What is the daily movement of the earth. Annual and daily movements of the earth

The earth is involved in several types of movement: around own axis, along with other planets of the solar system around the sun, along with solar system around the center of the Galaxy, etc. However, the most important for the nature of the Earth are movement around its own axis and around the sun.

The movement of the earth around its own axis is called axial rotation. It is carried out in the direction from west to east(counterclockwise as viewed from the North Pole). Period axial rotation is approximately 24 hours (23 hours 56 minutes 4 seconds), i.e. earth days. Therefore, the axial movement is called daily.

The axial motion of the Earth has at least four main consequences : the figure of the earth; the change of night and day; the emergence of the Coriolis force; occurrence of ebbs and flows.

Due to the Earth's axial rotation, polar contraction, so its figure is an ellipsoid of revolution.

Rotating around its axis, the Earth “directs” one hemisphere, then the other, towards the Sun. On the illuminated side day, on unlit - night. Length of day and night in different latitudes determined by the position of the Earth in orbit. In connection with the change of day and night, a daily rhythm is observed, which is most pronounced in wildlife objects.

Earth's rotation "forces" moving bodies deviate from the direction of its original movement, and in Northern Hemisphere - to the right, and in the Southern - to the left. The deflecting action of the earth's rotation is called Coriolis forces. The most striking manifestations of this power are deviations in the direction of travel air masses (the trade winds of both hemispheres acquire an eastern component), ocean currents, river flows.

The attraction of the Moon and the Sun, together with the axial rotation of the Earth, cause the occurrence of tidal phenomena. A tidal wave circles the Earth twice a day. Ebb and flow are characteristic of all geospheres of the Earth, but they are most clearly expressed in the hydrosphere.

No less important for the nature of the earth is its orbital motion around the sun.

The shaving of the Earth has an elliptical shape, that is, at its different points, the distance between the Earth and the Sun is not the same. AT July Earth is further from the Sun (152 million km), and therefore its orbital motion slows down slightly. As a result, the Northern Hemisphere receives more heat than the Southern Hemisphere, and summers are longer here. AT January the distance between the Earth and the Sun is minimal and equals 147 million km.

Period orbital movement is 365 full days and 6 hours. Everyone fourth year counts leap year, that is, it contains 366 days, insofar as for 4 years, extra days accumulate. It is generally accepted that the main consequence of orbital motion is the change of seasons. However, this is not only the result annual movement Earth, but also because of the inclination of the earth's axis to the plane of the ecliptic, and also due to the constancy of the value of this angle, which is 66.5°.

The Earth's orbit has several key points that correspond to the days of the equinoxes and solstices. June, 22 – day summer solstice. On this day, the Earth is turned towards the Sun by the Northern Hemisphere, so it is summer in this hemisphere. The sun's rays are incident at right angles on a parallel 23.5°N- northern tropic. On the Arctic Circle and within it - polar day, on the Antarctic Circle and south of it - polar night.

December 22, in winter solstice, the Earth in relation to the Sun occupies, as it were, the opposite position.

During the equinoxes, both hemispheres are equally illuminated by the Sun. The sun's rays fall at right angles to the equator. Throughout the Earth, except for the poles, the day is equal to the night, and its duration is 12 hours. At the poles there is a change of polar day and night.

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Motion double planet Earth-Moon and tidal friction.

Lighting belts.

DAILY AND ANNUAL ROTATION OF THE EARTH

1. Daily rotation of the Earth and its significance for geographical envelope.

2. The annual rotation of the Earth around the Sun and its geographical significance.

The earth makes 11 different movements, of which the following are of great geographical importance: 1) daily rotation around the axis; 2) annual circulation around the Sun; 3) movement around the common center of gravity of the Earth-Moon system.

The axis of rotation of the Earth is deviated from the perpendicular to the plane of the ecliptic by 23 0 26.5'. The angle of inclination when moving in orbit around the Sun is conserved.

The axial rotation of the Earth occurs from west to east or counterclockwise when viewed from the North Pole of the World. This direction of motion is inherent in the entire Galaxy.

