Change of seasons in different hemispheres. Seasons on the planets of the solar system

The change of seasons is inextricably linked to the tilt of the earth's axis.. Our blue planet moves around the Sun in an elliptical orbit (Latin orbita - track, road). In addition, the Earth rotates around its own axis. We do not feel all this diversity of movements in outer space. Every morning, a bright star rises from the horizon in the east, rolls across the sky in a hot white disk, and then disappears below the horizon in the west. Crimson sunset turns into twilight, and then night falls on the earth.

In winter, the Sun peeps out from behind the horizon for only a third of the day. Dawn comes late, and dusk is always early. In summer, the picture is quite different. The luminary climbs high into the sky and moves across the sky for a long time. His travel time reaches 16 hours. People wake up when dawn is already dawning outside the window, and fall asleep without waiting for sunset.

The tilt of the earth's axis is to blame for all this. The earth's axis refers to an imaginary line connecting the North and South Poles. Moreover, it is located at an inclination with respect to the plane of the ecliptic. This means that at certain times the North Pole is closer to the Sun than the South Pole. And at other times, the opposite is true - the South Pole is closer, and the North is farther.

The angle between the axis and the plane is currently 23.44 degrees. But this value is not constant. Every year it changes by 0.47 seconds, and in the direction of decrease.

The Earth's orbit is not a perfect circle with the Sun at its center. This is an ellipse with an eccentricity of 0.0167. Therefore, the planet has the minimum and maximum remote points in the orbit. At aphelion, the distance to the star is 152.083 million km, and at perihelion, this value is respectively equal to 147.117 million km.

The planet passes perihelion around January 3rd. At this time, the Southern Hemisphere is turned towards the Sun, where summer is in full swing. Due to more close range it receives more solar energy than North hemisphere. However, this effect and the change of seasons are in no way connected. Although there is more solar energy, all of its excess is absorbed by the waters of the oceans. Their bulk is just concentrated in the southern regions of the planet.

Winter, summer, spring and autumn depend only on the tilt of the earth's axis. As the Earth moves around the Sun, this tilt does not change. That is why, on one part of its trajectory, our blue planet is more turned towards the luminary by its lower half. And on the other part of the path, the upper half receives more heat.

Imagine that you are standing near a fire. The face and chest are warm, but the back is cool. Without changing the position of the body, go around the fire and stand on the other side. Now the back is heated, and the face and chest are deprived of heat. The same thing happens to the planet when it revolves around the yellow star.

The moments when the height of the sun above the horizon reaches a maximum or minimum are called solstice. The summer solstice falls on June 21-22. This is the longest day of the year. But the shortest day is observed during the winter solstice. It falls on December 21-22. In the spring of March 20-21 and in the autumn of September 22-23, equinox. These are periods when the length of the day is equal to the length of the night.

The change of seasons in different hemispheres occurs for different periods time. So in the Northern Hemisphere, autumn comes after 93.6 summer days and lasts 89.9 days. Winter, respectively, lasts 89 days, and spring accounts for 92.8 days. IN southern hemisphere summer period ends after 89 days. Autumn lasts 92.9 days. Winter is given 93.6 days, and spring has 89.9 days. We owe it all to axial tilt and Earth's orbit. It is they who are responsible for different annual periods and give us warm summer and cold winter days.

To explain to students the reason for the change of seasons on Earth is probably the most difficult task for any teacher of astronomy. No matter how hard the teacher tries to explain that the change of seasons has nothing to do with how far the Earth is from the Sun, many or even most students do not believe this. Surveys have shown that even graduates Harvard University think that summer is when the earth is closest to the sun, and winter is when the earth is farthest from the sun.

At the same time, students forget that when it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere. And when it's summer in Australia, it's winter in Russia. But both Australia and Russia are on the same planet Earth.

True reason the change of seasons is the tilt of the earth's axis (Fig. 5.2). The axis of rotation, an imaginary line connecting the north and south poles of the earth, is not perpendicular to the plane of the earth's orbit along which it moves around the sun. And the deviation of the axis from the perpendicular is 23.5 °. The axis points north to a point among the stars near the North Star. (Actually, the axis slowly changes its direction and over time will point not to Polaris, but to another star.)

