ozone interacts well with other compounds and is considered one of the following. Therefore, it is used to destroy bacteria, viruses, microorganisms, and to purify water and air.

Negative effects of ozone

What does ozone affect? A characteristic feature of this gas is its ability to quickly interact with other substances. If in nature there is an excess of standard indicators, then as a result of its interaction with human tissues, dangerous substances and diseases can arise. Ozone is a potent oxidizing agent, upon interaction with which the following are quickly destroyed:

• natural rubber;
• metals other than gold, platinum and iridium;
• Appliances;
• electronics.

At high concentrations of ozone in the air, human health and well-being deteriorate, in particular:

• the mucous membrane of the eyes is irritated;
• the functioning of the respiratory system is disrupted, which will lead to paralysis of the lungs;
• there is general fatigue of the body;
• headaches appear;
• allergic reactions may occur;
• burning in the throat and nausea;
• there is a negative effect on the nervous system.

Beneficial properties of ozone

Does ozone purify the air? Yes, despite its gas, it is very useful for humans. In small concentrations it has excellent disinfectant and deodorizing properties. In particular, it has a detrimental effect on harmful microorganisms and destroys:

• viruses;
• various types of microbes;
• bacteria;
• fungi;
• microorganisms.

Most often, ozone is used during flu epidemics and outbreaks of dangerous infectious diseases. With its help, water is purified from various types of impurities and iron compounds, while enriching it with oxygen and minerals.

Interesting information about ozone, its scope

Excellent disinfecting properties and the absence of side effects have led to the emergence of demand for ozone and its widespread use in various sectors of the economy. Today, ozone is successfully used for:

• meeting the needs of the pharmaceutical industry;
• water purification in aquariums and fish farms;
• disinfection of swimming pools;
• medical purposes;
• cosmetic procedures.

In the medical industry, ozonation is practiced for ulcers, burns, eczema, varicose veins, wounds and dermatological diseases. In cosmetology, ozone is used to combat skin aging, cellulite and excess weight.

The influence of ozone on the life of living beings

What is ozone? How does it affect life on Earth? According to scientists, 10% of ozone is in the troposphere. This ozone is a component of smog and acts as a pollutant. It negatively affects the respiratory organs of people and animals and slows down the growth of plants. However, its quantity is very small to significantly harm health. A significant part of the harmful ozone in smog is the products of the functioning of cars and power plants.

Much more ozone (about 90%) is found in the stratosphere. This absorbs biologically harmful ultraviolet radiation from the Sun, thereby protecting people, flora and fauna from negative effects.

The ozone layer is a kind of blanket that reliably protects our planet from ultraviolet radiation. On September 16, 1987, the Protocol on Ozone Depleting Substances was signed in Montreal. Its essence was to stop the production of chemicals that destroy the ozone layer of the planet. In honor of this date, the International Day for the Preservation of the Ozone Layer was established, which is celebrated annually on September 16 since 1995. AiF.ru told some interesting facts about the ozone layer of the planet.

The ozone layer is part of the Earth's stratosphere at an altitude of 12 to 30 km (depending on latitude). It arose under the influence of solar ultraviolet radiation, which broke molecular oxygen O2 into atoms. These atoms then combined with other O2 molecules and became ozone - O3. Essentially, the higher the concentration of ozone, the better it protects biological organisms from solar radiation.

The phrase “ozone hole” did not come about because holes were actually found in the ozone. This term arose due to satellite images of the total ozone content in the atmosphere over Antarctica, which showed how the thickness of the ozone layer changes depending on the season.

Depletion of the ozone layer and exposure to freons

People first started talking about the thinning of the ozone layer in 1957. Some researchers do not see a problem in the process of fluctuations in the thickness of the ozone layer. At the end of the polar winter and at the beginning of the polar spring, the ozone layer decreases, and after the onset of the polar summer it increases.

CFCs, used in the production of household aerosols, insulation foaming agents and refrigerators, are believed to have a negative impact on the ozone layer. As soon as relevant research appeared, the manufacturers of these substances tried to discredit the hypothesis.

However, the fact that freon affects the depletion of the ozone layer was proven by researchers Paul Crutzen, Mario Molina and Sherwood Rowland in 1995. For this they were awarded the Nobel Prize.

Ozone holes

The main emissions of CFCs occur in the Northern Hemisphere, and the most intense depletion of the ozone layer is observed over the Antarctic. Why? It turns out that freons move well in the layers of the troposphere and stratosphere, and their “lifetime” is calculated in years. The wind carries freons throughout the atmosphere, including to Antarctica. At very low temperatures, an unusual chemical reaction occurs - chlorine is released from freons on the ice crystals of stratospheric clouds and freezes. When spring arrives, the ice melts and chlorine is released, which destroys ozone.

Is the ozone layer only depleted over Antarctica? No. The ozone layer is thinning over both hemispheres, as proven by long-term measurements of ozone concentrations in different parts of the planet.

Global warming

Not all scientists agree on global warming. Although warming was recognized as a scientific fact at the UN Madrid Conference in 1995, some still consider it a myth and provide their own evidence.

According to the most common view in the scientific field, global warming is a reality and is happening due to human activities. The thinning of the ozone layer plays a significant role in this.

As follows from recent observations, northern rivers remain frozen on average 2 weeks less than before. In addition, the melting of glaciers continues.