The time of rotation of the Earth around its axis can be determined from the Sun and from the stars. solar days called the time interval between two successive passages of the Sun through the meridian of the observation point. Due to the complexity of the movement of the Sun and the Earth, the true solar day change. Therefore, to determine the average solar time, such days are used, the duration of which is equal to the average length of the day during the year.

Due to the fact that the Earth moves in the same direction in which it rotates around its axis, the solar day is somewhat longer than the actual time of a complete revolution of the Earth. The actual time of a complete rotation of the Earth is determined by the time between two passages of a star through the meridian of a given place. A sidereal day is equal to 23 hours 56 minutes and 4 seconds. That's what it is real time daily turnover of the earth.

Angular velocity rotation , i.e., the angle by which any point on the surface of the Earth rotates in any period of time is the same for all latitudes. In one hour, the point runs 15 0 (360 0: 24 hours = 15 0). Line speed depends on latitude. At the equator it is equal to 464 m/s, decreases towards the poles.

Time of day - morning, afternoon, evening and night - on the same meridian begin at the same time. However, the labor activity of people in different parts Earth requires an agreed account of time. For this purpose, introduced standard time.

The essence of zone time lies in the fact that the Earth, in accordance with the number of hours in a day, is divided by meridians into 24 zones, going from one to the other pole. The width of each belt is 15 0 . The local time The average meridian of one zone differs from the neighboring zone by 1 hour. In fact, the boundaries of time zones on land are not always drawn along meridians, but often along political and geographical boundaries.

The rotation of the Earth around its axis provides an objective basis for constructing graticule. In a rotating sphere, two points are objectively distinguished, to which a coordinate grid can be attached. These points are poles that do not participate in rotation, and therefore are fixed.

Earth's axis of rotation - this is a straight line passing through the center of its mass, around which our planet rotates. The points of intersection of the axis of rotation with the Earth's surface are called geographic poles ; there are two of them - north and south. north pole called the one from which the planet rotates counterclockwise, like the whole galaxy.

The line of intersection of a great circle, the plane of which is perpendicular to the axis of rotation, with the surface the globe called geographic or earthly equator . We can say that the equator is a line that is equidistant from the poles at all points. The equator divides the Earth into two hemispheres: northern and southern. The opposition between the northern and southern hemispheres is not only purely geometric. The equator is the line of change of seasons and the deviation of moving bodies to the right and left, and it is also the visible path of the movement of the Sun and the entire sky.

Small circles, the planes of which are parallel to the equatorial, intersecting with the earth's surface, form geographical parallels. The distance of the parallels, as well as all other points, from the equator is expressed geographical latitude . From point of view rotary motion Earth's latitude is the angle between the plane earth's equator and a plumb line at that point. In this case, the Earth is taken as a homogeneous ball with a radius of 6,371 km. In this case, latitude can be understood as remoteness desired point from the equator in degrees. Unlike geographical latitude, geodetic latitude is defined not only on a ball, but also on a spheroid as the angle between the equatorial plane and the normal to the spheroid at a given point.

Great circle intersection line passing through geographic poles and through the desired point, with the surface of the globe is called meridian given point. The plane of the meridian is perpendicular to the plane of the horizon. The line of intersection of these two planes is called noon line . There is no objective criterion for determining the prime meridian. By international agreement the meridian of the observatory in Greenwich (outskirts of London) was taken as the initial meridian.

Longitudes are counted from the prime meridian. Geographic longitude called dihedral angle between the meridian planes: the starting point and the desired point, or the distance in degrees from the starting meridian to a specific location. Longitudes can be counted in one direction, in the direction of the Earth's movement, that is, from west to east, or in two directions. This rule, however, allows exceptions: for example, Cape Dezhnev, extreme point Asia, can be considered both at 170 0 W and at 190 0 E.

The conventionality of counting longitudes makes it possible to divide the Earth not along the initial meridian, but along the principle of full coverage of the continents .