Rice. 5.2. Change of seasons

At present, the North Star (i.e., the one pointed to by the north pole of the Earth) is

The axis of the Earth is directed "up" through the North Pole and "down" - through the South. When the Earth is on one side of its orbit, the "up" axis also points roughly towards the Sun, since the Sun is high in the sky at noon in the Northern Hemisphere. Six months later, the "up" axis will now point away from the Sun. In fact, the axis always points in the same direction in space, but now the Earth is on the opposite side of the Sun.

Summer comes to the Northern Hemisphere when the axis directed upwards through the North Pole points approximately towards the Sun. In this situation, the Sun is higher above the horizon at noon than in all other seasons of the year, so it illuminates the Northern Hemisphere better and gives more heat. At the same time, the axis passing down through the South Pole is directed away from the Sun, so the Sun at noon is lower above the horizon than at any other time of the year, and illuminates the Southern Hemisphere worse. At this time, winter comes in Australia.

There are more daylight hours in summer than in winter because the Sun is higher above the horizon. Therefore, it takes him more time to first rise to this height, and then descend. And because the day is longer, it's warmer this time of year.

As the Earth moves in its orbit around the Sun, the Sun appears to move across the sky in a circle called the ecliptic (discussed in Chapter 3). The plane of the ecliptic is inclined to the plane of the equator at exactly the same angle as the axis of the Earth - 23.5 °. From this point of view, we define the following concepts.

The moment when the center of the visible solar disk crosses the celestial equator. The vernal equinox occurs when the sun moves from the southern hemisphere of the celestial sphere to the northern hemisphere and usually occurs around March 21st. The autumn equinox occurs around September 23rd. Near the equinox, the length of the day in the middle latitudes is approximately equal to the length of the night.

When the Sun moves from the southern hemisphere of the celestial sphere to the northern, i.e., crosses the celestial equator "from bottom to top", the first day of spring comes, which is called the day spring equinox. It falls on March 20-21. In the southern hemisphere of the Earth, astronomical autumn comes, and in the Northern hemisphere - astronomical spring. Near the equinox, the length of the day in the middle latitudes is approximately equal to the length of the night.

When the Sun reaches its highest (northern) point on the ecliptic, it is day summer solstice . Falls around June 21-22. From this day in the Northern Hemisphere begins astronomical summer, and in the South - astronomical winter.

When the Sun moves from the northern hemisphere of the celestial sphere to the southern, i.e., crosses the celestial equator "from top to bottom", this is the beginning of autumn, the day autumn equinox. It usually falls around September 23rd. An astronomical spring is coming in the Southern Hemisphere of the Earth, and an astronomical autumn is coming in the Northern Hemisphere.

When the Sun reaches its lowest (southern) point on the ecliptic, it is day winter solstice. Approximately on December 21-22. From that day on, astronomical winter begins in the Northern Hemisphere, and astronomical summer begins in the Southern Hemisphere.

Most people are so used to the fact that the seasons are something settled that they don’t even think about why they change. Moreover, many do not come up with the idea that there may be not 4, but more. Let's talk about all this in detail, but succinctly.

How many times are there in a year

It would seem - the question is simply childish. After all, everyone knows that there are exactly four seasons: spring, summer, autumn and winter. However, this is obvious to any person in our country, Europe and America. But there are other options for dividing the year into seasons.

For example, in India, where the year is also divided into 12 months, there are as many as six seasons! True, each of them consists of only two months. This is easy to explain - proximity to the equator, large coastline, frequent change weather - all this made the ancient Hindus come up with a completely new system meeting the needs of local residents.

Even more surprising may seem the system of the Saami - the indigenous inhabitants of Finland and the surrounding regions. Here the calendar consists of as many as eight seasons!

So, as you can see, when asked how many seasons there are, in different points Earth can get quite different answers.

How is the year divided into seasons?

Let's look at the European system that operates in our country, and is also the most common throughout the world.

True, and here everything is not too clear. For example, in our country, the seasons are rigidly tied to the calendar - for simplicity and convenience. But the weather is not going to obey the conventions invented by man. Therefore, the astronomical time of the year does not always coincide with the calendar time. For example, winter starts on December 1 and ends on February 28 (or 29). For the summer, the frames are also set quite clear - from to August 31. Everything is simple and clear. However, many will agree that the first two weeks of September are usually much more summer-like than the last two weeks of May. Therefore, some people agree with the statement that old calendar(Julian), abolished after the Revolution of 1917, was more accurate and reliable.

