Distribution of heat and precipitation on the ground. Heat distribution over the earth's surface

Atmosphere- the air shell surrounding the globe, associated with it by gravity and taking part in its daily and annual rotation.

Atmospheric air consists of a mechanical mixture of gases, water vapor and impurities. The composition of the air up to an altitude of 100 km is 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.03% carbon dioxide, and only 0.01% is accounted for by all other gases: hydrogen, helium, water vapor, ozone. The gases that make up the air are constantly being mixed. The percentage of gases is fairly constant. However, the carbon dioxide content changes. Burning oil, gas, coal, and a decrease in the number of forests leads to an increase in the content of carbon dioxide in the atmosphere. This contributes to an increase in the air temperature on Earth, since carbon dioxide passes solar energy to the Earth, and the thermal radiation of the Earth delays. Thus, carbon dioxide is a kind of "insulation" for the Earth.

There is little ozone in the atmosphere. At an altitude of 25 - 35 km, a concentration of this gas is observed, the so-called ozone screen (ozone layer). The ozone screen performs the most important function of protection - it detains the ultraviolet radiation of the Sun, which is destructive for all life on Earth.

Atmospheric water is in the air in the form of water vapor or suspended condensation products (drops, ice crystals).

Atmospheric impurities(aerosols) - liquid and solid particles found mainly in the lower atmosphere: dust, volcanic ash, soot, ice crystals and sea salt, etc. The amount of atmospheric impurities in the air increases during strong forest fires, dust storms, volcanic eruptions ... The underlying surface also affects the amount and quality of atmospheric impurities in the air. So, over the deserts there is a lot of dust, over the cities there are many small solid particles, soot.

The presence of impurities in the air is associated with the content of water vapor in it, since dust, ice crystals and other particles serve as nuclei around which water vapor condenses. Like carbon dioxide, atmospheric water vapor serves as a "heat insulator" for the Earth: it delays radiation from earth surface.

The mass of the atmosphere is one millionth of the mass of the earth.

The structure of the atmosphere. The atmosphere has a layered structure. Layers of the atmosphere are distinguished based on the change in air temperature with height and other physical properties(Table 1).

Table 1.The structure of the atmosphere

Sphere of atmosphere	Height of the lower and upper bounds	Temperature change with altitude
Troposphere		Downgrade
Stratosphere	8-18 - 40-50 km	Enhancement
Mesosphere	40-50 km - 80 km	Downgrade
Thermosphere		Enhancement
Exosphere	Above 800 km (conventionally, it is believed that the atmosphere extends to an altitude of 3000 km)

Troposphere— the lower shell of the atmosphere, containing 80% air and almost all water vapor. The thickness of the troposphere is not the same. At tropical latitudes - 16-18 km, in temperate latitudes - 10-12 km, and in polar latitudes - 8-10 km. Everywhere in the troposphere, the air temperature drops by 0.6 ° С for every 100 m ascent (or 6 ° C for 1 km). The troposphere is characterized by vertical (convection) and horizontal (wind) air movements. All types of air masses are formed in the troposphere, cyclones and anticyclones appear, clouds, precipitation, and fog are formed. Weather forms mainly in the troposphere. Therefore, the study of the troposphere has special meaning... The lower layer of the troposphere, which is called surface layer, it is highly dusty and contains volatile microorganisms.

The transitional layer from the troposphere to the stratosphere is called tropopause. The rarefaction of air in it sharply increases, its temperature drops to -60 ° From above the poles to -80 ° From over the tropics. The lower air temperature over the tropics is due to powerful ascending air currents and a higher position of the troposphere.

Stratosphere- the layer of the atmosphere between the troposphere and the mesosphere. The gas composition of the air is similar to the troposphere, but contains much less water vapor and more ozone. The highest concentration of this gas (ozone screen) is observed at an altitude of 25 to 35 km. Up to an altitude of 25 km, the temperature changes little with altitude, and above it begins to rise. Temperatures vary with latitude and season. Nacreous clouds are observed in the stratosphere; it is characterized by high wind speeds and jet streams of air.

The upper atmosphere is characterized by polar lights and magnetic storms. Exosphere- the outer sphere from which light atmospheric gases (for example, hydrogen, helium) can flow into space... The atmosphere does not have a sharp upper boundary and gradually passes into outer space.

The presence of the atmosphere is of great importance to the Earth. It prevents excessive heating of the earth's surface during the day and cooling at night; protects the Earth from ultraviolet radiation The sun. A significant part of the meteorites burns up in the dense layers of the atmosphere.

Interacting with all the shells of the Earth, the atmosphere participates in the redistribution of moisture and heat on the planet. It is a condition for the existence of organic life.

Solar radiation and air temperature. The air is heated and cooled from the earth's surface, which in turn is heated by the sun. The entire totality of solar radiation is called solar radiation... The main part of solar radiation is scattered in the world space, only one two-billionth part of solar radiation comes to the Earth. Radiation is direct and diffuse. Solar radiation that reaches the surface of the Earth in the form of direct sunlight emanating from the solar disk on a clear day is called direct radiation... Solar radiation that has undergone scattering in the atmosphere and arrives at the surface of the Earth from the entire firmament is called scattered radiation... Scattered solar radiation plays a significant role in the energy balance of the Earth, being the only source of energy in the surface layers of the atmosphere in cloudy weather, especially at high latitudes. The combination of direct and scattered radiation entering a horizontal surface is called total radiation.

The amount of radiation depends on the duration of the illumination of the surface by the sun's rays and the angle of their incidence. The smaller the angle of incidence of the sun's rays, the less solar radiation the surface receives and, therefore, the less the air above it heats up.

Thus, the amount of solar radiation decreases when moving from the equator to the poles, since the angle of incidence of the sun's rays and the duration of illumination of the territory in winter time decrease.

The amount of solar radiation is also affected by cloudiness and transparency of the atmosphere.

The greatest total radiation exists in tropical deserts. At the poles on the day of the solstices (at the North - on June 22, at the South - on December 22), with a non-setting Sun, the total solar radiation is greater than at the equator. But due to the fact that the white surface of snow and ice reflects up to 90% of the sun's rays, the amount of heat is negligible, and the surface of the earth does not heat up.

The total solar radiation reaching the Earth's surface is partially reflected by it. Radiation reflected from the surface of the earth, water or clouds on which it falls is called reflected. But still, most of the radiation is absorbed by the earth's surface and turns into heat.

Since the air heats up from the surface of the earth, its temperature depends not only on the factors listed above, but also on the height above sea level: the higher the terrain is, the lower the temperature (decreases by 6 ° C with every kilometer in the troposphere).

