A message about why it is raining. How to explain to a child why it rains? That is, the reason for everything is global weather changes

Every person has encountered this natural phenomenon. We have all hidden from the rain under umbrellas many times and have long been accustomed to checking before a walk whether there are any clouds in the sky. And the most curious are sure to ask the question, where does this rain come from?

Where does water for rain come from in the sky?

It turns out everything is very simple. Under the influence of the sun's heat, tiny droplets of water evaporate from the Earth's surface. These droplets are very small, almost invisible to the eye, such small droplets are called water vapor.

Water evaporates from the leaves of trees, from the surface of the earth and even from the surface of our body. Most water, of course, evaporates in the form of steam from the water surface of rivers, lakes, seas and oceans.

Evaporation over water can be seen in the early morning when steam begins to form droplets directly above the water. You can also see such steam when the kettle is boiling.

Rising higher and higher, the steam enters the cold layers of the atmosphere and collects into water droplets and tiny pieces of ice. After all, the temperature at the top, where the clouds gather, is about zero degrees. The wind collects droplets into huge fancy clouds. You can see before the rain how white clouds gather into a cloud and darken before your eyes. This is because such a large amount of water collects in the sky that it does not allow sunlight to pass through.

It happens that droplets freeze due to low temperatures and, together with raindrops, fall to the ground. It's hailing.

The droplets in the cloud connect with each other, become heavier and begin to fall to the ground. So it starts to rain.

Why does it rain more often in autumn?

It rains in Russia in autumn even less often than in summer. According to weather forecasters greatest number precipitation falls in June. And in the fall because large quantity cloudy days It seems to us that autumn is rainy.

In winter, evaporating water vapor does not even have time to form droplets, but immediately turns from steam into fluffy snowflakes. Yes, yes, snowflakes are formed from steam. And then instead of rain in winter it snows.

Now you know how water gets into the atmosphere and why it's raining. Once on the soil in the form of rain or snow, the water goes into The groundwater, into the seas, oceans, rivers, lakes, and other bodies of water, and it all starts again and again. This a natural phenomenon called the water cycle in nature.

Without such a water cycle, our planet would turn into a lifeless desert.

You can even set up a small water cycle at home. To do this, cover with a transparent lid and put on fire. You will see how the steam will rise and settle on the lid in the form of droplets. And the drops will fall down, only to rise up again, turning into steam. Such wonderful rain in a pan.

> Why is it raining?

How is rain formed?– description for children and adults: why it rains on Earth, diagram of the water cycle, amount of precipitation, rain on other planets.

Rain brings joy to farmers in the heat and sadness to melancholic people. You're glad to see him if you can't stand it anymore summer heat and get angry if you had to go shopping. However, why does it rain at all and how is it formed on the planet?

Let's start with the fact that rain is a liquid type of precipitation. Here you can’t do without deciphering the water cycle. It all starts with the Sun evaporating water from various bodies of water, provided that the air temperature is above 0°C. The steam then rises into the atmosphere, where it condenses into water droplets. Their weight makes them fall to the ground again.

This is the well-known water cycle in nature. It is often used to describe the journey of a liquid from bottom to top and back again. For the appearance of rain, two points are important: saturation and coalescence.

Saturation

In this process, invisible water vapor condenses on microwave particles, creating tiny droplets. Usually this criterion is conveyed under the guise relative humidity– percentage of total number water vapor that can persist at a certain air temperature.

The amount of water vapor retained before saturation (100% humidity) and transformation into a cloud depends on its temperature level (the warmer, the more).

Merger

This process occurs when the air becomes saturated. Then the water droplets begin to merge to create larger ones (occurs due to turbulence in the airspace).

They combine until their weight breaks through the air resistance and they fall as rain. It is important to understand that rain is the main source fresh water for many countries and also provides the necessary conditions in various ecosystems.

Measurement

In order to record the amount of precipitation, special rain sensors were invented. Most often, they are represented by two cylinders (like a nesting doll) filled with water. The internal one is filled first and transfers water to the second. The remaining precipitation in the outside gives overall rating in millimeters.

There is also a clinometer, and the cheapest option is a cylinder with a measuring stick. Precipitation is also monitored by weather radar.