For the geographic envelope and the nature of the Earth as a whole, the axial rotation of the Earth is of great importance, in particular:

1. The axial rotation of the Earth creates the basic unit of time - a day, dividing the Earth into two parts - illuminated and unlit. With this unit of time in the process of evolution organic world the physiological activity of animals and plants turned out to be coordinated. The change of tension (work) and relaxation (rest) is an internal need of all living organisms. Obviously the main synchronizer biological rhythms there is an alternation of light and dark. This alternation is associated with the rhythm of photosynthesis, cell division and growth, respiration, the glow of algae, and many other phenomena in the geographical envelope.

The most important feature depends on the day thermal regime earth's surface– change of day heating and night cooling. At the same time, not only this change in itself is important, but also the duration of the periods of heating and cooling.

The daily rhythm is also manifested in inanimate nature: in heating and cooling rocks and weathering, temperature conditions, air temperature, ground precipitation, etc.

2. The most important meaning of the rotation of geographic space is to divide it into right and left. This causes the paths of moving bodies to deviate to the right in the northern hemisphere and to the left in the southern hemisphere.

Back in 1835 the mathematician Gustave Coriolis formulated the theory of relative motion of bodies in a rotating frame of reference . rotating geographic space and is such a fixed system. Deviation of movement to the right or left is called Coriolis force or Coriolis acceleration . The essence of this phenomenon is as follows. The direction of movement of bodies, of course, is rectilinear relative to the axis of the World. But on Earth, it occurs on a rotating sphere. Under the moving body, the horizon plane turns to the left in the northern hemisphere and to the right in the southern hemisphere. Since the observer is on a solid surface of a rotating sphere, it seems to him that the moving body deviates to the right, while in fact the horizon plane goes to the left. All masses moving on Earth are subject to the action of the Coriolis force: water in oceanic and sea currents, air masses in the process of atmospheric circulation, matter in the core and mantle.

3. Rotation of the Earth (together with spherical shape) in field solar radiation(light and heat) determines the west-east extension natural areas and geographic zones.

4. Due to the rotation of the Earth, ascending and descending air currents, disordered in different places, acquire predominant helicity. Air masses obey this pattern, ocean waters, and also, probably, the substance of the nucleus.

Earth commits full turn around the Sun in 365 days and 6 hours. For convenience, it is customary to assume that there are 365 days in a year. And every four years, when the extra 24 hours “accumulate”, there comes leap year, in which not 365, but 366 days (29 - in February).

In September, after summer holidays you come back to school, autumn comes. The days are getting shorter and the nights are longer and cooler. In a month or two, leaves will fall from the trees, migratory birds will fly away, and the first snowflakes will swirl in the air. In December, when the snow covers the earth with a white veil, winter will come. The most short days in a year. The sunrise at this time is late and the sunset is early.

In March, when spring comes, the days lengthen, the sun shines brighter, the air becomes warmer, streams begin to murmur all around. Nature comes to life again, and soon the long-awaited summer begins.

So it has been and will always be from year to year. Have you ever wondered why the seasons change?

Geographic Consequences of the Earth's Movement

You already know that the Earth has two main movements: it rotates on its axis and orbits around the Sun. Wherein earth's axis inclined to the plane of the orbit by 66.5°. The movement of the Earth around the Sun and the tilt of the earth's axis determine the change of seasons and the length of day and night on our planet.

Twice a year, in spring and autumn, there come days when the length of the day on the whole Earth is equal to the length of the night - 12 hours. Day spring equinox comes March 21-22, the day of the autumnal equinox September 22-23. At the equator, day is always equal to night.

The longest day and the shortest night on Earth occur in the Northern Hemisphere on June 22, and in the Southern Hemisphere on December 22. These are the summer solstice.

After June 22, due to the movement of the Earth in orbit, in the Northern Hemisphere, the height of the Sun above gradually decreases, the days become shorter, and the nights become longer. And in the Southern Hemisphere, the Sun rises higher above the horizon and daylight hours increase. The southern hemisphere is getting more and more solar heat, and the North - less and less.