However, in other countries of the Northern Hemisphere, where the Gregorian calendar is also used, the problem is solved in a very original way. The fact is that here the seasons are not the dates on the calendar, but the position of the stars in the sky. In other words, the new season begins not on the first day of the month, as people decided, but on the day of the solar equinox or solstice. The binding is really more reliable - after all, the climate on Earth depends primarily on the Sun.

Thus, in some countries it is believed that summer begins on June 22, autumn on September 23, winter on December 22, and spring, respectively, on March 21. It is no coincidence that once in Russia New Year It was celebrated exactly on March 22 - after the spring equinox, when the day became a few seconds, but longer than the night.

Why the seasons change

Another seemingly fairly simple question that not every person can answer, even if he received a secondary education.

It's about the rotation of the earth. As you know, it rotates around its axis, making a revolution in a little more than 24 hours. And so the days come. But the planet also revolves around the sun. Because of this, the season changes. Let's talk about this mechanism in more detail.

Imagine the circle that the Earth describes as it revolves around the Sun. Now imagine the axis around which the Earth rotates in a day. So, it turned out that this axis is not at all perpendicular to the circle. Indeed, in this case all year round the weather on Earth would be the same - the seasons would not exist.

But it's not. As scientists managed to calculate, the angle between the axis and the circle is approximately 66.6 degrees. But this is not a constant - this angle has changed many times in the past and will certainly change many times in the future. Of course, even the slightest change in slope leads to dramatic changes in climate.

So, as already mentioned, the sun's rays fall on the Earth not under direct rays. Even for the equator, which warms up most actively on the planet, this brings certain changes (we will discuss them below), and for the Northern and Southern hemispheres the difference becomes simply huge. On one of them, the sun's rays fall under relatively direct rays, which allows them to be absorbed by the earth and water, which are actively heated. But at the same time, the sun's rays almost do not fall on the other hemisphere, more precisely, they fall at such an angle that most of the heat is simply reflected. Of course, this leads to hot summers and cold winters.

This can also explain the polar night and day - while one pole is illuminated day and night, the other does not receive at all. sunlight and warmth.

Briefly about summer

According to many people (especially, of course, children), summer is best time of the year. But the climate does not always agree with this conclusion.

Summer lasts in our country from August 31, according to another European system- from June 22 to September 22. In temperate latitudes, it is associated with the highest temperature and, as a rule, heavy rainfall. It was at this time that nature appears in full glory - green forests, flowering fields.

However, closer to the equator, everything changes dramatically, especially in regions with a sharply continental climate. The heat here becomes unbearable, there is practically no precipitation, the winds are burning, blowing out the last moisture. Surviving in such conditions is really difficult - you either need not to go outside during the peaks of the heat, or have such a habit instilled from childhood.

What is autumn

What time of year does summer end? Any child will answer without hesitation - autumn. And many will add that this is the saddest time. Summer is over, winter is coming - for many people this causes bouts of nostalgia and even melancholy. Autumn lasts from September 1 to December 31, or from September 23 to

By this time, nature brings abundant fruits and prepares for winter. People are harvesting, storing supplies that will allow them to survive the cold half a year. Foliage on trees (except evergreens) turns yellow or reddens and falls off. Many birds and even some animals migrate to warmer climes, where it will be possible to get food, it is easy to survive the cold season.

In some regions of the earth, it is a borderline state between wild and fierce winter rains - at this time they manage to live a full life cycle some plants and animals.

A little about winter

If we talk about the seasons, this is the coldest. It lasts according to the calendar from December 1 to February 28 (in a leap year to February 29). And by astronomical standards - from December 22 to March 20.

Snow falls in the northern regions. In some places, it lies for as long as half a year, while in others it falls out in a matter of hours, only to fall out again after a few days or weeks.

Closer to the equator during these months there are torrential rains. Moisture-loving plants, fish and reptiles are in a hurry to live a whole epoch out of their lives until the fertile water evaporates.