Changing of the climate

Of course, climate changes, like global warming, greatly influence the usual amount of precipitation. Increased emissions carbon dioxide increased the mark average temperature Worldwide. This means that much more water has evaporated.

Over the past century, precipitation north of 30° has increased, but in the tropics it has decreased. It may be noted that the Northern and South America, Northern Europe and Asia have become wetter. But the drought has intensified in Africa and southern Asia.

Rain on other planets

Yes, we are not the only world where it rains. In our solar system there is wet precipitation, although it has virtually no connection with water. For example, on Venus it rains all the time, but you wouldn't want to walk under this stream made of sulfuric acid!

It forms high in the atmosphere, where the wind accelerates to 360 km/h. But the droplets immediately evaporate because the surface is heated to 460°C. On Saturn's moon Titan, this is methane rain. It generally has an active hydrological cycle, where hydrocarbon takes the place of water.

Recently we received even more amazing curiosities. Liquid helium rain can occur on Saturn and Jupiter. It is believed that due to the colossal pressure, “diamond sediments” are present on all gas giants. And it's not a joke. The planets contain methane, which when pressurized forms diamonds.

And another fascinating case is coronal solar rain. This occurs during a coronal mass ejection, during which the plasma cools and falls to the surface. Even whole splashes are created.

Rain is one of the most common weather phenomena. However, not everyone knows why it rains, even though teachers gave this information in elementary school. The global water cycle begins with heat. Under the scorching rays of the sun, liquid evaporates from the surfaces of reservoirs, rivers, seas and oceans. It turns into steam and rushes upward. In countries with high humidity, small bubbles can be easily noticed.

Reasons for appearance

The sciences that study any type of precipitation are called meteorology and climatology. They identify 4 main reasons:

1. Elevated landforms.
2. Ascending movement of air masses.
3. The presence of water vapor, which contributes to the formation of precipitation in the form of rain.
4. Meeting and interaction of cold and warm air flows.

You can conduct a small experiment at home and see clearly how the global water cycle occurs.

To do this, you need to take a small container, fill it with water and put it on the fire to boil. The pan must be covered with a transparent lid. As the liquid heats up, it will begin to turn into steam, and small droplets will begin to accumulate on the surface of the lid, and then fall back into the pan of boiling water and turn into steam again.

Rising movements

The sun's rays heat the earth, and the process of moisture evaporation begins. This happens not only with soil, but also with water surfaces. The evaporated liquid is in the air. According to the laws of physics, warm air moves to the upper layers of the atmosphere along with the water bubbles it contains.

Basic physical concepts - absolute humidity (the amount of steam that is currently contained in the air) and relative humidity (in relation to the humidity that is observed at a given temperature). The hotter the air, the more water vapor it contains.

All air currents contain moisture, but the higher it rises, the lower the air temperature becomes. It begins to condense and clouds appear in the sky. When the temperature reaches its lowest point and the cloud is no longer able to hold the amount of moisture it contains, it begins to rain.

The process is similar to what happens with ascending air masses. The rule of precipitation formation only works if the water bubbles have somewhere to come from - from a leaf plate, water surface, freshly plowed soil, etc.

But if a person is, for example, in the Sahara Desert, Sun rays will not cause rain, since the moisture has nowhere to come from.

Yesterday it poured, today it pours, on last week I never left the house without an umbrella. The forecast for next week is wet. This is summer, right? I'm calling with this question to the head of the situation center of Roshydromet, Yuri Varakin.

- Yuri Evgenievich, what’s wrong?

In the second half of June, we in Moscow and the Moscow region, of course, exceeded the norm for precipitation. Well, now let's add it. So what to do? A powerful cyclone is located north of Syktyvkar and with its waves gives heat on one side and increases precipitation on the other. It is rainy not only in the Central zone, but also on the upper Volga, in the northern Urals, on Black Sea coast Caucasus. Gelendzhik, Tuapse, Sochi, Adler are also under the rain.

- But this was not the case in previous years! What's happening?

It doesn't happen year after year. This time, unconventional conditions arose in our country due to the fact that the previous few weeks there had been abnormal heat over the entire Western Europe from England to Spain and Germany. They have heat, we have rain and cold. In theory, at the peak of summer in Moscow, the average daytime temperature should be 25 degrees and above, but now it’s 15 degrees and rainy.

