home · Balanced diet · The climate of the Russian plain is marine. Climatic features of the Russian plain. Relief and geological structure

The climate of the Russian plain is marine. Climatic features of the Russian plain. Relief and geological structure

The East European Plain, also often referred to as the Russian Plain, is one of the largest plains on Earth. The length from west to east is about 2.4 thousand km, from north to south - 2.5 thousand km. In the north, the East European Plain is washed by the Barents and White Seas. In the west it borders on the Central European Plain (approximately along the valley of the Vistula River). In the southwest it approaches the mountains (Sudet and others) and the Carpathians. In the south it goes to the Black, Azov and Caspian seas and the Crimean mountains and the Caucasus. In the southeast and east it is bounded by the western foothills of the Urals and Mugodzhary.

On the Russian Plain are the European part, Lithuania, Estonia, Latvia, Belarus, Moldova, most of Ukraine, the western part of Poland and the eastern part of Kazakhstan.

Relief features and landscape

The relief is gently sloping and flat, formed as a result of faults in tectonic rocks. According to relief features, the East European Plain can be divided into three bands: central, southern and northern. In the center of the plain, vast uplands and lowlands alternate with each other. In the north and south, there are mainly lowlands with occasional low elevations.

Although the modern relief of the plain is of tectonic origin, there are no tangible earthquakes in our time.

The East European Plain consists of uplands with heights of 200-300 m above sea level and lowlands along which large rivers flow. The average height of the plain is 170 m, the highest on Bugulma-Belebeev Upland 479 meters in the Ural part. Maximum mark Timan Ridge slightly less (471 m).

The highest part Russian Plain - northeast. Here, the average absolute height is about 400 m. As you approach the coastline of the Arctic Ocean, the terrain decreases. In the southern part of the upland, it often alternates with lowlands. And in the very south, in the Caspian zone, the lowland is at negative levels - 10-18 m below sea level.

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For the southern extramoraine region of the East European Plain large uplands with an erosive ravine-gully relief are characteristic (Volynskaya, Podolskaya, Pridneprovskaya, Azovskaya, Central Russian, Volga, Ergeni, Bugulminsko-Belebeevskaya, General Syrt, etc.) and outwash, alluvial accumulative lowlands and plains belonging to the region of the Dnieper glaciation , Oksko-Donskaya, etc.). Wide asymmetric terraced river valleys are characteristic.

in the southwest(The Black Sea and Dnieper lowlands, the Volyn and Podolsk uplands, etc.) loess and loess-like loams are found everywhere, from which flat watersheds with shallow steppe "saucers", also called depressions, were formed.

In the northeast plains (High Trans-Volga, Common Syrt, etc.), where bedrocks come to the surface, watersheds are complicated by terraces, and peaks are weathered remnants, the so-called shikhans.

In the south and southeast- flat coastal accumulative lowlands (Black Sea, Azov, Caspian).

Age, formation theory and tectonic structure

At the base of the Russian platform lies an ancient folded crystalline basement, which is over 1.5 billion years old. The basement protrudes to the surface in the areas of the Baltic and Ukrainian shields, on the rest of its area there is a thick layer of sedimentary rocks dating back to Proterozoic before Cenozoic. The thickness of the platform varies from 35 to 55 km.

At the base of the East European Plain lie Russian stove with a Precambrian crystalline basement and in the south the northern edge Scythian plate with Paleozoic folded basement. The boundary between the plates in the relief is not expressed.

As a result of the shields coming to the surface, the Central Russian Upland and the Khibiny Mountains were formed. Not far from the Tsimlyansk reservoir there is a significant geological anomaly, the so-called Main East European Fault.

Climate

The East European Plain is so large that it is located in 4 climatic and 8 natural zones. Climatic zones:

  • arctic;
  • subarctic;
  • moderate;
  • subtropical.

Natural areas:

  1. arctic deserts;
  2. tundra;
  3. taiga;
  4. the woods;
  5. forest-steppe;
  6. steppe;
  7. semi-deserts;
  8. desert.

