Air contains thousands of tons of water. The ordinary in the unusual. How much does a cube of air weigh?

Everything is important in science.

Water and life

According to generally accepted scientific theory, life on our planet is, so to speak, a local phenomenon. It originated a long time ago, when favorable conditions for this existed on Earth. And it originated in the ocean, that is, in water. This process itself was a long one, lasting billions of years. They went to ensure that from suitable chemical compounds dissolved in the ocean, organic matter, which laid the foundation for the simplest living beings. New billions of years have passed, and life has spread throughout the planet. Nowadays it exists in various forms and forms almost everywhere - in water, on land and in the air.

But its organic connection with water remained. It is impossible to imagine many processes occurring in the body without the participation of water. Take, for example, feeding living things. All nutrients that enter the body in one way or another must be transferred into solution, and this requires water.

Dehydration of the body is fatal. This was experimentally shown in pigeons: with the loss of one fifth of the water contained in the bird’s body, it dies, despite the preservation of all other conditions of existence. And the hardest thing for a person to bear is the lack of water: for him, thirst is more dangerous and worse than hunger. In the human body, water makes up sixty-five percent of the total weight. If its content for any reason decreases by ten to twenty percent, the person will certainly die.

In each organ of our body, in each of its cells, various biochemical processes are continuously taking place, and the most complex transformations of one substance into another occur. From the food entering the body, substances necessary for the normal functioning of all organs and the vital functions of the body are produced. Water is an indispensable participant in all these biochemical reactions, water is also a kind of orderly; with its help, unnecessary and harmful metabolic products are removed from the body - a kind of waste from biochemical production.

Numbers are usually boring things. But sometimes it is difficult to do without them for the simple reason that in such cases they add clarity to the story.

Here are a few such illustrative examples in numbers.

To grow one kilogram of plant food - grains, vegetables, an average of two tons of water is required. To “grow” one kilogram of meat you need twenty tons of it!

A person consumes an average of sixty tons of life-giving moisture per year just through nutrition. Add to this another three hundred tons of water to satisfy his other vital needs. Total three hundred and sixty tons for one person!

To produce just one ton of steel, synthetic fiber or paper, hundreds of cubic meters of water are required. Even the extraction of coal and oil cannot be done without water; on average, it is consumed: about five tons per ton of coal, up to one hundred and thirty tons per ton of oil. In other words, the fuel industry consumes as much water per year as it is brought by some large river, for example the Dnieper.

It has been calculated (we must, of course, keep in mind: this calculation is approximate) that our national economy, including meeting the needs of the population, consumes five hundred to six hundred cubic kilometers (kilometers!) of water per year. Academician A.P. was right. Karpinsky, who called water “the most precious fossil.”

Where is this fossil stored? Water is everywhere: in oceans and seas, in rivers and lakes, springs and swamps, on high mountains and at the poles. About a fifth of the soil is water. There is a lot of it below, in the deeper horizons of the earth’s crust. Let's say, at a depth of up to a kilometer in the earth's crust, more than four million cubic kilometers of water are stored.

There is also a lot of it in the atmosphere: on average, about twenty thousand tons “hang” over each square kilometer of the Earth’s surface - in the form of steam.

If you look at our planet from above from space, then it would be more correct to call it not Earth, but Water, because land occupies a much smaller area on its surface than oceans and seas. Scientists say that there are about one billion three hundred and fifty million cubic kilometers of water on our planet. Is this a lot? Of course, a lot. But...

The World Ocean is large and vast; ninety-seven percent of all water reserves on the planet are concentrated in it. However, sea water is not suitable for drinking and cooking - it contains many different salts. It is also not suitable for many industries, including, first of all, Agriculture. In order for sea water to be suitable for such use, it must be freed from salts, that is, desalinated. Technically, this problem is not that difficult. All you need is a cost-effective source of energy to make the game, as they say, worth the trouble. There are two paths outlined here: the first is the creation of industrial desalination plants based on nuclear power plants, the second is the use of “free” solar energy for the same purposes. We have a pilot plant based on a nuclear power plant already operating in the Caspian Sea, in the city of Shevchenko. The city and its entire economy are fully supplied with desalinated water.

Where are the other three percent of the world's water reserves?

Two of them are glaciers and polar ice caps of the planet, another is atmospheric moisture (0.001 percent of the world’s reserves is hardly worth taking into account), groundwater (most of the last, third percent falls on them) and, finally, , Rivers and lakes. They are still the main suppliers of water, although their share in the global water balance is no more than one hundredth of a percent! Let's put it bluntly: not much...

Many cities in the world experience an acute shortage of fresh water - Tokyo and Paris, New York and Philadelphia. In a word, there is a lot of water on Earth, and at the same time there is little of it.

Fresh water, this truly unique and universal source of life, in our time - a time of rapid scientific and technological progress, rapid growth of cities and industry - is becoming an even more valuable resource of the planet.

Everything flows

Water is an eternal traveler. She is in a state of endless circulation. It is not easy to trace her path in detail. But in general terms it is possible.

The sun's rays heat the surface of the planet and evaporate a huge amount of moisture. Water vapor rises into the air from the surface of seas, rivers, lakes, and from the soil. All plants evaporate water. Its vapors are exhaled by animals.

Water turns into gas at any time of the year, even in winter, in severe frost. But the higher the temperature, the more vapor there is in the atmosphere. In summer, at twenty degrees Celsius, each cubic meter of air can contain up to seventeen grams of moisture. If new water vapor enters such saturated air, it will already condense and turn back into water.

In other words, tiny droplets appear in the air. It is these, as well as ice crystals, if the air is cold, that form the familiar clouds. For water vapor to condense, however, it is necessary that there be solid particles of atmospheric dust in the air, which play the role of nuclei that precipitate water vapor molecules. There are usually a lot of such particles in the atmosphere.

Air currents carry water vapor and clouds across the Earth. Winds blowing from warm seas carry especially a lot of moisture. The oceans are the main supplier of moisture to the atmosphere. Saturated with water, air masses, moving over continents, gradually lose it in the form of rain or snow.

The fate of drops of water falling from the sky is different. Some of them fall into streams or rivers, into lakes or directly into the sea and from there again evaporate into the air over time. Some of the rainwater is retained in puddles and plants, but soon, heated by the sun, it again sets off on a journey through the ocean of air. A lot goes into the ground.

Having traveled in the kingdom of Pluto for days, months, sometimes for many years, a water droplet again appears cold and purified, as if having really been in purgatory, on the surface, and then runs with others into the sea or immediately soars up to the clouds.

Why is it raining!

The answer is not at all that simple. And to get acquainted with the nature of this atmospheric phenomenon so common to all of us, to know about its features and capabilities is very important. Why?

The better we know the mechanism of rain formation, the sooner and more reliably we will be able to take control of one of the greatest processes of nature - the water cycle.

Various forms of clouds forming in the blue sky. They look like big pieces of cotton wool. They resemble in their appearance the feathers of some bird. Sometimes the clouds have a wavy appearance, and sometimes the sky is covered with a continuous, monotonous gray veil, in which the rays of the sun go out for a long time.

Clouds, as we have already said, are accumulations of water droplets and ice crystals. But they begin to fall to the ground only when they become large enough. While the cloud consists of very small droplets, they are supported by rising air currents.

What leads to an increase in water droplets in a cloud? The first reason: more and more particles of water vapor from the air are deposited on the smallest droplets - in other words, the process of condensation of water vapor continues in the cloud. And second: individual droplets, moving in the cloud in all directions, often collide with each other and sometimes merge. However, both of these ways do not always lead to rain.

If a cloud consists of only droplets of water, then the enlargement of the droplets in it proceeds very slowly. To form just one raindrop, at least a million small cloud drops must join together!

Completely different conditions are created in powerful mixed clouds, which in their upper part consist of ice crystals, and in the lower part - of water droplets. Here, the formation of a rain cloud occurs much faster. Such mixed clouds in our latitudes can produce heavy rain and sometimes downpour.

Powerful rain clouds usually form on days when it is hot and there is a lot of moisture in the air. Having arisen in a stream of moist air rising from the heated earth, such a cloud grows rapidly. Increasing in size, it rises higher and higher. If the conditions for its growth are favorable, then soon the cloud reaches the high layers where the cold reigns. At an altitude of eight kilometers, the air temperature often drops to thirty degrees below zero. With such intense cold, water droplets at the top of the cloud begin to turn into crystals. Gradually, the thickness of the cloud formation can reach several kilometers. Its top, illuminated by the sun, becomes like a huge snowy mountain. It hangs like a dark bulk over the ground.

When it starts to rain, rising air currents replenish this thundercloud with ever new reserves of moisture. This continues until the flow of moist air weakens. In the summer, cumulus clouds sometimes accumulate a truly gigantic amount of water - each cubic kilometer of such a cloud can contain an average of up to a thousand tons.

Of course, the picture drawn here of the formation of clouds and their transformation into rain or snow clouds is obviously simplified; in reality, this whole process (both in general and in “details”) is much more complex and it cannot be said that it has been studied in all details. But if you look at this picture as an approximate diagram, then it is correct.

By the way, about the word “cloud”. Usually in dictionaries, and even in colloquial speech, we understand this word as a cloud in general, from which precipitation is already falling or will soon fall. But meteorological specialists have their own terminology. They include their most varied forms as rain clouds - both in origin and in physical properties: cumulonimbus and nimbostratus, as well as stratocumulus, altostratus and stratus. Plus many transitional forms.

We are very often mistaken when we think that the darker the approaching cloud, the heavier the rain it will rain. “Well, it’s pouring out now!” - we say and hurry to get to a safe shelter. Meanwhile, the amount of rain and even whether it will fall or not depends in no way on how black the rain cloud is.

Watch and you will see: clouds of a threatening, gloomy appearance often pass without shedding a drop. The fact is that they usually consist of very small droplets and the supply of moisture in them is not so great. But when a dark rain cloud with a leaden tint hangs over us, expect rain, and a lot of it.

In the footsteps of the accused

Summer rain passes quickly. Having thundered, the thunderstorm passes, and the sun appears again over the washed, brightened earth. But streams of rainwater continue their destructive work.

A stream that is completely invisible at first leaves behind a deep trace in a short time, especially somewhere on a slope with easily eroded soil. These gullies with a narrow bottom and steep walls often become the seeds of a future ravine. Shower after shower, stream after stream of melt water in the spring - and now a small and seemingly harmless gulley has turned into a ravine, one of the most terrible enemies of agriculture. Over the course of a year, meltwater alone washes away and carries away many tons of fertile soil from fields and arable lands.

Under suitable conditions, the ravine digs deeper into the ground, now it is no longer just a ravine, but a real gorge, along which stormy streams rush in spring and during rainstorms.

Here is a description of such a gorge from the book of geographer A.P. Nechaeva. He saw him near Volsk in the Saratov province (this happened at the end of the last century).

