How did the climate and the large size of the continent affect the natural diversity of Eurasia? Arid climate of temperate latitudes. I swear by the sky, the owner of the stellar paths, and in the sky you put on what was promised to you. I swear by the Lord of heaven and earth, for this is the Truth, as well as

The main factors influencing the formation of the Earth's climate include solar radiation, atmospheric circulation and the nature of the underlying surface. Of no small importance in the formation of the climate are also the following factors: height above sea level, the influence of ocean currents, the influence of relief, distance from the ocean, etc. With the combined influence of factors, the climate is formed in different regions of the globe.

Geographic latitude.

Number of applicants solar heat depends on a number of factors. The decisive factor is the angle of incidence of the sun's rays (Fig. 28). With distance from the equator, the warming of the Earth's surface by the sun decreases, the climate becomes colder and colder.

Rns. 28. Influence of the angle of incidence of the sun's rays on the Earth's climate.

Solar radiation arrives at the upper boundary of the atmosphere in strict dependence on the geographical latitude. We got acquainted with the circulation of the atmosphere, which is the second climate-forming factor in the previous paragraph.

Influence of the underlying surface.

Underlying surface- these are the components of the earth's surface (land and water surface, mountains and plains, forest and desert, etc.), which carry out heat exchange and moisture exchange with the atmosphere and affect its state. For example, a forest decreases the daily amplitude of soil and air temperatures, on the contrary, a significant daily amplitude is observed in the desert.

The influence of the relief.

With increasing altitude, the air temperature decreases. Mountains impede the movement of air masses - as a rule, the penetration of humid oceanic air onto the mainland. For this reason, most of the delayed precipitation falls at the foot of the mountains.

On the plains open areas air masses move freely.

Influence of oceans and ocean currents.

Warm currents contribute to the formation of precipitation, making the climate more humid and milder, cold currents prevent the formation of precipitation and the penetration of humid air onto the mainland, leading to the formation of deserts and areas with an arid (arid) climate on land. For example, due to the influence of cold currents, coastal deserts were formed - Namib, Western Sahara, Atacama.

The influence of the anthropogenic factor.

With the development of human society, a new factor has appeared that affects the climate of the planet. In cities, the air temperature is higher than in the surrounding area. Dusty air contributes to the formation of fogs, clouds, which reduces the level of total radiation.

Sulfur dioxide contamination of the atmosphere has contributed to the acid rain, poisoning the soil, reservoirs, forests. Pollution can be transported over long distances by air masses and, together with precipitation, can be deposited far from sources of pollution.

The basis of modern climatic zoning is based on long-term climatic observations.

Climaticzoning- This is the division of territories into belts, zones and areas with more or less homogeneous climate conditions. The boundaries of climatic zones and zones do not always coincide with the lines of parallels, and do not always go around the globe. -Zones can be broken into areas that do not overlap with each other.

There are several classifications of climatic zoning. For example, V. Keppenaz's research is based on the distribution of average air temperatures and the amount of precipitation. According to the nature of the geographical landscapes determined by the climate, the classification of L.S. Berg. B.P. Alisov's classification was created according to features general circulation atmospheres associated with climate types.

The characteristics of the Earth's climates given below basically correspond to the regionalization of B.P. Alisov (Table 8).

Table 8. Climatic zones

Climatic zone (and climatic regions)		Climate features
Arctic (Antarctic)		The belt occupies the Kolyarnge region. The arctic air mass dominates (in the Southern Hemisphere - Antarctic). In the Northern Hemisphere, the belt is located in the north of Eurasia and North America, including Baffin's Land, Greenland, Peninsula Taimyr, Novaya Zemlya, Spitsbergen, islands of the Arctic Ocean. On the territory of the Arctic climatic zone, the rate of the air nature does not rise above 0 ° С, and with distance to the poles it always remains negative. The most severe temperatures are observed in Antarctica, where an absolute minimum on the planet -89.2 ° C was recorded at Vostok station. There is little rainfall - less than 250 mm per year. Most of the belt is occupied by cover glaciers.
Subarctic (subantarctic)		Geographic belt between the arctic (Antarctic) belt and temperate. The climate is cold; average temperature of the warmest month from+ 5 ° C to + 10X1, cold from -5 XI on the western outskirts to -30 ° C, -40 ° C (-50 XI) in the central parts. In summer, the western transport of moderate air masses and cyclonic activity prevail, in winter - the arctic air masses and the influence of anticyclones. Average annual precipitation exceeds evaporation. Deep freezing of soils is characteristic.
Moderate
Marine type The climate is formed under the influence of the ocean atmosphere. Most pronounced over the oceans. It also spreads to areas of the continents that are exposed to frequent effects of sea air masses (For example, the extreme west of Europe, a number of oceanic wasps are on the right). The climate is characterized by intense cyclonic activity, cool summers and warm winter... V coastal areas breezes often occur in summer. Due to the fact that water masses are heated and cooled more slowly than land, the warmest time over the oceans in the Northern Hemisphere is often August, and the coldest time is February (vice versa in the Southern Hemisphere).
Moderate continental type The climate is formed in the Northern Hemisphere. Typical for many European countries (except for the South), the European part of Russia. Unlike North America (the Cordillera mountain ranges separate the western coast with a maritime climate from the inland regions with a continental climate) Europe is open to the unhindered penetration of sea air from the Atlantic Ocean. This is facilitated by the dominant temperate latitudes ah western transport of air masses, flat relief. As you move inland, the air becomes drier, the temperature rises in summer and decreases in winter.
Continental type The openness of the territory in the west of Eurasia allows air mass to penetrate further into the interior of the mainland. The air transforms, turns into continental. The climate is getting drier, the summer is hotter and the winter is colder. Cooling of the earth's surface and air in winter is the reason for the formation of the Asian (Siberian) anticyclone. Asian anticyclone covers most Kazakhstan, Western and Eastern Siberia Russia, Mongolia. Due to the smaller size of North America and the frequent arrival of cyclones, the winter Canadian anticyclone is less stable than the Asian one. Winters in North America are less severe. Winter cyclones lead to extreme temperature fluctuations. Precipitation in winter falls in the form of snow, a snow cover is established, which protects the soil from freezing. The snow cover creates a moisture reserve (in spring).
Monsoon type The climate is typical for the territories of southern Sakhalin, Of the Far East Russia, northeast China, northern Japan. It is created due to the predominance of continental air masses in winter, carried from the mainland to the ocean, and in summer, sea air masses entering from the ocean to the mainland during intense cyclonic activity. On the mainland of Asia, it is characterized by little snow, dry, cold winters and rainy summers. Precipitation and relative humidity have a pronounced annual variation with a maximum in summer.
Subtropical
Mediterranean type The climate is formed under the influence of tropical air mass in summer, and moderate in winter. It is characterized by hot, dry summers and mild rainy winters. The climate is observed in the Mediterranean countries, on the Black Sea coast of the Crimea and the Caucasus. Climate varieties are found in subtropical latitudes on the Pacific coast of North and South America, in the southwestern regions of Africa and Australia. In most of the Mediterranean, the average monthly air temperature in summer is 20-25 ° C, in winter 5-12 ° C, precipitation usually falls 400-600 mm per year (in
mountains in places up to 1 OOO mb ^ with a maximum in the winter season. Constant
no snow cover is formed.
Pacific Rim (North America) occupies a narrow strip
west coast covering California and northern
of the peninsula of the same name. Shower area typical dry summer and
relatively rainy winter. Summer temperatures are here
much lower than at the same latitudes of Europe, which
are explained by the influence of the cold California current.
In summer, clear skies and high
temperature of the earth's surface and air. Sand in places
heats up to 80 ° and the vegetation in the lowlands is almost all
burns out. Hence the name "California", which,
in Spanish means "Hot bake".
Continental type
Region continental climate occupies the north of Iran
highlands and some regions of Central Asia. Summer is different
high temperatures(tropical heat). Winter versus
tropical is much colder. In some areas the temperature
may decrease to -8 ° C and below. Continental type
differs in aridity.
The continental area in North America covers
the inner plateaus and plateaus of the Cordilleras. It is characterized by
dry hot summers and relatively cold winters. Here
there is little rainfall, so the desert landscape prevails.
Annual and daily temperature amplitudes in this area
big enough.
Monsoon type
It is characterized by significant differences in moisture
seasons of the year. The winter monsoon moves from the central regions
Asia towards the ocean. With him comes the dry continental
air, as a result of which the temperature drops sharply sometimes even
up to 0 ° С, and for 3-4 months there may be no precipitation.
At the end of May, the wind direction changes. Air masses
move from ocean to land, causing heavy rainfall on
coast.
Due to the influence of the monsoons, southern Asia is the only place on the planet where
border two transitional climatic zones: subtropical and
subequatorial (no tropical belt). The Atlantic-Monsoon region covers the southeastern states of the United States and the northern part of the Florida Peninsula. In summer, monsoon air masses bring a lot of precipitation from the Atlantic, and in winter, cold continental air penetrates here. Therefore, winters are dry and quite cold here, sometimes with snowfalls.
Tropical	The northern and southern tropical zones are distinguished. In the Northern Hemisphere, the belt occupies the territory of Mexico, islands Caribbean, North Africa (except for the Mediterranean), the Arabian Peninsula. In the Southern Hemisphere it captures the Andes (from the equator to the Southern Tropic), southern part Brazil, South Africa, Central Australia. The prevailing air mass is tropical, which forms a zone of constant increased pressure with clear weather throughout the year. Thus, the weather in the tropics is entirely dependent on the height of the sun above the horizon. Maximum air temperature recorded in Libya + 58 ° C. The belt is characterized by sharp temperature changes during the day and throughout the year, as well as low precipitation. On islands and coastal areas, where especially warm currents flow, a warm and at the same time humid maritime tropical climate is formed.
Subzquatorial	Located between the equatorial and tropical zones (in the Northern and Southern Hemispheres). Equatorial air mass dominates in summer, tropical in winter (In summer, equatorial western
		monsoons, and in winter phonic eastern). Using atlas maps, identify territories with a subequatorial belt,describe the climate.
Equatorial		The belt of the Earth, located on either side of the equator, between the subequatorial belts. Equatorial air mass dominates, characterized by high temperature and humidity. The climate is due to the large influx of solar energy, it is constantly hot and humid.

