Distribution of heat on the ground. Distribution of heat over the earth's surface The supply of fresh water on the earth is
With the help of this video tutorial, you can independently study the topic "The distribution of sunlight and heat". First, discuss what determines the change of seasons, study the diagram of the Earth's annual rotation around the Sun, paying special attention to the four most remarkable dates in terms of solar illumination. Then you will find out what determines the distribution of sunlight and heat on the planet and why it is uneven.
Rice. 2. Illumination of the Earth by the Sun ()
In winter, the southern hemisphere of the Earth is better illuminated, in summer - the northern one.
Rice. 3. Scheme of the annual rotation of the Earth around the Sun
Solstice (summer solstice and winter solstice) - moments when the Sun's height above the horizon at noon is highest (summer solstice, June 22) or lowest (winter solstice, December 22). In the southern hemisphere, the opposite is true. On June 22, the greatest illumination by the Sun is observed in the Northern Hemisphere, the day is longer than the night, a polar day is observed beyond the polar circles. In the southern hemisphere, again, the opposite is true (i.e. all this is typical for December 22).
Polar Circles (Arctic Circle and Antarctic Circle) - parallels, respectively, with latitude north and south about 66.5 degrees. North of the Arctic Circle and south of the Antarctic Circle, there is a polar day (in summer) and a polar night (in winter). The area from the Arctic Circle to the Pole in both hemispheres is called the Arctic Circle. Polar day - a period when the Sun at high latitudes does not descend beyond the horizon around the clock.
polar night - the period when the Sun at high latitudes does not rise above the horizon around the clock - a phenomenon opposite to the polar day is observed simultaneously with it at the corresponding latitudes of the other hemisphere.
Rice. 4. Scheme of the illumination of the Earth by the Sun by zones ()
Equinox (vernal equinox and autumnal equinox) - moments when the sun's rays touch both poles and fall vertically at the equator. The spring equinox occurs on March 21st, and the autumnal equinox on September 23rd. These days both hemispheres are lit the same, day is equal to night,
The main reason for the change in air temperature is a change in the angle of incidence of sunlight: the more vertically they fall on the earth's surface, the better they warm it up.
Rice. 5. The angles of incidence of the sun's rays (at the position of the Sun 2, the rays warm up the earth's surface better than at position 1) ()
On June 22, the sun's rays fall most steeply on the northern hemisphere of the Earth, thereby warming it up to the greatest extent.
Tropics - The Northern Tropic and the Southern Tropic are parallels, respectively, with latitudes north and south of about 23.5 degrees. On one of the solstice days, the Sun is above them at noon at its zenith.
The tropics and polar circles divide the Earth into light belts. Illumination belts - parts of the Earth's surface bounded by the tropics and polar circles and differing in lighting conditions. The warmest zone of illumination is tropical, the coldest is the polar one.
Rice. 6. Light belts of the Earth ()
The sun is the main luminary, on the position of which the weather on our planet depends. The moon and other cosmic bodies have an indirect effect.
Salekhard is located on the line of the Arctic Circle. An obelisk to the Arctic Circle has been erected in this city.
Rice. 7. Obelisk to the Arctic Circle ()
Cities where you can watch the polar night: Murmansk, Norilsk, Monchegorsk, Vorkuta, Severomorsk, etc.
Homework
Clause 44.
1. Name the days of the solstice and the days of the equinox.
Bibliography
The main
1. An initial course in geography: textbook. for 6 cl. general education. institutions / T.P. Gerasimova, N.P. Neklyukova. - 10th ed., Stereotype. - M .: Bustard, 2010 .-- 176 p.
2. Geography. 6th grade: atlas. - 3rd ed., Stereotype. - M .: Bustard; DIK, 2011 .-- 32 p.
3. Geography. 6th grade: atlas. - 4th ed., Stereotype. - M .: Bustard, DIK, 2013 .-- 32 p.
4. Geography. 6 cl .: cont. maps: M .: DIK, Bustard, 2012 .-- 16 p.
Encyclopedias, dictionaries, reference books and statistical compilations
1. Geography. Modern Illustrated Encyclopedia / A.P. Gorkin. - M .: Rosmen-Press, 2006 .-- 624 p.
Literature for preparing for the State Examination and the Unified State Exam
1. Geography: Initial course: Tests. Textbook. manual for students of 6 cl. - M .: Humanit. ed. center VLADOS, 2011 .-- 144 p.