Affects the temperature and distribution of land and water, which are heated unevenly. Land heats up quickly and cools quickly, water heats up slowly, but retains heat longer. Thus, the air over land is warmer during the day than over water, and colder at night. This influence affects not only the diurnal, but also the seasonal characteristics of the change in air temperature. Thus, in coastal areas, under the same conditions, the summer is cooler and the winter is warmer.

Due to the heating and cooling of the Earth's surface day and night, during the warm and cold seasons, the air temperature changes throughout the day and year. The highest temperatures of the surface layer are observed in the desert regions of the Earth - in Libya near the city of Tripoli +58 ° С, in Death Valley (USA), in Termez (Turkmenistan) - up to +55 ° С. The lowest are in the interior regions of Antarctica - up to -89 ° С. In 1983, at Vostok station in Antarctica, -83.6 ° С is the minimum air temperature on the planet.

Air temperature- a widely used and well-studied characteristic of the weather. The air temperature is measured 3-8 times a day, determining the average daily; according to the daily average, the monthly average is determined, according to the monthly average - the annual average. The maps depict the temperature distribution isotherms. Typically July, January and annual temperatures are used.

Atmosphere pressure. Air, like any body, has a mass: 1 liter of air at sea level has a mass of about 1.3 g. For every square centimeter of the earth's surface, the atmosphere presses with a force of 1 kg. This is the average air pressure above sea level at latitude 45 ° at a temperature of 0 ° C corresponds to the weight of a mercury column with a height of 760 mm and a section of 1 cm 2 (or 1013 mb.). This pressure is taken as normal pressure. Atmosphere pressure - the force with which the atmosphere presses on all objects in it and on the earth's surface. The pressure is determined at each point of the atmosphere by the mass of the overlying column of air with a base equal to one. With increasing altitude, atmospheric pressure decreases, since the higher the point is, the lower the height of the air column above it. As it rises upward, the air is rarefied and its pressure decreases. In high mountains, the pressure is much less than at sea level. This regularity is used when determining the absolute height of the terrain by the magnitude of pressure.

Baric stage- the vertical distance at which atmospheric pressure decreases by 1 mm Hg. Art. In the lower layers of the troposphere, up to a height of 1 km, the pressure decreases by 1 mm Hg. Art. for every 10 m of height. The higher, the slower the pressure decreases.

In the horizontal direction near the earth's surface, the pressure changes unevenly, depending on time.

Baric gradient- an indicator characterizing the change in atmospheric pressure above the earth's surface per unit distance and horizontally.

The magnitude of pressure, in addition to the height of the terrain above sea level, depends on the air temperature. The pressure of warm air is less than that of cold air, because due to heating it expands, and when it cools, it contracts. With a change in air temperature, its pressure changes. Since the change in air temperature on the globe is zonal, zoning is also characteristic of the distribution of atmospheric pressure on the earth's surface. A low pressure belt stretches along the equator, at 30-40 ° latitudes to the north and south - high pressure belts, at 60-70 ° latitudes the pressure is lowered again, and in polar latitudes - areas of high pressure. The distribution of belts of high and low pressure is associated with the peculiarities of heating and air movement at the Earth's surface. In equatorial latitudes, the air heats up well throughout the year, rises and spreads towards tropical latitudes. Approaching 30-40 ° latitudes, the air cools down and descends, creating a belt of increased pressure. In polar latitudes, cold air creates areas of increased pressure. Cold air constantly descends, and in its place comes air from temperate latitudes. The outflow of air to polar latitudes is the reason that a low pressure belt is created in temperate latitudes.

Pressure belts exist all the time. They are only slightly shifted to the north or south, depending on the season ("following the Sun"). The exception is the low pressure belt of the Northern Hemisphere. It only exists in the summer. Moreover, over Asia, a huge area of low pressure is formed with its center in tropical latitudes - the Asian minimum. Its formation is explained by the fact that over a huge land mass, the air warms up strongly. In winter, the land, which occupies significant areas in these latitudes, is greatly cooled, the pressure above it increases, and areas of increased pressure are formed over the continents - the Asian (Siberian) and North American (Canadian) winter maximums of atmospheric pressure. Thus, in winter, the belt of low pressure in the temperate latitudes of the Northern Hemisphere "breaks". It persists only over the oceans in the form of closed areas of low pressure - the Aleutian and Icelandic minima.

The influence of the distribution of land and water on the patterns of change in atmospheric pressure is also expressed in the fact that throughout the year, baric maxima exist only over the oceans: Azores (North Atlantic), North Pacific, South Atlantic, South Pacific, South Indian.

The atmospheric pressure is constantly changing. The main reason for a change in pressure is a change in air temperature.

Atmospheric pressure is measured using barometers... The aneroid barometer consists of a hermetically sealed thin-walled box, inside of which the air is rarefied. When the pressure changes, the walls of the box are pressed in or protruded. These changes are transmitted to the arrow, which moves on a scale, graduated in millibars or millimeters.

The maps show the pressure distribution over the Earth. isobars... Most often, the maps indicate the distribution of isobars in January and July.

The distribution of areas and belts of atmospheric pressure significantly affects air currents, weather and climate.

Wind- horizontal air movement relative to the earth's surface. It occurs as a result of an uneven distribution of atmospheric pressure and its movement is directed from areas of higher pressure to areas where the pressure is lower. Due to the continuous change in pressure in time and space, the speed and direction of the wind are constantly changing. The direction of the wind is determined by the part of the horizon from which it blows (the north wind blows from north to south). Wind speed is measured in meters per second. With height, the direction and strength of the wind change due to a decrease in the friction force, as well as in connection with a change in pressure gradients.

So, the reason for the wind is the difference in pressure between different territories, and the reason for the difference in pressure is the difference in heating. The deflection force of the Earth's rotation acts on the winds.

Winds are diverse in origin, character, meaning. The main winds are breezes, monsoons, trade winds.

Breeze— local wind (sea coasts, large lakes, reservoirs and rivers), which changes its direction twice a day: during the day it blows from the side of the reservoir to the land, and at night - from land to the reservoir. Breezes arise from the fact that during the day the land heats up more than the water, which is why the warmer and lighter air above the land rises and colder air flows from the side of the reservoir to its place. At night, the air above the reservoir is warmer (because it cools more slowly), so it rises up, and in its place the air masses move from the land - heavier, cooler ones (Fig. 12). Other types of local winds are hair dryer, bora, etc.

Rice. 12

Trade winds- constant winds in the tropical regions of the Northern and Southern Hemispheres, blowing from high pressure belts (25-35 ° N and S) to the equator (into the low pressure belt). Under the influence of the Earth's rotation around its axis, the trade winds deviate from their original direction. In the Northern Hemisphere, they blow from northeast to southwest, in the Southern Hemisphere - from southeast to northwest. The trade winds are characterized by high stability of direction and speed. The trade winds have big influence on the climate of the territories under their influence. This is especially evident in the distribution of precipitation.

