What is climate in a nutshell. Climatic zones and types of climates in Russia. Extreme climatic indicators

10.03.2020

The air temperature here is constant (+24° -26°C), at sea temperature fluctuations can be less than 1°. The annual amount of precipitation is up to 3000 mm, and in the mountains of the equatorial belt, precipitation can fall up to 6000 mm. More water falls from the sky than evaporates, so there are many wetlands and dense, moist forests - jungles. Remember the adventure films about Indiana Jones - how hard it is for the main characters to make their way through the dense vegetation of the jungle and escape from crocodiles who love the muddy waters of small forest streams. All this is the equatorial belt. Its climate is greatly influenced by the trade winds, which bring abundant rainfall from the ocean.

Northern: Africa (Sahara), Asia (Arabia, south of the Iranian Highlands), North America (Mexico, Western Cuba).

Southern: South America (Peru, Bolivia, Northern Chile, Paraguay), Africa (Angola, Kalahari Desert), Australia (central part of the mainland).

In the tropics, the state of the atmosphere over the mainland (land) and the ocean is different, therefore, a continental tropical climate and an oceanic tropical climate are distinguished.

The oceanic climate is similar to the equatorial one, but differs from it by less cloudiness and steady winds. Summers over the oceans are warm (+20-27°С), and winters are cool (+10-15°С).

Above the land-tropics (mainland tropical climate), a high-pressure area prevails, so rain is a rare visitor here (from 100 to 250 mm). This type of climate is characterized by very hot summers (up to +40°С) and cool winters (+15°С). The air temperature during the day can change dramatically - up to 40 ° C! That is, a person can languish from the heat during the day and shiver from the cold at night. Such drops lead to the destruction of rocks, the creation of a mass of sand and dust, so dust storms are frequent here.

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This type of climate, as well as tropical, forms two belts in the Northern and Southern hemispheres, which are formed over the territories of temperate latitudes (from 40-45 ° North and South latitude to the Arctic Circles).

In the temperate zone, there are many cyclones that make the weather capricious and give out either snow or rain. In addition, westerly winds blow here, which bring precipitation all year round. Summer in this climatic zone is warm (up to +25°-28°С), winter is cold (from +4°С to -50°С). The annual precipitation is from 1000 mm to 3000 mm, and in the center of the continents only up to 100 mm.

In the temperate climate zone, unlike the equatorial and tropical, the seasons are pronounced (that is, you can make snowmen in winter and swim in the river in summer).

The temperate climate is also divided into two subtypes - maritime and continental.

Marine dominates the western parts of North America, South America and Eurasia. It is formed by westerly winds blowing from the ocean to the mainland, so it has rather cool summers (+15 -20°С) and warm winters (from +5°С). Precipitation brought by western winds falls all year round (from 500 to 1000 mm, in the mountains up to 6000 mm).

Continental prevails in the central regions of the continents. Cyclones penetrate here less often, therefore, there are warmer and drier summers (up to + 26 ° C) and colder winters (up to -24 ° C), and the snow lasts a very long time and melts reluctantly.

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polar belt

It dominates the territory above 65°-70° latitude in the Northern and Southern Hemispheres, therefore it forms two belts: the Arctic and the Antarctic. The Polar Belt has a unique feature - the Sun does not appear here at all for several months (polar night) and does not go below the horizon for several months (polar day). Snow and ice reflect more heat than they receive, so the air is very cold, and the snow does not melt almost all year. Since an area of high pressure is formed here, there are almost no clouds, the winds are weak, the air is saturated with small ice needles. The average summer temperature does not exceed 0°С, and in winter it is from -20° to -40°С. Rain falls only in the summer in the form of tiny droplets - drizzle.

Between the main climatic zones are transitional, having the prefix "sub" in the name (translated from Latin "under"). Here, the air masses change seasonally, coming from neighboring belts under the influence of the Earth's rotation.

a) Subequatorial climate. In summer, all climatic zones shift to the north, so equatorial air masses begin to dominate here. They shape the weather: a lot of precipitation (1000-3000 mm), the average air temperature is +30°C. The sun reaches its zenith in spring and scorches mercilessly. In winter, all climatic zones shift to the south, and tropical air masses begin to dominate in the subequatorial zone, winter is cooler than summer (+14 ° C). There is little rainfall. Soils dry out after summer rains, so in the subequatorial zone, unlike the equatorial zone, there are few swamps. The territory of this climatic zone is favorable for human life, therefore it is here that many centers of the emergence of civilization are located.