Find the geographic objects indicated by v the text of the paragraph on the map.

Geographical Dictionary

Climatic zoning -it is the division of territories into belts, zones and regions with more or less homogeneous climate conditions.

By children barking surface- these are the components of the earth's surface (land and water surface, mountains and plains, forest and desert, etc.) that carry out heat exchange and lago exchange with the atmosphere and affect its state.

? Questions and tasks

1. List the main climate-forming factors. Give examples of their influence on the Earth's climate.

2. What is the underlying surface? Why is the underlying surface related to the yushmat-forming factors?

3. What factor appeared as a result of the development of human society?

4. What is climatic zoning? Do the boundaries of climatic zones always coincide with the lines of parallels? Why?

5. Describe climatic zones and climatic regions of the world.

Work in a notebook

Complete the table using the paragraph text and geographic maps.

Territory	Climatic zone (climatic about blast)	About the climate

Try to answer

Determine which climatic regions are characterized by the following climatograms?

This i know

2. What factors influence the climate of Eurasia?

The main influence on the climate of Eurasia is exerted by its gigantic size and relief.

3. Tell us about the influence of the relief on the climate of the mainland.

The relief has a huge impact on the climate of the mainland. Especially high and extended mountain systems. There are no high mountains on the western outskirts, and the high-altitude Alpine-Himalayan belt runs in the south. Therefore, moist air masses from the Atlantic Ocean penetrate deep into the continent. Air masses from the Arctic Ocean and the Indian Ocean penetrate the mainland until they meet mountains on their way. Since the air masses from the Indian Ocean pass a very small way and give up all the moisture on the windward slopes of the Himalayas, the wettest place on Earth is located here.

4. What explains the wide spread of continental climate types in Eurasia? In what areas of Eurasia is the monsoon climate widespread?

The wide distribution of continental climate types in Eurasia is explained by the large area of ​​the continent and the presence mountain systems in the south and east of the mainland.

5. Choose the correct answer. The most long river in Eurasia: a) Indus; b) Yangtze; c) Volga; d) Yellow River.

That i can

6. Using the map in Figure 33, compare the areas occupied by certain climatic zones in Eurasia and North America; in Eurasia and southern continents. Note the similarities and differences.

In Eurasia and North America, climatic zones occupy similar areas, relative to the size of the continents. In Eurasia, a large part of the continent falls on the temperate zone. The subarctic belt passes through a narrower strip and the subequatorial belt occupies a larger area. There is no equatorial climate zone in North America.

Eurasia has few similarities with the southern continents. There is no arctic or subarctic belt on the southern continents. There are similarities with South America: the area of ​​the tropical belt is less than the subequatorial one.

7. Referring to Figure 163, trace how the January 00С and + 80С isotherms pass. Compare the geographic location and January temperatures of Paris and Vladivostok; Basra and Shanghai; Lisbon and Shanghai.

Paris and Vladivostok are located respectively on the western and eastern coasts of the mainland in temperate latitudes. Based on the coordinates, Paris is located in more northern latitudes. However, January temperatures in Paris fluctuate in the range of 0 ... + 80C, and in Vladivostok - -8 ... -160C. Such high winter temperatures in Paris are associated with the influence of warm air masses from the Atlantic Ocean (temperate maritime climate).

Basra and Shanghai are at roughly the same northern latitudes, but Shanghai is located at east coast and Basra is the coast of the Persian Gulf. Winter temperatures in Basra are + 8 ... + 160C, in Shanghai - 0 ... + 80C. This can be explained by the fact that Shanghai is located in the subtropical climatic zone and in January is in the zone of the winter monsoon. Basra is already located in the tropical zone, where the warm air masses of the Arabian Peninsula dominate.

In Lisbon, which is located on the Atlantic coast, January temperatures are around + 80C. In Shanghai, the temperatures are in the range 0 ... + 80C. With all this, Lisbon is located in more northern latitudes. The fact is that in winter, warm air masses from the ocean dominate in Lisbon, while cold air masses from the mainland dominate in Shanghai.

Of great importance for the formation of the climates of the southern continents is the influence of the oceans washing them, where there are similar systems of circulation of water masses. In tropical latitudes, cold currents pass along the western shores of all three continents: Peruvian, Benguela, Canary, West Australian, and along the eastern ones - warm currents: Guiana, Brazilian, Mozambique, Cape Needle, East Australian. In the equatorial region, warm inter-trade countercurrents approach the coasts of South America and Africa from the west. From the north, all three continents are washed by the waters of the warm seas: the Caribbean, Mediterranean, Timor, Arafur, and from the south - by the current of the Western Winds, from which the main cold currents branch off Southern hemisphere... Cold currents, moving along the eastern periphery of tropical maxima from high to low latitudes, retain their properties for a long time and a powerful inversion layer develops in them, which prevents convection. Along the western coasts of the continents, a strip of arid tropical climate a. Above the warm currents off the eastern coasts, air from low latitudes, already saturated with moisture, receives additional portions of water vapor, becomes unstably stratified, and the elevated eastern margins of all three continents receive quite a lot of precipitation.

Significant differences in the climates of the equatorial-tropical latitudes largely depend on the different structure of the surface of the Southern Tropical continents... The main factor that determines the specificity of the climates of South America is the existence of a high mountain barrier of the Andes along the western edge of the continent and a strip of plains stretching from the mouth of the river. Orinoco through the Amazon, Gran Chaco, Pantanal and the Laplat Plain to the mouth of the Parana.

This flat "corridor" is open to the north and south, and from the east it is separated from the Atlantic by the Guiana and Brazilian highlands. Along the eastern slope of the Andes, a leeward area of ​​low pressure (a kind of "wind tunnel") is formed, in which air masses converge, atmospheric fronts are formed, and cyclogenesis takes place. This process is especially pronounced in the summer, when the mainland warms up more, but it does not stop in winter. In this regard, in the central parts of the continent, the features of the continentality of the climate are weakening: the annual temperature amplitudes in the tropics and subtropics are somewhat less, and the amount of precipitation is greater than in the areas of the tropical and subtropical belts in internal parts other continents. According to these features, the climates of South America have some similarities with the inland regions of North America, with the difference that they are located in different climatic zones. This similarity is due to the similarities in the orographic structure of both Americas.

The relief of Africa is more uniform in height. In general, the surface is elevated, and more at the edges than in the central regions.

Within the continent, there are a number of vast basins surrounded by low mountains, plateaus and plateaus: the Great Karoo, Kalahari, Okavango, Congo, the basins of the Middle Niger, White Nile, Lake Chad, the Bodele depression, vast flat Sahara basins, and many smaller closed depressions. In them, the degree of continentality of climates increases. In general, such a surface structure without sharp contrasts in heights contributes to the manifestation of global regularities of general circulation and the law of zoning.

The surface of Western Australia is a system of shallow basins. The orographic structure is somewhat similar to that of the Sahara. Moisture conditions are formed here in a similar way. The lowlands along the western slopes of the East Australian Mountains act as a "flat corridor" through which cold air masses can penetrate far north. Due to the existence of such a corridor, the amount of precipitation along the slopes is higher, and the temperatures in the plains are slightly lower than in the central regions of the mainland.