Monsoons— winds that, depending on the seasons of the year, change direction to the opposite or close to it. In the cold season, they blow from the mainland to the ocean, and in the warm season - from the ocean to the mainland.

Monsoons are formed due to the difference in air pressure arising from the uneven heating of land and sea. In winter, the air is colder over land and warmer over the ocean. Consequently, the pressure is higher over the mainland, lower - over the ocean. Therefore, in winter, air moves from the mainland (areas of higher pressure) to the ocean (above which the pressure is lower). In the warm season, the opposite is true: monsoons blow from the ocean to the mainland. Therefore, in the areas of distribution of monsoons, precipitation falls, as a rule, in summer. Due to the rotation of the Earth around its axis, the monsoons deviate in the Northern Hemisphere to the right, and in the Southern Hemisphere - to the left of their original direction.

Monsoons are important part of general circulation of the atmosphere. Distinguish extratropical and tropical(equatorial) monsoons. In Russia, extratropical monsoons operate on the territory of the Far East coast. Tropical monsoons are more pronounced, they are most typical for the South and South-East Asia, where in some years several thousand millimeters of precipitation falls during the wet season. Their formation is explained by the fact that the equatorial low-pressure belt is slightly displaced to the north or south, depending on the season ("following the Sun"). In July, it is located at 15 - 20 ° N. sh. Therefore, the southeastern trade wind of the Southern Hemisphere, rushing to this low pressure belt, crosses the equator. Under the influence of the deflecting force of the Earth's rotation (around its axis) in the Northern Hemisphere, it changes its direction and becomes southwestern. This is the summer equatorial monsoon, which endures sea air masses equatorial air to latitude 20-28 °. Meeting the mountains of the Himalayas on its way, wet air leaves a significant amount of precipitation on their southern slopes. At Cherrapunja station in North India, the average annual precipitation exceeds 10,000 mm per year, and in some years even more.

From the high-pressure belts, the winds also blow towards the poles, but, deviating to the east, they change their direction to the west. Therefore, in temperate latitudes prevail westerly winds, although they are not as constant as the trade winds.

The prevailing winds in the polar regions are northeastern winds in the Northern Hemisphere and southeasterly in the South.

Cyclones and anticyclones. Due to the uneven heating of the earth's surface and the deflecting force of the Earth's rotation, huge (up to several thousand kilometers in diameter) atmospheric vortices - cyclones and anticyclones are formed (Fig. 13).

Rice. 13. Diagram of air movement

Cyclone - an ascending vortex in the atmosphere with a closed area of reduced pressure, in which the winds blow from the periphery to the center (counterclockwise in the Northern Hemisphere, clockwise in the Southern Hemisphere). The average speed of the cyclone is 35 - 50 km / h, and sometimes up to 100 km / h. In a cyclone, air rises upward, which affects the weather. With the appearance of a cyclone, the weather changes quite sharply: winds intensify, water vapor rapidly condenses, generating powerful clouds, precipitation falls.

Anticyclone- a descending atmospheric vortex with a closed area of increased pressure, in which winds blow from the center to the periphery (in the Northern Hemisphere - clockwise, in the Southern Hemisphere - counterclockwise). In the anticyclone, the air descends, becoming drier when warmed up, since the vapors contained in it move away from saturation. This, as a rule, excludes the formation of clouds in the central part of the anticyclone. Therefore, during the anticyclone, the weather is clear, sunny, without precipitation. Frosty in winter, hot in summer.

Water vapor in the atmosphere. There is always a certain amount of moisture in the atmosphere in the form of water vapor evaporated from the surface of oceans, lakes, rivers, soil, etc. Evaporation depends on air temperature, wind (even a weak wind increases evaporation three times, since all the time carries away the air saturated with water vapor and brings new portions of dry), the nature of the relief, vegetation cover, the color of the soil.

Distinguish volatility - the amount of water that could evaporate under given conditions per unit of time, and evaporation - the amount of water actually evaporated.

In the desert, evaporation is high and evaporation is negligible.

Air saturation... At any given temperature, the air can accept water vapor up to a certain limit (up to saturation).

The higher the temperature, the more maximum amount water can contain air. If you cool unsaturated air, it will gradually approach the saturation point. The temperature at which a given unsaturated air goes to saturation is called dew point. If the saturated air is cooled further, then excess water vapor will begin to thicken in it. Moisture will begin to condense, clouds will form, then precipitation will fall.

Therefore, to characterize the weather, it is necessary to know relative humidity - the percentage ratio of the amount of water vapor contained in the air to the amount that it may contain at saturation. Absolute humidity- the amount of water vapor in grams , located in this moment in 1 m 3 of air.

Precipitation and its formation.Precipitation- water in liquid or solid state, falling from the clouds. The clouds are called accumulations of water vapor condensation products suspended in the atmosphere - water droplets or ice crystals. Depending on the combination of temperature and degree of moisture, droplets or crystals of various shapes and sizes are formed. Small droplets float in the air, larger ones begin to fall in the form of drizzle (drizzle) or light rain. Snowflakes form at low temperatures.

The scheme of precipitation formation is as follows: the air cools (more often when it rises upwards), approaches saturation, water vapor condenses, precipitation is formed.

Measurement of the amount of precipitation is carried out using a rain gauge - a cylindrical metal bucket 40 cm high and a cross-sectional area of 500 cm 2. All measurements of the amount of atmospheric precipitation are added up for each month, and the average monthly, and then the annual amount of precipitation is displayed.

The amount of precipitation in the territory depends on:

air temperature (affects the evaporation and moisture holding capacity of the air);
sea currents (above the surface of warm currents, the air heats up and is saturated with moisture; when it is transferred to neighboring, colder regions, precipitation is easily released from it. surface, it expands, its saturation with moisture decreases, and precipitation is not formed in it);
atmospheric circulation (where air moves from sea to land, precipitation is higher);
the heights of the place and the direction of the mountain ranges (the mountains force the moisture-saturated air masses to rise up, where, due to cooling, condensation of water vapor and the formation of precipitation occur; there is more precipitation on the windward slopes of the mountains).

Precipitation is uneven. It obeys the law of zoning, that is, it changes from the equator to the poles. In tropical and temperate latitudes, the amount of precipitation changes significantly when moving from the coasts to the interior of the continents, which depends on many factors (atmospheric circulation, the presence of ocean currents, relief, etc.).