Spring Features

Finally, we move on to spring. Perhaps most people, when asked what time of the year is the most romantic, will name it. No wonder - it wakes up, and the person seems to wake up after long winter feels refreshed. Hormones enter the blood in an increased amount, which changes both the well-being and behavior of people.

It lasts according to the calendar from March 1 to May 31. According to the astronomical cycle - from March 21 to June 21.

In regions with a temperate climate, nature is awakening at this time, preparing for a difficult summer. And in others, on the contrary, actively living with an abundance of moisture and the absence of too high temperatures animals and plants are preparing for hibernation or minimal activity - it is better to endure the hellish heat in this state.

What about in the Southern Hemisphere?

As mentioned above, the Earth is facing the Sun with one hemisphere - sometimes the South, then the North. As a result, the climate on them is very different. Surprisingly, for residents of Argentina, Brazil, Mozambique, Australia, the hottest months are January and February. But in July and August they wrap up warmer to survive the cold season.

Spring in the Northern Hemisphere corresponds to autumn in the Southern Hemisphere and vice versa. Surprising but true.

Conclusion

This article comes to an end. Now you know that the seasons are a serious stage in the life of man and nature. And also you can easily talk about how and why spring replaces winter, and summer invariably comes to autumn.

Please tell me how did you spend this weekend? Riding a bike, sunbathing in the sun or playing snowballs, making a snowman? What clothes do you put on before going out?

It turns out that we do so many interesting things every day, based on the time of year. In the summer we relax in nature, in the fall we collect a herbarium from leaves, in the winter we go skating and skiing, and in the spring we throw off warm clothes and rejoice gentle sun. Every season brings something different and new. Each season changes our way of life, the type of clothing, affects walks and entertainment. Remember the school lesson on the theme of the seasons in the subject of natural history.

A bit complicated?
Then here: Seasons for children +3 to> 7

Four Seasons:

The seasons are made up of four seasons: summer, when the days are longest and the sun rises high above the horizon; winter - the days are short and the nights are long; inter-seasonal seasons spring and autumn, which account for the period of transitional change of seasons of summer and winter.

(for the temperate zone, the central part of Russia)

Summer is replaced by a cool autumn, then the winter cold sets in, and then the long-awaited spring thaw comes - and so on an infinite number of times, from year to year. What is the mystery of this natural phenomenon Why does the seasons change on Earth?

In order to fully visualize the picture of how this happens, it is worth telling how the globe moves in space.

There are two of these movements:

• 1) The earth around its axis (a conditional line passing through the center of the northern and south poles) makes a complete revolution in a day. Thanks to this astronomical phenomenon, day follows night. When it is a hot afternoon on the continents facing the Sun, it is deep night on the dark continents.


• 2) The Earth moves in an elliptical path around the Sun, making a full revolution within 1 year.

What causes the change of seasons?

The Earth's orbit is elliptical, not circular, and in this orbit there is a point closest to the Sun (perihelion), where the Sun is about 147 million km, and the farthest (aphelion 152 million km). This 3% difference in distance results in about a 7% difference in the amount of solar energy the Earth receives at perileg and aphelion. However, there is a big misconception that the closer the Earth is to the Sun, the warmer, and vice versa, the farther away, the colder. It is not right! Just at perihelion in the Northern Hemisphere, January falls, the middle of the coldest season of winter.

Interestingly, the position of the Earth has nothing to do with the change of seasons at all. The key role is played by the angle of inclination of the Earth's axis, which is 23.5 °. When the Earth moves around the Sun during the year, then the Northern Hemisphere, then the Southern Hemisphere turns out to be turned. It is on the hemisphere that is closer to the Sun that summer comes, since it receives 3 times more sunlight and heat. And on the other, facing further from the Sun, and receiving less heat and sundial, at that time winter is coming.

If there were no tilt angle and the globe moved around the Sun in a strictly vertical position, there would be no seasons at all, since any points the globe on the illuminated side, the Suns would be equally removed, as a result of which the air would warm up evenly.

What the seasons look like in the northern hemisphere

Summer

During the year the Earth moves in its orbit, the northern hemisphere, due to the angle of inclination of the axis, is located closer to the Sun and the summer season begins there. Daylight hours increase in duration, and in areas located closer to the pole, even at midnight it is light outside.