The subequatorial climate forms two belts. The northern ones include: the Isthmus of Panama (Latin America), Venezuela, Guinea, the Sahelian desert belt in Africa, India, Bangladesh, Myanmar, all of Indochina, South China, part of Asia. The southern zone includes: the Amazonian lowland, Brazil (South America), the center and east of Africa and the northern coast of Australia.

b) Subtropical climate. Tropical air masses prevail here in summer, and air masses of temperate latitudes prevail in winter, which determines the weather: hot, dry summers (from + 30 ° C to + 50 ° C) and relatively cold winters with precipitation, and stable snow cover is not formed.

c) Subpolar climate. This climatic zone is located only on the northern outskirts of Eurasia and North America. In summer, humid air masses come here from temperate latitudes, so the summer is cool here (from + 5 ° C to + 10 ° C). Despite the small amount of precipitation, evaporation is low, since the angle of incidence of the sun's rays is small and the earth warms up poorly. Therefore, in the subpolar climate in the north of Eurasia and North America, there are many lakes and swamps. In winter, cold arctic air masses come here, so the winters are long and cold, the temperature can drop to -50°C.

Remember

What do you know from the 6th grade geography course about the conditions that determine the climate?

The climate is determined by the latitude of the area (the angle of incidence of sunlight), the nature of the underlying surface, and the general circulation of the atmosphere.

This I know

1. List the main climate-forming factors. What is the most important factor?

The main climate-forming factors are geographic latitude, general atmospheric circulation and the nature of the underlying surface. The most important factor is the geographic latitude of the area.

2. Explain how the underlying surface affects the climate of the territory?

First, different temperature conditions and humidity are formed over the surface of the oceans and land. Over the oceans there is more humidity, less fluctuations in temperature. On land, the climate changes with distance from the coasts inland. At the same time, temperature fluctuations increase, cloudiness and precipitation decrease. Currents influence the climate. Cold currents along the coast make the climate of the coasts cool and very dry. Warm currents make the climate milder. Relief and the absolute height of the terrain play an important role in shaping the climate.

3. Give examples of the influence of remoteness from the oceans on the climate of the territory.

A vivid example of the influence of remoteness from the oceans on climate is the difference between the climate of the coasts and inland regions of Eurasia. The coasts of the mainland have a mild climate with warm summers and mild winters with frequent thaws. Up to 800 mm of precipitation falls here. The interior regions are characterized by dry, hot summers and very frosty winters with little snow.

4. How does the main climatic zone differ from the transitional one?

In the main climatic zone, one air mass dominates throughout the year. In transitional zones, two air masses replace each other.

This I can

5. On the map "Climatic zones and regions of the Earth" name the main and transitional climatic zones.

Transitional belts have the prefix "sub-" in the name.

6. Determine the type of climate according to the totality of signs: January temperature -10 ... -150С, July +20 ... +250С. precipitation falls throughout the year, but with a summer maximum. The annual amount of precipitation is 250-300 mm. What continents have this type of climate?

This is a temperate continental type of climate. It is represented in Eurasia, North America.

7. Based on the climate diagram (see Figure 35), determine the type of climate.

The climate is characterized by small temperature fluctuations. The air temperature does not fall below 10 0С in winter, summer temperatures - +20…+250С. Precipitation has a winter maximum. Such characteristics may have a subtropical Mediterranean type of climate.

8. Fill in the table

It's interesting to me

9. In what climate zone would you like to go on vacation in summer? What clothes will you especially need when traveling?

To have a rest in the summer I would go to the subtropical Mediterranean climatic zone. The Mediterranean climate is extremely favorable for human life, which is why the most famous summer resorts are located here. Valuable subtropical crops are grown here: citrus fruits, grapes, olives.

When traveling, you will need light clothing made from natural fabrics that would not leave exposed skin, beachwear and hats.

Russia is the largest country in the world, its area is 17 million square meters. km.; its length from west to east is almost 10,000 km, and from north to south - 4,000 km. Due to this length, the country is located in several climatic zones, which continue to be studied in the 8th grade. Learn briefly about the climate of Russia.

general characteristics

The climate of the whole of Russia is characterized by a clear division into warm and cold seasons. From north to south, there is a decrease in temperature differences and a warming climate. The eastern part of the country is colder than the western part. This is due to the fact that the western part is most influenced by the ocean, which moderates the climate. The following climatic zones are defined in the country:

arctic;
subarctic;
moderate;
subtropical.

