The belts of the planet. Regularities in the placement of natural zones What is the reason for the different ratio of heat and moisture

Heat zones

Throughout the geological history of the Earth, the relationship between ocean and land has changed, which suggests that the heat balance of the planet was not constant. Geographic zoning changed, heat zones changed. It becomes obvious that the modern geographic zoning was once completely unusual for the planet. Scientists believe that neither glaciers nor cold seas most of the time on Earth simply did not exist, and the climate was much warmer than it is now. The temperature contrasts between the poles and the equator were small, impenetrable forests grew in the arctic region, and reptiles and amphibians inhabited the entire Earth. Thermal zoning first appeared in southern hemisphere and in north hemisphere, its formation took place later.

The main process of the formation of zoning took place in quaternary Cenozoic era , although its first signs appeared $ 70 million years ago. With the advent of man, the heat zones were already the same as they are now - one hot zone, two moderate, two cold zones... The boundaries between the belts underwent changes, for example, the border of the cold belt, once passed through the modern Moscow region and the Moscow region was occupied by the tundra zone. The mention of heat zones can be found in the Greek historian Plibia($ 204 - $ 121 BC). According to him, there were $ 6 $ heat belts on Earth - two hot, two moderate, two cold. Travelers' notes also contain such information. These data indicate that people have long known about the existence of heat zones. They explained their presence by the fact that the Sun at different latitudes heats the surface of the Earth in different ways, and attributed this to the different angle of inclination of the sun's rays. In northern latitudes, the sun is low above the horizon and produces little heat per unit area, so it is colder there. This is how the concept “ klima T". This pattern was known as early as $ 2.5 thousand years ago and remained indisputable until recently. This explanation was questioned relatively recently.

Observations have shown that Arctic and Antarctic per unit area receives very little solar heat in the summer. But for a long polar day, the total radiation is much higher than at the equator, which means that it should also be warm there. However, summer temperatures rarely rise above $ 10 degrees. This means that the thermal regime cannot be explained by a single difference in the supply of solar heat. Today, everyone knows that character also plays an important role. underlying surface. Albedo snow and ice is very large and reflects up to $ 90 $% of solar radiation, and the surface not covered with snow reflects only $ 20 $%. The albedo of the Arctic surface will decrease if snow and ice melt, and this will change the existing thermal zones of the northern hemisphere. With the rise in the water temperature in the Arctic basin, forests will come to the place of the modern tundra. After the collapse of Gondwana, the process in the southern hemisphere went something like this.

Definition 1

Heat zones- These are vast territories located along the parallels around the globe with certain temperature conditions.

It must be said that the formation of heat belts on the planet depends on how it will be distributed over the surface of the Earth and what will be spent on, and not only on the amount of solar heat entering the limits of a particular zone.

Moisturizing belts

In natural processes, not only certain thermal conditions play a role, but conditions play an even greater role. humidification... Moisture is determined by two factors: the amount of precipitation and the intensity of their evaporation.

Definition 2

Moisturizing- This is the ratio between the amount of precipitation in a given area and the amount of moisture evaporated at a given temperature.

Their distribution on the planet, in principle, is also associated with geographic zoning. From the equator to the poles, their average number decreases, but this pattern is violated by geographic and climatic conditions.

The reasons are as follows:

• Free air circulation is disturbed by the location of the mountains;
• Downward and upward currents of air in different parts of the planet;
• Variability in cloudiness distribution.

Mountains can be located both in the latitudinal and in the meridional direction, and most of the precipitation is delayed windward slopes and with leeward very little or no precipitation falls on the side. The equatorial region is dominated by ascending air currents - warmed up light air rises, reaches the saturation point and brings an abundance of precipitation. In tropical latitudes, air movement downward, the air moves away from the saturation point and dries up, so very little precipitation flows along the tropics, which contributed to the formation of deserts and dry steppes here. Precipitation zoning recovers north and south of the tropics and persists up to the poles. Distribution cloudiness also has its own meaning. Sometimes it happens that different amounts of precipitation fall on one street.

Evaporation determines the conditions of humidification on the planet and is entirely regulated by the amount of residual radiation. The quantity fumes characterized by the amount of moisture evaporated at a given temperature.

