Why is it cold in winter and hot in summer, why is it so hot in summer, why is it so cold in winter?

In the summer, the sun shines in direct sunlight, and it feels hotter as if you put your hand right above the candle flame. In winter, the sun shines obliquely, just like you put your hand on the edge of a candle flame, and it feels like it's hot on it, why it's cold in winter and hot in summer.

"Season" is derived from the Latin verb "serere", which means "to sow seeds". It can be seen that the term "season" originally referred only to the spring when sowing seeds were suitable.

But at the beginning of the Middle Dynasty, the other three seasons were added to the meaning of the word "season", and the year was divided into four parts: winter, the wet and cold season; Autumn is the season of growth and importance; Summer, in ancient Sanskrit, originally referred to as a year.

The daily life and romance of humans are influenced by the four seasons, and in addition, they have the most boring astronomical background. Because the direct result of the annual journey of the earth around the sun is the cycle of the seasons. Here, I will present this as concisely as possible.

The Earth rotates once every 24 hours and revolves around the Sun once a day. In order to ensure that the calendar is uniform, humans accumulate the days of each year into one piece, so that every four years there is a leap year, that is, the year has 366 days. But there are no leap years for years ending in two "zeros"; There is an exception, however, that those years that are divisible by 400 are leap years.

Schematic diagram of the principle of the generation of the four seasons (drawn by NetEase Exploration).

The year 1600 A.D. was the last exception, and the next time was 2000 A.D. The Earth's orbit around the Sun is not a perfect circle, but an ellipse. Although it is not yet a complete ellipse, it has added a great deal of complexity to the study of the Earth's movements.

In addition, the plane between the central axis of the Earth and the Sun and the Earth is not a right angle, but an inclination. As the Earth revolves around the Sun, its central axis maintains this inclination from beginning to end, which is the direct cause of the alternation of seasons around the world. Every year on March 21, the sun shines evenly on exactly half of the earth's surface, so on this day, day and night are equally divided around the world.

After 90 days, when the Earth is a quarter of its orbit, the Arctic is all facing the Sun and the Antarctic is facing away from the Sun, so that the six-month day at the North Pole begins and the South Pole falls into a six-month night. When the sunny summer arrives in the northern hemisphere, the inhabitants of the southern hemisphere spend the long cold nights reading by the fire.

But while the inhabitants of the northern hemisphere skate at Christmas, Argentines and Chileans are suffering from the scorching heat of summer, and when the United States is hit by a heat wave, they are sharpening their skating blades.

September 23 is the second important date of the change of seasons, the second day of the year when day and night are equally divided around the world. Then, on December 21, the North Pole kisses goodbye to the Sun and the South Pole faces the Sun, at which point the Northern Hemisphere enters a harsh winter and the Southern Hemisphere enters a bitter summer. However, the unique tilt of the Earth's axis and the rotation of the Earth are not the only reason for the formation of the cycle of seasons.

Do the children understand?

Agree with the upstairs. But there are also reasons why the days are long and the nights are short.

In the Northern Hemisphere, the sun shines directly on the earth in summer, and the weather is hot when the sunshine hours are long.

In summer, the sunlight hits the earth obliquely, and the sunshine hours are short, so the weather is cold.

Why is it so hot in summer? Because in the summer, because the earth rotates exactly the closest distance to the sun, the sun rotates in the summer, and the earth is far away from the sun, so it feels very cold.

The reason for the temperature is that the hot and cold weather is determined by the temperature.

This has to do with the rotation and revolution of the earth. I can't say the specifics, you can open the geography textbook and review it again.

In winter, it is far away from the direct point of the sun, the solar altitude is small, and the radiation is weak; The days are short, the daylight hours are short, the solar radiation obtained is less, and the temperature is low, so the winters are cold.

In summer, it is close to the direct point of the sun, the sun is high and the radiation is strong; The days are long, the sunshine hours are long, the solar radiation is obtained, and the temperature is high, so the summer is hot.

The year is divided into four seasons: spring, summer, autumn and winter, and the cause of the four seasons, the distance of the earth from the sun, has little relationship with the cold and hot climate. The four seasons are formed mainly because the equator and the ecliptic (the path through which the sun travels as seen on Earth) are obliquely intersected. When the Earth moves, the direction of its axis in space does not change.

In winter, the sun's rays are obliquely shining on the ground, and the ground is less heated per unit area, and the days are short, and the daily sunlight is short, that is, the heating time is short, and then because the atmosphere on the periphery of the earth absorbs a part of light and heat, when the light is irradiated, the thicker the atmosphere, the more absorbed, so it causes cold winter. In summer, on the other hand, the sun hits the ground directly, the days are long, and the light passes through the atmosphere and is thin, so the climate is hot. The rainy season in spring and autumn is between winter and summer, so the climate is mild.

It is because in winter, the height angle of the sun is smaller, the sunlight is obliquely shining on the earth, the energy density of the sun reaching the earth is smaller, and the earth gets less energy from the sun, so the winter is cold; And in summer, the height angle of the sun is large, the sunlight is almost direct to the earth, the energy density of the sun reaching the earth is very large, and the earth gets more energy from the sun, so the summer is hot.