Within each zone, zonal climate types are distinguished, changing in the direction from north to south, and climatic regions, directed from west to east. Russia's climate is influenced by factors such as relief and proximity to the ocean. The table shows climate zones for different regions of the country.

Now consider what is happening with the climate in Russia in each zone.

Rice. 1. Climate map of Russia

Arctic

This belt occupies the north of the country. The following areas fell into the area of the Arctic climate:

Subarctic

The subarctic climate zone includes the area near the Arctic Circle. It is characterized by severe weather conditions. Winters are cold and long, summers are short and cool, with constant winds and high humidity. Permafrost is not located throughout the territory; instead, there are a large number of swamps.

In summer, air masses from the temperate zone dominate here, and in winter - arctic ones. The Siberian part of the country differs from the eastern one by its pronounced continentality. The average temperature in July is plus 15 degrees, in January - minus 30 degrees.

Moderate

Most of the country is located in the temperate zone. There is a clear delimitation of the seasons here. The natural zone of this belt is the taiga. In the temperate climate zone, there are four climatic areas with different characteristics:

continental;
temperate continental;
sharply continental;
monsoon.

continental climate observed on the territory of Western Siberia. It has low humidity and moderate rainfall. The average temperature in winter is -19 degrees, in summer - plus 20 degrees.

temperate continental is the climate of the European part of the country. Features of this climate zone:

remoteness from the seas and oceans;
low cloud cover;
strong winds.

The territory is represented by different natural zones - from the taiga to the steppe. This causes a significant difference in humidity - the northern areas are characterized by high humidity, and the southern ones are low. The climate of central Russia is characterized by slight temperature fluctuations. In winter, the average temperature here is minus 10 degrees, and in summer - plus 20 degrees.

Sharply continental climate characteristic of Eastern Siberia, an area far removed from the oceans. In summer it is cool and humid here. In winter it is cold and there is little snow. The average temperature in January is -25 degrees, in July - plus 19 degrees.

Cities with a monsoon climate in Russia are located in the southern part of the Far East. It is characterized by a change in weather conditions, depending on the circulation seasonal winds (monsoons). Winters are cool and wet. Summers are also cool and there is a lot of rainfall. The temperature in winter is -22 degrees, in summer - plus 17 degrees.

Subtropical

This belt occupies the European south of Russia. Only the northern part of the subtropical zone is located on the territory of our country, so the climate here is more moderate. This is the best region for living and farming. Summers are hot and dry here, and winters are mild and short. The mountainous regions are more arid, while the sea is humid and warm.

The Black Sea coast is the only region of the country where even in winter the temperature does not fall below zero, and snow is very rare.

Rice. 3. In Russia, the subtropics occupy a small strip along the Black Sea

What have we learned?

From this article on geography, we learned that Russia is located in four climatic zones, and also found out which one is the most favorable for living. Of the arctic, subarctic, temperate and subtropical, the last one is the most optimal. But most of the country is still located in a temperate climate.

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In the direction from north to south, our country is located in the arctic, subarctic and temperate climatic zones. But significant climate changes are also observed within each belt: both when moving from west to east (climatic regions), and when moving from north to south (zonal). For example, five subtypes of the temperate climate zone are distinguished: temperate continental, continental, sharply continental, monsoonal, and the climate of the eastern coasts. Each of the types is characterized by its own temperature regime, the prevailing types of weather according to the seasons of the year.

Arctic climate zone (climate of arctic deserts and tundra)

It is typical for the coast of Russia and for islands located in the ocean. All year round, within this climate, arctic ones dominate. In winter, the temperature drops to -40-50°С, and in summer it is not higher than 4°С. A significant part of solar radiation is reflected by the snow surface. Associated with the passage here are the weakening of frosts and heavy snowfalls. The amount of precipitation is up to 300 mm, however, moisture is excessive due to low evaporation.