Precipitation on more territory the globe occurs unevenly throughout the year. Near the equator, the amount of precipitation changes insignificantly during the year; in subequatorial latitudes, there is a dry season (up to 8 months) associated with the action of tropical air masses, and a rainy season (up to 4 months) associated with the arrival of equatorial air masses. Moving from the equator to the tropics, the duration of the dry season increases and the rain season decreases. In subtropical latitudes, winter precipitation prevails (they are brought by moderate air masses). In temperate latitudes, precipitation falls throughout the year, but in the inner parts of the continents, more precipitation falls in the warm season. Summer precipitation also prevails in polar latitudes.

Weather- the physical state of the lower atmosphere in a certain area at a given moment or for a certain period of time.

Weather characteristics - air temperature and humidity, atmospheric pressure, cloudiness and precipitation, wind. Weather is an extremely variable element of natural conditions, subject to daily and annual rhythms. The daily rhythm is due to the heating of the earth's surface by the sun's rays during the day and nighttime cooling. The annual rhythm is determined by the change in the angle of incidence of sunlight throughout the year.

Weather is of great importance in human economic activity. Weather studies are carried out at meteorological stations using a variety of instruments. According to the information received at the meteorological stations, synoptic maps are drawn up. Synoptic map- a weather map on which the atmospheric fronts and weather data at a certain moment (air pressure, temperature, wind direction and speed, cloudiness, position of warm and cold fronts, cyclones and anticyclones, precipitation pattern) are plotted with conventional signs. Synoptic maps are compiled several times a day, their comparison allows one to determine the paths of movement of cyclones, anticyclones, atmospheric fronts.

Atmospheric front- zone of division of air masses of different properties in the troposphere. It occurs when the masses of cold and warm air approach and meet. Its width reaches several tens of kilometers at a height of hundreds of meters and a length of sometimes thousands of kilometers with a slight slope towards the Earth's surface. The atmospheric front, passing through a certain territory, dramatically changes the weather. Warm and cold fronts are distinguished among atmospheric fronts (Fig. 14)

Rice. 14

Warm front is formed with the active movement of warm air towards cold air. Then warm air flows onto the receding wedge of cold air and rises along the plane of separation. It cools down when it rises. This leads to condensation of water vapor, cirrus and stratus clouds and precipitation. With the arrival of a warm front, atmospheric pressure decreases; as a rule, warming and heavy, drizzling precipitation are associated with it.

Cold front formed when cold air moves towards warm air. Cold air, being heavier, flows under the warm air and pushes it up. In this case, stratocumulus rain clouds arise, from which precipitation falls in the form of showers with squalls and thunderstorms. Cooling, increased wind and increased air transparency are associated with the passage of the cold front. Great importance have weather forecasts. Weather forecasts are made on different time... Usually the weather is predicted for 24 - 48 hours. Making long-term weather forecasts is associated with great difficulties.

Climate- a long-term weather regime typical for a given area. The climate influences the formation of soil, vegetation, fauna; determines the regime of rivers, lakes, swamps, influences the life of the seas and oceans, the formation of relief.

The distribution of climate on Earth is zonal. There are several climatic zones on the globe.

Climatic zones- latitudinal bands of the earth's surface, which have a homogeneous air temperature regime, due to the "norms" of the arrival of solar radiation and the formation of the same type of air masses with features of their seasonal circulation (table 2). Air masses- large volumes of air in the troposphere with more or less the same properties (temperature, humidity, dustiness, etc.). The properties of air masses are determined by the territory or water area over which they are formed.

Characteristics of zonal air masses:

equatorial - warm and humid;

tropical - warm, dry;

moderate - less warm, more humid than tropical, seasonal differences are characteristic;

arctic and antarctic - cold and dry.

Table 2.Climatic zones and air masses acting in them

Climatic zone	Active zonal air masses
	Summer	In winter
Equatorial	Equatorial
Subequatorial	Equatorial	Tropical
Tropical	Tropical
Subtropical	Tropical	Moderate
Moderate	Moderate latitudes (polar)
Subarctic Subantarctic	Moderate	Arctic Antarctic
Arctic antarctic	Arctic Subantarctic

Within the main (zonal) types of VM, there are subtypes - continental (forming over the mainland) and oceanic (forming over the ocean). The general direction of movement is characteristic of the air mass, but inside this volume of air there can be different winds. The properties of air masses change. Thus, maritime temperate air masses, carried by westerly winds to the territory of Eurasia, gradually warm up (or cool) when moving eastward, lose moisture and turn into continental temperate air.

Climatic factors:

the geographical latitude of the place, since the angle of inclination of the sun's rays depends on it, which means the amount of heat;
atmospheric circulation - prevailing winds bring certain air masses;
ocean currents (see about atmospheric precipitation);
the absolute height of the place (the temperature decreases with the height);
remoteness from the ocean - on the coasts, as a rule, there are less abrupt temperature changes (day and night, seasons); more rainfall;
relief (mountain ranges can trap air masses: if a moist air mass meets mountains on its way, it rises, cools, moisture condenses and precipitation falls).

Climatic zones change from the equator to the poles, as the angle of incidence of the sun's rays changes. This, in turn, determines the law of zoning, i.e., the change in the components of nature from the equator to the poles. Within the climatic zones, climatic regions are distinguished - a part of the climatic zone that has a certain type of climate. Climatic regions arise due to the influence of various climate-forming factors (features of atmospheric circulation, the influence of ocean currents, etc.). For example, in the temperate climatic zone of the Northern Hemisphere, areas of continental, temperate continental, maritime and monsoon climates are distinguished.

General circulation of the atmosphere- a system of air currents on the globe, which facilitates the transfer of heat and moisture from one region to another. Air moves from high pressure areas to low pressure areas. Areas of high and low pressure are formed as a result of uneven heating of the earth's surface. Under the influence of the Earth's rotation, air currents deviate to the right in the Northern Hemisphere, and to the left in the Southern Hemisphere. In equatorial latitudes, due to high temperatures, there is a constant low pressure belt with weak winds. The heated air rises and spreads at a height to the north and south. At high temperatures and ascending air movement, with high humidity, large clouds are formed. Falls here a large number of precipitation.

Approximately between 25 and 30 ° N. and y. sh. the air sinks to the surface of the Earth, where, as a result, high pressure belts are formed. Near the Earth, this air is directed towards the equator (where there is low pressure), deviating in the Northern Hemisphere to the right, in the Southern Hemisphere - to the left. This is how trade winds are formed. There is a calm zone in the central part of the high-pressure belts: the winds are weak. Due to the descending currents of air, the air is dried and warmed up. Hot and dry areas of the Earth are located in these zones.

In temperate latitudes with centers around 60 ° N. and y. sh. the pressure is low. The air rises and then rushes to the polar regions. In temperate latitudes, western air transport prevails (the deflecting force of the Earth's rotation acts).

