Explanation of the seasons. Seasons on the planets of the solar system

Spring has come. The gray and dull snow disappeared from the fields, and the sun became warmer and more gentle. Nature awakens: the first greenery begins to emerge, the buds on the trees swell and bloom, and return migratory birds, and living creatures get out of holes and nests. Soon summer, autumn, winter and again will come spring will come. Seasons change on our planet from year to year.

But what ensures these cyclical changes in nature? The main reason for the change of seasons is the tilt of the axis of our planet relative to the ecliptic plane, i.e. the plane of rotation of the Earth around the Sun. The Earth's axis is tilted from the ecliptic plane by 23.44°. If this angle were equal to zero, the seasons would never change on the planet, the length of day and night would be the same, and the sun would rise above the horizon to the same height throughout the year.

Do seasons change on other planets in the solar system?

Mercury

If we take into account only that indicator that has a decisive influence on the formation of the seasons on Earth, the tilt of the rotation axis, then Mercury should not have the seasons we are accustomed to. However, Mercury moves in a very elongated orbit, approaching the Sun at perihelion by 46 million km and moving away by 70 million km at aphelion, which has a significant influence on the formation of Mercury's weather. Being at a short distance from the Sun, the illuminated side of Mercury heats up to an average of +300°C (maximum: +427°C) and the Mercury summer begins. In the far part of the orbit, winter sets in; even during the day at this time the temperature does not rise above 107°C, and at night it drops to -193°C.

Sunrise on Mercury occurs only once every two years (every 176 days), but it is the hottest sunrise in the entire system.

At the same time, almost no sunlight reaches the poles of Mercury due to the minimal inclination of the rotation axis to the ecliptic plane (0.01°). In these dark and cold regions, polar ice caps have been discovered, although they are only 2 meters thick.

Interestingly, a day (175.94 Earth days) on Mercury lasts twice as long as a year (87.97 Earth days).

On Venus, like on Mercury, there is also no change of seasons. Venus' rotation axis angle is an impressive 177°, in other words, this planet has an inverted orientation, and the actual inclination angle is only 3°. Orbital eccentricity, i.e. its degree of deviation from the circle is extremely small (0.01) and therefore does not make any adjustments to the weather. All year round A hot summer reigns on the surface of the planet: average temperature exceeds +400°C.

It reigns on Venus all year round sultry heat, average temperature about +400°C.

Mars

Mars is similar to our planet in many ways. The inclination of the axis of rotation of Mars relative to the plane of its orbit is 25.2°, which is only slightly greater than that of Earth. The eccentricity of the Red Planet's orbit is also slightly larger. As a result, the Martian climate is slightly more seasonal, in other words, the difference (especially in temperature) between at different times year is more pronounced.

Another one interesting feature Martian seasons is that they differ significantly in different hemispheres of the planet. So in southern hemisphere hot summers and Cold winter, while in the north there are no such contrasts - both summer and winter here are mild.

Jupiter

The axis of rotation of the giant planet is inclined by only 3.13° relative to the orbital plane, and the degree of deviation of the orbit itself from the circle is also minimal (0.05). In other words, the climate here is not seasonal and is constant throughout the year.

Saturn

The tilt of Saturn's rotation axis is 29°, so the change of seasons on this planet is characterized by more pronounced differences in the amount of sunlight, and therefore temperature, than on Earth. Each season - be it summer or autumn - lasts about 7 years on the giant planet. Depending on the time of year, Saturn can change its color. Eight years ago, when Cassini first approached the planet, it was winter in the northern hemisphere and this part of Saturn had a blue tint. Today the south is painted blue - winter has arrived there. According to astronomers, this phenomenon occurs due to the intensity of ultraviolet radiation - in winter it decreases, with the arrival of summer it increases.

Winter on Saturn's southern hemisphere. The blue haze that covers the south pole of the planet is a direct consequence of the drop in temperature, i.e. the arrival of winter. 10 years ago, in 2004, exactly the same blue fog enveloped North Pole gas giant.

Uranus

The angle of inclination of the planet's rotation axis is 97.86° - in other words, Uranus lies on its side slightly upside down. This factor explains the rather specific change of seasons. During solstices, only one of the planet's poles faces the Sun. The change of day and night that is familiar to us is characteristic only of the equator; the remaining parts of Uranus are under the cover of the polar day or polar night for 42 Earth years.

Voyager 2 photograph of Uranus

At the pole facing the Sun, dramatic changes: the temperature increases significantly, the upper layers of the atmosphere slowly begin to acquire bright colors, replacing the pale blue hue, the speed of winds and the number of clouds increase.