From the north to the tropics, the moistening of the Earth's surface decreases. In the taiga zone it is close to $ 1 $, in the steppe zone the moisture will be $ 2 $, and in the deserts more than $ 3 $. In the south, the potential for evaporation is much greater than in the north.

Example 1

Let's consider an example... The soil in the steppes warms up to $ 70 $ degrees. The air is dry and hot. If the field is irrigated, everything will change, it will be more humid and cooler. The earth will come to life and turn green. The air here was hot, not because the influx of heat from the Sun is greater than in the north, but because there is very little moisture. Evaporation began from the irrigated field, and part of the heat was spent on this. Thus, the conditions for moistening the Earth's surface depend not only on fumes but also from amount of precipitation.

Pressure belts

Normal is the atmospheric pressure at sea level at a latitude of $ 45 $ degrees at a temperature of $ 0 $ degrees. Under such conditions, it is $ 760 $ mm Hg, but it can vary over a wide range. The increased air pressure will be more than normal, and the lower will be less normal with a mark of $ 760 mm. rt. Art.

With altitude atmospheric pressure goes down because the air becomes thinner. The surface of the planet, which has different heights, will have its own pressure value.

Example 2

For example, $ Perm $ is located at an altitude of $ 150 $ m above sea level and every $ 10.5 $ m the pressure will decrease by $ 1 $ mm. This means that at the height of Perm, normal atmospheric pressure will not be $ 760 mm, but $ 745 $ mm Hg. Art.

Due to the fact that during the day there is a change in temperature and air movement, the pressure will be go up twice and go down twice... In the first case, in the morning and in the evening, in the second case, in the afternoon and midnight. On the continents, during the year, the maximum pressure will be observed in the winter, and the minimum in the summer.

Over the surface of the Earth, the distribution of pressure is zonal, because the surface is heated unevenly, which leads to a change in pressure.

There are $ 3 $ belts on the planet, where low pressure and $ 4 $ high pressure dominated belts. Low atmospheric pressure will be in equatorial latitudes and in temperate latitudes, but here it will change with the seasons of the year. High atmospheric pressure is typical for tropical and polar latitudes.

Remark 1

At the surface of the Earth on the formation of belts atmospheric pressure the influence is exerted by the uneven distribution of solar heat and the rotation of the Earth. In view of the fact that the hemispheres are heated by the sun in different ways, there will be some displacement of the pressure belts: in the summer period - the displacement goes to the north, in the winter period - to the south.

Geographic zones of continents and oceans. These are the largest zonal complexes of the geographic envelope. Each geographic zone on the continents has its own set natural areas, their natural processes and rhythms. Geographic zones are heterogeneous inside. They differ in different modes of humidification and continental climate, which contributes to the division of belts into sectors. The coastal and internal sectors of the geographic zones differ from each other in the mode of precipitation, seasonal rhythms, set and strike of natural zones. Geographic belts are also distinguished in the oceans, but here they are more homogeneous, and their features are determined by the properties of oceanic water masses.

Natural areas to a lesser extent than the belts, they have a latitudinal orientation. This is due to the fact that humidification conditions affect the formation of natural zones, in addition to temperature conditions.

On the map "Geographic zones and natural zones of the world" you can see that in different geographic zones, the same or similar natural zones are repeated. For example, forest zones exist in the equatorial, subequatorial, tropical, subtropical and temperate zones. Several zones also have semi-desert and desert zones. Scientists explain this by repeating the same ratios of heat and moisture on different continents... This phenomenon was named the law of natural zoning. Natural zoning in the plains is called horizontal (latitudinal), and in the mountains - vertical (high-altitude). The number of altitude zones depends on geographic location mountain system and its height.

Each natural area has its own zonal features components. Any natural zone is easy to recognize by the flora and fauna. For example, equatorial humid forests are distinguished by the greatest diversity of plants and animals on Earth. And, in addition, all living things grow here to gigantic proportions.

Giants of the equatorial forest. In the equatorial forest, the vines reach over 200 m in length; the diameter of a rafflesia flower is 1 m, and its mass can reach 15 kg. Ispolian moths with a wingspan of up to 30 cm also live here, and the bats with a wingspan of up to 1.7 m, and cobras up to 5 m long, and the largest among the existing snakes - the anaconda - reaches a length of 11 m!

