Why is it so much warmer in summer than in winter? Why is it cold in winter? Reader on why it is hot in summer and cold in winter.

Line UMK E. V. Saplina. The world (1-4)

The world

Geography

Why is it cold in winter and warm in summer?

“Why is it hot in summer?” - this children's question is very relevant, given the time of year. In winter, it will be replaced by another - “Why is it cold in winter?”, accompanied by an attempt to warm frozen palms through mittens. In our new column “Why” we will regularly answer in clear and in simple language to the most interesting questions of preschoolers and schoolchildren.

“Why is it hot in summer and cold in winter?” - this question is asked by both preschoolers and schoolchildren. It would seem, well, what is the difficulty: the tilt of the axis, the rotation of the earth, the Sun... But when you try to explain to a child, you begin to get confused yourself.

Answer to the question: the reason is the angle of the Earth's axis

Our planet Earth moves around the Sun, and the Earth's axis itself is located at an angle to the plane of this movement.

Around the Sun, the Earth rotates in an elliptical orbit, close to circular, at a speed of about 107,000 km/h in the direction from west to east. Average distance to the Sun 149,598 thousand km

Due to the elliptical shape of the orbit, the distance between the Earth and the Sun varies. The closest point in orbit to the Sun is called perihelion - at this moment the star is approximately 147 million kilometers away. The farthest is called “aphelion” - 152 million km. A 3% difference in distance results in about a 7% difference in the amount of solar energy the Earth receives while in those orbital locations.

But the main thing is that it is not the distance that changes, but angle of incidence of sunlight on the surface,- that’s why there are seasons.

The planet's axis forms an angle of 66.56° with the orbital plane. Accordingly, the equatorial plane forms an angle of 23.44° with the ecliptic plane.

If it were not for this tilt, then day and night anywhere on Earth would be the same in duration, and during the day the Sun would rise to the same height throughout the year.

The tilt of the Earth's rotation axis. Source: wikipedia.org

3 Geographical Reasons for the Change of Seasons

Seasonal changes in the length of daylight hours: in summer the days are long and the nights are short; in winter their ratio is reversed.

Seasonal changes in the height of the sun at midday above the horizon. In summer in temperate latitudes at noon the Sun is closer to the zenith than in winter, and therefore the same amount of solar radiation in summer is distributed over a smaller area earth's surface.

Seasonal changes in the path length of solar rays in the atmosphere affect the degree of their absorption. The Sun located low above the horizon gives less heat and light than the Sun located high, closer to the zenith, since the sun's rays in the first case overcome a thicker layer of the atmosphere.

The textbook for grade 2 continues the new integrated course “The World Around us.” The main goal of the textbook is to give initial information about Earth and Space: from mythological ideas of ancient people to modern scientific ideas. The UMK includes an electronic application posted on the website of the Drofa publishing house, as well as workbook For independent work students and Toolkit containing thematic planning and comments on all course topics.

The equator does not move away from the Sun, is there no winter and summer there?

Yes. There are no seasons at the equator because it is always at the same - and close - distance from the Sun. During the calendar year, the sun's rays at the equator fall vertically (at right angles) onto the earth, warming the surface and the air above it well. In fact, it is always summer there. And the closer to the equator, the longer the summer and the shorter the winter.

Contest

This time we will not ask you to calculate anything, as we did in the material “Why is the sea salty?” Send us to social media your “whys”: this could be a question that worried you as a child, or it could be a question that a child or student recently asked. Among all participants we will choose the 3 most interesting questions and reward their authors with book prizes!

Everyone knows from school that our planet rotates both around the Sun and around its own axis - an imaginary line connecting two poles - north and south. This arrangement of things affects the changing seasons and time of day.

If you ask the question why it is cold in winter, the most common answer will be: the Sun has moved away from the Earth to the maximum possible distance. There is some truth in this statement, but only partially, because other factors also influence the change of seasons.