2. Tests. Geography. 6-10 grades: Study guide / A.A. Letyagin. - M .: OOO "Agency" KRPA "Olymp": "Astrel", "AST", 2001. - 284 p.
1.Federal Institute of Pedagogical Measurements ().
2. Russian Geographical Society ().
3.Geografia.ru ().
Video tutorial 2: Atmosphere structure, meaning, study
Lecture: Atmosphere. Composition, structure, circulation. Distribution of heat and moisture on the Earth. Weather and climate
Atmosphere
Atmosphere can be called an all-pervading shell. Its gaseous state allows it to fill microscopic holes in the soil, water is dissolved in water, animals, plants and humans cannot exist without air.
The conditional thickness of the envelope is 1500 km. Its upper boundaries dissolve in space and are not clearly marked. The atmospheric pressure at sea level at 0 ° C is 760 mm. rt. Art. The gas shell consists of 78% nitrogen, 21% oxygen, 1% other gases (ozone, helium, water vapor, carbon dioxide). The density of the air envelope changes with rise in height: the higher, the more rarefied the air. This is why climbers can experience oxygen deprivation. The very surface of the earth has the greatest density.
Composition, structure, circulation
Layers are distinguished in the shell:
Troposphere, 8-20 km thick. Moreover, at the poles, the thickness of the troposphere is less than at the equator. This small layer contains about 80% of the entire mass of air. The troposphere tends to heat up from the surface of the earth, therefore its temperature is higher near the earth itself. With a rise up 1 km. the temperature of the air envelope decreases by 6 ° C. In the troposphere, there is an active movement of air masses in the vertical and horizontal directions. It is this shell that is the "factory" of the weather. Cyclones and anticyclones are formed in it, westerly and easterly winds blow. All water vapor is concentrated in it, which condenses and sheds rain or snow. This layer of the atmosphere contains impurities: smoke, ash, dust, soot, everything we breathe. The layer bordering the stratosphere is called the tropopause. This is where the temperature drop ends.
Approximate boundaries stratosphere 11-55 km. Up to 25 km. There are minor changes in temperature, and above it begins to rise from -56 ° C to 0 ° C at an altitude of 40 km. Another 15 kilometers, the temperature does not change, this layer was called the stratopause. The stratosphere contains ozone (O3), a protective barrier for the Earth. Due to the presence of the ozone layer, harmful ultraviolet rays do not penetrate the earth's surface. Recently, anthropogenic activity has led to the destruction of this layer and the formation of "ozone holes". Scientists claim that the cause of the "holes" is the increased concentration of free radicals and freon. Under the influence of solar radiation, gas molecules are destroyed, this process is accompanied by glow (northern lights).
From 50-55 km. the next layer begins - mesosphere, which rises to 80-90 km. In this layer, the temperature decreases, at an altitude of 80 km it is -90 ° С. In the troposphere, the temperature rises again to several hundred degrees. Thermosphere stretches up to 800 km. Upper bounds exosphere are not determined, since the gas is scattered and partially escapes into outer space.
Heat and moisture
The distribution of solar heat on the planet depends on the latitude of the place. The equator and the tropics receive more solar energy, since the angle of incidence of the sun's rays is about 90 °. The closer to the poles, the angle of incidence of the rays decreases, respectively, the amount of heat also decreases. The sun's rays passing through the air shell do not heat it up. Only when it hits the ground, the sun's heat is absorbed by the surface of the earth, and then the air is heated from the underlying surface. The same happens in the ocean, except that water heats up more slowly than land and cools more slowly. Therefore, the proximity of seas and oceans affects the formation of the climate. In summer, the sea air brings us coolness and precipitation, in winter it warms, since the ocean surface has not yet wasted its heat accumulated over the summer, and the earth's surface has cooled down quickly. Marine air masses form above the surface of the water, therefore, they are saturated with water vapor. Moving over land, air masses lose moisture, bringing precipitation. Continental air masses, formed above the earth's surface, are usually dry. The presence of continental air masses brings hot weather in summer and clear frosty in winter.