Neptune

On Neptune, the rotation axis is tilted by 30°, so the seasons here are similar to those on Earth, but the planet’s distance from the Sun makes its own adjustments. A year on Neptune is almost 165 earthly years, therefore, each season lasts, no more no less, 41 years! Summer began in the southern hemisphere in 2005 and will last until 2046.

Seasons- parts of the year that differ in climatic characteristics. For example in temperate latitudes there are 4 seasons - spring, summer, autumn and winter, and in tropical areas - dry and rainy climatic seasons.

How the seasons change

The seasons clearly depend on astronomical phenomena. As the Earth moves in orbit around the Sun, the climate on Earth also changes (Fig. 1). The figure shows four positions of our planet. So the time of year is considered the period during which the Earth passes between these positions. The earth completes a circle in 365 days. Home The angle of the Earth's inclination (23.5) plays a role in the implementation of the seasons. It is the tilt of the Earth that brings one side halfway, then the other halfway around the Sun. In other words, either the Northern or Southern hemisphere of the Earth is closer to the Sun relative to the entire planet. If there were no such angle of inclination, seasons would not exist. Over the entire journey (year), the Earth would be illuminated and heated equally relative to the Sun.

Difference in the length of the seasons

The duration of the seasons and their changes depend on speed movement of the Earth in orbit around the Sun. The closest point in the orbit to the Sun is called - perihelion. It's January 2nd. At this time, the Earth has a high speed, which is why winter is very shorter than other seasons in the Northern Hemisphere. And in the south it’s the other way around. Also from this emerge indirect and direct reasons for the change in seasons. Direct ones include:

• Seasonal changes in the length of daylight hours. In summer, the days are long and the nights are short. In winter it's the opposite.
• Seasonal changes in the height of the sun at midday above the horizon.
• Seasonal modifications in the path length of solar rays in the atmosphere affect the degree of their absorption. Absorption occurs in

Indirect ones include:

• spherical shape of the earth
• Parallelism of sun rays
• The tilt of the Earth about its axis

Difference between hemispheres

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

The seasons in the Northern and Southern Hemispheres are opposite. The earth has climatic zones. This exists because physical characteristics surface of the earth and water. On different continents climatic seasons begin differently relative to the astronomical time of year.

In hot countries, the seasons appear slightly differently than in mid-latitudes. For example, in India there is a very severe drought in winter. In winter, the winter monsoon blows from the land to the sea. In spring, the winds blow from the sea to the land, thereby bringing moisture with them.

The North and South Poles have the same climate. Always Winter. The difference between Winter and Summer is the amount of light, not heat. In spring and summer, the sun moves across the sky all the time, so the day is around the clock. In winter it is continuous night.

four periods of the year (spring, summer, autumn and winter) characterized by certain average temperatures. The beginning of each season has a clear astronomical boundary. The ecliptic (the apparent path of the Sun's movement across the celestial sphere) is divided by four points - the spring and autumn equinoxes and the summer and winter solstices - into 90° sectors. The period during which the Sun passes through one of these sectors is called the season. Spring in the Northern Hemisphere and autumn in the Southern Hemisphere begin when the Sun passes through the initial circle of declination and its right ascension is 0° (vernal equinox). Summer in the Northern Hemisphere and winter in the Southern Hemisphere occur when the sun's right ascension is 90° ( summer solstice). Autumn in the Northern Hemisphere and spring in the Southern Hemisphere begin when the sun's right ascension is 180° (autumn equinox). The beginning of winter in the Northern Hemisphere and summer in the Southern Hemisphere is considered winter solstice when the sun's right ascension is 270°.

Intertropical space. In the low latitudes between the Northern and Southern Tropics, temperatures are always high and vary little from month to month. Annual amplitude temperatures (the difference between the temperatures of the warmest and coldest months) never exceeds 11 ° C, and near the equator it is less than 2 ° C. Seasonal differences are due to the distribution atmospheric precipitation. In such areas, with the exception of the equatorial strip itself, where there are no seasonal changes at all, winter corresponds to a dry season, and summer to a wet one.

Temperate latitudes are characterized by clearly expressed seasonal changes temperatures The cold season is called winter, the warm season is called summer, and autumn and spring are transitional seasons. Temperate latitudes experience a wide variety of conditions. In some regions it is very hot in summer (from +32 to +38° C), in others it is cool (on average +10° C). Winters can be very mild (+4°C) or very cold (on average 23°C). Moreover, since at these latitudes the contrasting arctic and subtropical air masses, the weather here is very unstable and changes quickly both from day to day and from year to year.

Polar regions. Towards the poles from the Arctic and Southern Polar Circles, two types of climate are distinguished: ice sheet climate and tundra climate (the latter only in the Northern Hemisphere). The differences between the seasons within the ice sheets are that in summer there is a polar day, in winter there is a polar night, and in spring and autumn there is a change of day and night. Summer temperatures here are only sufficient to ensure the melting of the surface layer of snow. In tundra regions, average temperatures above 0°C occur for two to four months. see also METEOROLOGY AND CLIMATOLOGY.