“Numerous ravines furrowed the area, running like dark snakes in all directions. I had never seen real ravines before, and it’s no wonder that they attracted my attention. The next day after my arrival, I went on an excursion and, turning off the road into the first ravine I came across, I was amazed by the picture that unfolded in front of me. I suddenly found myself in a wild, dark and damp gorge. The sun's rays did not reach its bottom. And the further I walked, the higher the walls rose. Above me, only a narrow strip of blue sky was visible. In places the ravine received side tributaries, and here the picture became downright majestic... Here and there the walls emerged in the form of ruined fortresses with towers and battlements. The area took on the appearance of a bizarre mountainous country...

Suddenly a distant clap of thunder was heard, followed by another, a third, more and more distinct and stronger. A thunderstorm was approaching. Several large drops fell on my face. I walked just as carelessly, without thinking about what was happening. Meanwhile, clouds covered the entire narrow sliver of blue sky. A whirlwind swept overhead. Dust swirled over my head. It was completely dark in the ravine. I realized that there would be a downpour and water would rush down the ravine. And it became clear to me that I was trapped. There is no way to climb straight up these steep, loose cliffs. We need to save ourselves... And, stumbling over the stones that covered the bottom of the ravine, I started to run. And the rumbles of thunder were heard closer and closer. I ran as fast as I could. Suddenly a dull noise came from somewhere in the distance. There was no doubt that it was water rushing in a stormy stream down the ravine. I doubled my running. Meanwhile the noise was getting closer. And as soon as I managed to run out onto the road, a muddy stream of water burst out of the ravine. I climbed up to the steep bank of the newly formed river, and, seeing its frantic play, I realized what danger I was exposed to. The water was all foamy. Turning over stones and tearing off huge blocks of earth from the banks, she rushed madly forward.”

In our country there are many ravines in the Central Russian, Volga and Volyn-Podolsk uplands, in the foothills of the Carpathians, and in the Donbass. The reason for this lies in the characteristics of the climate and soil. Under the top layer of black soil there are rocks that are also easily washed away by water.

In some places, a very minor crack in the dried soil, a road rut, or a furrow is enough for deep gullies to appear at the first heavy rain - a ravine is born. The formation of such wounds on the soil is also facilitated by the fact that droughts alternate with downpours. Huge masses of water rush into the cracks of the parched earth, erode them, and remove the top fertile layer of soil.

Ravines are dangerous not only because they literally steal from us the land on which we grew bread or grazed livestock. They are still drying her out. After all, what is, in essence, a ravine? This is a naturally dug channel, akin to what reclamation workers cut through a swamp when they want to drain it. But there is a swamp, and here, let’s say, is a steppe, already suffering from periodic droughts. And then there is a ravine that sucks out underground moisture, which is why streams, ponds, and wells often dry up if this miraculous canal lies not far from them.

They fight ravines inventively, although not always successfully. Where a ravine has already begun, measures are taken to prevent it from growing; where it has already formed, it may be advisable to turn it into a chain of ponds with controlled flow. Correct crop rotations are also of great importance, which lead to the strengthening of the top layer of soil and prevent its erosion.

What does rain threaten?

“...Tropical downpours have been pouring in Honduras for the fifth day now. Streams of raging water swept away 20 settlements. The coffee and grain crops were completely destroyed over a huge area. According to the latest official data, 126 people died, 20 thousand were left homeless.”

This message was distributed by telegraph agencies at the end of May 1982. And two days later, the number of flood victims in this country already reached sixty thousand people.

We often read such messages in newspapers. “A destructive downpour, which did not stop for several days,” wrote the Parisian L’Humanité in December 1981, “hit the southwestern regions of France and caused an unprecedented flood in these parts. The wind drove the storm clouds from the Atlantic, where a storm had been raging for 24 hours. After two days of continuous torrential rains, the elements seemed to begin to recede, but after some time the downpours hit the entire southwestern part of France with renewed force. As a result of the flood, a catastrophic situation developed in this area of ​​the country...

In the Landes department, many famous pine forests have died: the ground under the trees has been completely washed away. In Agen, the administrative center of the Lot-et-Garonne department, several neighborhoods were flooded, leaving hundreds of residents cut off from the rest of the city. In Riolle-Bas, Saint-Antonin-Noble-Valais, people were rescued by helicopters. Even where the water has subsided, it is almost impossible to move: the streets are covered with a thick layer of mud.”

Floods caused by heavy rains are a perennial disaster that plagues people. Legends associated with it, such as the biblical myth of the Flood, are found in the folklore of many nations. Sometimes traces of the floods mentioned in legends are also discovered during archaeological excavations.

Information about violent floods and high waters is found in Russian chronicles, church and city memorial records, but all this information is scattered and random. Only since 1876 did our country begin to conduct regular observations on rivers, primarily, of course, those that were distinguished by their waywardness and more than once gave free rein to their elements.

And where there is a natural disaster, there is usually a disaster.

“In the summer of 6978 (that is, in our chronology - in 1470) ... - we read in the Pskov Chronicle. - That same spring, the water was great and strong, filling the rivers and lakes; for many years the water had not been like this; and along the Great River, as the ice flowed, a lot of Christians were torn up in the choir and their supplies were carried away, and lands, some fields were torn up by ice, and others were washed away by water.”

Now, when the Moscow River is regulated, when measures are taken to prevent flooding every spring, Muscovites need not fear that they will be caught by surprise by a river overflowing its banks. This has happened before. In 1908, the water in the Moscow River rose by more than ten meters, and a fifth of the city was flooded. The roofs were dotted with residents of flooded houses, tables, benches, logs, carts, hay were floating along the river and along the streets...

One of the sadly memorable floods of our time occurred in Italy. This happened in 1951. There were heavy rainfalls in the Alps for several days in a row. Even the smallest rivers turned into turbulent streams. The Po River overflowed and, breaking through dams and dikes in several places, rushed into houses, gardens, vineyards, and flooded dozens of villages. Almost everywhere there were human casualties. Thousands of people were forced to spend several days on the roofs of houses and in trees - without food or warm clothing.

The consequences of this flood were especially severe for Polesine, a typically rural region of northern Italy. According to the writer Carlo Levi, in those days this region was a water desert: it simply did not exist - it disappeared under water.

Floods caused by the Po and another river, the Adige, which also originates in the Alps, have happened before. The whole history of Polezine is the history of the struggle of many generations of peasants against the elements, the history of efforts to curb the water, to protect themselves from it. The 1951 flood is considered by Carlo Levi to be one of the most destructive in the current century.

Just statistics for now

What's going on in the skies? Why do they suddenly begin to pour streams of water onto the ground so mercilessly?

One of the reasons for heavy rains is particularly strong heating of moist soil in the hot summer. The mass of moisture evaporating from the surface of the earth forms (often this happens right before our eyes) huge heavy clouds. The “thickness” of the cloud layer reaches six – eight, or even ten kilometers. From them, from clouds oversaturated and overloaded with water, showers pour down.

Showers of this origin are especially characteristic of tropical latitudes. In our latitudes, shower clouds are formed, as a rule, differently - during a frontal meeting of differently heated air masses, when cold air wedges into warmer air and a complex, violent process develops along the entire line of the atmospheric front. Experts call this process convection. Its physical meaning is that large air masses move with the transfer of heat and other physical factors. The formation of cumulonimbus clouds, carrying showers and thunderstorms, is associated with it.

Each of us has seen a small, far from accurate, but visual model of this process more than once in our lives, opening a window in winter, in severe frost. There is no fog outside - clean, frosty air, but, rushing through your window, for some reason it begins to swirl. And it swirls because in our home the air is warm, saturated with vapors, and they condense in the frosty air flow. The more moisture in the room air, the thicker and more noticeable the clouds of frost.

In the spring of 1965, a cold air mass invaded the European part of our country from the north at high speed, and the temperature dropped to ten to twelve degrees. And before that, even in the Kirov region the temperature rose to twenty-five to twenty-eight degrees. Moving to the southeast, the cold air wedged deeper and deeper into the heated air, saturated with evaporation. As a result, over a gigantic territory, from Moldova to the Kirov region, a thunderstorm road with downpours stretched for thousands of kilometers. In one day, the Central Institute of Forecasts received sixty warnings about thunderstorms and strong winds from weather stations located within a radius of two hundred to three hundred kilometers around Moscow.

Rain on time is a blessing. Always. This cannot be said about severe downpours, when it seems as if the sky itself has opened up and water pours like a wall onto the ground. Yes, even if with hail. But they are especially dangerous in the tropics. It is even difficult for residents of temperate climates to imagine how abundant water they are there. With one tropical rain, as much water is often poured onto the ground as we get in several years.

In the northeastern part of India, in the Cherrapunji region, near the Himalayan mountains, is the rainiest place on Earth. An average of twelve and a half meters of precipitation falls here throughout the year. This means that if the rainwater that spilled here did not flow into the river and into the soil, it would cover the surface with a layer of this thickness.

There are many other places in India where rainfall is very heavy. Therefore, severe floods are very frequent on the rivers of this country.

Autumn 1978. As a result of heavy rains, the waters of the Ganges River flooded large areas. The houses of half the inhabitants of the city of Benares were flooded. There was a threat of an outbreak of epidemics - the bodies of the dead, who did not have time to be burned, were carried away by water (Hindus consider Benares a sacred city - they come here to die, they are cremated here). In Uttar Pradesh, India's most populous state, soldiers and emergency workers tried to reach hundreds of thousands of people cut off by flooding "the worst in living memory," Indian newspapers said. One hundred passenger trains were canceled - the railway track in many places was deep under water, and in other areas it was littered with fragments of rocks, stones, and covered with silt. The flood lasted more than a month and claimed over a thousand lives.

Nature presents similar surprises even to Australia, where almost two-thirds of the territory has a desert or semi-desert climate and where most rivers (and there are not many of them there) are channels without water. They are called "screams". But after the rains you can expect anything from them, even floods. One of these floods destroyed the city of Windsor.

One of the largest floods in the world, caused by tropical rain, is the flood in December 1887 in the Chinese province of Henan. It was a real disaster. The Yellow River overflowed its banks and broke through a huge dam near the city of Kaifeng, and everything that rose above the ground was mercilessly washed away. A large territory, equal in area to Holland, temporarily turned into a lake. Nine hundred people died...

The Chinese call the Yellow River the yellow beast, the river of disasters. Indeed, she often makes devastating raids on the earth. Where its dirty yellow waters raged, only ruins remain.

In general, catastrophic floods in China occur almost regularly. In July 1981, over three days, more than two hundred, and in some areas almost four hundred and seventy millimeters of rain fell across most of Sichuan province, southwest China. Streams of water from the mountains rushed into the Yangtze River and its tributaries, and they overflowed their banks. Twenty-five counties were under water, in some places its level reached five meters.

Thousands of dead, hundreds of thousands left homeless - this is the result of this latest atmospheric cataclysm.