Weather and climate
Weather- the state of the troposphere in a given place for a certain period of time.
Climate- long-term weather regime typical for the given area.
The weather can change during the day. Climate is a more constant characteristic. Each physical-geographical region is characterized by a certain type of climate. The climate is formed as a result of the interaction and mutual influence of several factors: the latitude of the place, the prevailing air masses, the relief of the underlying surface, the presence of underwater currents, the presence or absence of water bodies.
There are belts of low and high atmospheric pressure on the earth's surface. Equatorial and temperate belts of low pressure, at the poles and in the tropics, the pressure is high. Air masses move from high pressure to low pressure. But since our Earth rotates, these directions deviate, in the northern hemisphere to the right, in the southern hemisphere to the left. Trade winds blow from the tropical zone to the equator, westerly winds blow from the tropical zone to the temperate zone, and polar east winds blow from the poles to the temperate zone. But in each belt, land areas alternate with water areas. Depending on whether the air mass has formed over land or over the ocean, it can bring heavy rains or a clear sunny surface. The amount of moisture in the air masses is influenced by the relief of the underlying surface. Moisture-saturated air masses pass over flat areas without obstacles. But if there are mountains on the way, heavy humid air cannot move through the mountains, and is forced to lose some, or even all of the moisture on the slope of the mountains. The east coast of Africa has a mountainous surface (Drakensberg Mountains). The air masses that form over the Indian Ocean are saturated with moisture, but all the water is lost on the coast, a hot dry wind comes inland. This is why most of southern Africa is deserted.
If the thermal regime of the geographic envelope was determined only by the distribution of solar radiation without its transfer by the atmosphere and hydrosphere, then at the equator the air temperature would be 39 ° С, and at the pole -44 ° С.Already at latitude 50 ° the zone of perpetual frost would begin. The actual temperature is 26 ° C at the equator and -20 ° C at the North Pole.
As can be seen from the data in the table, up to latitudes of 30 ° solar temperatures are higher than the actual ones, that is, an excess of solar heat is formed in this part of the globe. In the middle, and even more so in the polar latitudes, the actual temperatures are higher than solar, that is, these belts of the Earth receive additional heat to the sun. It comes from low latitudes with oceanic (water) and tropospheric air masses during their planetary circulation.
Comparing the differences between solar and actual air temperatures with the maps of the Earth - atmosphere radiation balance, we will be convinced of their similarity. This once again confirms the role of heat redistribution in the formation of climates. The map explains why the southern hemisphere is colder than the northern: it receives less advective heat from the hot zone.
The distribution of solar heat, as well as its assimilation, occurs not in one system - the atmosphere, but in a system of a higher structural level - the atmosphere and hydrosphere.
- Solar heat is spent mainly over the oceans for the evaporation of water: at the equator 3350, under the tropics 5010, in the temperate zones 1774 MJ / m 2 (80, 120 and 40 kcal / cm 2) per year. Together with the steam, it is redistributed both between zones and within each zone between the oceans and continents.
- From tropical latitudes, heat with trade wind circulation and tropical currents enters the equatorial ones. The tropics lose 2510 MJ / m 2 (60 kcal / cm 2) per year, and at the equator the heat gain from condensation is 4190 MJ / m 2 (100 or more kcal / cm 2) per year. Consequently, although the total radiation in the equatorial belt is less than the tropical one, it receives more heat: all the energy spent on the evaporation of water in the tropical belts goes to the equator and, as we will see below, causes powerful ascending air currents here.
- The northern temperate belt from warm ocean currents coming from equatorial latitudes - the Gulf Stream and Kuroshio receives on the oceans up to 837 MJ / m 2 (20 or more kcal / cm 2) per year.
- By western transfer from the oceans, this heat is transferred to the continents, where a temperate climate is formed not up to latitude 50 °, but much to the north of the Arctic Circle.
- The North Atlantic Current and atmospheric circulation significantly warm the Arctic.
- In the southern hemisphere, only Argentina and Chile receive tropical heat; the cold waters of the Antarctic Current circulate in the Southern Ocean.
Topic: DISTRIBUTION OF SUNLIGHT HEAT ON THE EARTH.