In the north from the Rybachy Peninsula to Yamal along the coast lies the Arctic desert. Winters in this zone are long and abnormally cold. The temperature drops below -50°C. In summer it rarely gets + 10°C. During the year, the average temperature is between -10 and 0°C. Precipitation is more frequent in the warm season.

To the south, the arctic desert passes into the tundra and forest-tundra. Here the climate is slightly milder, and the average January temperature ranges from -10°C to -40°C. In July, the thermometer readings reach +11 - +14°C. Precipitation is 150 - 300 mm, but evaporation is low, which contributes to the formation of extensive wetlands.

Taiga-forest zone

The taiga-forest zone occupies the largest part of the East European Plain (about 60% or almost 700 thousand square kilometers) and requires a more detailed description. In this natural enclave, the climatic conditions can be described as temperate continental. The climate here is actively influenced by Arctic and Atlantic air masses.

Winter in the taiga-forest zone of the Russian Plain lasts from 5 to 6 months, depending on the distance from the Arctic. The average winter temperature scale is -10°C. With the invasion of Arctic anticyclones (1-2 times per season), frosts reach abnormal values ​​of -30°C - -40°C. The thickness of snow cover in the middle lane is 40 - 90 cm.

Spring starts at the end of March. The snow melts unsteadily, the process can continue until mid-April. Frosts are possible until the first decade of June.

The average duration of summer is three months. Summer temperatures are low, averaging +19°C. However, with the advent of the Siberian and Central Asian anticyclones, it becomes hot: the thermometers exceed +19°C. Precipitation in summer falls quite often, in total the summer norm is around 150 mm. This is about a third of the annual rate.

Autumn is usually quite short and rainy. The temperature is rarely higher than +9 - +11°C. Wet snow begins to fall from the end of October. From the beginning of November, the transition to winter begins.

Forest-steppe

In the region of the 50th parallel, broad-leaved forests begin to give way to forest-steppes. They occupy about a quarter of the Russian Plain (150 thousand sq. Km).

The type of climate also belongs to the temperate, however, in this natural zone it is already much milder. Winter comes at the very end of November with the establishment of permanent snow cover. Winter cold fluctuations occur from -9°C to -15°C. The temperature rarely reaches low values. The snow cover is up to 40 cm and completely disappears in March.

Spring is warm and short: it begins in April, and by the end of May, summer weather is already established. With the advent of summer, precipitation increases significantly and in the first two months more than 60% of the average annual rate falls (from 300 to 600 mm). The temperature regime is much warmer than in the forests: the night temperature is +19°C, and during the day it soars up to +36°C.

Summer ends in the second half of September.

Autumn lasts more than 2 months with quite comfortable temperature indicators: the thermometer scale drops to zero only by mid-November.

Further south are the Russian steppes.

In addition, the steppe zone is also present on. In relation to the previous natural zones, they occupy a small area.

The zone is located in the temperate zone, however, it is much warmer than all the previous ones. The duration of the warm season is six months or more. Winter lasts from December to March. In April, warm spring weather is already stable. From mid-May the temperature rises to +30°C. A long and warm summer is setting in.

In summer, the thermometer drops below +30°C very rarely. The summer period turns into autumn only at the beginning of October. Moreover, positive temperatures last until mid-November. The transition to winter weather usually occurs in mid-December. There is little precipitation: only 150 - 300 mm falls during the year.

Semi-deserts and deserts

The East European Plain, in its southeastern part, captures two natural zones that are not quite typical for Russia: semi-deserts and deserts.

Some of the following regions of Russia include the following territories:

  • Kalmykia
  • Astrakhan
  • Volgogradskaya
  • Rostov

These two natural enclaves are very similar to each other, it is possible to separate them only very conditionally. The climate here is sharply continental and arid. The temperature regime and the level of precipitation almost do not differ from the steppe zone. In deserts, the amount of precipitation is 160 - 110 mm per year.

Dry subtropics located on the territory of the Novorossiysk region and on the Crimean peninsula. The climate here is dry and hot. Winters are very warm and with high humidity. Precipitation falls more than 700 mm per year.

A comparative analysis in the table shows how diverse the climate of the Russian Plain is:


Rivers and lakes

Most of the rivers of the East European Plain belong to the basins of the Atlantic and Arctic Oceans.