Causes of cold weather in winter

Distance

In the process of rotation, our planet actually approaches the star and then moves away. The maximum distance at which two celestial objects are located (at aphelion, if we speak in scientific terms) is 152.1 million km, the minimum (in scientific terms it will be “at perehelion”) is 147.1. The formation of this opinion was influenced by the fact that the Earth has a spherical shape and moves in orbit in the form of an oval. When the surfaces of the planet and star move away, the sun's rays stop delivering their heat and therefore the temperature drops. North hemisphere finds itself in this position between December and February.

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Short day

But the arrival of cold weather is influenced not only by the distance between the Sun and Earth. The axis of our planet is tilted relative to the orbit, the angle of which is 23.5 degrees. The North Pole is always directed towards a star called Polaris, which causes the Earth to tilt towards the Sun for 6 months and the same period of time for the deviation of the planet from the star. Thus, the angle of inclination removes the surface, making the day shorter. The sun's rays simply do not have enough time to warm the Earth.

Change in the atmosphere

In addition, the Sun rises less high in the sky. The combination of two facts results in a decrease in temperature, which leads to a decrease in evaporation. The concentration of water vapor is the main criterion for heat retention at the surface; its decrease leads to the escape of heated air into space. A decrease in temperature causes better dissolution in the atmosphere of carbonic acid, which can absorb infrared radiation. When its proportion decreases, thermal radiation occurs faster.

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Winter and summer in different parts of the planet

In the northern hemisphere it is winter, in the southern hemisphere it is summer. And vice versa. This happens because for one half of the year the northern hemisphere of the Earth tilts towards the Sun, and for the second half it deviates. That's why some celebrate the New Year and Christmas holidays when it's cold, while others celebrate it when it's hot.

But there is also such a thing as geographical zones. And the climate varies depending on the distance separating it from the equator - the conventional line dividing the planet into the northern and southern hemispheres. The equator is perpendicular to the Earth's axis of rotation, so the angle of inclination is not decisive. The temperature in the regions passing along this conditional line is approximately the same throughout the year and is equal to 24-28 degrees with a “+” sign. This part of the land receives more heat, light and solar radiation, because the rays fall at right angles.

If you are interested in this question and are looking for an answer to this question, then after reading this article you will definitely find the answer.

Why is it so cold in winter?

The temperature in winter directly depends not on the distance of the planet to the Sun, but on the angle of inclination of the Earth. The tilt axis of our planet passes through 2 poles: South and North. While the angle of inclination moves the Northern Hemisphere away from the Sun, the days become shorter, the sun's rays fall less on the earth's surface and warm it up worse. As a result of such phenomena, winter comes.

Why is it so hot in summer?

In summer, everything happens the other way around - the North Pole is at a very close distance to the Sun, due to this, it receives maximum amount sun rays, the day becomes longer, the air temperature increases. As a result of such phenomena, summer comes.

Why is it so much warmer in summer than in winter? In summer, the sun's rays hit the Earth perpendicularly, due to this, solar energy is more concentrated and warms the soil faster than usual, so it is very hot in summer. In winter, these same rays do not fall perpendicularly to the earth's surface; they glide without warming up either the soil or the water. The air does not heat up and remains just as cold. In summer, the flow of solar energy is much greater than in winter, then it weakens and becomes smaller.

(short correct answer: because the earth's axis is tilted, and therefore much more light falls on one of the hemispheres than on the other, and they smoothly change places after six months)

I was once asked this question during an interview (for a programmer).
Despite the fact that I studied at the physics department of Moscow State University, I did not know the answer.
So he said: “mmm... I don’t know.” Everyone was still surprised, like no one had answered like that before.
It seems they didn’t take me there, or didn’t write to me later, I don’t know, that was a long time ago.

I came home, started googling, researching, and discovered the answer to this seemingly simple, but in fact simply wonderful and brilliant in its simplicity question.

It turned out that they can have fun testing people: watching how a person will behave when you ask him this question, and in public, so that others can hear, but not be able to interfere.