It seems that similar catastrophes in the distant past could not but give rise to myths and legends about the flood, which were then interpreted by various religions in the spirit of their teachings.

global flood

The Bible did not ignore him either. This is how she substantiates both the flood itself and its terrible consequences: “And the Lord said: I will destroy from the face of the earth man whom I created, from man to beast, and every creeping thing, and the birds of the air, I will destroy: for I repented that I made them.”

Only Noah and his family were pleasing to God. According to God's instructions, the righteous man built an ark into which he was allowed to take “two and two of all flesh.”

The Bible goes on to say that it rained for forty days and nights. The flood began, and “the high mountains that are under the whole sky were covered.” All living things perished, except, of course, those who were in the ark. One hundred and fifty days passed, and the water began to recede. Noah's Ark stopped on the mountains of Ararat...

Historians have found that the biblical flood myth is, in fact, a retelling of more ancient sources. Almost the same legend, for example, is contained in one of the Assyrian legends, written down on clay tablets that were kept in the library of the Assyrian king Ashurbanipal (7th century BC). The Assyrians, in turn, retell the legend of the Sumerians, the most ancient people of Mesopotamia, who created the first writing here.

The Sumerian flood myth is part of the epic about Gilgamesh, the famous traveler, “who has seen everything, to the ends of the world, who has known the seas, who has crossed all the mountains.”

The hero of the flood myth in the Sumerian legend is the sage Ziusudra, called Utnapishtim in a later manuscript. Both names mean the same thing: “He passed through a life of long days.”

One day, the legend says, the god of fresh water and wisdom Za visits Utnapishtim at night and informs him of the gods’ decision to drown humanity. God recommends that he make an ark and load all his property and living creatures onto it. He builds an ark of rectangular shape and enormous size, which is launched with difficulty into the water. The ark had six tiers and was divided into seven parts, and its bottom into nine compartments. Utnapishtim loaded it with his gold, silver and domestic animals, as well as steppe cattle and animals, took all his family and relatives and, when the rain began, closed and tarred all the doors of the ark.

The following describes the flood. The wind, storm and rain continued for six days and seven nights. On the seventh day the storm subsided, the waters calmed down, and Utnapishtim saw: there was water all around, as far as the eye could see. After twelve miles (which probably ranges from eighty-four to one hundred and twenty kilometers), an island appeared, to which the ark landed. It was Mount Nitsir, now Pir Omar Gudrun, in the west of the Iranian Plateau, four hundred and fifty kilometers north of Shuruppak, within the southern Mesopotamia.

Utnapishtim released a dove, then a swallow, but they, not finding a dry place, returned. A raven, released later, saw that the water had receded and never returned. Then Utnapishtim left the ark and made a sacrifice to the gods.

The Sumerian myth is almost no different from the biblical one. A slight difference in details is quite legitimate, given that the Bible is separated from the Epic of Gilgamesh by at least one and a half millennia. During this period, much fell out of people’s memory, something was added and conjectured by later retellers.

So, the biblical legend widely known today is just a retelling of much more ancient folk tales. But was there really such a global flood? Is there any convincing confirmation of the main thing in this legend - that once heavy rains flooded all the land on the globe?

Alas, there is no such evidence. The opposite has been scientifically proven: such a global flood has never happened. Even in the most distant geological eras, when a warm climate reigned on the planet and many parts of modern land were covered by shallow seas (by the way, there was no modern animal world then, including, of course, humans), not all continents were flooded.

Another question is interesting here: aren’t the legend based on some real events, which were then incredibly exaggerated by religious fantasy and recorded in the sacred books?

Let us remember that the Sumerians lived along the middle and lower reaches of the high-water Tigris and Euphrates rivers. Here, in Mesopotamia, in Mesopotamia, long before Ancient Greece and especially Ancient Rome, arose ancient civilizations with high culture for that time. Many records have been preserved from them, made with special cuneiform signs on clay tablets. And when the information contained in them about the “universal flood” was studied in detail, some important details were revealed that were not in the biblical version of this legend.

Even in the last century, the Austrian geologist E. Suess drew attention to the fact that the Sumerian description of the flood mentions cracks that appeared in the ground. Later, historians found information here about a huge black cloud that moved in from the south before unprecedented downpours began. These and other data gleaned from cuneiform sources have allowed scientists to more clearly imagine the real picture of what happened here in Mesopotamia several thousand years ago.

Obviously, the flood occurred in the lower reaches of the Euphrates. It was a devastating flood caused simultaneously by a tropical cyclone and an earthquake, or more precisely, a seaquake - its source was at the bottom of the sea. With such earthquakes, huge waves are formed - tsunamis, which, having reached the low shores in these places, could cause terrible destruction (we'll talk about this later) and flood a large area on the plain. And then the earth “opened up” (cracks), which sometimes accompanies earthquakes. All this apparently led to such huge casualties that it left a long memory in the history of mankind.

But for all that, the catastrophe was not a “global flood,” but a phenomenon, an event of a local nature, although for the inhabitants of Mesopotamia it might have seemed like the end of the world. After all, according to the ideas of those who lived here then, Mesopotamia was both the beginning and the end of the whole world, the whole world.

By the way, the Sumerian myth speaks of only one flood. It is quite possible that there were several similar floods in these places. But in the minds of people of that time, who did not know or understand the causal relationships in nature, they merged into one thing - a punishment sent down to them from above for disobedience to the gods. In later religions, this idea of ​​retribution for sins, for unbelief and disobedience was further developed. Hence, apparently, the borrowing of the Sumerian myth by the ancient Jews and its inclusion in the Bible - in the Old Testament, which later became a holy book for Christians.

Supporters of the biblical version of the global flood, in order to prove its reality, refer to this.

that the legends of other peoples who did not live in Mesopotamia speak about a similar event. Even more than that - far from her, on another continent. Indeed, the legend of the Quiche Indians (South America, Guatemala) speaks of something similar. According to this legend, the god of fear Huracan (hence the word “hurricane”) decided to destroy all life on earth with water and fire. A large wave rose and overtook the people - because they forgot their creator and did not thank him, they were killed and drowned. Resin and tar from the sky. The earth was plunged into darkness, and heavy rains fell day and night. People climbed houses, but the houses collapsed and buried them; they climbed trees, but the trees threw them off their branches; they tried to hide in caves, but the caves were closed. Everyone died.

The tribes that inhabited Mexico in ancient times had a legend about how God destroyed the giants who lived there by flooding the land with water. The natives of Canada also talk about a terrible flood, when the water rose to the mountain peaks...

Well, maybe the global flood really is not a fairy tale? No! Legends about disasters, when many people died in water and fire, only say that floods - not global, but local - happened repeatedly at different times and in different places. And here one thing is certain: their causes were not supernatural, but completely natural - earthquakes and seaquakes, severe hurricanes and tsunamis.

“The same summer there will be a bucket...”

In the list of disasters associated with atmospheric life, there is a kind of antipode to high water levels - unprecedentedly severe droughts. In the chronicles of past centuries one can find many mournful records about this. “That same summer,” the Russian chronicler wrote in 1162, “there was great heat and great heat throughout the whole summer, and all kinds of life and abundance were on the hill, and the lakes and rivers dried up, the swamps burned out, and the forests and lands burned.”

Such droughts were accompanied by famine.

When drought years followed one after another, death decimated entire nations, and in many countries all life came to a standstill. And this was not only the case in the past. Nowadays, reports of severe droughts and the innumerable disasters they bring to people are not so rare. The peoples of several regions of Africa and Asia suffer especially greatly from them.

In 1972...1974, drought struck the countries lying on the southern border of the Sahara. In Senegal, Niger, Mali, Guinea-Bissau, and Upper Volta, hundreds of thousands of people died from hunger and thirst. More than three million head of cattle died. Less than ten years passed, and trouble came here again: for two years - 1980 and 1981 - not a drop of rain fell in the Sahara countries. The water from the wells has gone, the springs have dried up, and the lakes have become shallow.

These years were equally difficult due to drought in the countries of East Africa. All the way from Djibouti and Ethiopia to Uganda and Sudan, the earth was cracked by thirst and turned white. “This human tragedy is staggering,” newspapers wrote in 1980. – It’s even scary to think how many people die... The fate of individual people no longer affects anyone. Starvation threatens everyone.”

Twenty-five African countries have suffered such a tragedy...

Showers, rains, droughts... How much they mean for life on Earth, what a huge role they played in the fate of humanity in the past and continue to play now. It cannot be said that the dependence of people and their economic activities on the vagaries of the weather is now the same as it was before. But it is there, and quite significant. But people from time immemorial have dreamed of being free from it. Too much water is bad, too little is bad. The farmer, having sowed grain, wanted it to grow well, not to get wet, watered by endless rains, or not to burn out under the scorching rays of the sun. And he prayed to heaven for this, hoping for the mercy of the Almighty. Sometimes it seemed to him that the prayer had achieved its goal: blessed rain suddenly fell on the field sweltering under the heat. If the Almighty remained deaf and did not want to help, the farmer obediently blamed himself - with something, apparently, he had angered God... One lucky coincidence, that is, when the rain would have passed anyway and without prayer, spurred both the thoughts and feelings of the believers. The clergy cleverly took advantage of this.

And somewhere aside from the religious worldview, and even often in spite of it, gradually, observations accumulated from century to century - the basis of experimental knowledge, which took the form of signs. Practical people trusted omens more than prayers.

In fact, a sign is the same forecast, only compiled intuitively, “not according to science.” It may come true, or it may not come true. And not only because it was not compiled according to science, but mainly because nature is not immune from accidents. Therefore, even today, making a forecast is not a simple matter, although the scientific and technical equipment of a modern specialist working in this field cannot be compared with what people had in the past. Many factors must be taken into account, and many of them have not yet been studied or identified; not all relationships in nature have been revealed. It is necessary to process a gigantic volume of scientific information - it is so gigantic that it is almost impossible to cope with it without the help of electronic computers. And the result is a forecast, the reliability of which is not always, or rather, not one hundred percent guaranteed. This especially applies to long-term forecasts.

Increasing the reliability of the forecast is a task facing a complex of sciences studying global geophysical processes. Along with this, scientists hope to solve another, more radical one - learning to control the weather. Isn't this a baseless fantasy? “We live in an era when the distances from the wildest fantasies to completely real reality are shrinking with incredible speed” - these words of M. Gorky are confirmed by the entire course of the modern scientific and technological revolution. At first, this problem will be solved, apparently, on a limited scale - within a specific locality or region. A number of successful experiments give hope that this is quite achievable. Thus, by dispersing special substances in the atmosphere, it was possible, if necessary, to clear the sky (over the airport), or make a cloud rain, or accelerate and intensify the condensation of water vapor in the atmosphere with the formation of clouds...

The future will show what the solution to the problem will actually be.

Interesting facts about water.