Subarctic belt (tundra and forest-tundra climate)

This type of climate is characteristic of the territory located beyond the Arctic Circle, and in the eastern regions it extends almost to 60 ° N. In summer, humid air masses come from here, so the summer is cool here (from + 5 ° С in the north to + 14 ° С in the south), but frosts are also possible. In winter, the weather in this climate is influenced by arctic air masses, so the winters here are long and their severity increases from west to east (temperatures can reach -50°C). In connection with the passage of Arctic cyclones, this climate is characterized by large clouds and strong winds. The annual amount of precipitation is up to 600 mm, with a maximum in summer. The moisture coefficient here is greater than unity, since low temperatures contribute to low evaporation, which leads to territories.

Temperate climate

Since this climate is typical for a large territory of Russia, there are differences in temperature and different areas within it, associated with the distribution of different air masses. In temperate, five types are distinguished, replacing each other from west to east.

temperate continental climate

It is typical for the European part of Russia. The influence is great here, from where humid sea air masses come all year round, relatively warm in winter and cool in summer. Summers are warm here (up to +24°С), winters are mild (from -4°С to -20°С), with frequent thaws. Precipitation is 600-800 mm, with the largest amount of precipitation occurring in the western regions. The change in moisture from excessive to insufficient in the area of dominance of the temperate continental climate contributes to the formation of a change in natural zones from to steppe in the European part of Russia.

continental climate

Climate is a long-term weather regime characteristic of a given area due to its geographical location.

Climate is a statistical ensemble of states through which the system passes: hydrosphere → lithosphere → atmosphere over several decades. Climate is usually understood as the average value of weather over a long period of time (of the order of several decades), that is, climate is the average weather. Thus, the weather is an instantaneous state of some characteristics (temperature, humidity, atmospheric pressure). The deviation of the weather from the climatic norm cannot be considered as climate change, for example, a very cold winter does not indicate a cooling of the climate. To detect climate change, a significant trend in the characteristics of the atmosphere over a long period of time of the order of ten years is needed. The main global geophysical cyclical processes that form the climatic conditions on Earth are heat circulation, moisture circulation and general circulation of the atmosphere.

In addition to the general concept of "climate", there are the following concepts:

free atmosphere climate - studied by aeroclimatology.
Microclimate
Macroclimate - the climate of territories on a planetary scale.
Surface air climate
local climate
soil climate
phytoclimate - plant climate
urban climate

The climate is studied by the science of climatology. Climate change in the past is studied by paleoclimatology.

In addition to the Earth, the concept of "climate" can refer to other celestial bodies (planets, their satellites and asteroids) that have an atmosphere.

Climatic zones and climate types

Climatic zones and climate types vary significantly in latitude, ranging from the equatorial zone to the polar zone, but climatic zones are not the only factor, the proximity of the sea, the atmospheric circulation system and altitude above sea level also have an important influence.

In Russia and on the territory of the former USSR, a classification of climate types was used, created in 1956 by the famous Soviet climatologist B.P. Alisov. This classification takes into account the features of atmospheric circulation. According to this classification, four main climatic zones are distinguished for each hemisphere of the Earth: equatorial, tropical, temperate and polar (in the northern hemisphere - arctic, in the southern hemisphere - antarctic). Between the main zones there are transitional belts - subequatorial belt, subtropical, subpolar (subarctic and subantarctic). In these climatic zones, in accordance with the prevailing circulation of air masses, four types of climate can be distinguished: continental, oceanic, the climate of the western and the climate of the eastern coasts.

equatorial belt

Equatorial climate - a climate where winds are weak, temperature fluctuations are small (24-28 ° C at sea level), and precipitation is very plentiful (from 1.5 thousand to 5 thousand mm per year) and falls evenly throughout the year.

subequatorial belt

Tropical monsoon climate - here in summer, instead of the easterly trade winds between the tropics and the equator, the westward air transport (summer monsoon) occurs, bringing most of the precipitation. On average, they fall almost as much as in the equatorial climate. On the slopes of the mountains facing the summer monsoon, precipitation is the greatest for the respective regions, the warmest month, as a rule, occurs immediately before the onset of the summer monsoon. Characteristic for some areas of the tropics (Equatorial Africa, South and Southeast Asia, Northern Australia). In East Africa and Southwest Asia, the highest average annual temperatures on Earth (30-32 ° C) are also observed.
Monsoon climate on tropical plateaus

tropical belt

Tropical dry climate
Tropical humid climate

subtropical belt

mediterranean climate
Subtropical continental climate
Subtropical monsoon climate
Climate of high subtropical highlands
Subtropical climate of the oceans

Temperate zone

temperate maritime climate
temperate continental climate
temperate continental climate
Moderate sharply continental climate
temperate monsoon climate

subpolar belt

subarctic climate
subantarctic climate

Polar belt: Polar climate

arctic climate
Antarctic climate

The classification of climates proposed by the Russian scientist W. Köppen (1846-1940) is widespread in the world. It is based on the temperature regime and the degree of moisture. According to this classification, eight climatic zones with eleven types of climate are distinguished. Each type has precise parameters for temperature values, the amount of winter and summer precipitation.