In savannas and woodlands, herbaceous vegetation alternates with individual groups of trees - acacias, eucalyptus, baobabs. Forest-free natural zones are found in the temperate zone, such as steppes. They cover vast areas on two continents - in Eurasia and North America.

Extremely poor flora is a feature of the desert zone on almost all continents and in most geographic zones. The Arctic and Antarctic deserts, which are almost completely covered with ice, are distinguished by special conditions (Fig. 16). At first glance, such a desert seems generally lifeless. Material from the site

Rice. 16. Zone of the arctic desert

Forest zones of the temperate zone are widespread on the continents of the northern latitudes. The flora is rich here, although in comparison with the equatorial forest there are fewer species. It is represented by both coniferous and deciduous tree species. The natural zones of the temperate zone have been significantly changed due to economic activity person.

• Geographic zones exist on continents and oceans. Geographic zones are subdivided into sectors due to climatic features.
• Natural zones are repeated in different geographic zones, which is explained by the similarity of temperature and moisture conditions.
• Natural areas can be easily recognized by their flora and fauna.

On this page material on topics:

• Abstract of the expansion of geographic zones and natural zones of the world

• Regularities of the distribution of forms of the earth's surface 12

• Natural zones of the world regularity of the geographic envelope

• Name any natural area

• 1. Integrity - it is manifested in the fact that a change in one component of a natural complex inevitably causes a change in all the others and the entire system as a whole. Changes made in one place of the shell are reflected in the entire shell.

  2. Rhythm Is the recurrence of similar phenomena over time. Rhythms are periodic (have the same duration) and cyclical (have an unequal duration). In addition, there are daily, annual, secular, supersecular rhythms. Change of day and night, change of seasons, cycles of solar activity (11 years, 22 years, 98 years) are also examples of rhythms. Most of the rhythms are associated with a change in the position of the Earth in relation to the Sun and Moon. A certain rhythm can be traced in mountain-building cycles (period 190-200 million years), glaciations and other phenomena.

  3. Zoning – natural change all components of the geographic envelope and the envelope itself from the equator to the poles. Zoning is due to the rotation of the spherical Earth around the inclined axis and the flow of sun rays reaching the earth's surface. Due to the zonal distribution of solar radiation over the earth's surface, there is a regular change in climates, soils, vegetation and other components of the geographic envelope. On Earth, most exogenous phenomena are zonal.

  So the processes of frost physical weathering are most active in the subpolar and polar latitudes. Temperature weathering and aeolian processes are characteristic of arid regions of the world (deserts and semi-deserts). Glacial processes take place in the polar and high mountain regions of the Earth. Cryogenic - are confined to the polar, subpolar, temperate latitudes of the northern hemisphere. The formation of weathering crusts is also subordinate to zoning: the laterite type of weathering crust is characteristic of zones of humid and hot climates; montmorillonite - for dry continental; hydromica - for moist cool, etc.

  Zoning is manifested primarily in the existence of geographic zones on Earth, the boundaries of which rarely coincide with parallels, and sometimes their direction is generally close to the meridian (as, for example, in North America). Many zones are ruptured and expressed not on the entire continent. Zoning is typical only for flat areas. In the mountains there is altitudinal zonality ... In the change of horizontal zones and in the change of altitude zones, one can find similarities (but not identical). The mountains of each natural zone are characterized by their own range of altitudinal zonation (a set of belts). The higher the mountains and closer to the equator, the more complete the range of altitudinal zones is. Some scientists (for example, S.V. Kalesnik) believe that altitudinal zonation is a manifestation azonality ... Azonality on Earth is subject to phenomena caused by endogenous forces. The phenomenon of sectorality (western, central and eastern parts of the continents) is referred to azonal phenomena. A variety of azonality is considered intrazonality (intrazonal).

  Differentiation of the geographic envelope is the division of a single planetary natural complex into objectively existing natural complexes of a different order (rank).

  The geographic envelope has never been the same everywhere. As a result of unequal development, it turned out to be composed of many natural complexes. A.G. Isachenko determines natural complex as a natural, historically determined and territorially limited combination of a number of components: rocks with their inherent relief, the surface layer of air with its climatic features, surface and underground waters, soils, groups of plants and animals.

