The sun radiates energy in all directions. The amount of this energy is very large. Part of it reaches the Earth.

On the path of solar energy to the surface of the Earth is the atmosphere. It absorbs some of the energy, transmits some to the earth's surface, and reflects some back into space. The atmosphere absorbs about 17% of energy, reflects about 31%, and transmits the remaining 52% to the Earth's surface.

It should be understood that when it is said “absorbed and reflected” by the atmosphere, it means not only that this is done by the air, but also by clouds, dust particles, and more.

The solar energy that passed through the Earth's atmosphere and reached its surface is predominantly absorbed by this very surface. If all the energy that reaches the Earth from the Sun is taken as 100%, then 48% is absorbed by the surface. The remaining 4% (52% that passes through the atmosphere minus 48%) is reflected from the Earth's surface.

When the atmosphere lets you through Sun rays, it hardly heats up. But the surface of the Earth that they reach heats up. As a result, the surface already becomes a source of heat for the atmosphere, and therefore the lower layers of the troposphere have a higher temperature than those lying above. This can be observed in the mountains, when the air temperature decreases with altitude, and there may be snow and ice on the tops of the mountains, although at the bottom there may be summer temperatures.

The reasons for the change of seasons become relevant for each person. Already in childhood, the child begins to ask questions. Why does winter come? What is happening to our planet? Why in different countries different climate?

The first and main explanation is to create optimal climatic conditions for human habitation. Temperatures across the planet are becoming comfortable for living.

What does astronomy say about the changing seasons?

Spring, summer, autumn, winter are eternal and unchangeable natural phenomena. The reason for such natural phenomena the movement of the globe becomes outer space. The Earth moves in a conventional orbit, which has the shape of an elongated circle.

Unfortunately, many people still live by stereotypes school programs, where the explanation for why winter comes was the approach and distance of the planet from the Sun during its movement.

Astronomers have long refuted this theory and claim that the change occurs due to the axis of rotation of the planet. It is tilted by 23 degrees, so the sun's rays heat different parts of the Earth unevenly. different time.

Why is it very cold in winter?

The Earth's orbit around the sun takes 1 year or 365 days. During the entire movement, the planet rotates along its conventional axis, which becomes

When the north turns towards the Sun, it receives maximum amount rays, while in the south such rays will fall “casually” onto the earth’s surface.

Autumn and winter are those periods of time when the Earth is at its maximum distance from the Sun. The day becomes short, and the sun shines, but does not warm.

The minimum amount of heat from the celestial body is explained simply. The rays fall to the surface obliquely, the sun does not rise high above the horizon, so the warming of the air will be slow.

What happens to air masses in winter?

When the air temperature drops, evaporation decreases and air humidity changes. When the concentration of water vapor in the atmosphere decreases, the ability to trap heat on the Earth's surface is also reduced to a minimum.

The transparent atmospheric mass of air is not capable of absorbing infrared radiation, which heats the air and the surface of the earth. Why is it cold in winter? Only because the surface and air cannot retain heat, which is already supplied in minimal quantities.

What's the sun like in winter?

It is extremely important to explain to children about the sun and its changes in winter. Here the emphasis should be placed on the fact that the Sun is a huge, hot star around which a large number of planets revolve.

The sun has an enormous temperature; no person or aircraft can approach it, as it will simply melt and destroy them.

Thanks to solar energy and rays, life is possible on planet Earth: trees grow, animals and people live. Without solar heat all living things will die in a short period of time.

Solar energy and rays in winter do not heat as intensely, but can cause more damage to the skin. This feature has a logical explanation: the entire surface of the planet, which should reflect the rays, is light and mirror-like, since it is covered with snow. The human body cannot reflect; it receives ultraviolet rays and is actively saturated with them. Doctors emphasize that tanning in winter is more dangerous than in summer. The skin is oversaturated with ultraviolet radiation from the sun and can even get burned.

Why winter comes can be explained to children and adults by knowing the basics of astronomy. But what does winter nature conceal in itself, what Interesting Facts Are winter known to science and people?

  • Snowflakes. Scientists have repeatedly studied snowflakes that fall to the surface of the earth. Such work requires special training, equipment and scrupulousness. The discovery for people was that snowflakes can have 7 types: star crystals, needles, columns, columns with tips, transparent dendrites, snowflakes of irregular shape.

  • Speed ​​of snow mass. For many, snow is a soft, airy substance, but large quantities snow mass, it can descend from the surface of the earth in the form of an avalanche. The minimum speed of such an avalanche is 80 km/h, the maximum is 360 km/h. A huge mass of snow destroys everything in its path. If a person falls under an avalanche, he dies due to the enormous weight or lack of oxygen.
  • For most of the world's population, the question of why winter comes is not relevant. They don’t even know that there may be a sharp change in air temperature, the readings will drop below 0, and it will snow. In some kingdoms of hot countries, they organize games on artificial snow made of sugar to amuse their subjects.

Why does winter come? Every child asks this question sooner or later. Using the material presented, every parent will be able to answer this question easily and interestingly.

The sun illuminates the earth. It shines even when we cannot see it behind the clouds. The cloudiest day is still a day. And only when the sun disappears behind the horizon, night and darkness sets in. this web page

The sun warms our earth with its rays. Its warmth penetrates even through the clouds. And on the cloudiest day it is still warmer than at night. When the sun disappears below the horizon, the air begins to become fresher, and by the end of the night it usually cools down greatly. This means that light and heat depend on the sun. But why doesn’t the sun always heat equally? We all know: in the morning it heats weakly, during the day it bakes strongly, and in the evening it heats less again. The same can be observed at different times of the year. In winter, the rays of the sun, even on the clearest day, provide little warmth. In the spring they begin to warm up more strongly, and in the summer they become so hot that people try to hide in the shade.