The shortest day in the Northern Hemisphere is on December 22, and in the Southern Hemisphere on June 22. This is the winter solstice.

At the equator, the angle of incidence of the sun's rays on the earth's surface and the length of the day change little, so it is almost impossible to notice the change of seasons there.

On some features of the motion of our planet

There are two parallels on Earth, on which the Sun at noon on the days of the summer and winter solstices is at its zenith, that is, it stands directly above the observer's head. Such parallels are called tropics. On the Northern Tropic (23.5 ° N), the Sun is at its zenith on June 22, on the Southern Tropic (23.5 ° S) - on December 22.

The parallels located at 66.5° north and south latitude are called the polar circles. They are considered the boundaries of the territories where polar days and polar nights. The polar day is the period when the Sun does not fall below the horizon. The closer from polar circle to the pole, the longer the polar day. At the latitude of the Arctic Circle, it lasts only one day, and at the pole - 189 days. In the Northern Hemisphere at the latitude of the Arctic Circle, the polar day begins on June 22 on the day of the summer solstice, and in the Southern Hemisphere - on December 22. The duration of the polar night varies from one day (at the latitude of the polar circles) to 176 (at the poles). All this time the Sun does not appear above the horizon. In the Northern Hemisphere, this natural phenomenon begins on December 22, and in the Southern Hemisphere on June 22.

It is impossible not to note that wonderful period at the beginning of summer, when the evening dawn converges with the morning and twilight, white nights last all night. They are observed in both hemispheres at latitudes exceeding 60, when the Sun at midnight falls below the horizon by no more than 7 °. In (about 60° N) white nights last from June 11 to July 2, and in Arkhangelsk (64° N) from May 13 to July 30.

Light belts

The consequence of the annual motion of the Earth and its daily rotation is an uneven distribution sunlight and heat on the earth's surface. Therefore, there are belts of illumination on Earth.

Between the northern and southern tropics on both sides of the equator lies tropical belt illumination. It occupies 40% of the earth's surface, which accounts for the largest number sunlight. Between the tropics and the polar circles in the southern and northern hemispheres are temperate zones illumination, receiving less sunlight than the tropical zone. From the Arctic Circle to the Pole, each hemisphere has polar belts. This part of the earth's surface receives the least amount of sunlight. Unlike other belts of illumination, only here there are polar days and nights.

The earth makes 11 different movements. Of these, the most important geographical importance possess diurnal movement e around the axis and annual circulation around the sun.

The following definitions are introduced: aphelion- the most remote point in orbit from the Sun (152 million km), the Earth passes through it on July 5. Perihelion- the nearest point in orbit from the Sun (147 million km), the Earth passes through it on January 3. The total length of the orbit is 940 million km. The farther from the Sun, the slower the speed. Therefore, in the northern hemisphere, winter is shorter than summer. The earth rotates on its axis from west to east, making a complete revolution per day. The axis of rotation is constantly inclined to the plane of the orbit at an angle of 66.5°.

diurnal movement.

The movement of the earth around its axis is from west to east , a complete revolution is completed in 23 hours 56 minutes 4 seconds. This time is taken as day. At the same time, the Sun is rises in the east and moves to the west. The daily movement has 4 consequences :

• compression at the poles and the spherical shape of the Earth;
• the change of night and day;
• the emergence of the Coriolis force - the deviation of horizontally moving bodies in the Northern Hemisphere to the right, in the Southern Hemisphere - to the left, this affects the direction of movement of air masses, sea ​​currents etc.;
• occurrence of ebbs and flows.

Earth's annual revolution

Earth's annual revolution is the movement of the earth in an elliptical orbit around the sun. The earth's axis is inclined to the plane of the orbit at an angle of 66.5°. When revolving around the Sun, the direction of the earth's axis does not change - it remains parallel to itself.

geographical consequence annual rotation Earth is change of seasons , which is also due to the constant tilt of the earth's axis. If the earth's axis did not have an inclination, then during the year on Earth the day would be equal to the night, the equatorial regions would receive the most heat, and it would always be cold at the poles. The seasonal rhythm of nature (the change of seasons) is manifested in a change in various meteorological elements - air temperature, its humidity, as well as in a change in the regime of water bodies, the life of plants and animals, etc.