Lesson objectives:- to form an idea of the Sun as the main source of energy that determines the processes in the atmosphere; about the features of the illumination of the belts of the Earth.
- identify the reasons for the uneven distribution of sunlight and heat on Earth.
Develop skills to work with cartographic sources
Educating students for tolerance
Equipment: globe, climate map, physical. world map, atlases, contour maps
During the classes:
I.Organization of students for the lesson.
II. Homework check ( fill in the table).
Similarities | Differences |
|
Weather | Climate |
|
General indicators: temperature, atmospheric pressure, precipitation | Indicators are different every time | Average long-term indicators |
Spatial certainty(specific territory) | Very volatile | Relatively stable |
Have an impact on a person | Affects other features of nature |
III... Learning new material.
To explain the new material, the teacher uses a globe and a table lamp, which will be the "Sun".
The lower the sun is above the horizon, the lower the air temperature.
The highest position of the Sun is in the sky of the Northern Hemisphere in June, and at this time there is the height of summer. The lowest is in December, and at this time it is winter there, most of our country is covered with snow.
The change of seasons occurs because the Earth moves around the Sun and the Earth's axis is tilted to the plane of the Earth's orbit, as a result of which the globe is turned towards the Sun more by the Northern or Southern hemispheres. The sun is at different heights above the horizon. In the warm season, it is high above the horizon and the Earth receives a lot of heat. In the cold season, the Sun is low above the horizon, and the Earth receives less heat.
The Earth makes one revolution around the Sun per year, and when moving around it, the inclination of the Earth's axis remains unchanged.
(The teacher turns on the table lamp and moves the globe around it, keeping the tilt of its axis constant.)
Some people incorrectly believe that the seasons are changing because the sun is closer in summer and farther from the Earth in winter.
The distance from the Earth to the Sun for the change of seasons is notaffects.
At that moment when the Earth with the Northern Lolus, as it were, “turned” to the Sun, and the Southern Lolus “turned away” from it, it was summer in the Northern Hemisphere. The sun stands high above the horizon at the North Pole and around it; it does not set below the horizon all day long. It's a polar day. South of the parallel 66.5 ° N. NS. (polar circle) the merger of day and night occurs every day. The opposite picture is observed in the Southern Hemisphere. When the globe moves, fix the students' attention on four positions of the Earth:December 22, March 21, June 22 and September 21. At the same time, show the boundaries of light and shadow, the angle of incidence of the sun's rays on the parallels marked with flags. Analysis of figures in the text of the paragraph.
North hemisphere | Southern Hemisphere |
|
22 nun | 1) more illuminated; 2) the day is longer than the night; 3) the entire circumpolar part during the day is illuminated to a parallel of 66.50 s. NS. (polar day); 4) the rays of the Sun fall vertically not 23.50 with. NS. (summer solstice) | 1) less illuminated; 2) the day is shorter than the night; 3) the entire circumpolar part during the day in the shade up to the parallel of 66.50 S. NS. (polar night) (winter solstice) |
1) both hemispheres are equally illuminated, day is equal to night (12 h); 2) the rays of the sun fall vertically at the equator; (autumnal equinox) (spring equinox) |
||
1) less illuminated; 2) the day is shorter than the night; 3) the entire circumpolar part during the day - in the shade up to 66.50 s . NS. (polar night) (winter solstice) | 1) more illuminated; 2) the day is longer than the night; 3) the entire circumpolar part is illuminated up to 66.5 ° S during the day. NS. (polar day); 4) the rays of the Sun fall vertically at 23.50 S. NS. (summer solstice) |
|
1) both hemispheres are equally illuminated, day is equal to night (12 hours each); 2) the rays of the sun fall vertically at the equator; (vernal equinox) (autumnal equinox) |
||
Illumination belts.
The tropics and polar circles divide the earth's surface into belts of illumination.
1. Polar belts: north and south.
2. Tropical belt.
3. Temperate zone: north and south.
Polar circles.
Parallels 66.50 sec. sh and 66.50 s. w call polar circles... They are the boundaries of areas where there are polar days and polar nights. At a latitude of 66.50, people on the summer solstice see the Sun above the horizon for a full day, that is, all 24 hours. Six months later, all 24 hours are polar night.