Winter

Further, in the process of its movement along the orbit, the Earth turns out to be on the other side with respect to the Sun, and now the angle of inclination removes the northern hemisphere from the warm rays of the sun and winter sets in there. The darkness of the day is increasing, and the daylight hours are getting shorter. And at this time, summer comes to the continents of the southern hemisphere.

This is what the change of seasons looks like on the continents of the Earth:

Interestingly, the inhabitants of the equatorial and tropical zones know firsthand about the onset of cold weather. Here, seasonal changes occur so smoothly that they are practically not felt, because the equator, regardless of the position of the planet in orbit, is almost always the same distance from the Sun.

Equinox Periods:

• The vernal equinox- 20 - 21 March. The sun moves from the southern hemisphere to the northern.
• autumnal equinox- 22 - 23 September. The sun moves from the northern hemisphere to the southern.

That is why the seasons for the Northern Hemisphere are opposite to the seasons for the Southern Hemisphere. During the period between the months of March and September, during the day, the Northern Hemisphere faces the Sun most of the time and it receives more heat from the sun's rays than the southern hemisphere of the earth. This is the period of summer in the Northern Hemisphere when the days get longer and the nights get shorter.

Six months later, the position of the earth to the sun changes, but the tilt remains. Now in the Southern latitudes of the Earth's hemisphere, the days are getting longer and the sun is rising higher, while in northern latitudes hemisphere winter is coming. This cycle of time during the year is enough to heat or cool certain parts of the planet. That is why the seasons gradually change and are divided into seasons.

The earth is made up of climatic zones corresponding to a particular climate. This is due to various physical properties land and water surfaces in various parts of the globe. Therefore, on different continents climatic seasons begin differently in relation to the astronomical seasons.

So, on one continent, snowfall may occur in winter, and rain in summer, and on another continent there may not be snow and rain at all for a long period of time, but the heavy rainy season will fall on a strictly defined season of the year.

Climate zones on Earth:

• equatorial belt- spring and autumn are dry seasons, while summer and winter are characterized by increased rainfall.
• tropical belt - dry, hot weather lasts most of the year and only once a year, during the rainy season, it falls a large number of precipitation. also this season is relatively cold season of the year.
• Temperate zone (Western Europe, central part Russia) spring and summer are relatively dry with short-term precipitation, autumn and winter are characterized by a lot of precipitation and stable snow cover.
• Arctic and Antarctica- the seasons change only in the form of a change of polar day and night, changes in weather conditions are practically not traced and the temperature always remains below zero.

And this is how the Norwegian photographer Eirik Solheim saw the seasons, combining the footage from the same place into 40 seconds of a unique video of the change of seasons:

(One year in 40 seconds. Eirik Solheim)

A unique video about the change of seasons. All seasonal changes in nature whole year in just 40 seconds. The author took one photo almost every day for a year, the result was the reduction of an unusual experiment into a short video that clearly demonstrates how nature changes through all four seasons.

To summarize: summer comes at the moment when the hemisphere in which we live is more turned towards the sun and receives more heat, and when the sun shines less in our hemisphere, then winter comes. This does not depend on the distance of the Earth from the Sun, but is due to the inclination of the earth's axis of 23.5 °.

We all see that the seasons change: in summer we sunbathe and swim in open natural reservoirs, pick meadow flowers, sit by the fire; in autumn we admire the colorful beauty of the forest; in winter we go sledding and skiing, and in spring we enjoy the warm sun and watch how quickly the buds on the trees burst and turn into a green outfit. But why does the season change?

The main reason for the change of seasons is the tilt of the Earth's axis of rotation.

But first, let's talk about what the term "seasons" means. These are four periods into which the year is conditionally divided. Pay attention to the word "conditional".

In astronomy, there are:

1) calendar seasons, which are accepted in most countries of the world - the division of the year into four seasons of three months each. Here it is just clear that the division is conditional, because. the calendar date of the onset of winter (or another season) may not coincide with the actual weather.

2) Astronomical seasons- are counted from the points of the solstice (summer / winter) and equinox (spring / autumn).

Let's figure out what the "points of the solstice" and "equinoxes" are.

Solstice- this is the moment of passage of the Sun through the points of the ecliptic (the great circle of the celestial sphere, along which the apparent annual movement of the Sun occurs), the most distant from the equator of the celestial sphere.