Circulation of the atmosphere

The general scheme of the distribution of the centers of action, their displacements and changes over the seasons, the interaction of baric maxima and VTC is repeated on all the Southern Tropical continents and the oceans washing them. Therefore, in the equatorial and tropical latitudes within all three continents, the circulation of trade winds and equatorial monsoons prevails. An important role is played by the circulation processes characteristic of the intertropical zones of convergence of air masses. In summer, conditions for the circulation of the tropical belt (trade wind type) spread to subtropical latitudes, and in winter these areas fall into the zone of western air mass transfer and cyclonic activity characteristic of the temperate zones of both hemispheres.

The trade wind circulation has a significant impact on the formation of climates in the tropical zone. In the tropical latitudes of all Southern Tropical continents, the trade winds are directly involved in the formation of the climates of the eastern coasts.

Rushing along the western periphery of the oceanic baric maxima towards the Equatorial Depression, they contribute to precipitation on the eastern slopes of the marginal uplifts. When moving inland, especially in the inner basins, the air warms up and moves away from saturation. This dependence of the amount of precipitation on the slope exposure is very characteristic of the trade-wind circulation zones, since in the stably stratified flow the sediments are mainly of orographic origin.

In South America, the trade winds from the Azores maximum enter the Caribbean Andes and the Guiana Highlands, and from the South Atlantic - to the Brazilian Highlands. The windward slopes of these uplifts receive a relatively large amount of precipitation, especially in summer, when the trade winds are stronger.

The circulation of the trade wind type plays an especially large role in the formation of the climate of the northern, widest part of Africa, which, moreover, is located in the immediate vicinity of the huge continental block. The Mediterranean Sea also has a significant influence here.

In summer, air masses rush from an area of ​​increased pressure (a spur of the Azores baric maximum over the Mediterranean Sea) to a zone of reduced pressure over warmed up North Africa. They have the characteristic features of the trade winds: a downward vertical movement and the presence of a compression inversion layer. Moving inland, it quickly warms up and moves away from saturation. This process is especially well expressed in the inner depressions of the Sahara, where air moves down the slopes. Thermal convection occurs above the heated surface, but it does not lead to the formation of clouds and precipitation, since the level of condensation is very high in hot air, usually above the trade-wind inversion layer. Even if clouds do arise, they are high, shallow, and precipitation from them usually does not reach the earth's surface. Sometimes fronts of the trade wind type are formed here between the local continental and the marine tropical air that came here from the Atlantic or from the Mediterranean Sea. Clouds, mainly convective behind the frontal, can form, and rains, usually torrential, can pass. This process is sporadic and irregular. Most often, precipitation falls on the windward northern and northwestern slopes of the mountains of North Africa, where orographic convection plays the main role.

In winter, air masses are formed in the Sahara and neighboring Arabia in the high pressure belt of tropical latitudes. From here they move, firstly, to the north towards the winter baric depression over the Mediterranean Sea, where they participate in the formation of the polar front. The air of the Sahara in the warm sector of Mediterranean cyclones causes an increase in temperature on the sea coasts. In the countries of North Africa, a dry hot and dusty air stream from the Sahara is called hamsin, which means "fifty" in Arabic, since this wind blows on average 50 days a year, mainly in winter. spring time... Second, air masses from the high pressure belt move south towards the equatorial depression. They form three main streams: the Arabian in the east, the Egyptian in the center, and the so-called harmattan in the west. All of them do not differ in properties from trade winds. Over the vast expanses of the Sahara and the Sudan Plains, clouds do not form and precipitation does not fall. The restructuring of the vertical circulation of these air masses occurs only within the equatorial depression, located at this time somewhat south of the equator.

Thus, in the region of North Africa up to about 17 ° N. NS. (except for the Mediterranean coast) throughout the year, tropical air masses dominate, which can be considered trade winds, which makes it possible to attribute the tropical climates of the Sahara to the continental version of the trade wind type.

In the tropics of South Africa, the structure of the underlying surface is different, and circulation processes develop differently. The mainland here has a smaller area and a greater height. The interaction of air currents from the Atlantic and Indian oceans with different properties.

In summer, they rush into the intertropical convergence zone, located above the heated inner basins. Air comes to the Atlantic coast with a southern component in the direction of travel. It is cold and has a stable stratification. The entire African coast in tropical latitudes receives almost no rainfall. The inversion characteristic of these air masses sustains and intensifies the cold Benguela Current. Warm, humid unstable masses coming from the equator, which received additional moisture above warm currents, come from. Passing through the coastal uplifts, both the one and the other air transforms, dries up. However, the Atlantic air masses remain colder than the Indian ones and flow under them, forming fronts. Frontal processes contribute to a slight increase in the amount of summer precipitation in the inner basins of South Africa.

In winter, the high-pressure belt of tropical latitudes closes over the land, precipitation is not formed. Only the coasts are still exposed to oceanic air currents, due to which, in the west, temperatures remain low (for these latitudes) with an almost complete absence of precipitation, and in the east, orographic precipitation falls, but in less quantity than in summer. The circulation here is trade wind, but climatic conditions still have different features than in North Africa.

Circulation conditions are similar in the tropical latitudes of Australia, since the structure of its surface has much in common with South Africa.

The difference is that the intertropical convergence zone in summer is located in the north of the continent, where the deep Australian baric depression forms. Air masses rush here from the Indian and Pacific Oceans. Unlike South Africa, central and northern Australia receives airflow from the south through the low-lying plains. All air masses that have come to the territory of a strongly heated continent quickly heat up above its surface. And yet they have different properties, depending on their initial state. When they meet, fronts are formed and precipitation falls in the north of the mainland and on the eastern edge of the Australian Plains. In winter, a fairly stable baric maximum and an area of ​​divergence and settling of air masses are formed over the continent. There is little rainfall in central Australia this season. They fall only on the section of temperate and tropical air in the southern part of the tropical belt. The eastern slopes of the mountain system receive enough moisture, which are also under the influence of the Pacific trade winds in winter.

The cold southern air flow off the western coast of Australia (along the eastern periphery of the Indian Ocean Maximum) is weaker than that of Africa and South America. It is especially weakened in winter, when the center of the maximum is shifted towards the African shores. Along the coast of Western Australia, cyclones of the polar front penetrate far to the north, forming in this season in the immediate vicinity of the southwestern edge of the mainland, therefore, the western coasts receive some precipitation in winter.

In addition to the trade wind circulation, the circulation of the equatorial monsoons is characteristic of the Southern Tropical continents, which occurs due to the seasonal displacement of the Equatorial Depression. Such circulation is developed in the wide subequatorial belts of South America (from about 10 ° N to 20 ° S), Africa (from about 17 ° N to 20 ° S) and northern Australia (to 20 ° S).

Under its influence, the climatic conditions of the subequatorial belts are formed, occupying significant areas on all the southern tropical continents.

Within the wide western part of the Amazon Lowland and in the basin of the river. Congo conditions prevail all year round low pressure and enhanced convection. In these areas, an area of ​​low pressure remains throughout the year, which only grows in season towards the summer hemisphere.

This is due to the waterlogging of the flat bottoms of vast depressions, formed from the surface by water-resistant clayey sediments (muddy sea, river and lacustrine alluvium). dense networks of rivers often overflow and flood wide floodplains. The runoff is very slow due to the small slopes of the surface. The groundwater level is high, since the impermeable strata lie at a shallow depth and lie horizontally with very small falls. The bottoms of the hollows are swampy and overgrown with aquatic and dense evergreen forest vegetation, which supplies a lot of moisture to the region. In conditions of constantly high temperatures, evaporation and transpiration keep the air in a state of high relative humidity. Humidly unstable stratification persists over the basins throughout the year, and powerful convection develops. Any air masses that come here acquire equatorial properties. Heavy rainfall from cumulonimbus falls almost daily, maintaining excess moisture.

In subtropical latitudes on the territory of the southern continents, circulation processes change seasonally. Only on the eastern coasts within this belt is the influence of the southern periphery of oceanic baric maxima felt all year round, and the movement of air masses proceeds mainly from the ocean to land. As a result, the eastern Cape Mountains, the Eastern Australian system and the so-called Wet Pampa (the eastern part of the subtropical plains of South America) receive rainfall throughout the year.

In the remaining areas of the subtropical belt, in summer, the influence of the eastern periphery of baric maxima is established and a stably stratified air flow with trade wind inversion takes place. In winter, the western transport of air masses and cyclonic activity prevail here. On the plains of the Laplat Lowland and the coast of the Great Australian Gulf, air flow freely penetrates from the south (usually in the rear of the cyclones of the polar and Antarctic fronts). This helps to reduce winter temperatures. In the temperate latitudes of South America and Tasmania, western air mass transfer and cyclonic activity dominate.