From the polar circles towards the poles, the duration of polar days and nights increases. So, at a latitude of 66.50 it is equal to 1 day, at a latitude of a day, a latitude of 80 ° - 134 days, at a latitude of 90 ° (at the poles) - approximately six months.
Throughout the space between the polar circles, there is a change of day and night (show the North and South polar circles on the globe and a map of the hemispheres and space, where there are polar days and nights).
Tropics ... Parallels 23.5 ° N NS. and 23.5 ° S. NS. are called tropical circles or just tropics. Above each of them, once a year, the midday Sun is at its zenith, those sun rays fall vertically.
Fizminutka
III... Securing the material.
Practical work:"Designation of light belts on contour maps of the hemispheres and Russia."
IV... Homework:Ш § 43; tasks in the text of the textbook.
V. Additional material (if there is time left in the lesson)
Seasons in poetry. N. Nekrasov
Winter.
It is not the wind that rages over the forest.
Streams did not run from the mountains,
Frost-voivode patrol
Bypasses his possessions.
Looks - are the blizzards good?
Forest paths brought
And are there any cracks, cracks,
And is there no bare ground?A. Pushkin
Spring.
Driven by the spring rays .- "
There is already snow from the surrounding mountains
Escaped by muddy streams
To the sunken meadows
A clear smile of nature
Through a dream meets the morning of the year ...
A. Maikov
It smells like hay over the meadows ...
In the song the soul is merry,
Women with rakes in rows
They walk, stirring hay ...A. Pushkin
Read also:
Reducing everything to abstraction and quantity |
1 polar belts
2 moderate belts
3 geographic zone
Tropical belt
136 The lithosphere is the upper shell of the Earth and the upper robes.
The earth's crust under the continents consists of
Sedimentary rocks
2 igneous
3 volcanic
4 metamorphic
Granite
Basalt
The earth's crust is thicker under
Continents
2 oceans
3 lakes
4 plains
139 The inner shells of the Earth include:
Core
2 lithosphere
3 platform
Mantle
5earth crust
Set the sequence of the location of the shells of the Earth in order of their distance from the center.
3: asthenosphere
4: crust
141 Exogenous processes include:
Erosion
2 volcanism
Aeolian processes
4 magmatism
5 earthquake
142 Endogenous processes include:
Tectonic movements
Volcanism
3 weathering
Metamorphism
5 accumulation
6 aeolian processes
143 Establish a correspondence between the sources of external and internal forces of the Earth.
1: external forces
2: internal forces
A) Sun
B) decay of radioactive elements of rocks
C) the earth's crust
D) weathering
144By origin mountains are:
Tectonic
2 folded
Volcanic
Erosive
6 young
145 Plains are:
Lowlands
Hills
4 depressions
Plateau
146 Plains of mainland Eurasia:
West Siberian
2 La Platskaya
Caspian
4Amazonian
5 Central North American
Specify a method for determining the absolute height of a place on the map
1 depth scale
Height scale
3 scale
4degree grid
The hydrosphere includes:
The waters of the oceans
Sushi water
The groundwater
4water in living organisms
5water in the bowels of the Earth
6atmospheric water
Set the sequence of the oceans in order of decreasing maximum depth.
2: Atlantic
3: Indian
4: Arctic
150. The property of water, which ensures its circulation in nature:
1 fluidity
2 solvent
3 heat capacity
Free transition from one physical state to another
151 The inland sea is:
1 Beringovo
2 Karskoe
Black
4 Barents
152 A continental bank or shelf is a shallow part that borders the continent with a depth of:
0 to 200 m
2 from 0 to 2500 m
3 from 0 to 1000 m
4 from 0 to 6000 m
153 The temperature of surface waters in the ocean decreases from:
Equator to Poles
2poles to the equator
3 zeroth meridian west
4Greenland to the equator
154 The supply of fresh water on Earth is:
Read in the same book: Geographic longitude is measured from ...
| Any point on the mainland Australia has ... | Spirals | Geysers | The main property of the biosphere | Dubrava | Selects forms and methods of development and education of schoolchildren by means of natural science | mybiblioteka.su - 2015-2018.
Angles of incidence of sun rays
The height of the sun has a significant effect on the intake of solar radiation. When the angle of incidence of the sun's rays is small, then the rays must pass their way through the thickness of the atmosphere.