The human body contains about 47 liters of water. It turns out that many of our organs contain a surprising amount of water. For example, muscles are 75% water, the liver is 70%, the brain is 79%, and the kidneys are 83%! But this body fluid is not pure water. In fact, it is a saline solution.

Riddles

1. I’ll look out the window; long Antoshka is walking

(Rain)

2.In the yard, in the cold - with mountain, and in the hut - with water

(Snow)

3. An eagle is flying across the blue sky.

Wings spread out

Covered up the sun

(Cloud)

4. It flowed, it was hot and easily under glass

(Ice on the river)

We are so accustomed to calling the planet we live on Earth, a globe, that we don’t even think about whether the person who first came up with this name made a mistake? But it’s really worth thinking about! What kind of globe is this if on its surface there is no more than 30%, and everything else is water: rivers, lakes, seas, oceans, swamps. And if the Earth could be straightened, made flat, like a table, then it would not be visible at all - it would all be hidden by a 150-meter layer of water. The globe... It would be more correct to call it a water globe, not a terrestrial one!

Water pollution.

With such a huge amount of water, people worry about its shortage! Is this legal?

The water of the Pacific Ocean alone will be enough for the needs of mankind for many years!

(Children may argue that the water in the oceans and seas is salty and is not suitable for human needs. Humans need fresh water.)

Is all fresh water safe for human health?

Tell us how people, without thinking, pollute the waters of rivers and lakes, seas and oceans.

The waters of the World Ocean are gradually becoming polluted by human waste. According to the World Environment Organization, humanity produces 20 billion tons of waste, and 85% of it is dumped into waterways.

It’s a shame to admit this, but humanity has long included rivers, seas and oceans in the sewerage system. Wastewater is most often discharged even without preliminary treatment.

The most amazing thing is that cleaning up human waste is not difficult - there are excellent technologies for this. But recycling costs money! Therefore, say, not very rich countries consider the construction of waste processing plants an unaffordable luxury.

Industrial and municipal waste is carried into the oceans mainly by rivers (Explain why) For example, hundreds of millions of tons of zinc, lead, copper, cadmium, mercury, and arsenic end up in the Arctic Ocean. All these poisons are deposited in the tissues of marine life. For example, North Sea cod in one mass sometimes contains up to 0.8 grams of mercury, which was absorbed into it from polluted water. It is estimated that after eating 5-8 of these fish, a person receives as much deadly mercury as is contained in a medical thermometer.

Accidents of oil ships have become a real scourge of the World Ocean. For example, in 1981, an English tanker crashed in the Lithuanian port of Klaipeda. 16,000 tons of fuel oil spilled into the sea. In the area of ​​the disaster, the thickets of special algae decreased 10 times

The main spawning grounds for herring. But it was an “ordinary” accident by world standards!

At the end of World War II, 170 thousand tons of toxic substances were sunk in the Norwegian fjords, and the coordinates of the burial site were... lost. The Norwegian authorities still cannot determine this place, but the poison can break out at any moment!

Water in oceans and seas, rivers and lakes, underground and in soil. On high mountains, in the Arctic, and Antarctica, water is found in the form of snow and ice. This is the water in solid state. Ice can be seen on our rivers and lakes when they freeze in winter. There is a lot in the atmosphere: clouds, fog, steam, rain, snow. Not all the water on Earth is located on the land surface. In the depths of the soil there are underground rivers and lakes

Without water, plants wither and may die. Animals, if deprived of water, quickly die: for example, a well-fed dog can live up to 100 days without food, and at least 10 without water.

Loss of water is more dangerous for the body than starvation: a person can live more than a month without food, but only a few days without water.

A person’s need for water, which he consumes with drinking and food, depending on the climate, is 3-6 liters per day.

WATER - a good friend and helper of a person. It is a convenient road: ships sail across the seas and oceans. Water overcomes drought, revives deserts, and increases the yield of fields and gardens. She obediently rotates turbines at hydroelectric power plants. Mineral spring water has a healing effect.

Rivers and lakes live thanks to their ability to cleanse themselves. So, for example, in 12 days in a river all the water is renewed, and in a lake mollusks and other small creatures pass the entire volume of water through themselves 6-8 times over the course of a year, thereby purifying it. But here, too, there is a limit beyond which a living system loses its ability to self-heal.

Here are some facts about the pollution of very large bodies of water and their consequences.

1. Thermal pollution is typical for large rivers, on the banks of which steelmaking or machine-building machines, heat and power plants are built. These enterprises use cold river water to cool industrial plants. They pour the water, which is fairly heated, almost hot, back into the river. This disrupts the temperature balance of the reservoir and overflows tropical viral diseases, valuable fish - salmon, trout, sturgeon - are dying. In muddy, green-smelling water, only a few species of fish survive - chub and roach. The Volga (show on map) is one of the rivers susceptible to thermal pollution.

2. About 150 million people live on the shores of the Baltic (show on map). Thousands of industrial enterprises work for their needs. As usual, they dump their waste into the sea. As a result, due to pollution, it is no longer possible to distinguish where there is fresh water and where there is salt water - they have all become poisonous. Baltic fishermen often come across cylinders of poisonous gas in their nets. They have been floating in the sea since the Second World War, many of them are damaged, which means that the deadly gas dissolved in sea water and had a destructive effect on environment. In the Baltic it is already possible to catch fish with a disfigured ridge, two heads or tails, and tumors on the body.

3. The Mediterranean Sea (show on the map) stretches between Africa and Europe. Until recently, coastal countries saw no end to tourists. Now the situation has changed. Sewage polluted the Mediterranean Sea so much that instead of having a good rest, people here began to suffer from gastrointestinal diseases.

4. Destructive human activity has not spared the Black Sea (show on map). Due to accidents on ships, the share of petroleum products in it in the area of ​​Tuapse (map) and Novorossiysk (map) is 9 times higher than the permissible norm.

Properties of water, Three states of water

Due to its fluidity, water can penetrate everywhere. Indeed, water is found almost everywhere on earth. There is a lot of it in the oceans and seas, less, but also a lot, in lakes, rivers, ponds and swamps. There is water underground too. If you start digging a well, you will find underground water at a depth of 7-12 meters (somewhere less, somewhere more).

Moreover, the entire soil is saturated with water. When digging a hole or digging up a garden, you discover that the soil is wet. It is not for nothing that in fairy tales and poems the earth is often called damp: “mother is the damp earth.”

An ordinary stone contains microscopic amounts of water in its smallest cracks. In living organisms - plants, animals and humans - it contains a lot of water. You may have heard that the human body consists of 8/10 water. Plants are 9/10 water. Water is essential for life. Without it, all living things die. For example, a person can live without food for several months.

Pure water is clear. If the water is not clear, it means that it contains some impurities, for example, silt. But some solids break down into such small particles in water that the resulting mixture remains clear. In this case, the substance is said to have dissolved in water, and the mixture is called a solution. We can say about water that it has a dissolving solution. To purify water (and not only water, but also other liquids) a filter is used. A filter is a device for purifying liquids. Water has no smell or taste. If the water has a taste, it means it contains some impurities.

The water is colorless. You ask: “What about the sea? Isn’t it deep?” The fact is that there is one more property of water: it can, like a mirror, reflect what it is in front of it (or, more precisely, above it). The sea is blue because the sky is reflected in it. Try the experiment at home. Resemble a large bowl or basin with water and try to see the reflection of surrounding objects and your own in it. It is better to look at the surface of the water not from above, but from the side, at an angle. Please note that the reflection does not prevent you from seeing the walls and bottom of the dishes behind it.

Water expands when heated and contracts when cooled. An alcohol thermometer is based on this property. The fact is that some part of the alcohol is water.

Water may evaporate. If water is heated to a temperature of 100 degrees, it boils and quickly turns into steam. But water can evaporate at lower temperatures. For example, if we place a saucer of water on the window of a room, after a few days all the water will disappear. We see that at room temperature water also evaporates, but much longer. Very cold water It also evaporates, although it takes even longer. When cooled, water vapor turns back into water.

Water may freeze. If water is cooled to 0 degrees, it quickly turns into ice.

If ice is heated to a temperature above 0 degrees, it will melt, that is, it will turn into water.

So, water in nature can be in three states: liquid, gaseous (steam) and solid (ice). Water can change from one state to another.

  1. Many fairy tales mention living and dead water. Does this really happen? In nature there are different types water. Ordinary water consists of oxygen and hydrogen. But if hydrogen is replaced by a heavier substance, deuterium, the result is so-called heavy water. In large doses it is called the death of the body. She can be called dead. Heavy water is an indispensable companion of ordinary water, but there is very little of it in natural water. There is almost 7000 times more potable water in natural water than heavy water, so you can drink it without fear. What kind of water can be called living? I'm melting. It contains less heavy water than water from a river or well. In addition, water formed from melted ice or snow for some time has a structure that is favorable to the life of the body. Animals and plants that receive melt water grow and develop faster than others. But there is one important condition! Melt water must be clean.

In the old days, people were interested in the question: “Where does rain come from?” What do you think?

Maybe there is also a sea, lake or river in the sky? People used to think so. But we know that nothing like that can happen there. Where does the water that pours from the sky come from? Before answering this question, let’s ask ourselves one more. You already know that water evaporates. Why hasn't all the water disappeared from the earth yet? There is one answer to these questions: because there is a water cycle in nature. The water that pours from the sky in the form of rain is the same water that previously evaporated from the earth's surface. You know that water can change from one state to another. It can turn into steam - evaporate or ice - freeze. Ice can become water again - melt. Water vapor, when cooled, turns into water. The ability of water to change from one state to another underlies the water cycle in nature. From the surface of oceans, seas, lakes, rivers and land, water evaporates and rises to the top. Water vapor cools in the air, turns into tiny droplets of water, snowflakes or tiny pieces of ice, collecting in clouds. In the clouds, these tiny droplets, snowflakes and ice flakes combine and fall to the ground in the form of rain, snow and hail. Rainwater, as well as water formed as a result of melting snow and ice, again ends up in rivers, swamps, lakes, seas and oceans. That's why they don't disappear. Water is always moving. First up, from earth to sky, in the form of water vapor, then down, from sky to earth, in the form of rain, snow or hail. And so again up, and again down, and so on for many millions of years.

What happens to water after it returns to earth as precipitation?

If rain fell, for example, over a sea or lake, it simply increased the amount of water in the sea or lake. What if above the ground? Some rainwater evaporates from the surface of the earth, but most of it is absorbed into the ground. What happens to such water? In order to answer this question, we must first know what the top layer of the earth consists of. And it consists of soil, sand and clay. The soil is located near the surface. Below the soil there is usually a layer of sand, and even lower there is a layer of clay.

What happens to rain and melt water absorbed into the ground? They easily seep through soil and sand, but clay holds them back. Water accumulates here and, if there is a slope, flows down. Sooner or later, on her way she will encounter a sharp drop in terrain, for example, a ravine or a deep depression. Groundwater will then appear on the surface of the earth. The place where groundwater naturally flows onto the earth's surface is called a spring or spring. The water flowing from the spring gives rise to a new stream. Streams merge together and form a river. Large, full-flowing rivers have a very modest beginning - small streams running from springs.