Climatic zoning

The interaction of the radiation factor, circulation processes and the influence of the underlying surface lead to the fact that different types of climates of the equatorial, subequatorial and tropical belts are most common on all three continents.

Equatorial belt

Typical equatorial climate characteristic of the Western Amazon and the Congo Basin. Equatorial types of temperature variations and precipitation regimes with two maxima and small fluctuations in seasons are expressed here.

Annual precipitation in the Congo Basin is 1200-1500 mm, in some places up to 2000 mm. In the Amazon, almost throughout the entire territory, it exceeds 2000-3000 mm. More abundant precipitation on the Amazonian lowland is explained by the fact that its area is much larger, and the processes of formation of equatorial air masses are more clearly manifested here.

The equatorial type of climate is also inherent in the northwestern coast of South America, where it is observed on a narrow strip of coastal plains and in the lower belt of the western slopes of the Andes. The climate of the northern coast of the Gulf of Guinea is close to the equatorial one. Affects the proximity of these areas with warmed in at equatorial latitudes waters of warm inter-trade countercurrents.

Above them throughout the year are MTSK, and the air masses have a humid unstable Stratification - they constantly retain the properties of equatorial air. Precipitation is especially abundant on the western slopes of the Andes and on the uplifts of the Guinean coast, where their annual amount can exceed 5000 mm, and at some points reaches 9000-10,000 mm. In contrast to the basins of the Congo and the Amazon, the summer maximum precipitation is expressed here. In South America, it is associated with some weakening of the BTZK in winter. On the Guinean coast, the difference between the average monthly precipitation amounts over the seasons is very significant: in some places they differ tenfold. However, even in these cases, the dry period is either absent or very short - one to two months. A sharp decrease in the amount of precipitation in winter in this area is due to the fact that harmattan reaches here. It is warmer than the sea air that forms over the Gulf of Guinea, it is located above it, therefore, an inversion layer is formed, which prevents the development of powerful convection.

Subequatorial belt

The climates of this belt are widespread and well expressed in South America, Africa and northern Australia.

The effect of the summer monsoon, which is associated with abundant convective precipitation, begins near the equator in spring and, as the territory warms up and the equatorial depression shifts, it moves towards the summer hemisphere (as they figuratively say, “following the sun,” that is, following the movement of the zenital standing of the sun to one of the tropics). The length of the rainy season decreases with distance from the equator. The subequatorial climatic zone within North Africa is rather clearly divided into regions with sufficient and insufficient moisture.

A strip with an arid climate, precipitation falling during 2-4 summer months in an amount of less than 1000 mm, with an average annual moisture coefficient of 0.33-0.55, and northern border and even lower, located in the north of the Sudanese plains on the border with the Sahara and is called the Sahel. The subequatorial belt in Northern Australia differs in similar conditions, except for the northernmost tip of the Cape York and Arnhemland Peninsulas, where the wet season is longer and there is more rainfall.

A peculiar type of subequatorial climate with even more arid conditions than even in the Sahel is formed on the northeastern ledge of South America within the Brazilian Highlands. Here the amount of precipitation in places decreases to 250 mm, and all of them fall in the summer in the form of short-term heavy rain... This type differs from the continental climate of deserts only in the regularity of precipitation. Such a nature of climatic conditions is apparently associated with the peculiarities of the configuration of the coastline and the structure of the surface of this region. The summer northwestern monsoon from the Atlantic, with the arrival of which the rains should fall, rushes through the low-lying plains of the Eastern Amazon to the depression located over the Western Amazon and Priandian plains. The raised northeastern edge of the Brazilian Highlands bypasses this stream from the north and only occasionally, intensifying, captures the entire ledge of the mainland. Then it rains here. The rest of the time, this area is under the influence of the southeastern trade winds of the South Atlantic. They give orographic precipitation only on the windward slopes of the mountains. The Somali peninsulas are also characterized by an arid climate in the conditions of circulation of equatorial monsoons. The southwestern summer monsoon, which could provide enough moisture for this area, meets the uplift of the East African Highlands. Passing through them, the air transforms and moves away from saturation. The monsoon, which forms at the northeastern periphery of the Indian baric maximum, is heading towards the South Asian depression. This stream moves along the coast of the Somali Peninsula and, as a rule, deviates to the east, without capturing land. As a result, the territory of the peninsula receives very little rainfall. In addition to these dry areas (Sahel, northeastern Brazilian Highlands and Somalia), within subequatorial belt climate conditions are formed with the course of precipitation and temperatures typical for the belt and with sufficient moisture (annual coefficient (1.55-1.00 and higher).

Tropical belt

The continental arid tropical climate is widespread in Africa and Australia. Striking features of this type of climate are extreme aridity, relatively large annual and sharp daily temperature ranges, strong winds, often with dusty and sandstorms are especially pronounced in the Sahara and in some deserts of Australia (Simpson Desert, Great desert Victoria, etc.). In these areas, precipitation falls less than 200 mm per year, in some places it does not happen at all for a number of years. The rest of the continental tropical climate (in South Africa, in vast areas in Australia, in the south of the Gran Chaco region in South America) receive more precipitation (250-500 mm), but they fall irregularly, and the humidity coefficient does not rise above 0 there. 33.

On the western coasts of the continents in the tropical zone, a type of climate of humid cold coastal deserts is formed, which is sometimes called the Garoua climate after the local name for the early morning cold fogs on the Peruvian coast, where the factors that determine the properties of this climate are most strongly manifested. Largest areas it ranks in South America and South Africa.

Along the South American coast of the Pacific Ocean, this climatic region stretches from the thirties latitudes of the Southern Hemisphere almost to the equator (up to about 5 ° S lat.). This is facilitated by the south and southwest flow of relatively cold air, which moves along the eastern periphery of the very extensive and stable South Pacific Maximum, located near the coast of South America throughout the year. The properties of the Peruvian current are also important: it is the most powerful of all those washing the western shores of the continents, and extends far north, almost to the equator. The cold air of high latitudes, moving above it, retains its properties for a long time. All signs of the Garoua climate: relatively low temperatures (especially in summer), negligible rainfall with high relative humidity (up to 90-100%), frequent night fog and dew, very pronounced on the coastal lowlands and on the western slopes of the Andean Cordilleras to heights of 1600-1800 m - in the north of the region and up to 2300 m and even higher - south of 17 ° S. NS. In the north of the region, there are years when El Niño appears in the near-equatorial waters off the coast of South America in summer. In this case, the conditions change dramatically: above warm waters During the El Niño currents, humid-unstable air stratification is established, powerful convection develops and heavy precipitation falls, that is, the climatic conditions become the same as in the North-Western (Equatorial) Andes. Such a sharp change in climatic conditions affects literally all components of nature and the life of the people of this region.

The rains erode the mountain slopes, which are almost devoid of vegetation. People are forced to struggle with excess moisture, while their entire lifestyle is associated with conditions of water scarcity. They are deprived of their livelihoods as fish leave the shores. Stocks of valuable fertilizer - guano - are washed off into the sea.

In Africa, the Garoua climate type is well expressed in Namibia (up to 12 ° S lat.) And less clearly in Western Sahara (up to 12 ° N lat.). Smaller than in South America, the spread of this climate is explained by the fact that the air circulation in the Atlantic is somewhat weaker than in the Pacific Ocean.

and water masses, forming such conditions. However, the influence of air masses penetrates further into the interior of the mainland due to. the absence of high mountain barriers here. Signs of the Garoua climate appear quite far from the coasts.

In Australia, similar climatic conditions are observed on the west coast between 20 ° and 30 ° S. sh., but their signs are much less pronounced than in South America and Africa. Much more precipitation falls here (200-500 mm per year). In the north of the region, it rains in the summer, as the northwest monsoon periodically penetrates here along the coast. South of precipitation winter, associated with cyclones of the polar front, located at that time near the southwestern edge of the continent. Summer temperatures are 4-6 ° C higher than in Namibia and the coastal deserts of South America. These differences are explained by weaker and less stable circulation in the Indian baric maximum than in the South Atlantic and South Pacific.

On the eastern coasts of all three continents in the tropical zone, climates are formed that, in some respects, resemble subequatorial climates: high temperatures are observed here all year round, a large amount of precipitation with a pronounced summer maximum. However, the course of temperatures is tropical with one maximum, and there is no dry period in the precipitation regime.

Throughout the year, the eastern outskirts of the Guiana and Brazilian Highlands, the highlands of South and East Africa, the eastern slopes of the Drakensberg Mountains and the ranges of the East Australian Mountain System receive precipitation, mainly orographic, due to the trade winds that move along the western periphery of the oceanic baric highs of tropical latitudes and heading from low to high latitudes. The air in them is warm, has a humid unstable stratification, moreover, it passes over warm currents. The currents intensify in the summer, when areas of low pressure form over land, and weaken somewhat in winter, when the pressure over the continents and oceans in tropical latitudes equalizes. But all year round, the eastern windward slopes of mountains and highlands receive precipitation, more in summer, less in winter. The number depends on the conditions of their formation. On the slopes of the low Australian and South African mountains, it reaches 1200-1500 mm per year. The higher outskirts of the Brazilian and Guiana Highlands and the insular highlands of Madagascar receive 2000 mm, and in some places even 3000 mm.