Solar radiation is partially absorbed, some of the rays are reflected from particles suspended in the air and reach the earth's surface in the form of scattered radiation.
The height of the sun changes continuously as the transition from winter to summer, as well as when the day changes.
The angle of incidence of the sun's rays reaches its maximum value at 12:00 (solar time). It is customary to say that at this moment in time the sun is at its zenith. At noon, the radiation intensity also reaches its maximum value. The minimum values of the radiation intensity are reached in the morning and in the evening, when the sun is located low above the horizon, also in winter. True, in winter, slightly more direct sunlight falls on the ground.
This is due to the fact that the absolute humidity of winter air is lower “and therefore it absorbs less solar radiation.
In fig. 37 shows how high the radiation intensity reaches on a perpendicular surface oriented towards the sun, despite the fact that the acute angle of incidence of the sun's rays changes.
The initial part of this curve reflects rather accurately the position on a clear March day. The sun rises at 6:00 in the east and slightly illuminates the eastern facade wall (only in the form of radiation reflected by the atmosphere).
Topic: Distribution of sunlight heat on earth
With an increase in the angle of incidence of sunlight, the intensity of solar radiation falling on the surface of the facade wall increases rapidly.
At about 8 am, the intensity of solar radiation is already about 500 W / m2, and it reaches its maximum value of about 700 W / m2 on the southern facade wall of the building a little earlier than noon.
Enlarge picture
When the globe rotates around its axis in one day, i.e.
That is, with the visible movement of the sun around the globe, the angle of incidence of the sun's rays changes not only in the vertical, but also in the horizontal direction. This angle in the horizontal plane is called the azimuth angle. It shows how many degrees the angle of incidence of the sun's rays deviates from the north direction if the full circle is 360 °.
The vertical and horizontal angles are interconnected so that when the seasons change, the angle of the sun's position in the sky is always the same twice a year at the same azimuthal angle values.
In fig. 39 shows the trajectories of the sun during its apparent movement around the globe in winter and summer on the days of the spring and autumn equinox.
By projecting these trajectories on a horizontal plane, a planar image is obtained, with the help of which it is possible to accurately describe the position of the sun on the globe. Such a solar trajectory map is called a solar chart or simply a solar map. Since the trajectory of the sun changes when moving from the south (from the equator) to the north, there is a specific solar map for each latitude.
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DISTRIBUTION OF HEAT AND LIGHT ON THE EARTH
The sun is the star of the solar system, which is a source of an enormous amount of heat and dazzling light for planet Earth. Despite the fact that the Sun is at a considerable distance from us and only a small part of its radiation reaches us, this is quite enough for the development of life on Earth. Our planet revolves around the Sun in an orbit.
If you observe the Earth from a spacecraft throughout the year, you can see that the Sun always illuminates only one half of the Earth, therefore, there will be day, and on the opposite half at this time there will be night. The earth's surface receives heat only during the day.
Our Earth heats up unevenly.
The distribution of sunlight and heat on Earth, heat zones, seasons
The uneven heating of the Earth is explained by its spherical shape, therefore, the angle of incidence of the sun's ray in different regions is different, which means that different parts of the Earth receive different amounts of heat.
At the equator, the sun's rays fall vertically, and they greatly heat the Earth. The farther from the equator, the less the angle of incidence of the ray becomes, and, consequently, these territories receive less heat. The same power beam of solar radiation heats a much smaller area near the equator, since it falls vertically. In addition, rays falling at a lower angle than at the equator - penetrating the atmosphere, pass a longer path in it, as a result of which part of the sun's rays is scattered in the troposphere and does not reach the earth's surface.
All this indicates that with distance from the equator to the north or south, the air temperature decreases, as the angle of incidence of the sunbeam decreases.
23 4 Next> End >>
How many different lighting? 5 pillars Belt for dogs ...
how many different lighting?
- 5 pol
- Belts Light illumination belts - the surfaces of parts of the Earth bounded by the tropics, polar circles and various lighting conditions.
It is located between the tropics in the tropical zone, where twice a year (and in the tropics once a year) you can see the midday sun at its zenith. From the polar circle to the pole, each hemisphere is the polar belt, here is the polar day and the polar night.