It has long been known that logic does not work for a person: everyone only adjusts and shuffles the facts so that at the end they can concoct those answers, decisions and conclusions that best suit him and will not cause him cognitive dissonance that he is not is right, that he is bad, that he is weak, that he made a mistake, that he was deceived, that he was mistaken, and the like.
And those around them perceive the persuasiveness of a speech almost entirely on emotions, and not on facts: it doesn’t matter what kind of nonsense the speaker will utter, if at the same time he looks adequate and “respectable,” preferably with a bunch of dignities like “Academician of Such-and-such Academy” or “ Honored Minister of So-and-So,” and if he seems “confident in his words,” and speaks in the style of “I have brought you the truth, believe,” if he speaks assertively, and overshadows his opponents with his charisma, neutralizing their counterarguments with all known rhetorical techniques and tricks such as allegory, hyperbolization, translation of the topic, personalization, and the like - thousands of them.

So, you ask a person this question: “Vasily, what do you think, why is there summer and winter?”
At first, a person is usually completely sure that he knows the answer to this question, and begins to answer: “Well, how?! What does why mean?! Everyone knows this: of course, because the Earth’s axis is tilted!”

In principle, this answer already contains the whole point - the words “everyone knows this.”
The classic school training system works here: Masha “knows” the answer to the question, Masha gets an “A”. In fact, a school is the same religious zombie institution as any parish theological seminary in the Middle Ages.
The person simply does not perceive the question that way.
Instead of “Do you know why Something like this?” he hears “But you don’t know, as they usually tell us, why Something Such and Such?”
That is, a person accepts the virtual reality that society has imposed on him as the real state of affairs, and at the same time sacredly believes in it, and automatically considers any doubt in it (society has developed this reflex) to be heresy.
It looks very funny from the outside, for example, when a person’s head is full of misconceptions that he does not question and firmly believes in, and when you try to explain to him something that goes beyond the framework, or something that challenges his beliefs, then a person, in especially advanced cases, immediately begins to demand “facts” and does not want to listen, much less believe. It is not without reason that they say that the best slave is the one who is completely sure that he is not a slave. And if a person comes across a low level of development (there are such people, just look at today’s crazy fascist Ukraine), then he will even begin to attack you, put pressure on you, aggressively and zealously defending his own virtual reality from destruction. For an analogy, imagine a slave who is confident that he is free, and at the same time zealously protects his master-enslaver.
This, of course, is not the person’s fault: people are designed this way, it is their nature, and there is nothing shameful in this. And no one is immune from this.

Returning to the question you asked, the fun begins when you answer the interlocutor that he cannot build a normal logical chain from the mantra from the “tilted axis” to the answer to the question asked, and that he, therefore, does not know the answer to this question.
Based on the reaction, one can make judgments about the person himself: will he behave aggressively in response, will he go into deep defense, inaccessible to logic, etc. In especially difficult and rare cases, after you reveal the correct answer, the person is so afraid of being wrong that he commits self-deception, and assures both you and himself that he said so from the very beginning.
Fear of error is programmed into human nature as a defense necessary in the early stages of the development of consciousness, but at the same time it is also one of the main factors hindering human development after passing initial stage development.

Regarding the answer to the question itself...
By intuition, of course, one can assume (and take on faith the noodles that are being hung on everyone’s ears somewhere) that because one pole, due to the tilt of the Earth, is always further from the Sun than the other, and therefore it is summer in one hemisphere , and in the other - winter.
And some people are sure that this distance is the reason for winter and summer. In fact, such a small distance of one pole compared to the other is not capable of providing a temperature difference (and if suddenly there is such a difference, then it is negligibly small).

The whole point is that the hemisphere that is tilted outward receives the same light, only at more slippery angles to the surface, and the hemisphere that is tilted inward receives light at angles that are steeper to the surface of the Earth.
Therefore, per unit area of the earth's surface in the cold hemisphere there is less incident sunlight than per the same unit area of the earth's surface in the hot hemisphere: for example, in the picture below you can clearly see that the “blue” part of the light, which falls on the cold hemisphere, almost half the size of the “yellow” part of the world, which falls in the hot hemisphere - that is why (and no other reason) it is hot in the hot hemisphere at this time of year, and cold in the cold hemisphere at this time of year.