- this is the moment when the center of the Sun in its apparent movement along the ecliptic crosses the celestial equator.

3) Phenology(a system of knowledge about seasonal natural phenomena), using the concept of "season", determines the duration and timing of the beginning of each climatic season in accordance with natural conditions. Season differs in its characteristic weather conditions and temperature.

So, the change of seasons is explained by: the annual revolution of the Earth around the Sun, the tilt of the Earth's axis of rotation relative to the orbit and the ellipticity of the orbit.

calendar seasons

In most countries northern hemisphere the following dates of the seasons are accepted:

• spring - March 1-May 31 (March, April, May);
• summer - June 1-August 31 (June, July, August);
• autumn - September 1-November 30 (September, October, November);
• winter - December 1-28 (29) February (December, January, February).

Recall that in northern hemisphere(north of the equator) are the continents and countries: Asia (temperate climate), Europe, North America, small part South America (north of the Equator) about ⅔ of Africa, north of the river Congo(Algeria, Benin, Burkina Faso, Gambia, Ghana, Guinea-Bissau, Djibouti, Egypt, Western Sahara, Cape Verde, Cameroon, Kenya, Ivory Coast, Liberia, Libya, Mauritania, Mali, Morocco, Niger, Nigeria, Senegal, Somalia, Sudan, Sierra Leone, Togo, Tunisia, Uganda, Central African Republic, Chad, Equatorial Guinea, Eritrea, Ethiopia, South Sudan), northern countries Oceania, located in the Northern Hemisphere: Marshall Islands, Micronesia, Palau, South American countries located in the Northern Hemisphere: Venezuela, Guyana, Colombia, Suriname, French Guiana.

IN southern hemisphere other dates of the seasons:

• spring - September 1-November 30;
• summer - December 1-28 (29) February;
• autumn - March 1-May 31;
• winter - June 1-August 31.

In the Southern Hemisphere (south of the equator) are the continents and countries:

Asia(in full), East Timor ( for the most part), Indonesia, Africa ( Angola, Botswana, Burundi, Zambia, Zimbabwe, Comoros, Lesotho, Madagascar, Mauritius, Malawi, Mozambique, Namibia, Rwanda, Swaziland, Seychelles, Tanzania, South Africa), mostly Gabon, Democratic Republic Congo, Republic of the Congo, partly Kenya, Sao Tome and Principe, Somalia, Uganda, Equatorial Guinea, Oceania ( Australia, Vanuatu, Nauru, New Zealand, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu, Fiji, mostly Kiribati).South America(Argentina, Bolivia, Paraguay, Peru, Uruguay, Chile, mostly Brazil, Ecuador, partly Colombia.

Astronomical seasons

As we have already said, the main reason for the change of seasons is the tilt of the earth's axis with respect to the plane of the ecliptic. If the Earth's axis were not tilted, then the duration of day and night in any place on the Earth would be the same, and during the day the sun would rise above the horizon at the same height throughout the year. And then there would be no change of seasons. But the Earth's axis forms an angle of 66.56° with the orbital plane. This is clearly seen in this diagram.

Astronomically, the seasons are measured from the points of the summer solstice, autumnal equinox, winter solstice and vernal equinox. There are two equinoxes in a year, when the sun moves from one point of the hemisphere to another: from the Northern Hemisphere to the Southern, and vice versa. spring and autumnal equinox are the transition point from one season to another. On these days, the sunrise begins almost exactly in the east, and the sunset almost exactly in the west.

The interval between the equinoxes is six months, and the whole year is considered to be tropical year, it lasts 365.2422 days. According to the Julian calendar, there are 365¼ days in a year. Therefore, every next year advances by 6 hours, and every fourth year is leap year, where one more day is added, which fall on February 29. Thus, every four years, an additional day returns the equinox to the beginning of the previous number.

Equinox Periods:

• Spring equinox - March 20 - 21. The sun moves from the southern hemisphere to the northern.
• Autumn equinox - 22 - 23 September. The sun moves from the northern hemisphere to the southern.

From March 20 (21) to September 22 (23), due to the tilt of the earth's axis, the Northern Hemisphere faces the Sun for most of the day, so there is more heat and light than in the Southern, where it is winter at this time. In summer, the days become longer and the position of the Sun is higher. Six months later, the Earth moves to the opposite point of its orbit. The axial tilt remains the same, but now the Southern Hemisphere is turned towards the Sun for most of the day, the days are getting longer and warmer. In the Northern Hemisphere, winter sets in at this time.