Distribution of sunlight and heat on Earth
In temperate regions located in the northern and southern hemispheres during the tropical and polar circles, the sun does not occur at the zenith, the polar day and polar night are not observed.
The Tjs emit light zone 5: north and south polarity, receiving only a little light and heat. A tropical zone with hot climatic-untrue and southern temperate zones that receive light and more heat than the polar ones, but less tropical.
Attention, only TODAY!
Posted by admin on Jan 1, 0001. This entry was posted in Homework. Permalink tab.
Section 30. Distribution of sunlight and heat on Earth (textbook)
§ 30. Distribution of solar light and heat on Earth
1. Remember why on Earth there is a change of day and night and seasons.
2. What is called the Earth's orbit?
Changes in the height of the Sun above the horizon during the year. To understand why throughout the year the Sun is at different heights above the horizon at noon, remember from the lessons of natural history the peculiarities of the Earth's movement around the Sun.
The globe shows that the earth's axis is tilted.
During the movement of the Earth around the Sun, the tilt angle does not change. Thanks to this, the Earth returns to the Sun more either in the Northern or Southern hemisphere. This changes the angle of incidence of the sun's rays on the earth's surface. And accordingly, one or the other hemisphere is more illuminated and heated.
If the earth's axis were not tilted, aperpendicular to the plane of the Earth's orbit, then the amount of solar heat at each parallel during the year would not change.
Then, in your observations by the high altitude of the midday Sun, you would record the same length of the gnomon's shadow for a whole year. This would indicate that during the year the length of the day is always equal to the night.
Then the earth's surface warmed up the same throughout the year and the city would not exist.
Lighting and heating of the Earth's surface throughout the year. On the surface of the spherical Earth, solar heat and light are unevenly distributed.
This is due to the fact that the angle of incidence of the rays at different latitudes is different.
You already know that the earth's axis is tilted to the plane of the orbit at an angle. Its northern end is directed towards the North Star. The sun always illuminates half of the Earth.
At the same time, the northern hemisphere is more illuminated (and the day lasts longer there than in the other hemisphere), then, on the contrary, the southern one. Twice a year, both hemispheres are illuminated in the same way (then the length of the day in both hemispheres is the same).
When the Earth is facing the Sun with its North Pole, then it illuminates and heats up the Northern Hemisphere more.
The days are getting longer than the nights. The warm season is coming - summer.
Distribution of heat and light on Earth
At the Pole and in the circumpolar part, the Sun shines around the clock and does not set over the horizon (Night does not come). This phenomenon is called a polar day. At the Pole, it lasts 180 days (six months), but the further south you go, the more its duration decreases at a parallel of 66.50pn. NS. This parallel is called Arctic Circle.
To the south of this line, the Sun sinks below the horizon and the change of day and night occurs in the usual order for us - every day. June 22 - The sun's rays will fall vertically (at the greatest angle - 900) Parallel 23.5 mon. NS. This day will be the longest and the shortest night of the year. This parallel is called Northern metropic, And the day of June 22 - summer solstice.
At present, the South Pole, distracted from the Sun, illuminates and heats up the Southern Hemisphere less.
It's winter there. The sun's rays do not reach the pole of the ipripolar part during the day. The sun appears over the horizon and the day does not come. This phenomenon is called polar night. At the Pole itself, it lasts 180 days, and the further to the north, the shorter it becomes, up to one day at a parallel of 66.50 S. NS. This parallel is called The southern polar circle. To the north of it, the Sun appears on the horizon and the change of day and night occurs every day.
Three months later, on September 23, the Earth will take such a position relative to the Sun, when the sun's rays equally illuminate both the Northern and Southern hemispheres.
Sheer rays of the sun fall on the equator. On the whole Earth, except for the poles, day is equal to night (12 hours each). This day is called the day of the autumnal equinox.
Three months later, on December 22, the Southern Hemisphere will return to the Sun. Summer will come there. This day will be the longest and the night the shortest.
A polar day will come in the polar region. The Sun's rays fall steeply on a parallel of 23.50 S. NS. On the other hand, it will be winter in the Northern Hemisphere, with the shortest day and the longest night. Parallel 23.50 S. are called Southernthe tropic and the day of December 22 - winter sun.