Subtropical belt

In this belt, on the western coasts of all three continents and northern Africa, the Mediterranean type of climate prevails. On the African shores of the Mediterranean Sea, the conditions for its formation are the same as on European and Asian ones. It differs in higher temperatures.

In summer, there are invasions of hot dusty air from the Sahara - the sirocco wind. In winter, in the warm sectors of cyclones, the Saharan air from the Khamsin often enters here, causing sudden temperature rises and dust storms. Sometimes in the rear of the cyclones, cold masses penetrate the African coast from the north. Then the temperatures drop, sometimes to negative values. Snow can fall and hold out on the coastal lowlands for several days. Snowfalls in winter are common on the slopes of the Atlas Mountains, and in upper belts snow ridges often lie for a long time. Aridity is increasing to the east and south.

On the western subtropical coasts of South America (30 ° -42 ° S), South Africa (south of 30 ° S) and South-Western Australia, temperatures are relatively low for these latitudes, since air enters here in summer along the eastern the periphery of oceanic baric maxima from higher latitudes, as well as in neighboring tropical belts, therefore, there is little precipitation here in summer with increased relative humidity, as in the Garoua climate region. In winter, cyclones of the western transport pass in these latitudes, and with them sea air masses. Precipitation falls - frontal, frontal, and orographic. Their annual number is 500-1000 mm, and on the western slopes of the Andes - up to 2000-3000 mm. In Australia, the influence of cyclones of western transport in winter affects up to the basin of the river. Murray and the southern ridges of the East Australian Mountains. Along the western coast of the mainland, these cyclones penetrate far north into the tropical belt. (This, by the way, is one of the reasons why the signs of the Garoua climate are poorly expressed on the western outskirts of tropical Australia.) The eastern coasts of the southern tropical continents in the subtropics are influenced by air masses flowing from the southwestern periphery of oceanic baric maxima throughout the year. This influence weakens somewhat in winter. However, the amount of precipitation changes little throughout the year. In summer, it is mainly orographic precipitation on the windward eastern slopes. In winter, when their number is reduced, cyclones of the western transport penetrate here from time to time. In their front part, the movement of air masses has an eastern component, and the eastern slopes again turn out to be windward. On the lowland Laplat lowland, the mechanism of sedimentation processes is somewhat different. Here, frontal sections are often formed between air masses that come here from the east (from the Atlantic), from the west (from the Pacific Ocean), from tropical latitudes, and the local continental air, which contributes to precipitation. The amount of precipitation decreases from east to west (from 2000 mm near the coast to 300-500 mm in the Andean regions), since the wettest air comes here from the Atlantic. Usually the eastern part of the territory is called Wet, and the western part is called Dry Pampa. The maximum precipitation in the entire region is summer, when the circulation flow to the heated continent increases. In winter, there are air intrusions from the south from high latitudes, causing cold snaps and strong winds from dust storms- diaper. The thin snow cover does not last long. With average monthly positive winter temperatures (10-14 ° C), frosts can be down to -10 ° C, which are quickly replaced by thaws. Summers are usually hot (average monthly temperatures are 26-27 ° C, on the Atlantic coast - lower). Even hotter periods are associated with intrusions of humid hot air from the north.

Temperate zone

The climates of the temperate latitudes of the Southern Hemisphere are formed only in a narrow part of South America (south of 42 ° S latitude), on Tierra del Fuego and in southern Tasmania. On the western slopes of the Patagonian Andes, the Fiery Mountains and Tasmania, the climate is maritime.

Throughout the year, these areas receive abundant rainfall from westerly transported sea air masses. Their number is from 2000 mm to 5000 mm, and in some places even more. Starting from an altitude of 1000-1500 m, snow falls and lies in the mountains, glaciers form, in places descending to the ocean. Summer here is cold for these latitudes. Even on the coast, the average summer temperatures barely reach 8-12 ° C, while in the mountains they can be negative. This is due to the influence of cold Antarctic air entering here in the rear of the cyclones. In eastern (leeward) Tasmania, summers are warmer (15-17 ° С). Winters are relatively mild for temperate latitudes: 4-6 ° С on the Pacific coast of South America and 8-10 ° С in Tasmania. Average monthly winter temperatures acquire negative values only in the Andes. The relatively high winter temperatures are associated with the influence of the warm sectors of cyclones.

The climatic conditions of Patagonia are peculiar. The air currents of the western transfer, descending from the Andes to the Patagonian plateau, dry up, and the annual precipitation here decreases to 130-250 mm. Even on the Atlantic coast, the climate is dry, as the cold Falklands Current maintains stable stratification. For temperate latitudes, there are quite high average monthly temperatures. In summer, over the warmed up Patagonian plains, the average temperatures are 20-22 ° C, but there are even frosts associated with the invasion of cold Antarctic air. In winter, with positive mean monthly temperatures (2-8 ° C), these invasions sometimes cause frosts of thirty degrees. Strong winds are common abrupt changes weather, little snow falls. Climatic conditions like these are hard to find anywhere else on the globe.

Antarctica climate

Antarctica has unique climatic conditions. The polar geographic position determines the uniqueness of climate-forming processes in comparison with all continents of the Earth. Even in comparison with the circumpolar regions Northern hemisphere the climate of Antarctica is extremely harsh. This is due to the fact that beyond the South Arctic Circle lies the continental block of the earth's crust, significantly elevated above sea level, isolated from the influence of warm water masses by the presence of the circumpolar current of the Western Winds. Over the sea expanses of Antarctica, nevertheless warmer than the mainland, an area of ​​low pressure forms all year round, "intercepting" the flows warm air from oceanic baric maxima. The movement of air masses is almost always directed from the continent towards the Antarctic depression. All these factors contribute to the cooling of the continent and the formation of an ice cover on it, which in turn reduces the radiation balance due to the high albedo and the heat balance due to the melting of ice.

As a result, even the summer mean monthly temperatures on the coast near the Arctic Circle have negative values, and in the central regions of the continent they drop to -30-33 ° C. In the winter months on the coast the average temperatures are -16-20 ° С, while on the ice dome their values ​​are uniquely low and -60-70 ° С. At the station "Vostok", located about 80 ° S. sh., was noted -89.2 ° С (the absolute minimum for the entire Earth), and the maximum summer - only -21 ° С. In summer, near the coast there are sometimes warming up to 8-10 ° C, and in oases, free of snow and ice in summer, and higher, but cold windy weather prevails there. Throughout the year, strong katabatic winds blow from the central regions of the continent, where the anticyclonic regime prevails, towards the Antarctic depression down the slopes of the ice sheet. On the coasts, storm winds of cyclones are added to them, which in summer capture the outskirts of the continent, since the Antarctic front at this time is located close to the coast. The passage of cyclones is accompanied by a drop in temperatures, snowfalls, blizzards. Such harsh climatic conditions affect all natural features.

Climate- this is a long-term weather regime typical for a particular area. It manifests itself in the regular change of all types of weather observed in this area.

The climate affects the living and inanimate nature... Water bodies, soil, vegetation, animals are closely dependent on the climate. Certain sectors of the economy, primarily agriculture, are also highly dependent on the climate.

The climate is formed as a result of the interaction of many factors: the amount of solar radiation entering the earth's surface; circulation of the atmosphere; the nature of the underlying surface. In this case, the climate-forming factors themselves depend on geographic conditions this area, primarily from geographic latitude.

The geographic latitude of the area determines the angle of incidence of the sun's rays, the receipt of a certain amount of heat. However, getting heat from the Sun also depends on proximity to the ocean. In places far from the oceans, there is little precipitation, and the mode of precipitation is uneven (in the warm period it is more than in the cold one), the cloudiness is low, the winter is cold, the summer is warm, annual amplitude temperature is high. This climate is called continental because it is typical for places located in the interior of continents. Above the water surface, a maritime climate is formed, which is characterized by: a smooth course of air temperature, with small daily and annual temperature ranges, large cloudiness, uniform and sufficiently large amount of atmospheric precipitation.

The climate is greatly influenced by sea ​​currents. Warm currents warm the atmosphere in the areas where they flow. So, for example, the warm North Atlantic current creates favorable conditions for the growth of forests in the southern part of the Scandinavian Peninsula, while most of the island of Greenland, which lies at about the same latitudes as the Scandinavian Peninsula, but outside the zone of influence of a warm current, is covered with a thick layer of ice all year round.