Atlantic Ocean Basin:

  • The Neva, Daugava (Western Dvina), Vistula, Neman, etc. flow into the Baltic Sea.
  • The Dnieper, Dniester, Yuzh flow into the Black Sea. Bug.
  • In the Sea of ​​\u200b\u200bAzov -, Kuban, etc.

Arctic Ocean Basin:

  • The Pechora flows into the Barents Sea.
  • In the White Sea - Mezen, Sev. Dvina, Onega and others.

To the basin of internal flow, mainly the Caspian Sea, belong (the largest river in Europe), Emba, Bolshoi Uzen, Maly Uzen, etc.

The rivers are fed mainly by melting snow. In the southwest, the plains of the river do not freeze every year, in the northeast the freeze lasts up to 8 months.

The hydrographic network has been significantly changed as a result of human economic activity. Canal systems appeared (Volga-Baltic, White Sea-Baltic, etc.) that connect all the seas washing the East European Plain.

The flow of many rivers, especially those flowing south, is regulated. Significant sections of the Volga, Kama, Dnieper, Dniester have been turned into cascades of reservoirs (Rybinsk, Kuibyshev, Tsimlyansk, Kremenchug, Kakhovskoe, etc.).

The lakes are numerous and have a different nature of origin:

  • glacial-tectonic (Ladoga and - the largest in Europe),
  • morainic (Chudsko-Pskovskoye, Ilmen, Beloe, etc.), etc.
  • salt lakes (Baskunchak, Elton, Aralsor, Inder) formed by salt tectonics, that is, some of them arose during the destruction of salt domes.

Flora

The East European Plain with its richest set of natural zones makes the flora of the region unique. All the vegetation characteristic of Russia grows here. An exception can only be plants growing in the highlands of the Caucasus and some flora samples.

The poorest vegetation is naturally arctic desert and tundra. Mosses, lichens, and small shrubs have adapted to life in the extreme conditions of the subarctic climate. Vegetation covers, however, are not ubiquitous and are represented in fragments.

With movement in forest-tundra a rare crooked forest and herbaceous plants appear, and mosses are everywhere and cover the entire surface of the earth. Mosses form the basis of the reindeer's diet.

In the taiga zone a complete set of conifers is presented: pine; spruce; larch; fir. The zone of mixed and broad-leaved forests, as well as the forest-steppe, are very similar in terms of representatives of the plant world (preserving, among other things, conifers). In different proportions, but each zone has the same plants: linden; ash; poplar; maple; oak; aspen.

In addition to tree crops from the taiga to the forest-steppe, Russian nature is rich in shrubs, both flowering and berry. A countless family of mushrooms hides in forests and forest belts throughout the warm season. Grass covers are represented by meadow and oak forbs.

steppe zone has significant differences in vegetation. The basis is the zonal distribution of the meadow steppe and forb or feather grass steppe. Half a thousand species of herbaceous (flowering and non-flowering) plants fill the steppe. The Don Valley is famous for its huge water meadows. Semi-deserts have much more sparse vegetation. Mostly feather grass and fescue. In addition, there are a number of semi-shrubs such as wormwood.

Herbaceous plants are represented by a small set of species that have adapted to seasonal existence: either they complete a full life cycle in one summer, or they are bulbous and persist until the next season (tulips, for example).

AT dry subtropics low-growing deciduous and evergreen shrubs grow. In deserts, only plants with a developed root system survive, which is able to keep them in weak soils and reach groundwater.

Fauna

The East European Plain is inhabited by animals of both western and eastern species. Tundra, forest, steppe and, to a lesser extent, desert animals are common here. Forest animals are the most widely represented. Western species of animals tend to mixed and broad-leaved forests (pine marten, black polecat, hazel and garden dormice, etc.). The western border of the range of some eastern species of animals (chipmunk, Siberian weasel, Ob lemming, etc.) passes through the taiga and tundra of the Russian Plain.

The fauna of the Russian Plain, more than any other part of the former USSR, has been changed by human intervention. The modern ranges of many animals are not determined by natural factors, but by human activity - hunting or changing the habitat of animals (for example, deforestation).