Puzzles

He has no arms, he has no legs

I was able to break out of the ground.

He us in the summer in the heat of the moment

Icy water gives water

(Spring)

Where the roots curl

On a forest path

small saucer

Hidden in the grass.

Everyone who passes

He will come, he will bend over -

And again they will gain strength on the road.

(Spring)

The pulse of our land

Pure, pure,

He hurries on his eternal journey,

To save the earth from thirst.

(Spring)

RIVERS

Streams flow from higher places to lower ones. At the same time, they connect with each other, forming a large deep stream. The more streams combine into one, the wider and deeper the resulting stream is. This is how streams form a river. A river is a water stream of significant size. A river differs from a stream in its greater width and depth of water flow. It is impossible to say exactly where the stream ends and the river begins. Sometimes it can be difficult to determine whether in front of us is a wide stream or a narrow river. But when the river becomes deep enough, no doubts arise. The river flows along the bed. A channel is a depression in the earth's surface along which a river moves. The channel is of natural origin and is usually made by the river itself. If you stand facing the direction of the river flow, then on the right there will be the right bank, and on the left – the left bank.

Both the river and the stream have a source. The source is the place where a water flow (river, stream) begins. The source of the stream is the spring from which it flows. What is considered the source of the river? After all, a river is often formed by several streams? In which case they are the source of the river. In some cases, you can tell exactly which spring the river originates from. Then this spring will be called the source of the river.

Each river has its own name (Moscow, Volga, Oka, Yenisei). Sometimes streams may have names. For example, Gremuchiy stream, Kholodny stream, Begunok stream.

It often happens that two rivers join into one. In this case, they say that one river flows into another. The river that flows into it is called a tributary, and the one into which it flows is called the main river. How to determine which of two rivers is a tributary and which is the main one? Usually the tributary is shorter than the main river. It is often narrow. What is the name of the river resulting from the confluence of two rivers? Sometimes it is new, but most often the name of the main river is retained. But the main river can meet a longer river on its way and become a tributary itself. The place where a river flows into another river, lake or sea is called an estuary. The mouth is the end of the river.

A river can be short, only a few tens of kilometers long, or it can stretch up to several thousand kilometers. If a river flows through a flat area, its flow is smooth, calm, and quite slow. In mountainous areas, river flows are turbulent, sometimes very fast.

In order for the river not to disappear, water must flow into it all the time. In both summer and winter, rivers are fed by groundwater coming from springs. These springs are located at its source and throughout the riverbed. In summer, a lot of water enters the rivers due to rain, in spring - due to melting snow.

So, a river is a large water stream flowing in a natural channel and having a source and an mouth. A stream is a small stream of water.

PUZZLES

No matter how you wind, where you wander -

Still he comes to the blue sea.

Even though the road is far,

But don't get lost

(River)

Shakes a little in the breeze

Ribbon in space.

The narrow tip is in the spring,

And the wide one is in time.

(River)

In winter I hide

I appear in the spring

I have fun in the summer

I go to bed in the fall

(River)

What road do they drive on for six months?

do they go for six months?

(River)

Lakes, ponds, swamps

Do you know what a lake is and what a pond is?

Lakes are large natural depressions on the land surface filled with water. Unlike rivers, lakes have neither a source nor an mouth, and the water in them does not flow anywhere. But this does not mean that the same water will remain in the lakes all the time.

Just like in a river, the water in the lake is constantly changing, one water leaves and another comes to replace it. Only in the river this change happens quickly, and that’s why we notice it. Then we say: “The river flows.” The water in a lake changes more slowly than in a river. We do not notice this change, so it seems to us that the water in the lake is motionless. In fact, some of the water gradually evaporates from the surface, while some is absorbed into the ground. Old water either evaporates from the surface of the lake or is absorbed into the ground. New water is brought by rivers and streams flowing into the lake, as well as rain and melting snow.

Lakes are of natural origin, that is, they were created by nature, not people. There are many natural depressions on the surface of the earth (natural, meaning not dug by people). Some of these depressions are filled with water from rivers, streams and springs, rain and melt water. This is how a river is formed. Lakes can be drained or drainless. Sewage lakes are those from which rivers flow; Rivers do not flow from drainless rivers. In drainage lakes the water is always fresh (unsalted), and in drainage lakes, with rare exceptions, it is salty. The water in a drainage lake is completely replaced within a few decades, and in a drainless lake within 200-300 years.

Lakes are our wealth. It is unacceptable to pollute the water in lakes, dump poorly purified water from factories and factories there, or wash cars in lakes. But, unfortunately, many lakes (as well as other bodies of water) are already polluted with harmful substances. In addition, there may be pathogenic microbes there. Therefore, you should not drink water from reservoirs. (At home on the album sheet there is a poster “Beware of the lake!”.)

It often happens that people dig a fairly large hole and fill it with water. This is how a pond turns out. Sometimes people fill existing natural depressions with water. In this case, you also get a pond. The important thing is that the pond is always created artificially. There is a third way to create a third pond - block the river with a dam. This is called “damming the river.” In this case, the pond is called a dam.

So - lakes are formed naturally, they are created by nature, ponds are created by people artificially.

PUZZLES

In the middle of the field

The mirror lies:

Blue glass,

Green frame

(Lake)

Young children look at him,

Color your own using scarves.

Young birch trees look at him,

Adjusting your hair in front of him.

Both the month and the stars - everything is reflected in it.

What do we call this mirror?

(Pond)

Not water, not land -

You can't sail away on a boat,

You can't get through it with your feet.

(Swamp)

Duckweed on top

And it’s tough to step on.

You won’t pass, you won’t swim -

You'll go around.

And you won’t drink water

With a bluish film.

(Swamp)

Everyone avoids this place.

Here the earth is

It's like dough

There are sedges, hummocks, mosses...

No foot support

(Swamp)

Oceans and seas

There are huge natural depressions filled with water. They are called oceans and seas. Open physical card peace. It takes on a blue color - these are all oceans. Oceans are huge expanses of water, very deep. The usual depth of the ocean is several kilometers. There are four oceans in total - several kilometers long. There are four oceans in total - the Pacific, Atlantic, Indian and Arctic. The sea is the part of the ocean that extends into the land, sometimes very far. These are the Mediterranean seas, which protrude less into the land, for example, the Barents and East Siberian seas in the north of our country.

How is the sea different from a lake? Firstly, seas are usually much larger than lakes. True, there are lakes that are larger than some seas. For example, Lake Baikal is larger than the Sea of ​​Marmara, and the African Lake Victoria is larger than the Sea of ​​Azov. Secondly, in the seas the water is always salty, and in the lakes it is usually fresh. Although there are lakes in which the water is salty. The main difference between a sea and a lake is that the sea is connected to the ocean either directly or through other seas. If we sail on a ship, we can always get from any sea to the ocean. Strictly speaking, being at sea, we are already in the ocean, since the sea is always part of the ocean. The lake is in no way connected to the ocean. The shores of the lake are closed. The only opportunity to sail from a lake to the ocean exists if a river flows out of the lake. For example, the Neva River flows from Lake Ladoga and flows into the Baltic Sea. But this does not make Lake Ladoga a sea. Even if a lake is connected to the ocean of a river, it remains a lake. Locate the Mediterranean, Aegean, Adriatic, Ionian, Tyrrhenian, Marmara, Black and Azov seas on the map. The Mediterranean Sea is called because it is connected directly to the Atlantic Ocean through the Strait of Gibraltar. The strait is not a river, it is part of the sea, part of the ocean. If this strait did not exist, the Mediterranean Sea would be considered a lake. The Aegean Sea is connected to the ocean through the Mediterranean Sea. The Adriatic, Ionian, and Tyrrhenian seas are also connected to them. Calculate how many seas you need to sail through to get from the Sea of ​​Azov to the Atlantic Ocean? Our country has the Caspian Sea. It is very large, the water in it is salty, so it was called the sea. However, this is a lake. Yes, yes, in fact, the Caspian Sea is just a lake, because it is not directly connected to any ocean. The Aral Sea is also a lake. That’s what they call them – Lake Caspian Sea, Lake Aral Sea. You may ask why the “sea” is kept in their name? Traditionally. Everyone is so used to these names that they don’t want to change them.

PUZZLES

Nobody salted, but salty

(sea)

Now blue, now green,

Now meek, now indignant,

Spread over half the earth.

Yachts and ships are friends with him.

And we are with you and him in the summer heat

I don't mind communicating all day long.

(sea)

wide in width,

Deeply deep,

Day and night it hits the shore,

You can't drink water from it,

Because it tastes bad -

And bitter and salty.

(sea)

OCEANS AND SEAS

There are four oceans on Earth. The largest of them is the Pacific Ocean. “Quiet” is just a name. In fact, the Pacific Ocean is often very rough. Why was he called Quiet? They say that when the first European travelers saw him, he was indeed very calm. This ocean occupies more than 1/3 of the earth's surface! He is also the deepest. It contains the so-called Mariana Trench, whose depth is 11,022 meters. The next largest and deepest is the Atlantic Ocean. It is half the size of the Quiet and occupies more than approximately 1/6 of the earth's surface. Its greatest depth is 8742 meters. The third largest and deepest is the Indian Ocean. It occupies about 1/7 of the earth's surface. Its greatest depth is 7209 meters. And finally, the smallest and shallowest ocean is the Arctic Ocean. It is named so because it is located around the North Pole of our planet and most of it is covered with ice. The Arctic Ocean occupies approximately 1/34 of the earth's surface. It is 12 times smaller than the Pacific, 6 times smaller than the Atlantic and 5 times smaller than the Indian Ocean. Its greatest depth is 5527 meters.

Each ocean has several seas. Sea is a part of the oceans that partially or completely (such as the Mediterranean) extends into land. The Pacific Ocean includes 13 seas, the Atlantic – 9, the Indian – 5, and the Arctic – 10 seas.

Glossary of terms

An endorheic lake is a lake from which no river flows. The water in almost all closed lakes is salty.

A swamp is an area with excessively moist soil, but without a continuous surface of water.

Raised bog is a bog covered with a layer of mossphagnum. The vegetation is poor; dwarf pines and lingonberries are occasionally found. Peat from high bogs is an excellent fuel, but a poor fertilizer.

A waterfall is a stream of water rapidly falling from a height.

Flow in - flow in, pour in (about the river).

The main river is a river into which another river (tributary) flows.

Frost is a thin layer of snow that forms on a cooling surface from water vapor.

Source is the place where a water flow (river, stream) begins.

A source (spring, spring) is a place where groundwater comes to the surface.

A key (spring, spring) is a place where groundwater comes to the surface.