An important role in the formation of the climate belongs relief. You already know that as the terrain rises, the air temperature decreases by 5-6 ° С for every kilometer. Therefore, on the high mountain slopes of the Pamirs, the average annual temperature is 1 ° C, although it is located slightly north of the tropic.

The location of mountain ranges has a great influence on the climate. For example, the Caucasus Mountains hold back moist sea winds, and significantly more precipitation falls on their windward slopes facing the Black Sea than on the leeward ones. At the same time, the mountains serve as an obstacle to cold northern winds.

The climate is also dependent on prevailing winds. On the territory of the East European Plain, westerly winds, coming from the Atlantic Ocean, prevail throughout almost the entire year, therefore winters in this area are relatively mild.

The regions of the Far East are under the influence of monsoons. In winter, winds constantly blow from the depths of the mainland. They are cold and very dry, so there is little rainfall. In summer, on the contrary, winds bring a lot of moisture from the Pacific Ocean. In autumn, when the wind dies down from the ocean, the weather is usually sunny and calm. it the best time years in the area.

Climatic characteristics represent statistical conclusions from long-term series of weather observations (in temperate latitudes, 25-50-year series are used; in the tropics, their duration may be shorter), primarily over the following main meteorological elements: atmospheric pressure, wind speed and direction, temperature and air humidity, cloudiness and precipitation. They also take into account the duration of solar radiation, the visibility range, the temperature of the upper layers of the soil and water bodies, the evaporation of water from the earth's surface into the atmosphere, the height and state of the snow cover, various atmospheric phenomena and ground hydrometeors (dew, ice, fog, thunderstorms, blizzards, etc.). In the XX century. The climatic indicators included the characteristics of the elements of the heat balance of the earth's surface, such as total solar radiation, radiation balance, values ​​of heat exchange between the earth's surface and the atmosphere, heat consumption for evaporation. Complex indicators are also used, i.e. functions of several elements: various coefficients, factors, indices (for example, continentality, aridity, moisture), etc.

Climatic zones

Long-term mean values ​​of meteorological elements (annual, seasonal, monthly, daily, etc.), their sums, frequency of occurrence, etc. are called climatic norms: the corresponding values ​​for individual days, months, years, etc. are considered as deviations from these norms.

Climate maps are called climatic(temperature distribution map, pressure distribution map, etc.).

Depending on the temperature conditions, prevailing air masses and winds emit climatic zones.

The main climatic zones are:

• equatorial;
• two tropical;
• two moderate;
• arctic and antarctic.

Transitional climatic zones are located between the main zones: subequatorial, subtropical, subarctic, subantarctic. In the transition zones, air masses change with seasons. They come here from neighboring zones, so the climate of the subequatorial zone in summer is similar to the climate of the equatorial zone, and in winter - to the tropical climate; the climate of the subtropical zones in summer is similar to the climate of the tropical, and in winter - with the climate of the temperate zones. This is due to the seasonal movement of the belts of atmospheric pressure over the globe following the Sun: in summer - to the north, in winter - to the south.

Climatic zones are subdivided into climatic regions. So, for example, in the tropical zone of Africa, areas of tropical dry and tropical humid climate, and in Eurasia, the subtropical belt is subdivided into areas of the Mediterranean, continental and monsoon climate. V mountainous areas altitudinal zonation is formed due to the fact that the air temperature decreases with height.

The variety of climates on Earth

Climate classification provides an ordered system for characterizing climate types, their regionalization and mapping. Let us give examples of the types of climate prevailing over vast territories (Table 1).

Arctic and Antarctic climatic zones

Antarctic and arctic climate dominates in Greenland and Antarctica, where average monthly temperatures are below 0 ° C. In the dark winter season, these regions do not receive any solar radiation at all, although there are twilight and aurora borealis. Even in summer Sun rays fall on the earth's surface at a slight angle, which reduces the effectiveness of warming up. Most of the incoming solar radiation is reflected by ice. Both summer and winter, the elevated regions of the Antarctic Ice Sheet are characterized by low temperatures. The climate of the interior regions of Antarctica is much colder than the climate of the Arctic, since the southern continent is large and high, and the Arctic Ocean softens the climate, despite the widespread distribution of pack ice. In summer, during short warmings, drifting ice sometimes melts. Precipitation on ice sheets falls in the form of snow or small particles of ice fog. The interior regions receive only 50-125 mm of precipitation annually, but more than 500 mm can fall on the coast. Sometimes cyclones bring clouds and snow to these areas. Snowfalls are often accompanied by strong winds that carry significant masses of snow, blowing it off the slope. Strong katabatic winds with blizzards blow from the cold ice sheet, carrying snow to the coast.

Table 1. Climates of the Earth

Climate type	Climatic belt	Average temperature, ° С		Mode and amount of atmospheric precipitation, mm	Circulation of the atmosphere	Territory
Equatorial	Equatorial			During a year. 2000	In the area of ​​low atmospheric pressure, warm and humid equatorial air masses are formed	Equatorial regions of Africa, South America and Oceania
Tropical monsoon	Subequa-torial			Mostly during the summer monsoon, 2000		South and Southeast Asia, West and Central Africa, North Australia
Tropical dry	Tropical			Throughout the year, 200		North Africa, Central Australia
Mediterranean	Subtropical			Mainly in winter, 500	In summer - anticyclones at high atmospheric pressure; in winter - cyclonic activity	Mediterranean, Southern coast of Crimea, South Africa, Southwest Australia, Western California
Subtropical dry	Subtropical			During a year. 120	Dry continental air masses	Inner parts of the continents
Moderate marine	Moderate			During a year. 1000	Westerly winds	Western Eurasia and North America
Moderate continental	Moderate			During a year. 400	Westerly winds	Inner parts of the continents
Moderate monsoon	Moderate			Mainly during the summer monsoon, 560		Eastern edge of Eurasia
Subarctic	Subarctic			Throughout the year, 200	Cyclones prevail	Northern outskirts of Eurasia and North America
Arctic (antarctic)	Arctic (Antarctic)			Throughout the year, 100	Anticyclones prevail	Water area of ​​the Arctic Ocean and mainland Australia

Subarctic continental climate formed in the north of the continents (see the climatic map of the atlas). In winter, arctic air prevails here, which forms in areas of high pressure. Arctic air spreads from the Arctic to the eastern regions of Canada.

Continental subrctic climate Asia is characterized by the largest annual amplitude of air temperature on the globe (60-65 ° С). The continentality of the climate reaches its maximum value here.

The average temperature in January varies across the territory from -28 to -50 ° C, and in lowlands and basins, due to stagnation of air, its temperature is even lower. A record for the Northern Hemisphere was registered in Oymyakon (Yakutia) negative temperature air (-71 ° C). The air is very dry.

Summer in subarctic belt although short, it is quite warm. The average monthly temperature in July ranges from 12 to 18 ° С (daily maximum - 20-25 ° С). Over the summer, more than half of the annual precipitation falls, amounting to 200-300 mm on the flat territory, and on the windward slopes of the hills - up to 500 mm per year.

The climate of the subarctic zone of North America is less continental in comparison with the corresponding climate in Asia. There are less cold winters and colder summers.

Moderate climatic zone

Moderate climate of the western coasts of the continents has pronounced features of the maritime climate and is characterized by the predominance of sea air masses throughout the year. It is observed on the Atlantic coast of Europe and the Pacific coast of North America. The Cordillera are the natural border separating the maritime coastline from the inland areas. The European coast, except for Scandinavia, is open to free access to maritime temperate air.

The constant transfer of sea air is accompanied by large clouds and causes protracted springs, in contrast to the interior of the continental regions of Eurasia.

Winter in temperate the western coasts are warm. The warming influence of the oceans is enhanced by warm sea currents washing the western shores of the continents. The average temperature in January is positive and varies across the territory from north to south from 0 to 6 ° С. During incursions of the Arctic air, it can decrease (on the Scandinavian coast to -25 ° С, and on the French coast - to -17 ° С). When tropical air spreads to the north, the temperature rises sharply (for example, it often reaches 10 ° C). In winter, on the western coast of Scandinavia, large positive temperature deviations from the average latitudinal temperature (by 20 ° C) are noted. The temperature anomaly on the Pacific coast of North America is less and does not exceed 12 ° C.

Summers are rarely hot. The average temperature in July is 15-16 ° C.

Even during the day, the air temperature rarely exceeds 30 ° C. Due to frequent cyclones, cloudy and rainy weather... There are especially many cloudy days on the west coast of North America, where cyclones are forced to slow down in front of the Cordillera mountain systems. In this regard, the weather regime in the south of Alaska, where there are no seasons in our understanding, is characterized by great uniformity. Eternal autumn reigns there, and only plants remind of the onset of winter or summer. Annual precipitation ranges from 600 to 1000 mm, and on the slopes of mountain ranges - from 2000 to 6000 mm.