The polar latitudes are characterized by low air temperatures and high pressures. Coming from temperate latitudes, the air descends to the Earth and is again directed to temperate latitudes with northeastern (in the Northern Hemisphere) and southeasterly (in the Southern Hemisphere) winds. There is little precipitation (Fig. 15).

Rice. 15. Diagram of the general circulation of the atmosphere

Atmosphere pressure- the pressure of atmospheric air on the objects in it and the earth's surface. Normal atmospheric pressure is 760 mm Hg. Art. (101325 Pa). As the altitude rises, the pressure drops by 100 mm for every kilometer.

Atmosphere composition:

The Earth's atmosphere is the Earth's air shell, consisting mainly of gases and various impurities (dust, water droplets, ice crystals, sea salts, combustion products), the amount of which is variable. The main gases are nitrogen (78%), oxygen (21%) and argon (0.93%). The concentration of gases that make up the atmosphere is practically constant, with the exception of carbon dioxide CO2 (0.03%).

The atmosphere also contains SO2, CH4, NH3, CO, hydrocarbons, HC1, HF, Hg, I2 vapors, as well as NO and many other gases in small quantities. A large amount of suspended solid and liquid particles (aerosols) are constantly found in the troposphere.

Climate and weather

Weather and climate are intertwined, but it's worth identifying the difference between them.

Weather- This is the state of the atmosphere over a certain area at a certain point in time. In the same city, the weather can change every few hours: fog appears in the morning, a thunderstorm begins by lunchtime, and by the evening the sky clears of clouds.

Climate- long-term, repetitive weather regime, typical for a certain area. The climate affects the terrain, water bodies, flora and fauna.

The main elements of the weather are precipitation (rain, snow, fog), wind, air temperature and humidity, cloudiness.

Precipitation- This is water in liquid or solid form, falling to the surface of the earth.

They are measured using an instrument called a rain gauge. It is a metal cylinder with a cross-sectional area of 500 cm2. Precipitation is measured in millimeters - this is the depth of the water layer that appeared in the rain gauge after precipitation.

Air temperature is determined using a thermometer - a device consisting of a temperature scale and a cylinder partially filled with a certain substance (usually alcohol or mercury). The action of a thermometer is based on the expansion of a substance upon heating and contraction - upon cooling. One of the varieties of the thermometer is the well-known thermometer, in which the cylinder is filled with mercury. A thermometer that measures air temperature should be in the shade so that the sun's rays do not heat it up.

Temperature measurement is carried out at meteorological stations several times a day, after which the average daily, monthly average or average annual temperature is displayed.

The average daily temperature is the arithmetic mean of temperatures measured at regular intervals throughout the day. The average monthly temperature is the arithmetic average of all average daily temperatures during the month, and the average annual is the arithmetic average of all average daily temperatures during the year. In one locality, the average temperatures for each month and year remain approximately constant, as any large temperature fluctuations are offset by averaging. Currently, there is a tendency for a gradual increase in average temperatures, this phenomenon is called global warming... An increase in the average temperature by a few tenths of a degree is imperceptible to humans, but it has a significant impact on the climate, since along with the temperature, the pressure and humidity of the air change, and the winds also change.

Air humidity shows how saturated it is with water vapor. Measure the absolute and relative humidity. Absolute humidity is the amount of water vapor in 1 cubic meter of air, measured in grams. When people talk about weather, they often use relative humidity, which shows the percentage of water vapor in the air to the amount that is in the air at saturation. Saturation is a certain limit to which water vapor is in the air without condensing. Relative humidity cannot exceed 100%.

The saturation limit is different in different parts of the world. Therefore, to compare humidity in different areas, it is better to use an absolute indicator of humidity, and to characterize the weather in a certain area - a relative indicator.

Cloudiness usually estimated using the following expressions: cloudy - the entire sky is covered with clouds, partly cloudy - there are a large number of individual clouds, clear - the amount of clouds is insignificant or they are absent.

Atmosphere pressure is a very important characteristic of the weather. Atmospheric air has its own weight, and for every point of the earth's surface, for every object and creature, located on it, presses the column of air. Atmospheric pressure is usually measured in millimeters of mercury. To make such a dimension understandable, let us explain what it means. For every square centimeter of surface, air presses with the same force as a column of mercury 760 mm high. Thus, the air pressure is compared with the pressure of the mercury column. A figure less than 760 indicates low blood pressure.

Temperature fluctuations

In any locality, the temperature is not constant. Temperatures drop at night due to lack of solar energy. In this regard, it is customary to distinguish the average day and night temperatures. Also, the temperature fluctuates throughout the year. In winter, the average daily temperature is lower, gradually increasing in the spring and gradually decreasing in the fall, in summer the highest average daily temperature.

Distribution of light, heat and moisture over the earth's surface

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.

The earth's axis is inclined to the orbital plane at an angle. Its northern end is directed towards the North Star. The sun always illuminates half of the earth. At the same time, either the Northern Hemisphere is more illuminated (and the day lasts longer there than in the other hemisphere), then, on the contrary, the Southern. Twice a year, both hemispheres are illuminated in the same way (then the length of the day in both hemispheres is the same).

The sun is the main source of heat and light on Earth. This huge sphere of gas, with a surface temperature of about 6,000 ° C, emits a large amount of energy, which is called solar radiation. It heats up our Earth, sets the air in motion, forms a water cycle, creates conditions for the life of plants and animals.

Passing through the atmosphere, part of the solar radiation is absorbed, part is scattered and reflected. Therefore, the flow of solar radiation, coming to the surface of the Earth, gradually weakens.

Solar radiation arrives at the Earth's surface in a direct and diffuse manner. Direct radiation is a stream of parallel rays coming directly from the solar disk. Scattered radiation comes from all over the sky. It is believed that the supply of heat from the Sun per 1 hectare of the Earth is equivalent to burning almost 143 thousand tons of coal.

The sun's rays, passing through the atmosphere, heat it little. The atmosphere is heated from the surface of the Earth, which, absorbing solar energy, converts it into heat. Particles of air, in contact with a heated surface, receive heat and carry it into the atmosphere. This is how the lower atmosphere heats up. Obviously, the more solar radiation the Earth's surface receives, the more it heats up, the more the air heats up from it.

Numerous observations of the air temperature showed that the highest temperature was observed in Tripoli (Africa) (+ 58 ° С), the lowest - at Vostok station in Antarctica (-87.4 ° С).

Solar heat gain and air temperature distribution depends on the latitude of the location. The tropical region receives more heat from the Sun than the temperate and polar latitudes. The equatorial regions of the Sun - a star receive the most heat Solar system, which is a source of an enormous amount of heat and dazzling light for the 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 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, the less heat is received by these territories. 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.