The water cycle in nature is the evaporation of water from the surface of the Earth, the transfer of water vapor by winds, the condensation of water vapor and the formation of vapors and the formation of clouds, precipitation (rain, snow, hail) and their flow into rivers, lakes, seas and oceans.

A glacier is an ice cover up to several tens of meters thick.

Forest swamp is one of the types of swamps. Covered with basic or birch forest, a layer of moss and grass.

The sea is a part of the ocean that partially or completely extends into land, a body of water with bitterly salty water. If the sea extends completely into the land, it is connected to the ocean through the strait and other seas.

A lowland swamp is a swamp whose surface is covered with a thick layer of grass. Birch trees and willow bushes are sometimes found here; little moss. Peat from lowland bog - good fertilizer, but bad fuel (leaves too much ash - clogs the tanks).

Lake is a natural body of water located in the depressions of the land; fed by underground and surface waters.

The ocean is a huge, very deep space. There are 4 oceans on Earth - Pacific, Atlantic, Indian, Arctic.

A tributary is a river that flows into another river (the main one).

A pond is an artificial (that is, man-made) body of water in a natural or dug depression, as well as a dammed place in a river. (A dammed place in a river is also called a dam).

A river is a water stream of significant size, flowing in a natural channel and having a source and an mouth.

A spring is a place where groundwater comes to the surface

Dew is atmospheric moisture that is deposited during cooling in small water droplets.

A channel is a depression in the earth's surface along which a river moves. The channel has a natural origin, usually made by the river itself.

The stream is a small watery stream.

A drainage lake is a lake from which at least one river flows. The water in such lakes is never salty.

The quagmire is the most dangerous place in the swamp; a place where a swamp sucks in a person or animal that gets there.

Fog is opaque air containing a lot of water vapor.

Estuary – the place where a river flows into a sea, lake or another river.

A filter is a device for purifying liquid.

FOR THE CURIOUS

For the curious

  1. What property of water do you think mom uses when she washes dishes or does laundry? Water is a universal solvent. It can dissolve many substances.
  2. What kind of water is called mineral water? Groundwater dissolves salts that are in the ground. Therefore, mineral water is water that contains a solution of mineral salts. Such waters are often medicinal.
  3. Let's say we have a mixture of sand, salt and sawdust. How to separate them from each other using water? We pour the entire mixture into water, the sawdust floats to the surface, the salt and sand settle. We will remove the sawdust and stir the water until the salt is completely dissolved. Then we pass it through the filter, the sand will settle on it. We will boil the resulting saline solution and keep it there until all the water has evaporated. Since the salt does not evaporate, it will remain at the bottom of the vessel.
  4. Despite the fact that there is a lot of water on Earth, it is distributed extremely evenly. In Africa and Asia there are vast areas devoid of water - deserts. An entire country – Algeria – lives on imported water. Fresh water is also delivered by ship to some Greek islands. About 3 billion people around the world lack clean drinking water.
  5. A person consumes 60 tons of water per year just through nutrition. And 300 tons of milk goes to satisfy his other vital needs. Even the extraction of coal and oil cannot be done without water: for 1 ton of coal - 5 tons of water, for 1 ton of oil - 130 tons.

FOR THE CURIOUS

  1. Rain cools the air and clears it of dust. Therefore, in the summer after rain it is easier to breathe.
  2. If you open a window in a cold room, white clouds of fog appear in a warm room. What is this? These are tiny droplets of water. In a warm room is a large number of pair. When we open the window, the air in the room will cool and the steam will turn into tiny droplets of water, forming fog. Then we closed the window. The water droplets turned into steam again and the fog disappeared.
  3. If we bring a dry cold object into warm room, then droplets of water will appear on it. What kind of miracle? The air contains steam. The steam comes into contact with a cold object, cools down and turns into water droplets.
  4. Almost all solar energy falling on the earth is spent on evaporating water from the surface of reservoirs: oceans, seas, rivers, lakes. Every year thousands of cubic kilometers of water rise into the atmosphere. Approximately 1/3 of atmospheric water returns as precipitation to the ocean, and 2/3 falls on land.
  5. If all the water vapor contained in the atmosphere fell to the ground in the form of rain, a layer of water 1 meter thick would form on land. But, fortunately, not all atmospheric water vapor falls on the ground in the form of rain and snow.
  6. Academician A.P. Karpinsky called water “the most precious fossil.” Where is this fossil stored? Water is everywhere: in reservoirs, on high mountains, at the poles. About 1/5 of the soil is water. At a depth of up to 1 km. More than 4 million square kilometers of water are stored in the earth's crust. And above each square kilometer of the Earth's surface hangs on average about 20 thousand tons of water in the form of steam.

FOR THE CURIOUS

  1. Hot water flows from some springs. Typically, such sources are found in the vicinity of mountains, especially volcanoes. How is water heated? On the surface of the earth it is difficult to feel the internal heat of our planet. But at a depth of 2-3 thousand meters, the temperature of the rocks reaches 100 degrees. Water at such a depth heats up greatly, expands through cracks and cracks and flows to the surface.
  2. The moisture contained in the soil is completely renewed in 1 year.
  3. The average residence time of water in the atmosphere is on average 10 days. However, in different areas it can reach 15 days, and in the central regions of Russia - 7.

FOR THE CURIOUS

  1. In Altai there is a village - Raspberry Lake. This settlement arose next to a lake, the water of which looks like raspberries. The water has a crimson color because crimson-colored crustaceans live in abundance in it. In the Kuril Islands, on the island of Kumanshir, there is a lake with milky white water due to the presence of hydrochloric and sulfuric acids in it. In Indonesia, at the top of one of the active volcanoes there are three small lakes: one filled with bright red water, another blue, and the third milky white. Red Lake owes its color to the presence of iron in its water. In the other two lakes, hydrochloric and sulfuric acids are dissolved in different concentrations. There is Lake Gokcha in the Caucasus. The water near its shores is yellowish, further away it is blue, and in the middle it is dark blue. Many lakes of the southern Andes play with a variety of colors: sometimes blue and green, sometimes steel and pearl. There is an ink lake in Algeria. The quality of its ink water can be tested even on paper. Two rivers flow into this lake. The water of one of them brings a lot of iron salts. Water contains many substances formed in the soil during the decomposition of plants. These substances mix and produce ink liquid
  2. On the island of Java there is a lake that blows bubbles. Steam and gases rising from its surface blow bubbles up to one and a half meters wide. They fly into the air like balloons and burst with a loud crash.
  3. In the USA there is the Great Salt Lake. It's unbearably hot here. In summer, even boating is not fun. Water skiing is also risky: falling can lead to broken bones. After all, the water in this lake consists of ¼ of petrified salt.
  4. In the Urals, in the Chelyabinsk region, there is Lake Sladkoe. The water here is truly unusual. You can wash clothes in it, and oil stains are washed off even without soap. Studies have shown that a lot of soda is dissolved in the water of the “sweet” lake. It helps with washing and leaves a sweetish aftertaste.
  5. One frightening, albeit infrequent, phenomenon is observed in the swamps. A column of water 20-30 meters high rises noisily from the depths. It was methane that escaped from under the bottom silt - a swamp gas formed during the decay of plant sediments. Emissions of swamp gas are sometimes accompanied by powerful eruptions of mud. A description of a powerful swamp eruption in Ireland in 1896 has been preserved. The Great New Rathmore Swamp threw out a stream of mud several kilometers long, which flooded everything in its path. One house was flooded with mud along with people. We observed a large eruption in the century before last near Lake Onega. In one of the swampy water meadows, a fountain of mud, silt and sand 4 meters high erupted for several days. And then a spring appeared in this place.

FOR THE CURIOUS

  1. The word “ocean” comes from the Greek “okeanos” - “a great river flowing around the whole earth.”
  2. The world ocean is the water shell of the globe, covering most of its surface. The waters of the world's oceans are completely renewed on average every 3 thousand years.
  3. Sargasso Sea. Not a single navigator has yet managed to land on the shores of this vast, mysterious sea. Christopher Columbus was the first to discover this sea, completely covered with floating algae - sargassum. The shores of this sea are conventionally considered to be the strong currents of the Atlantic Ocean. The Sargasso Sea is rich in animal diversity. In calm weather, small crabs and shrimps scurry around the shaky Sargassum “islands”. Tuna, mackerel, and swordtails are circling above them. This sea also keeps many secrets. Many ships and planes ended up in the Bermuda Triangle, located in this sea.

Do the crossword puzzle.

Water condition

Horizontally:

  1. In the morning the beads sparkled,

They covered all the grass with themselves.

And we went to look for them during the day -

We search and search, but we won’t find it.

2) Grows upside down.

It grows not in summer, but in winter.

The sun will warm it up a little -

She will cry and die.

3) When all the flowers withered,

We came from above.

We are like silver bees

We sat down on a thorny tree.

Vertically:

3) There’s a mountain in the yard,

and in the hut with water.

5) Does not burn in fire,

does not sink in water.

6) Milk floated over the river,

There was nothing to be seen.

The milk has dissolved -

It became visible far away.

7) The golden bridge spreads out

Seven villages, seven miles.

In addition to lakes and ponds, on the land surface you can find another type of reservoir - a swamp. A swamp is an area with excessively moist soil, but without a continuous surface of water. Swamps usually form in lowlands where clayey soil does not drain water well. Swamps can be very marshy, and walking through a swamp is life-threatening. You can fall into a quagmire - the swampiest place in the swamp. The quagmire sucks in a person or animal that gets there and it is very difficult, and sometimes simply impossible, to get out of it without outside help. Sometimes a bog seems like a flat meadow, absolutely safe. But walking along it can lead to death. Cranberries grow in many swamps. People often go to swamps to buy cranberries. But you can only go on such a hike with a person who knows the area well. In addition, poisonous snakes are often found there. Therefore, you can go there in high boots so that the snake does not bite your leg.

Do the crossword puzzle.

Water condition

Horizontally:

  1. In the morning the beads sparkled,

They covered all the grass with themselves.

And we went to look for them during the day -

We search and search, but we won’t find it.

2) Grows upside down.

It grows not in summer, but in winter.

The sun will warm it up a little -

She will cry and die.

3) When all the flowers withered,

We came from above.

We are like silver bees

We sat down on a thorny tree.

Vertically:

3) There’s a mountain in the yard,

and in the hut with water.

5) Does not burn in fire,

does not sink in water.

6) Milk floated over the river,

There was nothing to be seen.

The milk has dissolved -

It became visible far away.

7) The golden bridge spreads out

Seven villages, seven miles.

Game “Water Can’t Spill”

Russian has many educated expressions related to water. For example, “like sinking into water” - disappearing without a trace; “like being dropped into water” - having a sad appearance, etc. Remember which expressions correspond to the following values.