Three months later, on March 21, again both hemispheres will be equally illuminated, the day will be equal to the night.
The sun's rays fall steeply at the equator. This day is called spring equal.
In Ukraine, the highest altitude of the Sun at noon is 61-690 (June 22), the lowest is -14-220 (December 22).
Interesting geography
Words’ Slavic god of the sun
The ancient Slavs called the god of light and the sun Dazhbog.
In the well-known literary work "The Lay of Igor's Campaign" our ancestors - the Russians are called the grandchildren of Dazhdbog. Along with other gods, installed by Prince Vladimir in Kiev, stood Dazhbog. According to ancient myths, three solar brothers accompany him in the sky: Yarilo- God of the vernal equinox, Semiyarilo- God of the summer solstice and Kolyada- Gods winter solstice.
The birthday of the young Sun was considered the day of the winter sun. God was considered the guardian of this light-bearing troika Trojan- Lord of heaven, earth and the kingdom of the other world.
Rice.
Annual movement of the Earth around the Sun
Thermal belts of the Earth. Uneven heating of the earth's surface causes different air temperatures at different latitudes. Latitudinal bands with certain air temperatures are called thermal belts... The belts differ in the amount of heat coming from the Sun. Their strike dependence on the temperature distribution is well illustrated isotherms(From the Greek "iso" - Identical, "term" - Heat).
These are lines on the map, connecting points with the same temperature.
Hot Belt located along the equator, between the North and South tropics. It is bounded on both sides by isotherms of 20 ° C. It is interesting that the boundaries of the belt coincide with the boundaries of the distribution of palm trees on land and the coral in the ocean.
Here the earth's surface receives the greatest solar heat. Twice a year (December 22 and June 22) noon, the sun's rays fall almost vertically (at an angle of 900). The air from the surface gets very hot.
Therefore, it is hot there throughout the year.
Moderate belts(In both hemispheres) adjoin the hot belt. They stretched in both hemispheres between the Arctic circle and the tropic. The sun's rays fall on the earth's surface with some inclination. Moreover, the farther north, the darker the slope.
Therefore, the sun's rays heat up the surface less. As a result, the air heats up less. This is why temperate zones are colder than hot. The sun is never at its zenith there. Well-defined seasons: winter, spring, summer, autumn.
Moreover, the closer to the Arctic Circle, the longer and colder the winter. The closer to the tropics, the longer and warmer the summer. Moderate zones on the side of the poles are limited by the isotherm of the warm month 10 0С. It is the limit of the spread of forests.
Cold belts(Northern and Southern) of both hemispheres lie between the isotherms of 10 ° C and 0 ° C of the warmest month. The sun there in winter does not appear above the horizon for several months.
And in summer, although it does not go beyond the horizon for months, it stands very low above the horizon. Its rays only glide along the surface of the Earth and heat it weakly. The surface of the Earth not only heats up, but also cools the air. Therefore, the air temperatures are low there. Winters are cold and harsh, while summers are short and cool.
Two belt of eternal cold(northern and southern) are contoured by an isotherm with temperatures of all months below 0 ° C. Это царство вечных снигив и льда.
So, the heating and lighting of each area depends on the position in the heat zone, that is, on the latitude.
The closer to the equator, the greater the angle of incidence of the sun's rays, the more the surface heats up and the higher the air temperature. And vice versa, with the distance from the equator to the poles, the angle of incidence of the rays decreases, respectively, the temperature of the air decreases.
It is important to remember that the lines of the tropics and polar circles outside the thermal zones are taken conditionally. Since in reality the temperature of the air is also determined by a number of other conditions.
Rice.
Heat zones of the Earth
Questions and Tasks
1.Why does the height of the sun change during the year?
2.Which hemisphere the Earth will face to the Sun when in Ukraine: a) in the north on June 22; b) noon on December 22?
3.Where the average annual air temperature will be higher: in Singapore or Paris?
4. Why do average annual temperatures decrease from the equator to the poles?
5. In what heat zones are the continents Africa, Australia, Antarctica, North America, Eurasia?
6. In what heat zone is the territory of Ukraine located?
7. Find a city on the map of the hemispheres, if it is known that it is located at 430 zx.
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