Also in climatology, the following concepts related to climate characteristics are used:

Continental climate - “a climate that is formed under the influence of large land masses on the atmosphere; distributed in the interior of the continents. It is characterized by large daily and annual air temperature amplitudes.
Maritime climate is “the climate that is formed under the influence of oceanic spaces on the atmosphere. It is most pronounced over the oceans, but also extends to areas of the continents that are subject to frequent influences of sea air masses.
Mountain climates - "climatic conditions in mountainous areas." The main reason for the difference between the climate of the mountains and the climate of the plains is the increase in altitude. In addition, important features are created by the nature of the terrain (degree of dissection, relative height and direction of mountain ranges, exposure of slopes, width and orientation of valleys), glaciers and firn fields exert their influence. A distinction is made between the actual mountain climate at altitudes less than 3000-4000 m and the alpine climate at high altitudes.
Arid climate - "climate of deserts and semi-deserts". Large daily and annual air temperature amplitudes are observed here; almost complete absence or insignificant amount of precipitation (100-150 mm per year). The resulting moisture evaporates very quickly.
Humid climate - a climate with excessive moisture, in which solar heat comes in quantities insufficient to evaporate all the moisture coming in the form of precipitation.
Nival climate - "a climate where there is more solid precipitation than can melt and evaporate." As a result, glaciers are formed and snowfields are preserved.
Solar climate (radiation climate) - the theoretically calculated receipt and distribution of solar radiation over the globe (without taking into account local climate-forming factors.
Monsoon climate - a climate in which the cause of the change of seasons is a change in the direction of the monsoon. As a rule, in a monsoon climate, summers are abundant in precipitation and very dry winters. Only in the eastern part of the Mediterranean, where the summer direction of the monsoons is from land, and the winter direction is from the sea, the main amount of precipitation falls in winter.
trade wind climate

Brief description of the climates of Russia:

Arctic: January t −24…-30, summer t +2…+5. Precipitation - 200-300 mm.
Subarctic: (up to 60 degrees N). summer t +4…+12. Precipitation 200-400 mm.
Moderately continental: January t -4 ... -20, July t +12 ... +24. Precipitation 500-800 mm.
Continental climate: January t −15…-25, July t +15…+26. Precipitation 200-600 mm.
Sharply continental: January t -25 ... -45, July t +16 ... +20. Precipitation - more than 500 mm.
Monsoon: January t −15…-30, July t +10…+20. Precipitation 600-800. mm

Study Methods

To reveal the features of the climate, both typical and rarely observed, long-term series of meteorological observations are needed. In temperate latitudes, 25-50-year series are used; in the tropics, their duration may be shorter.

Climatic characteristics are statistical findings from long-term weather records, primarily over the following main meteorological elements: atmospheric pressure, wind speed and direction, air temperature and humidity, cloudiness and precipitation. They also take into account the duration of solar radiation, the visibility range, the temperature of the upper layers of soil and water bodies, the evaporation of water from the earth's surface into the atmosphere, the height and condition of the snow cover, various atmospheric phenomena and ground-based hydrometeors (dew, ice, fog, thunderstorms, snowstorms, etc.) . In the 20th century, climatic indicators included characteristics of the elements of the heat balance of the earth's surface, such as total solar radiation, radiation balance, heat exchange between the earth's surface and the atmosphere, and heat consumption for evaporation.

Long-term average values of meteorological elements (annual, seasonal, monthly, daily, etc.), their sums, frequencies, and others are called climatic norms; the corresponding values for individual days, months, years, etc. are considered as a deviation from these norms. To characterize the climate, complex indicators are also used, that is, functions of several elements: various coefficients, factors, indices (for example, continentality, aridity, moisture), etc.