The Earth's orbit has several important points corresponding to the days equinoxes and solstices.

June, 22 The summer solstice is the longest day of the year in the Northern Hemisphere and the shortest day in the Southern Hemisphere. On the Arctic Circle and inside it on this day - polar day , on the Antarctic Circle and inside it - polar night .

December 22- the day of the winter solstice, in the northern hemisphere - the shortest, in the southern - the longest day of the year. Within the Arctic Circle - polar night , the Antarctic Circle - polar day .

March 21 and 23 September- the days of the spring and autumn equinoxes, since the rays of the Sun fall vertically on the equator, on the whole Earth (except for the poles) day is equal to night.

Remember! What is called the Earth's orbit? What hemispheres does the equator divide the Earth into?

Every day the Sun rises in the morning, at noon it stands high in the sky, and in the evening it hides behind the horizon and night falls. Why is this happening?

Think! Or can the Sun illuminate the entire Earth at the same time? Why? Can they Sun rays to go through the Earth or go around it? Why?

Rice. 13. Rotation of the Earth around its axis

Earth - opaque cosmic body, which moves around its axis from west to east. When one side of the Earth, turned towards the Sun and illuminated by its rays, then opposite side at this time is in the shade. On the illuminated side it is day, on the unlit side it is night. The Earth makes a complete revolution around its axis in one day, which lasts 24 hours. Therefore, the rotation of the Earth around its axis causes a change of day and night.

Rotating around its axis, the Earth simultaneously moves in orbit around the Sun.

It is essential that the imaginary axis of the Earth is always located at the same angle. During the movement around the Sun, our planet returns to it more with either the Southern or the Northern hemisphere. When the Northern Hemisphere is turned to the Sun, it receives a lot of light and heat, and summer reigns on it. It is winter in the Southern Hemisphere at this time.

Rice. 14. Annual motion of the Earth around the Sun

The earth is constantly moving. Gradually, it turns more and more towards the Sun with the Southern Hemisphere and turns away from it with the Northern Hemisphere. Where it was summer, autumn comes, and in the Southern Hemisphere, after a cold winter, spring comes.

Continuing to move, after a while the Earth turns towards the Sun so that the Northern Hemisphere is illuminated and warmed even less, and the Southern Hemisphere even more. Then winter comes in the Northern Hemisphere, and summer in the Southern Hemisphere.

Subsequently, the Earth again begins to return to the Sun in the Northern Hemisphere. It gets warmer and spring comes, and autumn comes to the Southern Hemisphere.

So North and southern hemisphere Earth during its rotation around the Sun at the same time receive an unequal amount of sunlight and heat, which causes the change of seasons.

The Earth makes a complete revolution around the Sun in one year, which lasts 365 days 5 hours 48 minutes 46 seconds. This number is rounded up and for three years, 365 days are recorded in the calendar. For 4 years, 5 hours with minutes and seconds are added, and one more epoch is obtained. Therefore, every fourth year in the calendar appears on February 29th. A year of 366 days is called a leap year.

Discuss! What would the earth be like if the axis were not tilted?

Leap year.

Test your knowledge

1. Why is there a change of day and night on Earth?

2. What is a day? How long does it last?

3. Why do seasons change on Earth?

4. How long is a typical Earth year? What about leap?

5. According to Dima, if the Sun illuminates the Northern Hemisphere more, then spring comes on its territory. Is the boy right? Explain why.

Let's sum it up together

The earth simultaneously carries out daily and annual movement. The change of day and night is a consequence of its rotation around its axis, which lasts 24 hours - a day. A year is the period of time it takes for the Earth to complete one revolution around the Sun. It lasts approximately 365 days. The movement of the Earth around the Sun causes the seasons to change.

A highlight for the curious

The earth moves around its axis at a certain speed. It is greatest at the equator and is 464 m/s. average speed movement of the Earth around the Sun 30 km/sec.