  According to N.A. Solntsev's definition, natural complex - This is a piece of the earth's surface (territory), which is a historically determined combination of natural components.

  To identify natural complexes existing in nature, physical and geographical zoning is used.

  With a huge variety of natural complexes that make up the geographic envelope, a system of taxonomic (ordinal) units is needed. There is no such unified system yet. When identifying taxonomic units, both zonal and non-zonal (azonal) factors of differentiation of the geographic envelope are taken into account.

  The differentiation of the geographic envelope by azonal features is expressed in the division of the geographic envelope into continents, oceans, physical-geographical countries, physical-geographical regions, provinces, and landscapes. However, this approach in no way denies zoning as a general geographical pattern. In other words, all these natural complexes are necessarily zonal.

  geographic envelope

  geographic zone mainland

  country zone

  subzone region

  provinces

  landscape

  Differentiation of the geographic envelope according to zonal features is expressed in its division into geographic zones, zones, subzones, and landscapes.

  The main unit of physical and geographical zoning is the landscape. By definition S.V. Kalesnik, landscape - This is a specific territory, homogeneous in origin and development history, with a single geological foundation, a single type of relief, a common climate, common hydrothermal conditions and soils, and the same biocenosis.

  The smallest unit of physical and geographical zoning, the simplest, elementary natural complex is the facies.

  Lesson number 22 Grade 7 11/29/2017Lesson topic: "Practical work No. 5. « Analysis of thematic maps in order to identify the features of the location of geographic zones and natural zones of the Earth. "

  The purpose of the lesson:to learn how to determine the patterns of distribution of geographic zones and natural zones on separate continents and on the planet as a whole using thematic maps.
  

  Lesson type: learning new material lesson

  Equipment:textbook, atlas, map of geographic zones and natural zones of the world.
  
  

  Basic conceptsZoning latitudinal - a regular change of natural components and natural complexes in the direction from the equator to the poles and the formation of geographic zones and natural zones.
  Geographic zones of the Earth - the largest zonal subdivisions of the geographic envelope, extending in the latitudinal direction. Geographic zones are distinguished on the basis of taking into account the differences in the radiation balance, temperature regime and atmospheric circulation. This determines the formation of sharply different types of soil and vegetation cover. Geographic zones practically coincide with climatic zones and bear the same names (equatorial, subequatorial, tropical, etc.).
  Natural areas - physical and geographical zones, large parts of geographic zones, regularly changing from the equator to the poles and from the oceans to the interior of the continents. The position of natural zones is determined mainly by differences in the ratio of heat and moisture. Natural areas have a significant commonality of soils, vegetation and other components of nature.
  Altitudinal zonality - a natural change in natural complexes associated with a change in altitude, typical of mountainous terrain
  

  During the classes:

  1.Organizational moment

  2. Updating basic knowledge1. Indicate the patterns of location of geographic zones on the planet.
  - stretched in the direction from west to east along the geographical latitude;
  - are repeated symmetrically about the equator;
  - the boundaries of the belts are uneven due to the influence of the relief, currents, remoteness from the oceans.
  2. Why are there several natural zones within one geographic zone?
  Natural areas are influenced by air temperature and humidity, which may differ within one belt.
  3. What natural areas are located in the temperate zone?
  Taiga, mixed and deciduous forests, forest-steppe and steppe, deserts and semi-deserts, variable-humid monsoon forests, areas of altitudinal zoning.
  4. Why is there a change in natural zones in the mountains? What determines their number?
  A decrease in air temperature with height and an increase in precipitation is the main reason for the change in natural zones in the mountains, the height of the mountains and their proximity to the equator affect their amount.
  5. In what geographic zones is Russia? What natural areas are most typical for it?
  Rossya is located in the Arctic zone (zone of arctic deserts), in the subarctic zone (zone of tundra and forest-tundra), in the temperate zone (taiga, mixed and deciduous forests, forest-steppe and steppe, deserts and semi-deserts, variable-humid monsoon forests), subtropical zone ( dry and humid rigid-leaved forests and shrubs of the Mediterranean type), areas of high-altitude zoning.