The distribution of precipitation on the globe depends on how many clouds containing moisture form over a given area or how much the wind can bring. The air temperature is very important, because intensive evaporation of moisture occurs precisely at a high temperature. The moisture evaporates, rises and clouds form at a certain height.

The air temperature decreases from the equator to the poles, therefore, the amount of precipitation is maximum in the equatorial latitudes and decreases towards the poles. However, on land, the distribution of precipitation depends on a number of additional factors.

There is a lot of precipitation over coastal areas, and the amount decreases with distance from the oceans. There is more precipitation on the windward slopes of the mountain ranges and much less on the leeward slopes. For example, on the Atlantic coast of Norway, Bergen receives 1,730 mm of precipitation per year, and only 560 mm in Oslo. Low mountains also affect the distribution of precipitation - on the western slope of the Urals, in Ufa, an average of 600 mm of precipitation falls, and on the eastern slope, in Chelyabinsk, - 370 mm.

The largest amount of precipitation falls in the Amazon basin, off the coast of the Gulf of Guinea and in Indonesia. In some parts of Indonesia, their maximum values reach 7000 mm per year. In India, in the foothills of the Himalayas, at an altitude of about 1300 m above sea level, there is the wettest place on Earth - Cherrapunji (25.3 ° N and 91.8 ° E, here an average of more than 11,000 mm of precipitation falls) Such an abundance of moisture brings to these places the humid summer southwestern monsoon, which rises along the steep slopes of the mountains, cools and rains down heavily.

Oceans, whose water temperature changes much more slowly than the temperature of the earth's surface or air, have a strong mitigating effect on the climate. At night and in winter, the air over the oceans cools much more slowly than over land, and if oceanic air masses move over the continents, this leads to warming. Conversely, during the day and summer, the sea breeze cools the land.

The distribution of moisture on the earth's surface is determined by the water cycle in nature. Every second, a huge amount of water evaporates into the atmosphere, mainly from the surface of the oceans. Humid ocean air, sweeping over the continents, cools. The moisture then condenses and returns to the earth's surface in the form of rain or snow. Partly it remains in the snow cover, rivers and lakes, and partly returns to the ocean, where evaporation occurs again. This completes the hydrological cycle.

The distribution of precipitation is also influenced by the currents of the World Ocean. Over the areas near which warm currents pass, the amount of precipitation increases, since the air heats up from the warm water masses, it rises and clouds with sufficient water content are formed. Over the territories near which cold currents pass, the air cools down, descends, clouds do not form, and much less precipitation falls.

Since water plays an essential role in erosion processes, it thereby affects the movements of the earth's crust. And any redistribution of masses due to such movements in the conditions of the Earth rotating around its axis can, in turn, contribute to a change in position earth axis... During ice ages, sea levels drop as water accumulates in glaciers. This, in turn, leads to the proliferation of continents and an increase in climatic contrasts. A decrease in river runoff and a decrease in the level of the World Ocean prevent warm ocean currents from reaching cold regions, which leads to further climatic changes.

If the ocean floor expands in the suture zone of the mid-ocean ridge, it means that either the Earth's surface is increasing or there are areas where the oceanic crust disappears and sinks into the asthenosphere. Such areas, called subduction zones, have indeed been found in the belt bordering the Pacific Ocean and in a discontinuous strip stretching from Southeast Asia to the Mediterranean. All these zones are confined to deep-water trenches that encircle the island arcs. Most geologists believe that there are several rigid lithospheric plates on the Earth's surface that “float” across the asthenosphere. The plates can slide relative to one another, or one can sink under the other in the subduction zone. A unified model of plate tectonics provides the best explanation for the distribution of large geological structures and zones of tectonic activity, as well as the change in the relative position of continents.Seismic zones. Mid-ocean ridges and subduction zones are belts of frequent strong earthquakes and volcanic eruptions. These areas are connected by extended linear faults that can be traced throughout the globe... Earthquakes are associated with faults and very rarely occur in any other area. In the direction of the continents, the epicenters of earthquakes are located deeper and deeper. This fact explains the mechanism of subduction: the expanding oceanic plate dives under the volcanic belt at an angle of approx. 45° ... As the oceanic crust “slides off,” it melts, turning into magma, which is poured out through cracks in the form of lava onto the surface.Mountain building. Where ancient oceanic trenches are destroyed in the process of subduction, continental plates collide with each other or with plate fragments. As soon as this happens, the earth's crust is strongly compressed, an overthrust is formed, and the thickness of the crust almost doubles. Due to isostasy, the folded zone experiences an uplift and thus mountains are born. The belt of mountain structures of the Alpine stage of folding can be traced along the coast of the Pacific Ocean and in the Alpine-Himalayan zone. In these areas, numerous collisions of lithospheric plates and the uplift of the territory began ca. 50 million years ago. Older mountain systems, such as the Appalachians, are over 250 million years old, but at present they are so destroyed and flattened that they have lost their typical mountainous appearance and turned into an almost flat surface. However, as their "roots" are submerged in the mantle and float, they have experienced repeated ascent. And yet, over time, such ancient mountains will turn into plains. Most geological processes go through the stages of youth, maturity and old age, but this cycle usually takes a very long time.Heat and moisture distribution. The interaction of the hydrosphere and atmosphere controls the distribution of heat and moisture on the earth's surface. The ratio of land and sea largely determines the nature of the climate. When the land surface increases, a cold snap occurs. The uneven distribution of land and sea is currently a prerequisite for the development of glaciation.

The Earth's surface and atmosphere receive the most heat from the Sun, which, throughout the entire existence of our planet, emits heat and light energy with almost the same intensity. The atmosphere protects the Earth from returning this energy too quickly back into space. About 34% of solar radiation is lost due to reflection by clouds, 19% is absorbed by the atmosphere and only 47% reaches the earth's surface. The total inflow of solar radiation to the upper boundary of the atmosphere is equal to the return of radiation from this boundary into outer space. As a result, the heat balance of the "Earth - atmosphere" system is established.

The surface of the land and the air of the surface layer heats up quickly during the day and loses heat rather quickly at night. If there were no heat-trapping layers in the upper troposphere, the amplitude of fluctuations in daily temperatures could be much greater. For example, the Moon receives about the same heat from the Sun as the Earth does, but since the Moon has no atmosphere, its surface temperatures rise to about 101

° C, and at night they drop to -153° C. Oceans, whose water temperature changes much more slowly than the temperature of the earth's surface or air, have a strong mitigating effect on the climate. At night and in winter, the air over the oceans cools much more slowly than over land, and if oceanic air masses move over the continents, this leads to warming. Conversely, during the day and summer, the sea breeze cools the land.