1. Remain silent (Take some water into your mouth).

2. This is another way to say, it is unknown what the outcome will be. (Written on water with a pitchfork)

3. Guessed, predicted correctly (Like looking into the water)

4.Take advantage by taking advantage of other people's difficulties. (Catching fish in troubled waters)

5. Confuse others, deliberately create confusion in any issue. (Muddy the waters)

6. Be ready to do any act in the name of affection, idea. (Into fire and water)

7. About complete similarity. (As two drops of water)

8. You won’t get anything, it won’t matter. (Like water off a duck's back)

9. Avoid deserved punishment. (Come out dry from water)

10. Distant relative. (Seventh water on jelly)

11. A lot of unnecessary things. (Much water)

12. Do some useless work. (Drag the water in the mortar)

13.Live from hand to mouth, live in poverty. (Sit on bread and water.)

14.Hide all traces of the unseemly deed. (And ends in water)

15. Much time has come. (A lot of water has passed under the bridge)


A LETTER RECEIVED TO THE EDITOR

“WHEN IT RAINS, MY FRIEND PUT BUCKETS AND PANS UNDER THE GUTTERS AND COLLECTS THE RAINWATER. SHE WASHES THE LINEN WITH IT AND WASHES HER HAIR. BUT THERE'S A LOT OF TALK ABOUT ACID RAIN NOW, AND I'M NOT SURE MY FRIEND IS DOING THE RIGHT WAY. IS IT POSSIBLE OR NOT TO USE RAINWATER IN THE FARM?

Sincerely, V. G. Smolko, Donetsk region

An employee of the Research Institute of Hygiene named after F. F. Erisman of the Ministry of Health of the RSFSR, Candidate of Biological Sciences Elena Fedorovna GORSHKOVA, answers the reader’s question:

Let's first understand what rainwater is. Its main source is moisture evaporating from the surface of reservoirs and moist soil. The masses of water accumulating in the atmosphere are enormous: one cloud can contain hundreds of tons of water. They continuously move above the surface of the earth, redistributing not only heat and moisture, but also solids - various chemical elements, their salts, dust. An ordinary raindrop weighing 50 milligrams when falling washes 16 liters of air, and one liter of rainwater absorbs impurities contained in 300 thousand liters of air.

Thus, the composition of rainwater depends on the area over which the clouds formed, on air pollution where precipitation falls, on the direction of the wind and other circumstances.

The air, and therefore rainwater, is polluted primarily by transport, industrial and agricultural enterprises.

Motor transport “supplies” carbon monoxide, nitrogen and sulfur oxides into the atmosphere, and various industrial enterprises - arsenic, lead, and mercury compounds. In agricultural areas, the air is polluted with ammonia, carbon disulfide, pesticides, and pesticides. And this is not a list of all the substances that can return to the earth from the atmosphere along with rain.

The largest percentage of industrial emissions are sulfur and nitrogen compounds. When they react with water in the atmosphere, they turn into acids and fall to the ground in the form of so-called acid rain.

The term “acid rain” was introduced about a hundred years ago by the English chemist A. Smith, who identified the relationship between the level of air pollution and the acidity of precipitation. But their harmful consequences began to appear only 10-15 years ago. Today

almost all rain is “acidic” to one degree or another.

If he catches you on the road, open your umbrella or... put on a raincoat. Repeated exposure of the skin to rainwater can cause redness and flaking due to the acids contained in the precipitation.: accelerate the corrosion of metal structures, destroy sandstone, limestone, marble, acidify the waters of rivers and lakes, soil, which leads to the death of fish and forests.

In modern conditions, rainwater cannot be used for household purposes: you cannot wash your hair with it or wash clothes, as they did before, when the air was not so polluted. Moreover, you cannot drink rainwater, wash dishes with it, or cook food with it.

Most of our planet is covered with water. Oceans and seas make up three-quarters of the earth's surface, which also contains countless rivers and lakes. Snow and ice on mountain tops are also frozen water. A significant portion of the earth's water is found in the atmosphere. Each cloud contains thousands and sometimes millions of tons of water in the form of evaporation. From time to time, these vapors turn into water and fall to the ground as rain. Even the air we breathe contains a certain percentage of moisture. In other words, no matter where you are, you will definitely find water. Indeed, the room you are in at the moment contains from 40 to 50 liters of water. Look around! Don't you see her? Raise your eyes and look carefully at your arms, legs, body. 40-50 liters of water - that's you!

In fact, the human body is approximately 70% water. The cells of the body contain a large number of different substances, but none of them are as important as water. Water makes up the majority of the blood circulating in your body. And this is true not only for people: most of the body of all living beings is water. Without water, life is impossible.

Water is a substance created to become the basis of life. Every physical and chemical property uniquely designed for life.

Or here’s an amazing fact: all liquids freeze from the bottom up, and only water, on the contrary, freezes from the top down. This is the first unusual property due to which water exists on the surface of the earth and ice floats on water. But, think about it, if not for this property, most of our planet would be encased in ice, and life in its seas, lakes, ponds and rivers would be impossible; every winter the life of the seas and oceans would die out.

There are many places in the world where winter temperatures drop below 0 degrees, and sometimes significantly lower. The water in seas, lakes and other bodies of water cools, and part of it freezes. If the ice did not have the ability to float, it would sink to the bottom, and warmer layers of water would rise to the surface. When they come into contact with air whose temperature is below 0, they will also freeze and sink to the bottom.

This process will continue until there is no liquid water left. However, this does not happen. Instead, as water cools, it becomes heavier until it reaches 4º - at which point everything changes and it begins to expand and become lighter as the temperature drops. As a result, water with a temperature of 4º C remains at the bottom, above it is water with a temperature of 3 ° C, 2 ° C, etc. And only on the surface the water temperature reaches 0ºС, and there it freezes. But only the surface layer of water freezes; under the ice, the rest of the water remains in a liquid state, which makes it possible for underwater creatures and plants to live.

Note that the fifth property of water - the low thermal conductivity of ice and snow - is a critical part of this process. Due to low thermal conductivity, layers of ice and snow retain the heat of the water and prevent it from escaping into the atmosphere. As a result, even at very low temperatures, down to -50°C, the thickness of ice in the seas is never more than one to two meters. In addition, there are a lot of cracks in it, which makes it possible for seals and penguins living in polar regions to get to the water under the ice.

Let's think about what would happen if the water behaved “normally”, i.e. if, like all other liquids, the density of water increased with decreasing temperature, and the ice sank to the bottom.

In this case, the process of freezing of oceans and seas would begin from the bottom and spread upward, because there would be no layer of ice to retain heat. All lakes, seas and oceans of the Earth would turn into solid ice, on top of which there would be a layer of water only a few meters deep. Even if the air temperature increased, the ice at the bottom would never melt completely, and therefore life could not exist there. With dead seas, life on Earth would also be impossible.

But why does water behave “abnormally”?! Why does it suddenly begin to expand at 4ºC after contracting, i.e. Did you do what you were supposed to do? No one has yet been able to find an answer to this question.

Water is not only ideally suited for life, moreover, there is exactly as much of it on the planet as is necessary for normal life. It is quite obvious that such correspondences, the significance of which science was able to realize only in the twentieth century, cannot be an accident, but are the result of a purposeful, highly intelligent design.

Life on Earth, created for humans, is possible thanks to water, created specifically to serve as the basis for human existence and biological life in general. The Almighty Creator gave us life-giving water; thanks to the unique properties of water, according to His command, all living things grow, which nourishes us and supports our life.

The abstract on the discipline “Study of the Atmosphere” was completed by student of group EPb-081 Chinyakova A.O.

Checked by: Ph.D., Associate Professor Ryabinina N.O.

State Educational Institution of Higher Professional Education "Volgograd State University"

Volgograd 2010

In the atmosphere, water exists in three states of aggregation - gaseous (water vapor), liquid (raindrops) and solid (crystals of snow and ice). The water content in the atmosphere is relatively small - about 0.001% of its total mass on our planet. Nevertheless, this is an absolutely irreplaceable link in the natural water cycle.

The main source of atmospheric moisture is surface water bodies and moist soil; In addition, moisture enters the atmosphere as a result of evaporation of water by plants, as well as the respiratory processes of living beings. Calculations show that if the entire volume of water vapor in the atmosphere were condensed and distributed evenly over the surface of the globe, it would form a layer of water only 25 mm high. Much more rain falls as a result of the rapid circulation of the total supply of atmospheric moisture.

L. Amberge supplemented this statistical classification with a biogeographic classification.

1. Desert climates, with irregular precipitation: equatorial climates (coast of Peru), tropical (southwest Africa, southern Arabia), with noticeably distinct seasons of precipitation (Sahara, northern California, eastern Turkestan).

2. Climates of non-desert regions: intertropical with or without a dry season, extratropical continental and Mediterranean (with numerous variations), subpolar and polar.

It is very difficult to determine the index of aridity, or dryness, on which a number of authors worked, including E. de Martonne, Thornthwaite, Banyul and Gossen, Amberge.

Clouds and water vapor absorb and reflect excess solar radiation, and also regulate its entry to Earth. At the same time, they block oncoming thermal radiation coming from the Earth's surface into interplanetary space. The water content in the atmosphere determines the weather and climate of the area. It determines what temperature will be established, whether clouds will form over a given area, whether rain will come from the clouds, whether dew will fall. As it cools, it condenses, clouds form, and at the same time a huge amount of energy is released, which the water vapor returns to the atmosphere. It is this energy that makes the winds blow, carries hundreds of billions of tons of water in the clouds and moistens the surface of the Earth with rain. A complete renewal of the composition of water in the atmosphere occurs in 9...10 days.

Evaporation consists of water molecules breaking off from the water surface or moist soil, moving into the air and turning into water vapor molecules. In the air they move independently and are carried by the wind, and their place is taken by new evaporated molecules. Simultaneously with evaporation from the surface of soil and reservoirs, the reverse process also occurs - water molecules from the air pass into water or soil. Thus, atmospheric moisture is the most active link in the water cycle in nature.

The source of energy for the water cycle is solar radiation. The average annual energy is approximately 0.1-0.2 kW/m2, which corresponds to 0.73-1.4 million calories per square meter. This amount of heat can evaporate a layer of water from 1.3 to 2.6 m thick. These figures include all phases of the cycle: evaporation, condensation in the form of clouds, precipitation and all forms of impact on animal and plant life.

The main amount of water vapor is concentrated in the lower layers of the air shell - in the troposphere, at an altitude of up to several thousand meters, and almost the entire mass of clouds is located there. In the stratosphere (about 25 km above the Earth), clouds appear less frequently. They are called mother-of-pearl. Even higher, in the mesopause layers, at a distance of 50...80 km from the Earth, noctilucent clouds are occasionally observed. It is known that they consist of ice crystals and occur when the temperature in the mesopause drops to - 80 oC. Their formation is associated with an interesting phenomenon - pulsation of the atmosphere under the influence of tidal gravitational waves caused by the Moon.