Maybe during the day the sun is closer to the ground, which is why it warms more? Maybe it comes closer to us in the summer and moves away in the winter? No, this cannot be. After all, the earth rushes around the sun at almost the same distance from it.

From all this we can conclude: the rays of the sun heat most strongly when they fall vertically (at a right angle); they heat less if they fall obliquely (under acute angle). They provide the least amount of heat when they slide along the surface of the earth. This happens in the morning and evening when the sun stands low above the horizon.

The sun is the main source of life on planet Earth. It is the closest star to us. Others are located so far away that their light reaches us only after millions of light years. And if the Sun stops emitting its energy, all life on the Planet will definitely die.

Surely each of us at least once asked the question: “Why, in fact, in the summer we sunbathe from sunlight, but in the winter the same light is not able to even melt the ice a little?” So, let's figure it out.

How the Sun works

Studying the Sun is a very difficult task. It is impossible to send to him aircrafts, as they will simply burn out. But modern science There are many other ways to study an object that is far away, but at the same time emitting colossal energy. The distance to the Sun from Earth is 150 million km. It is this distance that allows life on our Planet to exist comfortably.

The diameter of the Sun's core reaches 175 thousand kilometers. The temperature inside the star is 14 million degrees Kelvin, and it is caused by thermonuclear reactions. We can say that this is a kind of nuclear furnace. All the heat originates in the core of the star, which then passes through several shells:

  • the photosphere is the first layer above the core, but the energy of the deeper layers does not reach here;
  • spicules are regular emissions from the next layer of the Sun;
  • The corona is the outermost shell of a star.
Interesting: prominences form in the corona. It is this shell that causes solar wind, which extends to the most remote corners solar system.

Visible light and solar energy are infrared rays and ultraviolet light, as well as electromagnetic waves, radiation and x-rays.

Important! All these waves reach the Earth and other planets of the solar system and in a certain way influence them, and especially those of them where there is an atmosphere.

Effect of rays

All living things are influenced primarily by UV rays. It is from their intensity that the ozone layer protects our Planet. The effect of ultraviolet rays on living organisms is manifested in the following:

  • they help ensure that metabolic processes occur in the human body;
  • thanks to this radiation, vitamin D is produced in the body, and without it normal human life is impossible;
  • blood flow increases;
  • tan appears.

UV rays also have a positive effect on the atmosphere. They cleanse it and make it more favorable for life. Infrared rays also have a thermal effect. Thanks to them, the surface of the Earth is warm. But although these rays affect the atmosphere, there are times when their influence becomes minimal.

In winter the sun warms less

In winter, the Sun does not heat as intensely, but this phenomenon can be explained from a scientific point of view. There is a decrease in the amount of solar heat reaching the Earth for the following reasons:

  • The Sun is located very low above the horizon, so the rays travel a longer path through the atmosphere;
  • In the morning and evening, for the same reason, it is not so hot, but in the evening it gets cold;
  • cold wind shortens the period of warmth that the Sun can give us;
  • In winter, the days are shorter and the nights are longer, which means that the period when infrared rays can affect the atmosphere is greatly reduced.
Also of no small importance is the fact that in winter the surface of the earth is covered White snow, which perfectly reflects the sun's rays, so the overall surface temperature decreases.

As we can see, although the Sun shines in winter, you can’t expect a tan from it.

The earth is heated by the sun. But why is it cold in winter even on sunny days? Everyone will tell you why our summers are warmer than our winters. Firstly, the sun warms us hotter in summer than in winter. Secondly, in summer the sun warms us every day longer than in winter, since our summer days are much longer than winter ones. But the sun shines and warms all day; although on cloudy days we do not see the sun in the sky and do not feel its hot rays, but even then the sun is in the sky, it shines and warms; only it itself is hidden behind clouds and fog.

It is not entirely clear, however, why the sun is hotter in summer than in winter. To explain this to yourself, you need to remember how the sun warms at different times of the day.

The sun is hottest during the day, when it is high in the sky. On the contrary, the sun is very weak in the early morning, when it has just risen and is still not high above the ground; The sun doesn’t give much heat even in the evening, when it’s ready to set.

Therefore, the point here is in the height of the sun: the higher the sun is, the more it heats. In fact, when the sun stands high above us and shines from above, as at noon, then its hot rays strike directly into the earth; they pour on us like rain. And when the sun is low in the sky, level with the earth, as at sunrise or sunset, then the rays from the sun go flatly, do not hit the ground, but fly over the ground, so that no matter how much heat the sun gives, almost all of this heat passes by us.

Now let's see what happens here in winter and summer. In winter, in December, our sun rises late and sets early. And in the summer, in June, our sun rises very early and sets late in the evening: it shines and warms in summer almost three times longer than in winter.

For this reason alone, our earth should receive more heat from the sun on a summer day than on a winter day.

But this is not enough. In summer, the sun rises above the ground much higher than in winter. Therefore, more hot rays fall from it to the ground.

But where does such terrible cold come from in winter that your hands freeze and instead of rain it snows? To do this, let's remember what happens on summer nights? As soon as the sun sets, the ground becomes cold, fresh dew settles on the grass, and in the morning, just before sunrise, a noticeable chill is already felt. In the month of August, when the nights become longer, there are even frosts in the morning, so that the ground and grass are covered with frozen frost.

This means that the earth cools down greatly at night, and the longer the night, the more the earth cools down by morning.

In winter the nights are much longer than in summer. Even in the fall, in the month of September, night is compared with day. From September to December, the nights become longer and the days shorter. At the beginning of December the nights are the longest. They are twice as long as a day. For a long time winter nights the earth is getting colder and colder, the cold is getting stronger; and then in January we experience the most severe, Epiphany frosts.