Usually cyclones come to us from the south or south-west - and bring heat. But the heat is “stuck” in Europe. And cyclones from the northeast began to make their way towards us, pumping in moisture and cool air. However, they cannot get further. In the region of Kazakhstan and the Volga region there is a blocking process. That's why all the moisture pours out here.

This is, of course, not good for vacationers. But for agriculture it’s a plus. The soil, reservoirs, and groundwater. Last summer and at the beginning of this season there was a moisture deficit.

- But there is a feeling of a universal flood...

Yes, as long as it rains. But so far the July climate norm has not been exceeded. July typically receives 30 percent more precipitation than June. In general, it’s too early to say that everything is flooded.

- Can we already say that this summer will also be anomalous - due to the heat in Europe, due to the rain here?

This is usually what happens - if somewhere is empty, it means somewhere is dense. For now, we can definitely say only that the scenario of 2010, when there was incredible heat for a long time, it was dry, fires were blazing, will not happen again. The moisture that forests received in June and the first ten days of July is enough to avoid drought and other similar disasters.

In general, we assume that the temperature in the first half of July will be only 1-1.5 degrees below normal. In the second half of the month, there may be days with temperatures above normal. So, on average, July 2015 will not stand out much compared to other years. Although in the last 4-5 years this July will indeed be one of the coldest and rainiest.

- Did last June fit within the standard framework?

Less than 1 percent of precipitation fell in the first half of June. And in the second - 140 percent. In general, it turned out to be 120 percent of the norm. It's not catastrophic either.

In July, one third of the monthly precipitation has fallen so far. But now it's only the 12th. And there will still be rain. Moreover, it will be watered with different intensity - there will be days when no more than 1-2 millimeters of precipitation will fall, and it may rain so much that 20 millimeters will accumulate in a day. The current climate change is characterized by very uneven precipitation.

- So the reason for everything is global weather changes?

Yes. But they do not lead to the fact that the whole world is immediately flooded or to the fact that everywhere immediately becomes warmer.

On the contrary, according to all classical theories of climate change in the Northern Hemisphere, blocking processes occur more often. And they lead to long periods of either dry or rainy weather.

If earlier cyclones moved from west to east for 5-6 days - and after 5 days the sun was shining again, now there may be no rain for a very long time, and then it rains for three days, or even a whole week, and immediately falls around the monthly norm of precipitation.

And further. If earlier temperature contrasts in summer between the frontal zones were 5, maximum 7 degrees, now the temperature is very short term may drop from 32-35 degrees to 12-15 degrees, as was the case in Siberia. And in the Moscow region, just recently it was 30-35, but now the temperature does not exceed 18 degrees.

- Again, everything will be blamed on human activity?

Of course, the anthropogenic factor influences the processes. But the main reason is that in the Northern Hemisphere the average daily temperature is rising much more at a fast pace than in Yuzhny. Plus – the area of ​​forests is decreasing, the desert area is increasing. All this affects climate change in the regions.

- Can we say that the next years will be unusual?

At meetings with employees of the Ministry of Emergency Situations, power engineers, specialists in agriculture we say that in the next 10-15 years we need to be prepared for climate change. And many countries are already restructuring their programs. India, for example. China is building or planning to build dams to provide itself with water. Moreover, on transboundary rivers that feed our territory. In particular, together with Mongolia a dam can be built on one of large rivers feeding Lake Baikal.

In the next 10 years, the main geopolitical struggle will unfold not for oil, but for water, for fresh resources.

The processes that we see now are just the tip of the iceberg.