In conditions of sufficient moisture, broad-leaved forests are developed on the coasts, and in conditions of excess, conifers. The lack of summer heat reduces the upper border of the forest in the mountains to 500-700 m above sea level.

Moderate climate of the eastern coasts of the continents has monsoon features and is accompanied by a seasonal change of winds: in winter, northwestern flows prevail, in summer - southeastern ones. It is well defined on the east coast of Eurasia.

In winter with northwest wind cold continental temperate air spreads on the coast of the mainland, which is the reason for the low average temperature of the winter months (from -20 to -25 ° C). Clear, dry, windy weather prevails. There is little precipitation in the southern regions of the coast. The north of the Amur region, Sakhalin and Kamchatka are often affected by cyclones moving over the Pacific Ocean. Therefore, in winter there is a thick snow cover, especially in Kamchatka, where its maximum height reaches 2 m.

In summer, with a southeasterly wind on the coast of Eurasia, maritime temperate air spreads. Summers are warm, with an average July temperature of 14 to 18 ° C. Precipitation is frequent due to cyclonic activity. Their annual number is 600-1000 mm, with most of them falling in summer. Fogs are frequent at this time of the year.

Unlike Eurasia, the east coast of North America is characterized by marine features climate, which are expressed in the predominance of winter precipitation and marine type annual course air temperature: the minimum occurs in February, and the maximum in August, when the ocean is warmest.

The Canadian anticyclone, in contrast to the Asian, is unstable. It forms off the coast and is often interrupted by cyclones. Winters are mild, snowy, wet and windy here. In snowy winters, the height of snowdrifts reaches 2.5 m. south wind ice often occurs. Therefore, some streets in some cities in eastern Canada have iron railings for pedestrians. Summers are cool and rainy. Annual precipitation is 1000 mm.

Moderate continental climate most clearly expressed on the Eurasian continent, especially in the regions of Siberia, Transbaikalia, northern Mongolia, as well as in the Great Plains in North America.

A feature of the temperate continental climate is a large annual amplitude of air temperature, which can reach 50-60 ° C. In winter months, with a negative radiation balance, the earth's surface is cooled. The cooling effect of the land surface on the surface layers of air is especially great in Asia, where a powerful Asian anticyclone forms in winter and cloudy, calm weather prevails. The temperate continental air forming in the area of ​​the anticyclone has low temperature(-0 ° ...- 40 ° C). In valleys and basins, due to radiation cooling, the air temperature can drop to -60 ° C.

In the middle of winter, the continental air in the lower layers becomes even colder than the arctic. This very cold air of the Asian anticyclone spreads to Western Siberia, Kazakhstan, southeastern regions of Europe.

The winter Canadian anticyclone is less stable than the Asian anticyclone due to the smaller size of the North American continent. Winters are less severe here, and their severity does not increase towards the center of the mainland, as in Asia, but, on the contrary, decreases somewhat due to the frequent passage of cyclones. Continental temperate air in North America has a higher temperature than continental temperate air in Asia.

The formation of a continental temperate climate is significantly influenced by geographic features the territory of the continents. In North America, the Cordillera mountain ranges are the natural boundary separating the maritime coastline from the inland continental regions. In Eurasia, a temperate continental climate is formed over a vast land area, approximately from 20 to 120 ° E. e. Unlike North America, Europe is open for free penetration of sea air from the Atlantic deep into the interior regions. This is facilitated not only by the western transport of air masses, which prevails in the temperate latitudes, but also by the flat relief, the strong indented coasts and the deep penetration into the land of the Baltic and North Seas... Therefore, a temperate climate of a lesser degree of continentality is formed over Europe in comparison with Asia.

In winter, the sea Atlantic air, moving over the cold land surface of the temperate latitudes of Europe, retains its physical properties, and its influence extends to all of Europe. In winter, with the weakening of the Atlantic influence, the air temperature decreases from west to east. In Berlin, it is 0 ° C in January, -3 ° C in Warsaw, and -11 ° C in Moscow. In this case, the isotherms over Europe have a meridional direction.

A broad front facing Eurasia and North America Arctic basin promotes deep penetration of cold air masses to the continents throughout the year. Intense meridional air mass transfer is especially characteristic of North America, where arctic and tropical air often replace each other.

Tropical air entering the plains of North America from southern cyclones, also slowly transforms due to the high speed of its movement, high moisture content and continuous low clouds.

In winter, a consequence of the intense meridional circulation of air masses is the so-called "jumps" in temperatures, their large day-to-day amplitude, especially in areas where cyclones are frequent: in the north of Europe and Western Siberia, the Great Plains of North America.

In the cold period, it falls in the form of snow, a snow cover forms, which protects the soil from deep freezing and creates a moisture reserve in the spring. The depth of the snow cover depends on the duration of its occurrence and the amount of precipitation. In Europe, a stable snow cover on the flat area forms east of Warsaw, its maximum height reaches 90 cm in the northeastern regions of Europe and Western Siberia. In the center of the Russian Plain, the height of the snow cover is 30-35 cm, and in Transbaikalia - less than 20 cm. On the plains of Mongolia, in the center of the anticyclonic region, the snow cover is formed only in some years. The absence of snow, along with low winter air temperatures, leads to the presence of permafrost, which is no longer observed anywhere on the globe at these latitudes.

In North America, on the Great Plains, snow cover is negligible. To the east of the plains, tropical air increasingly begins to take part in frontal processes, it aggravates frontal processes, which causes heavy snowfalls. In the Montreal area, the snow cover lasts up to four months, and its height reaches 90 cm.

Summers in the continental regions of Eurasia are warm. The average July temperature is 18-22 ° C. In the arid regions of southeastern Europe and Central Asia the average air temperature in July reaches 24-28 ° С.

In North America, continental air is somewhat colder in summer than in Asia and Europe. This is due to the lesser extent of the continent in latitude, the large indentedness of its northern part with bays and fjords, the abundance of large lakes, and the more intense development of cyclonic activity in comparison with the inner regions of Eurasia.

In the temperate zone, the annual precipitation on the flat territory of the continents varies from 300 to 800 mm, more than 2000 mm falls on the windward slopes of the Alps. Most of the precipitation falls in summer, which is primarily associated with an increase in the moisture content of the air. In Eurasia, there is a decrease in precipitation across the territory from west to east. In addition, the amount of precipitation also decreases from north to south due to a decrease in the frequency of cyclones and an increase in air dryness in this direction. In North America, a decrease in precipitation across the territory is noted, on the contrary, in the direction to the west. Why do you think?

Most of the land in the continental temperate zone is occupied by mountain systems. These are the Alps, Carpathians, Altai, Sayans, Cordillera, Rocky Mountains and others. In mountainous regions, climatic conditions differ significantly from the climate of the plains. In summer, the air temperature in the mountains drops rapidly with altitude. In winter, when cold air masses invade, the air temperature in the plains is often lower than in the mountains.

The influence of mountains on precipitation is great. Precipitation increases on windward slopes and at some distance in front of them, and decreases on leeward slopes. For example, differences in annual rainfall between the western and eastern slopes Ural mountains in some places they reach 300 mm. In the mountains, precipitation increases with height to a certain critical level. In the Alps, the level of the greatest amount of precipitation falls at an altitude of about 2000 m, in the Caucasus - 2500 m.

Subtropical climate zone

Continental subtropical climate determined by the seasonal change of temperate and tropical air. The average temperature of the coldest month in Central Asia is below zero in places, in the northeast of China -5 ...- 10 ° С. The average temperature of the warmest month is in the range of 25-30 ° С, while daily highs can exceed 40-45 ° С.

The most strongly continental climate in the air temperature regime is manifested in the southern regions of Mongolia and in the north of China, where the center of the Asian anticyclone is located in the winter season. Here the annual amplitude of air temperature is 35-40 ° С.

Sharply continental climate in the subtropical zone for the highland regions of the Pamirs and Tibet, the height of which is 3.5-4 km. The climate of the Pamirs and Tibet is characterized by cold winters, cool summers and low rainfall.

In North America, a continental arid subtropical climate is formed in closed plateaus and intermontane basins located between the Coastal and Rocky ridges. Summers are hot and dry, especially in the south, where the average July temperature is above 30 ° C. The absolute maximum temperature can reach 50 ° C and above. In Death Valley, a temperature of +56.7 ° C was recorded!