Ocean currents are a powerful thermoregulatory mechanism of the Earth. Thanks to them, an even moderate temperature is maintained in tropical oceanic regions and warm waters are transferred to colder high-latitude regions.

Since water plays an essential role in erosion processes, it thereby affects the movements of the earth's crust. And any redistribution of masses due to such movements in the conditions of the Earth rotating around its axis is capable, in turn, of contributing to a change in the position of the Earth's axis. During ice ages, sea levels drop as water accumulates in glaciers. This, in turn, leads to the proliferation of continents and an increase in climatic contrasts. A decrease in river runoff and a decrease in the level of the World Ocean prevent warm ocean currents from reaching cold regions, which leads to further climatic changes.

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 0 С, and at the pole -44 0 С. Already at latitude 50 0 N. and y.sh. the zone of eternal frost would begin. However, the actual temperature at the equator is about 26 0 C, and at the North Pole -20 0 C.

Up to latitudes 30 0 solar temperatures are higher than actual, i.e. in this part of the globe, an excess of solar heat is formed. In the middle, and even more so in the polar latitudes, the actual temperatures are higher than solar temperatures, i.e. 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.

Thus, 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.

Analysis of the distribution of heat in the hydrosphere and atmosphere allows us to draw the following generalizing conclusions:

1. The southern hemisphere is colder than the northern one, since there is less advective heat from the hot belt.
2. Solar heat is spent mainly over the oceans to evaporate water. Together with steam, it is redistributed both between zones and within each zone, between continents and oceans.
3. From tropical latitudes, heat with trade wind circulation and tropical currents enters the equatorial ones. The tropics lose up to 60 kcal / cm 2 per year, and at the equator, the heat gain from condensation is 100 or more cal / cm 2 per year.
4. The northern temperate belt from warm ocean currents coming from equatorial latitudes (Gulf Stream, Kurovivo), receives on the oceans up to 20 and more kcal / cm 2 per year.
5. Western transfer from the oceans transfers heat to the continents, where the temperate climate is formed not up to latitude 50 0, but much to the north of the Arctic Circle.
6. In the southern hemisphere, only Argentina and Chile receive tropical heat; the cold waters of the Antarctic Current circulate in the Southern Ocean.

In January, a huge area of above zero temperature anomalies is located in the North Atlantic. It stretches from the tropics to 85 0 N. and from Greenland to the Yamal-Black Sea line. The maximum excess of actual temperatures over the mid-latitude reaches in the Norwegian Sea (up to 26 0 С). The British Isles and Norway are 16 ° C warmer, France and the Baltic Sea are 12 ° C warmer.

An equally large and pronounced area of below zero temperature anomalies is formed in Eastern Siberia in January, centered in North-Eastern Siberia. Here the anomaly reaches -24 0 С.

In the northern part of the Pacific Ocean there is also an area of positive anomalies (up to 13 0 C), and in Canada - negative anomalies (up to -15 0 C).

The distribution of heat on the earth's surface on geographical maps using isotherms. There are maps of isotherms for the year and each month. These maps fairly objectively illustrate the thermal regime of a particular area.

Heat on the earth's surface is distributed zonal-regional:

1. The average long-term highest temperature (27 0 С) is observed not at the equator, but at 10 0 N. This warmest parallel is called the thermal equator.
2. In July, the thermal equator shifts to the northern tropic. average temperature at this parallel it is equal to 28.2 0 С, and in the hottest regions (Sahara, California, Tar) it reaches 36 0 С.
3. In January, the thermal equator shifts to the southern hemisphere, but not as significantly as in July to the northern one. The warmest parallel (26.7 0 С) is on average 5 0 S, but the hottest regions are located even further south, i.e. on the continents of Africa and Australia (30 0 C and 32 0 C).
4. The temperature gradient is directed towards the poles, i.e. the temperature decreases towards the poles, and in the southern hemisphere it is more significant than in the northern one. Difference between equator and North Pole is 27 0 С in winter 67 0 С, and between the equator and the South Pole in summer 40 0 С, in winter 74 0 С.
5. The temperature drop from the equator to the poles is uneven. In tropical latitudes, it occurs very slowly: at 1 0 latitude in summer 0.06-0.09 0 C, in winter 0.2-0.3 0 C. The entire tropical zone is in temperature relation turns out to be very homogeneous.
6. In the northern temperate zone, the course of the January isotherms is very complicated. Isotherm analysis reveals the following patterns:
- - in the Atlantic and Pacific oceans, heat advection is significant, associated with the circulation of the atmosphere and hydrosphere;
- - the land adjacent to the oceans - Western Europe and Northwest America - have high fever(on the coast of Norway 0 0 С);
- - the huge land mass of Asia is very cooled, on it closed isotherms outline a very cold region in Eastern Siberia, up to - 48 0 C.
- - isotherms in Eurasia go not from West to East, but from northwest to southeast, showing that temperatures are falling in the direction from the ocean inland; the same isotherm passes through Novosibirsk as on Novaya Zemlya (-18 0 С). It is as cold on the Aral Sea as on Svalbard (-14 0 C). A similar picture, but somewhat in a weakened form, is observed in North America;
7. The July isotherms are quite straightforward, because the temperature on land is determined by solar insolation, and the transfer of heat over the ocean (Gulf Stream) in summer does not noticeably affect the land temperature, because it is heated by the Sun. In tropical latitudes, the influence of cold ocean currents along the western coasts of the continents (California, Peruvian, Canary, etc.) is noticeable, which cool the adjacent land and cause the deviation of isotherms towards the equator.
8. In the distribution of heat over the globe, the following two regularities are clearly expressed: 1) zoning, due to the figure of the Earth; 2) the sector, due to the peculiarities of the assimilation of solar heat by the oceans and continents.
9. The average air temperature at the level of 2 m for the entire Earth is about 14 0 С, January 12 0 С, July 16 0 С. The southern hemisphere is colder than the northern hemisphere in the annual output. The average air temperature in the northern hemisphere is 15.2 0 С, in the southern - 13.3 0 С. The average air temperature for the entire Earth coincides approximately with the temperature observed at about 40 0 N. (14 0 C).

Basic concepts, processes, patterns and their consequences

Biosphere Is a collection of all living organisms on Earth. A holistic doctrine of the biosphere was developed by the Russian scientist V.I. Vernadsky. The main elements of the biosphere are: vegetation (flora), fauna (fauna) and soil. Endemic- plants or animals that are found on the same continent. Currently in the biosphere according to species composition animals prevail almost three times over plants, but the biomass of plants is 1000 times higher than that of animals. In the ocean, the biomass of the fauna exceeds the volume of the biomass of the flora. The biomass of the land as a whole is 200 times that of the oceans.