Fur-bearing animals and ungulates suffered the most, the former because of their valuable fur, the latter because of their meat. River beaver, marten and squirrel were the main subjects of fur trade and trade among the Eastern Slavs in the 9th-13th centuries. Already then, a thousand years ago, the beaver was valued very highly, and as a result of unregulated hunting, only a few individuals of this animal survived by the beginning of the 20th century.

As a result of centuries of human economic activity, the animal world of the Russian Plain was greatly impoverished. In the Soviet years, a lot of work was done to enrich the animal world: hunting is strictly regulated, reserves for the protection of rare animals have been created, re-acclimatization and acclimatization of valuable species are being carried out.

A number of reserves have been created on the East European Plain. The most famous and important are Belovezhskaya Pushcha, Voronezh, Askania-Nova, Astrakhan. Bison are protected in the dense mixed forests of Belovezhskaya Pushcha (Western Belarus). In the Voronezh Reserve, for the first time in the world practice, they began to successfully breed beavers in captivity. From here, beavers are taken from the Voronezh Reserve for reacclimatization to various regions of the former USSR.

The Askania-Nova steppe reserve (southern Ukraine) is known for its work on acclimatization and hybridization of a wide variety of animals from Asia, Africa and even Australia. The reserve is under the jurisdiction of the All-Union Research Institute of Acclimatization and Hybridization of Animals. M. F. Ivanov, whose employees bred valuable breeds of domestic sheep and pigs. The Astrakhan Nature Reserve was created in the Volga Delta to protect waterfowl and fish spawning grounds.

Minerals

The East European Plain has a specific composition of fossils due to its geological structure. Here is the world's largest (more than 50% of world reserves) iron ore basin. Its capacity is estimated at 100 billion tons or more.

Mineral resources are represented by iron ores of the Kursk magnetic anomaly. The main ore here is magnetite occurring in Proterozoic quartzites. But now mainly ore deposits are being developed in the weathering crusts of the Precambrian basement enriched with iron oxides. The balance reserves of the Kursk magnetic anomaly are estimated at 31.9 billion tons, which is 57.3% of the country's iron ore reserves. The main part lies within the Kursk and Belgorod regions. The average iron content in the ore exceeds the average for Russia and is 41.5%. Among the fields being developed are Mikhailovskoye (Kursk region) and Lebedinskoye, Stoilenskoye, Pogrometskoye, Gubkinskoye (Belgorod region). But the open method of mining ores has already led to the destruction of tens of thousands of hectares of land.

In the Belgorod region, bauxite reserves with an alumina content of 20 to 70% have been explored (Vislovskoe deposit).

There are chemical raw materials on the Russian Plain: phosphorites (the Kursk-Shchigrovsky basin, the Yegoryevskoye deposit in the Moscow region and the Polpinskoye deposit in the Bryansk region), potassium salts (the Upper Kama basin, one of the largest in the world - contains a quarter of the world's potassium reserves, balance reserves for all categories are over 173 billion tons), rock salt (again the Verkhnekamsk basin, as well as the Iletsk deposit in the Orenburg region, Lake Baskunchak in the Astrakhan region and Elton in the Volgograd region).

Such building materials as chalk, marls, cement raw materials, fine-grained sands are common in the Belgorod, Bryansk, Moscow, Tula regions. A large deposit of high-quality cement marls is Volskoye in the Saratov region. The Tashlinskoye deposit of glass sands in the Ulyanovsk region is a large raw material base for the entire glass industry in Russia and the CIS.

The Kiyembaevsk asbestos deposit is located in the Orenburg region. Quartz sands of the Dyatkovo (Bryansk region) and Gus-Khrustalnenskoe (Vladimir region) deposits are used for the production of artificial quartz, glass, and crystal glassware; kaolin clays from Konakovo (Tver region) and Gzhel (Moscow region) are used in the porcelain-faience industry.