Humid subtropical climate characteristic of the eastern coasts of the continents to the north and south of the tropics. The main areas of distribution are the southeastern United States, some southeastern regions of Europe, northern India and Myanmar, eastern China and southern Japan, northeastern Argentina, Uruguay and southern Brazil, the coast of Natal province in South Africa and the east coast of Australia. Summer in humid subtropics long and hot, with the same temperatures as in the tropics. The average temperature of the warmest month exceeds +27 ° С, and the maximum temperature is +38 ° С. Winters are mild, with average monthly temperatures above 0 ° C, but occasional frosts have a detrimental effect on vegetable and citrus plantations. In humid subtropics, the average annual precipitation ranges from 750 to 2000 mm, the distribution of precipitation over the seasons is quite even. In winter, rains and occasional snowfalls are brought mainly by cyclones. In summer, precipitation occurs mainly in the form of thunderstorms associated with powerful inflows of warm and humid oceanic air, characteristic of the monsoon circulation of East Asia. Hurricanes (or typhoons) occur in late summer and fall, especially in the Northern Hemisphere.

Subtropical climate with dry summers typical of the western coasts of the continents north and south of the tropics. In southern Europe and North Africa, such climatic conditions are typical for the Mediterranean coasts, which was the reason to call this climate also Mediterranean. A similar climate in southern California, central Chile, in the extreme south of Africa and in several areas in southern Australia. All these areas have hot summers and mild winters. As in the humid subtropics, there are occasional frosts in winter. Inland temperatures are much higher in summer than on coasts and are often the same as in tropical deserts... In general, clear weather prevails. Fogs are common on the coasts near which ocean currents pass in summer. For example, in San Francisco, summers are cool, foggy, and the warmest month is September. The maximum precipitation is associated with the passage of cyclones in winter, when the prevailing air currents mix towards the equator. Anticyclones and downdrafts over oceans cause dryness summer season... Average annual precipitation in a subtropical climate ranges from 380 to 900 mm and reaches its maximum values ​​on the coasts and slopes of the mountains. In summer, there is usually not enough rainfall for the normal growth of trees, and therefore a specific type of evergreen shrub vegetation develops there, known as maquis, chaparral, mal and, macchia and finbosh.

Equatorial climate zone

Equatorial type of climate distributed in equatorial latitudes in the Amazon basins in South America and Congo in Africa, on the Malacca Peninsula and on the islands South-East Asia... Usually average annual temperature about +26 ° C. Due to the high noon standing of the Sun above the horizon and the same day length throughout the year, seasonal temperature fluctuations are small. Humid air, cloudiness and dense vegetation prevent nighttime cooling and maintain maximum daytime temperatures below +37 ° C, lower than in higher latitudes. Average annual rainfall in the humid tropics ranges from 1,500 to 3,000 mm and is usually evenly distributed over the seasons. Precipitation is mainly associated with the intertropical convergence zone, which is located slightly north of the equator. Seasonal displacements of this zone to the north and south in some areas lead to the formation of two maximum precipitation during the year, separated by drier periods. Thousands of thunderstorms roll over the humid tropics every day. In between, the sun shines in full force.

Topic 2.EURASIA

Section 40. Climate

Remember or guess

1. How does geographic latitude affect the peculiarities of the climate of Eurasia?

2. How does the size and topography of the continent affect the climate?

3. What is the main difference between the main and transitional climatic zones?

General features of the climate

Factors affecting the climate of the mainland. Climatic features the continent is determined by its considerable size, its great length from south to north (from the equator to the arctic latitudes), from west to east, as well as by the structure of the surface - the presence of high mountain systems in the south and east, the spread of plains in the northern part. Mighty mountain ranges of ridges that rise in the south of Eurasia and along the eastern outskirts create difficulties for the penetration of air masses from the Pacific and Indian oceans inland. In the west and north, Eurasia is "open" to the influence of the Atlantic and the Arctic Ocean.

The structure of the surface, together with the geographical position and size of the continent, determined the location of the cold pole of the Northern Hemisphere in Oymyakon in the vastness of Eurasia. The Arabian Peninsula is home to one of the hottest regions in the world. There are also areas where an average of less than 50 mm of precipitation falls per year (on the Arabian Peninsula, in Central Asia), and the wettest place in the world - 12,000 mm (the village of Cherrapunji in India).

Climatic zones and types of climate

Climatic zones and regions of the northern part of Eurasia. Due to its great length from north to south, Eurasia is located in all climatic zones of the Northern Hemisphere, from the Arctic to the equatorial. The largest areas are occupied by the temperate belt, because it is in the temperate latitudes that the continent is most elongated from west to east.

Rice. 4.79. Climatic zones and regions of Eurasia (areas: 3-A - desert, 3-B - humid, 4-A - continental, 4-B - Mediterranean, 4-C - monsoon, 5-A - continental, 5-B - moderately continental , 5-B - marine, 5-G - monsoon).

Do you know?

There are several versions of where the true Cold Pole of the Northern Hemisphere is. In Verkhoyansk in last decade a temperature of -67.8 ° C was recorded. In Oymyakon, the Obruchev expedition in 1929 recorded a temperature of -71.2 ° C.

In the arctic and subarctic climatic zones, the western regions have a milder climate with relatively small temperature ranges due to the relatively warm winter and cool summer. In the east of the belts, the climate is characterized by very cold (up to -40 ...- 45 ° С) winter (Fig. 4.79).

Within temperate zone climatic conditions are very varied. The west coast has a maritime climate that is influenced by sea air masses from the Atlantic Ocean throughout the year. Therefore, summers are cool here, winters are relatively warm even in northern latitudes (on the coast of the Scandinavian Peninsula) (Fig. 4.80). Precipitation falls all year round. With the passage of cyclones, the weather changes rapidly, in summer there can be cold snaps, in winter there are frequent thaws.

Some features of the marine type of climate persist to the east (almost throughout the continental territory of Europe): unstable weather, relatively wet winters (low 4.81). However, with the distance to the east from the Atlantic Ocean, the difference between summer and winter temperatures increases: winter becomes noticeably colder. There is more precipitation in summer than in winter. This is an area of ​​transition from maritime to continental climate. This type of climate is called moderately continental.

Outside the Urals in Siberia and Central Asia, winters are very cold and dry; summers are hot and moderately humid. This is an area of ​​continental climate. It was formed under the influence of the fact that the territory is removed from the Atlantic Ocean, separated from the Pacific by mountains, and therefore in winter a huge area of ​​high pressure dominates here - the Asian maximum (Fig. 4.82).

Rice. 4.80. Climate diagram of London, which is located in the maritime region of the temperate zone

Rice. 4.81. The first snow sometimes falls in the Ukrainian Carpathians in early October, when the leaves of the trees only turn yellow

Rice. 4.82. Asian high and winter monsoons

On the east coast of the mainland, the climate is monsoon, with relatively warm and very humid summers and cold dry winters.

Climatic zones and regions of the southern part of Eurasia. In the subtropical zone on the plains, temperatures are positive all year round. Three climatic regions are distinguished here. In the west, there is a Mediterranean climate, where dry tropical air dominates in summer (hot, cloudless skies), and in winter, the sea air of temperate latitudes, which causes precipitation.

In the areas of the Near East uplands, the climate is subtropical continental with relatively cold (in places with temperatures below 0 ° C) winters and hot, very dry summers. Total amount precipitation is small, they fall in the winter-spring period.

In the east of the continent of the subtropical belt, there is an area of ​​monsoon climate with a characteristic precipitation regime (summer maximum, Fig. 4.83).

The tropical climate on the land of Eurasia reigns on the Arabian Peninsula, Mesopotamia, in the south of the Iranian Highlands and in the basin of the lower Indus. There are continental tropical air masses, very dry and hot, throughout the year. Summers are very hot (average temperatures in July are +30 ... + 35 ° С), winters are warm (average temperatures in January are +18 ... +24 ° С).

The amount of precipitation on the plains does not exceed 200 mm, and in some places - less than 50 mm per year (Fig. 4.84).

Rice. 4.83. Climate diagram of Beijing, which is located in the northern part of the subtropical monsoon climate

Rice. 4.84. Among large mammals camels are most adapted to life in arid desert conditions

At latitudes 10-20 ° Mon. NS. to the east of the Indus River, the tropical belt wedges and is replaced by a subequatorial climate. It covers most of the Indo-Gangetic lowlands, the Indian subcontinent and Indo-China, the southern part of China.

On peninsulas and islands south of 8 ° Mon. NS. an equatorial climate was formed. It is characterized by high temperatures, humidity and rainfall throughout the year (Figure 4.85).

Rice. 4.85. An afternoon rainstorm in the equatorial belt makes traffic difficult

After working through the paragraph, try to answer

1. Under the influence of what factors has formed the climate of Eurasia?

2. What are the features of the climate in the northern part of the continent?

3. What are the features of the climate in the southern part of the continent?

Apply knowledge, find out more

1. Analyze how it goes on climate map Eurasia summer isotherm +16 ° С.

2. Names of the territory of Eurasia with the highest annual precipitation.

3. Describe the climate of Sakhalin Island.