If you are familiar with the concept of a “solid angle” (the same geometric two-dimensional angle, only expanded to the concept of three-dimensional space - you get something like a cone)

, then I will tell you this: the same unit of area of the earth's surface receives a smaller share of light (and, therefore, less heat) in the cold hemisphere, because there the solid angle from the sun to this unit of surface will be smaller; and vice versa, the same unit of earth's surface area receives a larger share of light (and, therefore, more heat) in the hot hemisphere, because there the solid angle from the sun to this unit of surface will be greater.

If there are astronomers among you who need mathematical formulas, then you can find them on this page: in the “intensity” section, a formula is immediately given that relates the radiation intensity and the solid angle to the site. Here is a formula for making my speech pompous and official, and for increasing the “persuasiveness” of my reasoning

Since the intensity of sunlight is the same at any point in space (this is, by definition, a property of the intensity of a star’s radiation in astronomy), the energy transmitted by sunlight to the Earth’s surface depends only on the solid angle from the Sun to a unit area of the Earth’s surface: the larger the solid angle angle, the more energy it contains.

To refute the misconception that there is winter and summer because one hemisphere, due to the tilt, turns out to be a little further than the other, you can come up with some visual and obvious refutations in the style of “paradoxes”.

For example, what is the Earth's orbit around the Sun? Your interlocutor, of course, will answer that, naturally, it is ellipsoidal. And he will draw an ellipse on paper, so elongated. Where is the Sun located inside this ellipse? Your interlocutor will probably say that it’s in the center (an intuitive answer, that’s how we were all drawn in children’s books). Ask again if it is exactly there. If he is sure, then notice that, in fact, not in the center, but in one of the foci of the ellipse. If the ellipse is drawn very elongated, then the Sun will be strongly shifted to one side. Ok, if the Earth's orbit is a drawn elongated ellipse, and a small difference in the distances to each hemisphere due to the tilt of the Earth's axis of rotation would affect the temperature so much, then why, when we pass those two points of the ellipse that are closest to the Sun, Doesn't all life on Earth burn?

In fact, technically, your interlocutor dropped the correct phrase: technically, it is approximately an ellipse. Although in fact I would say that you are unlikely to distinguish it from a circle, because the eccentricity of this ellipse is 0.0167, and its largest diameter is 149.60 million kilometers, and the smallest is 149.58 million kilometers, that is, the difference in diameters - only about 20 thousand kilometers, that is, a little more than one tenth of a percent.

The sun is located at one of the focuses of this ellipse, and therefore is slightly shifted to one side.
(in the picture below, the ellipse, apparently for dramatic reasons, is unnaturally elongated in width - do not forget that in fact the Earth’s orbit is indistinguishable from a circle by eye)

If we now return to the question you asked your interlocutor about why everything did not burn up at the points of the ellipse that are closest to the Sun, then we can say that we now know that the Earth’s orbit is in fact a circle, and these points are closest to the Sun by only 10,000 kilometers, which is approximately equal to the diameter of the Earth, and therefore not so dramatic. Ok, I have a couple more paradoxes up my sleeve...

Now you can dig into the difference in distances from the Sun to the Earth in summer and winter (see picture). Ask your interlocutor that if his theory is correct, then why in July, that is, when it is summer in our hemisphere, the Earth is further from the Sun, and in January, when we have winter, the Earth, on the contrary, is closer to the Sun?

Further, if you count: 152,100,000 km - 147,300,000 km =~ 5,000,000 km. Five million kilometers - this is the difference in distances from the Earth to the Sun in summer and winter. If your interlocutor claims that the tiny difference in distances given by the tilt of the Earth’s axis somehow affects the temperature, then let’s calculate it - it will certainly not be greater than the diameter of the Earth, which is 12,742 km. Now compare a distance of ten thousand kilometers, which supposedly creates winter and summer, and a distance of five million kilometers, which, in this case, would freeze everything into permafrost or burn all living things. Ten thousand kilometers and five million kilometers. Millions, Karl!

And one more, last, fact that I noticed from a series of refutations of this false theory, which everyone firmly believes in: if only distance really played a role, then in this case one of the poles would completely melt once every six months, and an oasis would form there.

Here is another link, from the encyclopedia for children.