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Why do the seasons change? Ancient thinkers and astronomers of Greece believed that the change of seasons was explained by mystical reasons that had nothing to do with the movement of the planets in the solar system.

Moreover, for them the rest of the universe was in motion around our planet, while the Earth itself remained motionless. A similar model was preserved in the Middle Ages, for religious reasons.

Nicolaus Copernicus made a revolution by proving that the Earth and other planets move around the Sun, and, as we will see, it is this movement that explains the change of seasons.

Movement around the Sun is the answer to the question

Earth from the Elektro-L satellite. The video shows how the Earth changed from January 1 to December 31, 2012.

Our planet has two constant movements: it moves around its axis, and also revolves around the Sun. The first movement explains the change of day and night - one full revolution occurs in 24 hours, we call it a day. The second movement is the immediate cause of the change of seasons.

The axis of the planet is at an indirect angle to the sun's rays falling on it; if it were otherwise, the change of seasons would never occur, night and day would always be the same and last 12 hours, both at the equator, and in London, and in polar region

However, the axis is tilted with respect to the sun's rays and does not align with them. right angle, therefore, within six months, the northern hemisphere receives most of the sun's heat, providing the sun's rays with a larger surface area than the southern hemisphere. The same thing happens to the southern hemisphere during the other half of the year.

Why is it warmer in the South all year round?

Since the Earth is at different distances relative to the Sun during its orbit, summers in the southern hemisphere are warmer than summers in the northern hemisphere. This is explained by the fact that at the moment when the distance between the Earth and the Sun is minimal, it is the Southern Hemisphere that is closer to the Sun than the Northern Hemisphere.

Of course, in South Africa There is winter and snow falls, but winter in South Africa and Australia is much warmer than winter in Russia on the Yamal Peninsula or in the New Guinea archipelago.

The change of seasons, mounted on the basis of images of the geostationary satellite METEOSAT-9, obtained during the period from December 21, 2010 to September 20, 2011.

Conclusion

So, the change of seasons occurs due to two factors: firstly, it is the movement of the Earth around the Sun in an elliptical orbit, and secondly, it is an indirect angle between the Earth’s orbit and the sun’s rays. Without one of these two factors, the seasons would never change on Earth.

However, the question arises: what time of year would it be in this case on Earth? endless winter or eternal summer? Answer: neither one nor the other. The fact is that if the earth’s axis were not tilted, there would be eternal summer at the equator, where the rays fall at right angles, and the further from the equator, the colder it is. If our planet did not move around the Sun, but the axis was also inclined in relation to the sun's rays, there would be eternal summer in one of the hemispheres, and winter in the other, depending on the location of the Earth relative to the Sun.

07.10.2018 03:51 776

You guys are well aware that in nature there are four seasons: winter, spring, summer and autumn. Each season has its own natural and weather changes. Let's remember which ones?

The cold and snowy winter is replaced by spring. At this time it becomes warmer, the snow begins to melt, trees and plants come to life. Some animals wake up after hibernation. Birds make their nests. Trees develop buds from which leaves grow. After spring comes summer. In summer it becomes very warm, flowers bloom everywhere, grass grows, trees rustle with their leaves. Animals and birds lead a normal life. Summer gives way to autumn. It's getting colder outside. The leaves on the trees turn yellow and then fall to the ground. The flowers no longer bloom, and their petals fall off. Birds are flying south, and some animals are preparing for hibernation.

Why do the seasons change? Let's try to figure it out.

Our planet rotates not only around its own axis, but also around the Sun. The Earth's axis is a conventional line that crosses our planet through the north and south poles. Therefore, if you have a globe at home, please note that it is located at an angle. Thus, it shows that the Earth is tilted by 23.5 degrees.

There are 2 reasons for the change of seasons. The first reason is that the orbit in which the Earth revolves around the Sun is elongated in the shape of an ellipse. Therefore, at some point in time our planet will be further from the Sun, and at some point closer. The second reason is the Earth’s axis, which has already been described earlier. Because of its inclination, our planet, moving along its orbit, alternately exposes the celestial body to the northern and southern hemispheres. When Sun rays illuminate the northern hemisphere - summer is coming there, and in the southern hemisphere at that moment it is winter and vice versa.

To make this more clear to you guys, try shining a flashlight on a globe that is tilted. Holding the flashlight level, you will see that one part of the globe (either the bottom or the top) receives more light, and the other less.

And if in a day our planet makes a full revolution around its axis, then in a year it goes all the way around the Sun in its orbit.