Biocenosis- a community of interconnected living organisms inhabiting a section of the earth's surface with homogeneous conditions.

Altitudinal zonality- a regular change of landscapes in the mountains, due to the height above sea level. Altitudinal belts correspond to natural zones on the plain, with the exception of the belt of alpine and subalpine meadows located between the belts coniferous forests and tundra. The change of natural zones in the mountains occurs as if we were moving along the plain from the equator to the poles. The natural zone at the base of the mountain corresponds to the latitudinal natural zone in which the mountain system is located. The number of altitudinal zones in the mountains depends on the height of the mountain system and its geographical position. The closer to the equator the mountain system is located and the higher the altitude, the more altitude zones and types of landscapes will be represented.

Geographic envelope- a special shell of the Earth, within which the lithosphere, hydrosphere, the lower layers of the atmosphere and the biosphere, or living matter, are in contact, mutually penetrate and interact. The development of the geographic envelope has its own laws:

integrity - the unity of the shell due to the close relationship of its constituent components; manifests itself in the fact that a change in one component of nature inevitably causes a change in all the others;
cyclicity (rhythm) - the recurrence in time of similar phenomena, there are rhythms of different duration (9-day, annual, periods of mountain building, etc.);
circulation of matter and energy - consists in the continuous movement and transformation of all components of the shell from one state to another, which determines the continuous development of the geographical shell;
zoning and altitudinal zonation - a natural change natural components and natural complexes from the equator to the poles, from the foot to the tops of the mountains.

Reserve- a specially protected natural area, completely excluded from economic activities for the protection and study of typical or unique natural complexes.

Landscape- a territory with a natural combination of relief, climate, land waters, soils, biocenoses that interact and form an inextricable system.

National park- a vast territory, which combines the protection of picturesque landscapes with their intensive use for tourism purposes.

The soil- the upper thin layer of the earth's crust, inhabited by organisms, containing organic matter and possessing fertility - the ability to provide plants with the nutrients and moisture they need. The formation of a particular type of soil depends on many factors. The intake of organic matter and moisture in the soil determines the content of humus, which ensures soil fertility. The largest amount of humus is contained in chernozems. Depending on the mechanical composition (the ratio of different size mineral particles of sand and clay) soils are divided into clay, loamy, sandy loam and sandy.

Natural area- an area with close values of temperatures and humidity, regularly extending in the latitudinal direction (on the plains) along the Earth's surface. On the continents, some natural zones have special names, for example, the steppe zone in South America called pampa, and in North America prairie. Wet zone equatorial forests in South America - selva, the savanna zone occupying the Orinoco lowland - llanos, the Brazilian and Guiana highlands - campos.

Natural complex- a plot of the earth's surface with homogeneous natural conditions, which are due to the peculiarities of the origin and historical development, geographic location, operating within its limits by modern processes. In a natural complex, all components are interconnected. Natural complexes vary in size: geographic shell, mainland, ocean, natural area, ravine, lake ; their formation takes place over a long time.

Natural areas of the world

Natural area	Climate type	Vegetation	Animal world	Soil
Arctic (Antarctic) deserts	Arctic (Antarctic) marine and continental	Mosses, lichens, algae. Most of them are covered by glaciers	Polar bear, penguin (in Antarctica), gulls, guillemots, etc.	Arctic deserts
Tundra	Subarctic	Shrubs, mosses, lichens	Reindeer, lemming, arctic fox, wolf, etc.
Forest tundra	Subarctic	Birch, spruce, larch, shrubs, sedges	Elk, Brown bear, squirrel, white hare, tundra animals, etc.	Tundra-gley, podzolized
Taiga		Pine, fir, spruce, larch, birch, aspen	Elk, brown bear, lynx, sable, chipmunk, squirrel, white hare, etc.	Podzolic, permafrost-taiga
Mixed forests	Moderate continental, continental	Spruce, pine, oak, maple, linden, aspen	Elk, squirrel, beaver, mink, marten, etc.	Sod-podzolic
Broadleaf forests	Moderate continental, monsoon	Oak, beech, hornbeam, elm, maple, linden; on the Far East- cork oak, velvet wood	Roe deer, marten, deer, etc.	Gray and brown forest
Forest-steppe	Moderate continental, continental, sharply continental	Pine, larch, birch, aspen, oak, linden, maple with areas of forb steppes	Wolf, fox, hare, rodents	Gray forest, podzolized chernozems
Steppe	Moderate continental, continental, sharply continental, subtropical continental	Feather grass, fescue, thin-legged, herbs	Ground squirrels, marmots, voles, corsac, steppe wolf, etc.	Typical chernozems, chestnut, chernozem-like
Semi-deserts and temperate deserts	Continental, sharply continental	Wormwood, cereals, dwarf shrubs, feather grass, etc.	Rodents, saiga, gazelle, corsac	Light chestnut, salt licks, gray-brown
Mediterranean evergreen forests and shrubs	Mediterranean subtropical	Cork oak, olive, laurel, cypress, etc.	Rabbit, mountain goats, rams	Brown
Humid subtropical forests	Subtropical monsoon	Laurel, camellia, bamboo, oak, beech, hornbeam, cypress	Himalayan bear, panda, leopard, macaques, gibbons	Red soil, yellow soil
Tropical deserts	Tropical continental	Solyanka, wormwood, acacia, succulents	Antelope, camel, reptiles	Sandy, gray soils, gray-brown
Savannah		Baobab, Umbrella Acacias, Mimosas, Palms, Euphorbia, Aloe	Antelope, zebra, buffalo, rhino, giraffe, elephant, crocodile, hippo, lion	Red-brown
Monsoon forests	Subequatorial, tropical	Teak, eucalyptus, evergreen species	Elephant, buffalo, monkey, etc.	Red soil, yellow soil
Wet equatorial forests	Equatorial	Palm trees, hevea, legumes, vines, banana	Okapi, tapir, monkeys, forest pig, leopard, pygmy hippo	Red-yellow ferralite

Continental endemics

Mainland	Plants	Animals
Africa	Baobab, ebony, velvichia	Secretary bird, striped zebra, giraffe, tsetse fly, okapi, marabou bird
Australia	Eucalyptus (500 species), bottle tree, casuarines	Echidna, platypus, kangaroo, wombat, koala, marsupial mole, marsupial devil, lyrebird, dingo
Antarctica	—	Adelie Penguin
North America	Sequoia	Skunk, bison, coyote, grizzly bear
South America	Hevea, cocoa tree, cinchona, ceiba	Battleship, anteater, sloth, anaconda, condor, hummingbird, chinchilla, llama, tapir
Eurasia	Myrtle, ginseng, lemongrass, ginkgo	European bison, orangutan, Ussuri tiger, panda

The largest deserts in the world