  II. The practical part. Africa.1. In what geographic zones is the mainland?
  In the center - the equatorial belt, to the north and south of it subequatorial, along the tropics - tropical belts, the extreme north and south - subtropical belts.
  2. What natural zones are there in these zones?
  At the equator - evergreen humid equatorial forests, in the subequatorial zone - savannas and woodlands, in the tropical zone - deserts and semi-deserts, in the subtropics - rigid-leaved evergreen forests and shrubs. In the mountains - high-altitude zonation.
  3. Why are equatorial forests located only in the western part of the mainland?
  The Congo Basin and coastal lowlands are well moistened by air masses from the Atlantic Ocean (warm currents and trade winds). In the east, there is a high plateau - lower temperatures, little precipitation - a cold Somali current.
  4. Why is the latitudinal location of belts and natural zones prevalent in Africa?
  In Africa, plains prevail in the relief, therefore the law of latitudinal zoning is well manifested here.
  Output.Africa is located on the equator, which runs almost in the middle of the mainland, therefore, symmetry in the location of belts and zones is well manifested on the mainland, because of the plains, the law of latitudinal zoning operates, belts and natural zones stretch along latitude, each geographic zone has its own natural zones. The law of altitudinal zonality is manifested in the mountains.
  
  

  6.Reflection learning activities

  What's new I learned in the lesson ………

  It was difficult for me ... ..

  It was interesting to me……

  7 homework

  Paragraph 20, p. 76-79, tasks at the end of the paragraph

  Planet Earth is a unique source of life, within which everything develops naturally. Each continent is a separate biocomplex where people have adapted to live different types plants and animals. In geography, individual territories with a similar climate, soil, vegetation and animal world it is customary to call natural zones.

  Zoning types

  Zoning is the division of the territories of continents and oceans into separate parts, which are called zones. It is easiest to distinguish them from each other by the nature of the vegetation, because what animals can live in this region depends on it.

  

  Rice. 1. Nature on Earth

  There are three types of zoning in the pattern of distribution of natural zones:

  • Change of natural zones by latitude... Moving from the equator to the poles, one can notice how the complexes are replaced one after another in a horizontal position. This pattern is especially clearly seen on the Eurasian continent.
  • Zoning along the meridians... Natural areas also change in longitude. The closer to the ocean, the greater its impact on land. And the further inland to the continent, the more moderate the climate. This zoning can be traced in North and South America, Australia.
  • Vertical waist... As you know, the change of natural zones occurs in the mountains. The farther from the surface of the earth, the colder it becomes and the nature of the vegetation changes.

  Reasons for zoning

  The regularity of the location of natural zones is due to different amounts of heat and moisture in different territories. Where there is a lot of precipitation and a high level of evaporation, humid equatorial forests appear, where there is a lot of evaporation, and there is little precipitation - savannas. Where there is no precipitation at all and it is dry all year round - deserts and so on.

  The main reason for zoning is the difference in the amount of heat and moisture in different regions, moving from the equator to the poles.

  

  Rice. 2. Dawn in the steppe

  What is the reason for the different ratio of heat and moisture?

  The distribution of heat and moisture on Earth depends on the shape of our planet. As you know, it is spherical. The axis of rotation does not go straight, but has some inclination. This leads to the fact that the sun heats up different parts of the planet in different ways. To better understand this process, consider the figure.

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  Rice. 3. Distribution of solar energy on the planet

  The figure shows that where there is a lot of sun, the surface heats up more, which means more evaporation near the oceans, respectively, there will be enough rain. Deeper into the continent - evaporation is high, humidity is low, etc.

  So, let's highlight the main reasons for zoning:

  • spherical shape of the Earth;
  • rotation of the planet around its axis at an angle.

  The reason for the zoning in the mountains is the distance from the surface of the earth.

  What have we learned?

  Natural zones replace each other not only in latitude, but also in longitude. This is due to the remoteness or proximity to the ocean. In the mountains, a change in natural zones can be traced because the higher - the colder the climate. There are two main reasons that affect the regularity of the change in natural zones: the spherical shape of the Earth and the rotation of the planet along an inclined axis.

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