But the time of year also affects elliptical shape orbits: the seasons have different duration. During the year, the planet Earth either approaches the Sun or moves away from it, which is why the seasons differ in length on different continents of the globe.

For example, in the Northern Hemisphere, summer is longer - 93.6 days (and in the Southern 89 days), autumn - 89.8 days (and in the Southern it is longer - 92.8 days). Winter - 89 days (and in the South - 93.6), spring - 92.8 days (in the South - 89.8).

Climatic seasons

The times of the equinox and solstice must be the middle of the respective seasons. But the climatic seasons are relatively astronomically delayed due to many factors, because. the physical features of earth and water are different in certain places on the planet.

• In the equatorial zone(geographical belt of the Earth, located on both sides of the equator) in winter and summer there are heavy rains, and spring and autumn are relatively dry. This area is characterized trade winds(winds blowing between the tropics all year round. In Indian Ocean they turn into monsoons- winds that periodically change their direction: in summer they blow from the ocean, in winter from land.
• In the tropical zone the cold season is the rainy season, the hot season is the dry season. However, in deserts, rain may not fall even during the cold season.

• In the temperate zone(Western Europe, atlantic coast North America) most of the precipitation occurs in autumn and the first half of winter. In cold weather, snow falls on part of the territory. Spring and summer are characterized by episodic rains with cyclones (atmospheric eddies of huge diameter with reduced pressure air in the center). In the zone temperate continental and continental climate ( Eastern Europe, Southern Siberia The summer months are the wettest, while autumn and winter are drier. In the zone monsoon climate(Far East) Precipitation is more common in summer as heavy rains winter is dry and snowless.
• IN arctic and antarctic belts the change of seasons is expressed only in the change of polar day and polar night. Due to ongoing ice age difference in precipitation levels in different seasons small, and the temperature remains below zero.

Thus, the seasons for the Northern Hemisphere are opposite to the seasons for the Southern Hemisphere. When the Northern Hemisphere is turned towards the Sun, it receives more heat and light, the days become longer and the nights shorter. Six months later, the position of the Sun relative to the Earth changes, so already in the Southern Hemisphere the days become longer, the Sun rises higher, while winter begins in the Northern Hemisphere.

Central Russia is in the zone moderate and moderate continental climate .

spring nature begins to wake up from its winter sleep, this is the period of growth and flowering of plants. Changes are also taking place in the animal world - the breeding season begins, the laying of eggs in birds.

Hello, spring first grass!
How did it dissolve? Are you happy with the warmth?
I know you have fun and crush there,
They work together in every corner.
Stick out a leaf or a blue flower
Everyone hurry young root
Earlier than willow from tender buds
The first one will show a green leaf.

S. Gorodetsky

We see the active growth of plants, the beginning of the ripening of fruits and vegetables, the appearance of chicks.

• The hotter the day, the sweeter in the forest
• Breathe the dry resinous scent
• And I had fun in the morning
• Roam these sunny chambers!
• Shine everywhere, bright light everywhere
• Sand is like silk ... I cling to the gnarled pine
• And I feel: I'm only ten years old,
• And the trunk is a giant, heavy, majestic.
• The bark is rough, wrinkled, red,
• But how warm, how warm the whole sun!
• And it seems that it is not pine that smells,
• And the heat and dryness of a sunny summer.

I. Bunin "Childhood"

The growth of plants slows down, but they give us all their harvest abundantly, the trees shed their leaves, nature is preparing for rest.

Sad time! Oh charm!
Your farewell beauty is pleasant to me -
I love the magnificent nature of wilting,
Forests clad in crimson and gold,
In their canopy of the wind noise and fresh breath,
And the heavens are covered with mist,
And a rare ray of sun, and the first frosts,
And distant gray winter threats.

A.S. Pushkin

in winter nature is resting, many animals fall into hibernation. The natural cycle has ended. But only to start again.

wonderful picture,
How are you related to me?
white plain,
Full moon,

the light of the heavens above,
And shining snow
And distant sleigh
Lonely run.