Because the angle of inclination of the rotation axis of the earth travel ball causes different angles of sunlight, the heat obtained on the surface of the earth is also different, so there is a difference between cold and hot in the four seasons. When the sun is directly shining, the heat obtained by the earth's surface is high, and the temperature is high, which is summer, and conversely, when the sun is oblique, the heat obtained by the earth's surface is low, which is winter.

There is an angle of inclination on the Earth's axis, which causes the direct point of the sun to move back and forth between the Tropic of Cancer, which leads to different angles of sunlight and different amounts of energy obtained.

When the sun shines directly into the northern hemisphere, it is summer in the northern hemisphere and winter in the southern hemisphere.

Every year on the spring and autumn equinoxes, the sun shines on just half of the earth's surface evenly, and day and night are equally divided around the world.

This is because of the angle of sunlight.

The temperature of the four seasons is determined by the angle and time of day, and for us, those of us in the mid-latitudes of the Northern Hemisphere, the sun hits the ground almost vertically at noon around the time of the "summer solstice".

Around the time of the winter solstice, the sun shines very obliquely to the ground at noon. The size of the irradiation angle determines the amount of heat received by the earth, which causes the temperature to be high or low. In addition, around the "summer solstice", the sun rises from the northeast and sets in the northwest, and the sun is above the horizon for a long time, which makes the ground in a long period of sunlight and aggravate the rise of ground temperature.

On the contrary, around the "winter solstice", the sun rises in the southeast and sets in the southwest, and the sun is above the horizon for a very short time, and this situation of short days and long nights exacerbates the cooling of the ground. So the hot summer and the cold winter were formed.

Cold and heat are mainly determined by solar radiation!! (That's the key, understand this first).

Why is it cold in winter and hot in summer?

It is because in winter, the height angle of the sun is smaller, the sunlight is obliquely shining on the earth, the energy density of the sun reaching the earth is smaller, and the earth gets less energy from the sun, so the winter is cold; And in summer, the height angle of the sun is large, the sunlight is almost direct to the earth, the energy density of the sun reaching the earth is very large, and the earth gets more energy from the sun, so the summer is hot.

Because the Earth's orbit around the Sun is an ellipse, in winter, our Earth is closer to the Sun; In the summer, our earth is far from the sun.

The summer we are talking about is the summer in the Northern Hemisphere, because the Earth's rotation is declinated, so when the sunlight shines directly in the Northern Hemisphere (between the equator and the Tropic of Capricorn), the temperature in the Northern Hemisphere rises and the Southern Hemisphere falls, and vice versa, the Northern Hemisphere rises and the Southern Hemisphere falls.

In summer, the sun shines directly, and the heat radiation is concentrated, so it is hotter; In winter, the sun is obliquely shining, and the same heat radiation is distributed over a larger area, and the heat is naturally smaller.

Root cause.

It is in the temperate zone, and the axis of rotation of the earth is not perpendicular to the plane of its orbit, and the angle of deviation is 23 degrees 26 minutes (yellow-red angle). Depending on the season, the northern and southern hemispheres receive unequal sunlight, with the sunshine being more in summer and the other half in winter. Spring and autumn are transitional seasons, with the sun's direct point close to the equator, the sunshine in both hemispheres is equal, but the seasons follow the opposite trend – autumn in the southern hemisphere and spring in the northern hemisphere.

That is to say, in winter the sun is far away from us and receives less solar radiation, so it is cold, and in summer the sun is close to us and receives more solar radiation, so it is hot. Upstairs, people wear more clothes in winter, so it's cold, and in summer, people wear fewer clothes so it's hot, which is too idealistic.

China is located in the northern hemisphere, and the direct point of the sun is up to the northern latitude, that is, the Tropic of Capricorn, and the date of direct shooting of the Tropic of Cancer is the summer solstice. For example, if you take a flashlight to shine on a watermelon (up and down, down south, left, west, right east), you shine on the top third of the position (Tropic of Capricorn), the light in the northern hemisphere will be the most strong, and then at the top (North Pole), a polar day will be formed, (the South Pole) will become a polar night, the earth will turn from west to east, no matter how you turn the North Pole, the light time in other parts of the Northern Hemisphere will increase, so that the surface temperature in the northern hemisphere will rise, the air temperature will also rise, and there will be few cold and high pressure in the north to the south; The sun has a higher angle than in winter, the distance to penetrate the atmosphere is shorter, the solar radiation is stronger, the ground is less shady, and it absorbs more heat, so it forms summer, and the opposite is true in winter.

In winter, the sun shines directly on the southern hemisphere, and the sun obliquely rays in the northern hemisphere to get less light and heat, plus the days are short and naturally cold, and in summer, the sun directly hits the northern hemisphere, and the northern hemisphere receives more light and heat, plus the days are long, and it is naturally hot.