Special climate indicators are used in applied branches of climatology (for example, sums of temperatures of the growing season in agroclimatology, effective temperatures in bioclimatology and technical climatology, degree days in heating system calculations, etc.).

To assess future climate changes, models of the general circulation of the atmosphere are used.

climate-forming factors

The climate of the planet depends on a whole range of external and internal factors. Most external factors affect the total amount of solar radiation received by the planet, as well as its distribution over seasons, hemispheres and continents.

External factors

Earth orbit and axis parameters

The distance between the Earth and the Sun - determines the amount of solar energy received by the Earth.
The inclination of the Earth's axis of rotation to the plane of the orbit - determines seasonal changes.
The eccentricity of the Earth's orbit - affects the distribution of heat between the Northern and Southern hemispheres, as well as seasonal changes.

Milankovitch cycles - in the course of its history, the planet Earth quite regularly changes the eccentricity of its orbit, as well as the direction and angle of its axis. These changes are called "Milankovitch cycles". There are 4 Milankovitch cycles:

Precession - rotation of the earth's axis under the influence of the attraction of the moon, and also (to a lesser extent) the sun. As Newton found out in his Principia, the oblateness of the Earth at the poles leads to the fact that the attraction of external bodies turns the Earth's axis, which describes a cone with a period (according to modern data) of approximately 25,776 years, as a result of which the seasonal amplitude of the solar flux intensity changes by northern and southern hemispheres of the Earth;
Nutation - long-term (so-called secular) fluctuations in the angle of inclination of the earth's axis to the plane of its orbit with a period of about 41,000 years;
Long-term fluctuations in the eccentricity of the Earth's orbit with a period of about 93,000 years.
Movement of the perihelion of the Earth's orbit and the ascending node of the orbit with a period of 10 and 26 thousand years, respectively.

Since the described effects are periodic with a non-multiple period, sufficiently long epochs regularly occur when they have a cumulative effect, reinforcing each other. Milankovitch cycles are commonly used to explain the Holocene climate optimum;

Solar activity with 11-year, secular and thousand-year cycles;
The difference in the angle of incidence of the sun's rays at different latitudes, which affects the degree of heating of the surface and, consequently, the air;
The speed of rotation of the Earth practically does not change, it is a constantly acting factor. Due to the rotation of the Earth, there are trade winds and monsoons, and cyclones are also formed.
Falling asteroids;
The ebb and flow is caused by the action of the moon.

Internal factors

The configuration and relative position of the oceans and continents - the appearance of a continent in the polar latitudes can lead to ice cover, and the withdrawal of a significant amount of water from the daily cycle, also the formation of supercontinents Pangea has always been accompanied by a general aridization of the climate, often against the background of glaciation, and the location of the continents has a great influence on system of ocean currents;
Volcanic eruptions can cause short-term climate change, up to a volcanic winter;
The albedo of the earth's atmosphere and surface affects the amount of reflected sunlight;
Air masses (depending on the properties of air masses, the seasonality of precipitation and the state of the troposphere is determined);
The influence of the oceans and seas (if the area is remote from the seas and oceans, then the continentality of the climate increases. The presence of a number of oceans softens the climate of the area, with the exception of the presence of cold currents);
The nature of the underlying surface (relief, landscape features, the presence and condition of ice sheets);
Human activities (fuel combustion, emission of various gases, agricultural activities, deforestation, urbanization);
Heat flows of the planet.