Despite their apparent lightness and airiness, clouds contain a significant amount of water. Air in which the number of evaporating water vapor molecules is equal to the number of returning molecules is called saturated, and the process itself is called saturation. The water content of clouds, that is, the water content of water in 1 m3, ranges from 10 to 0.1 g or less. The higher the air temperature, the more water vapor it can contain. Thus, 1m3 of air at a temperature of +20 °C can contain 17 g of water vapor, and at a temperature of -20 °C only 1 g of water vapor. Since the volumes of clouds are very large (tens of cubic kilometers), even one cloud can contain hundreds of tons of water in the form of drops or ice crystals. These gigantic water masses are continuously transported by air currents over the Earth's surface, causing a redistribution of water and heat on it. Since water has an exceptionally high specific heat capacity, its evaporation from the surface of reservoirs, from the soil, and the transpiration of plants absorb up to 70% of the energy the Earth receives from the Sun. The amount of heat expended on evaporation (latent heat of vaporization) enters the atmosphere along with water vapor and is released there when it condenses and forms clouds. As a result, the temperature of water surfaces and the adjacent air layer noticeably decreases, so near bodies of water in the warm season it is much cooler than in continental areas that receive the same amount of solar energy.

The mass of clouds and water vapor contained in the atmosphere also significantly influence the radiation regime of the planet: with their help, excess solar radiation is absorbed and reflected, and thereby to a certain extent regulates its flow to the Earth. At the same time, clouds screen counter heat flows coming from the Earth's surface, reducing heat loss into interplanetary space. All this makes up the weather-forming function of atmospheric moisture.

Atmospheric precipitation, together with temperature, are the main climatic elements on which animals and vegetable world, as well as the economy of the inhabited zones of the globe. Precipitation is extremely uneven throughout the year. In equatorial regions, the largest amount of them falls twice a year - after the autumn and spring equinoxes, in the tropics and monsoon regions - in summer (with almost complete rainlessness in winter), in the subtropics - in winter. In temperate continental zones, maximum precipitation occurs in summer. The importance of precipitation is so great that some authors use only this single element to characterize climate: desert climate is characterized by precipitation of less than 12 cm per year, dry climate - precipitation from 12 to 25 cm, semi-dry - from 25 to 50 cm, moderately humid - from 50 to 100 cm, wet - from 100 to 200 cm and very wet - more than 200 cm.

The distribution of precipitation over the surface of the globe is basically as follows: very heavy precipitation (from 1.5 to 3 m per year) falls between 0 and 20° latitude, where there is one rainy season and one dry season; almost complete absence of precipitation is observed in the desert zone; precipitation of 400 to 800 mm falls between 30° and 40° latitude; there is little precipitation at high latitudes (70°).

Atmospheric moisture, in addition to the transfer of water and heat, also performs other, no less important functions, the essence and significance of which began to be studied quite recently. It turns out that the water contained in the atmosphere is actively involved in the transfer of masses of solids. The wind lifts soil particles into the air, removes foam from sea waves, and carries away tiny droplets of salt water. In addition, salts can enter the air in molecularly dispersed form, due to the so-called physical evaporation from the surface of the ocean. Therefore, the ocean can be considered the main supplier of chlorine, boron and iodine for the atmosphere, rain and river waters.

Thus, rain moisture, being in the cloud, already contains a certain amount of salts. During powerful circulation processes occurring in cloud masses, water and particles of salts, soil, dust, interacting, form solutions of a wide variety of compositions. According to Academician V.I. Vernadsky, the average salt content of the cloud is about 34 mg/l.

Dozens of chemical elements and various organic compounds are found in raindrops. Leaving the cloud, each drop contains an average of 9.3 * 10-12 mg of salts. On its way to the Earth, in contact with atmospheric air, it absorbs new portions of salts and dust. An ordinary raindrop weighing 50 mg, falling from a height of 1 km, “washes” 16 liters of air, and 1 liter of rainwater takes with it impurities contained in 300 thousand liters of air. As a result, with every liter of rainwater, up to 100 mg of impurities enter the Earth. Of the total amount of dissolved substances carried by rivers from the continents to the ocean, almost half returns back with precipitation. At the same time, for every square kilometer of the earth's surface there are up to 700 kg of nitrogen compounds alone (in terms of pure nitrogen), and this is already a tangible fertilizer for plants.

Sediments of coastal areas contain especially high levels of salts. For example, in England, rain with chlorine concentrations of up to 200 mg/l was recorded, and in Holland - up to 300 mg/l.

It is interesting to note that the function of rain as a carrier of mineral compounds and nutrients cannot be reduced to a simple calculation: so much fertilizer added means such and such an increase in yield. V.E. For many years, Kabaev traced a direct connection between the size of the cotton harvest and the amount of water in precipitation. In 1970, he came to an interesting conclusion: the stimulating effect of rain on crops is apparently caused by the presence of hydrogen peroxide in it. The normal content of H2O2 in precipitation (7...8 mg/l) is sufficient for atmospheric nitrogen to bind into compounds that enrich plant nutrition, the mobility of elements in the soil (primarily phosphorus) improves, and the process of photosynthesis is activated. Having established this function of rain, the scientist considers it possible to artificially deliver hydrogen peroxide to plants by adding it to the water when spraying.

Air humidity is characterized by several indicators:

Absolute air humidity is the amount of water vapor contained in the air, expressed in grams per cubic meter, sometimes also called elasticity or water vapor density. At a temperature of 0 °C, the absolute humidity of saturated air is 4.9 g/m3. In equatorial latitudes, absolute air humidity is about 30 g/m3, and in the polar regions - 0.1 g/m3.

The percentage ratio of the amount of water vapor contained in the air to the amount of water vapor that can be contained in the air at a given temperature is called relative humidity. It shows the degree of saturation of air with water vapor. If, for example, the relative humidity is 50%, this means that the air contains only half the amount of water vapor that it could hold at that temperature. In equatorial latitudes and polar regions, relative air humidity is always high. At the equator, with heavy clouds, the air temperature is not too high, and the moisture content in it is significant. In high latitudes, the air moisture content is low, but the temperature is not high, especially in winter. Very low relative humidity is typical for tropical deserts - 50% and below.

With the slightest drop in temperature, air saturated with water vapor is no longer able to contain moisture and precipitation falls out of it, for example, fog forms or dew falls. At the same time, water vapor condenses - passes from gaseous state into liquid.

Fog is a form of condensation of water vapor in the form of microscopic drops or ice crystals, which, collecting in the ground layer of the atmosphere (sometimes up to several hundred meters), make the air less transparent. The formation of fogs begins with the condensation or sublimation of water vapor on condensation nuclei - liquid or solid particles suspended in the atmosphere.

Fogs of water droplets are observed mainly at air temperatures above −20 °C, but can also occur at temperatures below −40 °C. At temperatures below −20 °C, freezing fogs predominate.

Fogs in populated areas are more often than away from them. This is facilitated by the increased content of hydroscopic condensation nuclei (for example, combustion products) in urban air. The highest number of foggy days at sea level - an average of more than 120 per year - is observed on the Canadian island of Newfoundland in the Atlantic Ocean.

According to the method of occurrence, fogs are divided into two types:

Cooling fogs are formed due to the condensation of water vapor when the air is cooled below the dew point.

Evaporation fogs are evaporation from a warmer evaporating surface into cold air over bodies of water and wet land areas.

In addition, fogs differ in the synoptic conditions of formation:

Frontal - formed near atmospheric fronts and moving with them. Air saturation with water vapor occurs due to the evaporation of precipitation falling in the front zone. A certain role in the intensification of fogs ahead of fronts is played by the drop in atmospheric pressure observed here, which creates a slight adiabatic decrease in air temperature.

Intramass - predominate in nature; as a rule, they are cooling fogs, formed in homogeneous air masses. They are usually divided into several types:

Radiation fogs are fogs that appear as a result of radiation cooling of the earth's surface and the mass of moist surface air to the dew point. Typically, radiation fog occurs at night in anticyclone conditions with cloudless weather and a light breeze. Radiation fog often occurs under conditions of temperature inversion, which prevents the rise of the air mass. After sunrise, radiation fogs usually dissipate quickly. However, in the cold season, in stable anticyclones they can persist during the day, sometimes for many days in a row. An extreme form of radiation fog, smog, can occur in industrial areas.

Advective fogs are formed due to the cooling of warm, moist air as it moves over a colder surface of land or water. Their intensity depends on the temperature difference between the air and the underlying surface and on the moisture content of the air. These fogs can develop both over the sea and over land and cover vast areas, in some cases up to hundreds of thousands of km². Advective fogs usually occur in cloudy weather and most often in the warm sectors of cyclones. Advection fogs are more persistent than radiation fogs and often do not dissipate during the day.

Sea fog is advective fog that arises over the sea during the transfer of cold air to warm water. This fog is evaporation fog. Fogs of this type are common, for example, in the Arctic, when air flows from the ice cover to the open surface of the sea.

Haze is a very faint fog. In haze, the visibility range is several kilometers. In the practice of meteorological forecasting, the following are considered: haze - visibility more/equal to 1000 m, but less than 10 km, and fog - visibility less than 1000 m. Heavy fog is considered when visibility is less than or equal to 500 m.

Fogs also include the so-called dry fogs (haze, haze), in these fogs the particles are not water, but smoke, soot, dust, and so on. The most common cause of dry fogs is smoke from forest, peat or steppe fires, or steppe loess or sand dust, sometimes lifted and carried by the wind over considerable distances, as well as emissions from industrial enterprises.

The transitional stage between dry and wet fogs is not uncommon - such fogs consist of water particles along with fairly large masses of dust, smoke and soot. These are the so-called dirty urban fogs, which are a consequence of the presence in the air of large cities of a mass of solid particles emitted during combustion by chimneys, and even more so by factory chimneys.

The fog water content indicator is used to characterize fogs; it denotes the total mass of water droplets per unit volume of fog. The water content of fogs usually does not exceed 0.05-0.1 g/m³, but in some dense fogs it can reach 1-1.5 g/m³. In addition to water content, the transparency of fog is affected by the size of the particles that form it. The radius of fog droplets typically ranges from 1 to 60 µm. Most drops have a radius of 5-15 microns at positive air temperatures and 2-5 microns at negative temperatures.

Dew is a type of atmospheric precipitation formed on the surface of the earth, plants, objects, roofs of buildings, cars and other objects.

As the air cools, water vapor condenses on objects near the ground and turns into water droplets. This usually happens at night. In desert regions, dew is an important source of moisture for vegetation. Quite strong cooling of the lower layers of air occurs when, after sunset, the earth's surface quickly cools through thermal radiation. Favorable conditions for this are a clear sky and a surface covering that easily gives off heat, such as grass. Particularly strong dew formation occurs in tropical regions, where the air in the ground layer contains a lot of water vapor and, due to the intense nighttime thermal radiation of the earth, is significantly cooled. At negative temperatures, frost forms.

The temperature at which water vapor in the air saturates it and condensation begins is called the dew point.