Answer from Oksana[guru]
The sun warms the water in the ocean, in the sea, in the river, in any puddle.
The water evaporates, turns into transparent steam and rises upward, to where warm air currents carry it along with them, because warm air is lighter than cold air, it always tends to rush upward.
Light water vapor rises higher and higher from the sun-heated earth, it climbs high, to where it constantly, even in the hottest summer day, very cold, like winter.
The steam is warm, and when it touches cold air, it turns into tiny droplets of water.
The droplets are light, like fluff, they stay in the air perfectly, soar and move all the time, because everyone is pushing them; new and new streams of warm air rising from the ground.
Warm air throws droplets even higher, cold air drags them down; So they fly, tiny travelers, now up, now down; they dance, merge together, become larger.
There are very, very many of them, and all together they form a cloud.
At the top of the cloud the droplets freeze - it is very cold there; they turn into pieces of ice, grow, become heavier, and now they can no longer stay in the cloud and fall down. And when they fall, they melt, because it’s much warmer below; They become droplets of water again, merge together - and it rains on the ground.
It rains because there is water
Constantly strives for the ground.
Because it's already cold
And in heaven someone can't sleep.
Because when I fell in love with you,
I got lost among three pines,
Because, not loving warmth,
Sad autumn has arrived.
The author of the poems, unfortunately I don’t know who...

Answer from Elena Maksimova[newbie]
When heavy black clouds gather in the sky, people say: “It will rain.” More often than not, it actually starts. But where did the clouds come from, and why does it rain from them? The reason for all this is the Sun. It heats the surface of the planet and the water in the oceans, lakes and rivers turns into steam. It mixes with air.
Rising warm air spreads water vapor into the atmosphere. Cooling down, the air gives up part of its load, and invisible water vapor becomes water again. Clouds form from its droplets. This process, the opposite of evaporation, is called condensation. Inside the cloud, tiny droplets gradually grow, collecting more and more moisture. Finally, the drops become so large that they can no longer be held aloft by air currents and fall to the ground in the form of rain.
Throughout the day goes by evaporation. Water vapor rises into the atmosphere. But in order for it to turn into clouds consisting of tiny droplets, solid particles are also needed on the surface of which the steam could condense. If there are no or very few dust particles or ice crystals in the air, condensation may not occur.
This is how events develop on a warm summer day, when in the morning the sun shines in the bright sky, and in the afternoon the clouds thicken and rain pours on the ground, sometimes a strong but short shower. These are local rains. Long, lingering rains, lasting two to three days, or even a week, bring powerful air vortices- cyclops. Residents of the European plain are showered with water that has evaporated from the surface. Atlantic Ocean. By determining the speed of movement of the cyclone, meteorologists can predict the time of onset of rainy weather.
Have you ever wondered why it rains? Who is crying there in heaven? Maybe someone is feeling bad there at this moment? It's so bad that I can't hold back my tears. And they drip to the ground, falling from the cheeks of an angel sitting on a gloomy gray cloud... Do you know why there are different types of rain? In summer, angels are happy, and their tears appear only from happiness. That's why it rains when the sun shines. And it is reflected in their eyes. And from these highlights we get a rainbow.
And by autumn, the angels begin to feel sad, they cry more and more often and hide their eyes in the clouds... Then the tears fall to the ground sadly, quietly... This is the autumn rain. In winter, angels begin to feel sad without love... And tears, falling from their eyes down to the ground, turn into snowflakes, cold, prickly... Here they are... different rains...
Source: link

Answer from Vitaly Norokh[newbie]
water evaporates, water drips. simple

Answer from User deleted[active]
and in the high layers of the atmosphere, steam condenses into water and falls to the ground - it’s simple

Answer from Anna[guru]
Rain is the result of a complex and long-term process involving the sun, earth and air. First the earth is warmed by the sun. As a result, the water of the oceans, seas, lakes, as well as the moisture contained in the soil, turns into water vapor. This steam is then mixed with air. This is how the evaporation process takes place.
And then, together with the lighter warm air, water vapor rises high into the sky, where it cools and turns into clouds. This process is called condensation.
What happens next to the water vapor inside the clouds? The tiny droplets of water contained in the clouds gradually grow, absorbing more and more moisture. Finally the drops become so heavy that the air currents are unable to hold them, and they fall to the ground as rain. That's why it rains.
The process of water evaporation occurs almost around the clock, and water vapor rises. But it doesn't rain every day. Invisible couples do not always turn into visible ones raindrops. This is explained by the fact that a certain surface is required for the condensation process to occur. If there are few or virtually no dust particles in the air, then condensation does not occur. Snowflakes and ice crystals that are high in the clouds contribute to the condensation process.
If warm and cold air currents collide in the atmosphere, it will most likely result in rain. Warm air contains a lot of moisture, which is cooled by cold air currents. Invisible vapors turn into heavy drops of water, which fall to the ground.