Atmospheric circulation

The general circulation of the atmosphere is a set of large-scale air currents above the earth's surface. In the troposphere, they include trade winds, monsoons, as well as air mass transfers associated with cyclones and anticyclones. Atmospheric circulation exists due to the uneven distribution of atmospheric pressure, caused by the fact that at different latitudes of the Earth its surface is heated differently by the sun and the earth's surface has different physical properties, especially due to its division into land and sea. As a result of the exchange of heat between the earth's surface and the atmosphere due to the uneven distribution of heat, there is a constant circulation of the atmosphere. The energy of the circulation of the atmosphere is constantly spent on friction, but is continuously replenished due to solar radiation. In the most heated places, the heated air has a lower density and rises, thus forming a zone of low atmospheric pressure. Similarly, a zone of high pressure is formed in colder places. The movement of air occurs from a zone of high atmospheric pressure to a zone of low atmospheric pressure. Since the area is located closer to the equator and farther from the poles, the better it warms up, in the lower layers of the atmosphere there is a predominant movement of air from the poles to the equator. However, the Earth also rotates on its axis, so the Coriolis force acts on the moving air and deflects this movement to the west. In the upper layers of the troposphere, a reverse movement of air masses is formed: from the equator to the poles. Its Coriolis force constantly deflects to the east, and the farther, the more. And in areas around 30 degrees north and south latitude, movement becomes directed from west to east parallel to the equator. As a result, the air that has fallen into these latitudes has nowhere to go at such a height, and it sinks down to the ground. This is where the highest pressure area is formed. In this way trade winds are formed - constant winds blowing towards the equator and to the west, and since the wrapping force acts constantly, when approaching the equator, the trade winds blow almost parallel to it. The air currents of the upper layers, directed from the equator to the tropics, are called antitrade winds. The trade winds and anti-trade winds, as it were, form an air wheel, along which a continuous circulation of air is maintained between the equator and the tropics. During the year, this zone shifts from the equator to the warmer summer hemisphere. As a result, in some places, especially in the Indian Ocean basin, where the main direction of air transport in winter is from west to east, in summer it is replaced by the opposite one. Such air transfers are called tropical monsoons. Cyclonic activity connects the tropical circulation zone with circulation in temperate latitudes, and between them there is an exchange of warm and cold air. As a result of interlatitudinal air exchange, heat is transferred from low to high latitudes and cold from high to low latitudes, which leads to the preservation of thermal equilibrium on Earth.

In fact, the circulation of the atmosphere is constantly changing, both due to seasonal changes in the distribution of heat on the earth's surface and in the atmosphere, and due to the formation and movement of cyclones and anticyclones in the atmosphere. Cyclones and anticyclones move generally towards the east, while cyclones deviate towards the poles, and anticyclones - away from the poles.

Thus are formed:

high pressure zones:

on both sides of the equator at latitudes of about 35 degrees;
in the region of the poles at latitudes above 65 degrees.

low pressure zones:

equatorial depression - along the equator;
subpolar depressions - in subpolar latitudes.

This pressure distribution corresponds to western transport in temperate latitudes and eastern transport in tropical and high latitudes. In the Southern Hemisphere, the zonality of atmospheric circulation is better expressed than in the Northern Hemisphere, since there are mainly oceans. The wind in the trade winds varies little, and these changes change little the nature of the circulation. But sometimes (on average, about 80 times a year) in some areas of the intratropical convergence zone (“an intermediate zone of approximately several hundred kilometers wide between the trade winds of the Northern and Southern hemispheres”), the strongest eddies develop - tropical cyclones (tropical hurricanes), which sharply, even catastrophically, they change the established circulation regime and the weather on their way in the tropics, and sometimes even beyond them. In extratropical latitudes, cyclones are less intense than tropical ones. The development and passage of cyclones and anticyclones is an everyday phenomenon. The meridional components of the atmospheric circulation associated with cyclonic activity in extratropical latitudes change rapidly and frequently. However, it happens that for several days and sometimes even weeks, extensive and high cyclones and anticyclones hardly change their position. Then, oppositely directed long-term meridional air transfers occur, sometimes in the entire thickness of the troposphere, which spread over large areas and even over the entire hemisphere. Therefore, in extratropical latitudes, two main types of circulation are distinguished over the hemisphere or its large sector: zonal, with a predominance of zonal, most often western, transport, and meridional, with adjacent air transports towards low and high latitudes. The meridional type of circulation carries out a much greater interlatitudinal heat transfer than the zonal one.

Atmospheric circulation also ensures the distribution of moisture both between climatic zones and within them. The abundance of precipitation in the equatorial belt is provided not only by its own high evaporation, but also by the transfer of moisture (due to the general circulation of the atmosphere) from the tropical and subequatorial belts. In the subequatorial belt, atmospheric circulation ensures the change of seasons. When the monsoon blows from the sea, it rains heavily. When the monsoon blows from the dry land, the dry season begins. The tropical belt is drier than the equatorial and subequatorial belts, since the general circulation of the atmosphere carries moisture to the equator. In addition, winds from east to west prevail, therefore, due to the moisture evaporated from the surface of the seas and oceans, quite a lot of rain falls in the eastern parts of the continents. Further west, there is not enough rain, the climate becomes arid. This is how entire belts of deserts are formed, such as the Sahara or the deserts of Australia.

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