Reserves of black and brown coal are concentrated in the Pechora, Donetsk and Moscow region basins. Brown coals from the Moscow Basin are used not only as fuel, but also as chemical raw materials. Its role in the fuel and energy complex of the Central Federal District of Russia is growing due to the high costs of importing energy carriers from other regions of the country. Moscow region coal can also be used as technological fuel for the region's ferrous metallurgy.

Oil and gas are produced at a number of fields within the Volga-Ural (Samara region, Tatarstan, Udmurtia, Bashkortostan) and Timan-Pechora oil and gas regions. There are gas condensate fields in the Astrakhan region, and the Orenburg gas condensate field is the largest in the European part of the country (over 6% of all Russian gas reserves).

Oil shale deposits are known in the Pskov and Leningrad regions, in the Middle Volga region (Kashpirovskoye deposit near Syzran) and in the northern part of the Caspian syneclise (Obshchesyrtskoye deposit).

In geography, the Russian Plain is considered to be an area that is the eastern, predominant in size part of the East European Plain, which is located on the territory of the Russian state. The plain is represented by a combination of alternating elevations (hills) and lowlands. The channels of large rivers are confined to the latter.

The climate of the territory under consideration is determined by a combination of the following factors:

  • large extent from north to south;
  • relief features: on the flat territory there are practically no natural obstacles for the free movement of air masses;
  • close proximity to two oceans.

The peculiarity of the climate of the Russian Plain owes its formation to two aspects: the uneven distribution of the level of solar radiation, which is associated with the meridional elongation of the territory, and the unhindered advection of oceanic air masses.

Air masses of the maritime Arctic type form over the surface of the northern seas (Kara, Barents Seas), and the sea air of temperate latitudes owes its formation to the seas of the Atlantic basin (Baltic, White).

Scientific geography identifies the Russian Plain as a separate physical and geographical area based on:

  • location on a single plate of the Precambrian East European Platform;
  • uniform temperate continental climatic type with characteristic features of the influence of the seas of the Atlantic;
  • a clear latitudinal zoning is observed throughout the territory: from the tundra to the steppe, natural zones successively replace themselves from north to south.

The climate of the plain is dominated by air masses of the continental type, the influence of the advection of marine masses of the marine type on it is most characteristic of the winter months, when they bring characteristic warming, accompanied by a large amount of precipitation. In summer, the arrival of marine air masses from the seas of the Atlantic basin brings, in addition to increasing humidity and precipitation, cooling. Characteristically, the movement of air masses from east to west, or - western movement. The continentality of air masses naturally increases as it moves to the east.

Cyclonic activity also depends on the season: in winter, cyclones are usually located along the Arctic front, however, without encountering relief obstacles on their way, they often go quite far to the south. In summer, several areas of cyclones form: arctic, polar-arctic occlusion zones in the north and temperate tropical - in the south of the plain.

Scientific geography within the Russian Plain, based on the criteria of an integrated zonal-azonal approach, additionally distinguishes 2 large natural regions: northern and southern.

Northern climatic region

The climate of the northern part of the Russian Plain consists mainly of three components: the influence of Arctic and polar air masses, the western movement of Atlantic air masses and the direct influence of the flat territory, which causes the formation of continental-type air masses. Sometimes, mainly in summer, tropical-type air masses get here.

Cold arctic air moves freely in a southerly direction, gradually heating up and transforming into air of temperate latitudes. Extremely rarely, in the summer period, if the anticyclone stays in the south of a given geographical area for a long time, it can be successively transformed into tropical air.

This climatic region is characterized by a long, rather cold winter with a large amount of precipitation in the form of snow. The average values ​​of January temperatures range from -20 0 С in the north-east of the territory to -10 0 С in its south-western part.

As already noted, in winter, the climate of the territory is significantly influenced by the Atlantic, so the west of the region is characterized by much warmer winters than its east: for example, in Kaliningrad, the average January temperature does not reach -5 0 C.

In summer, the solar radiation factor dominates the climate of the northern region. In the north, its deficiency causes a short cold summer with an average July temperature of about -8 -10 0 C. In the south of the allocated area, the air warms up much better, and the summer here is naturally much longer and warmer.

Southern climatic region

The difference between the southern climatic region of the Russian Plain and the northern one is due to the stable power of anticyclones, which causes a lesser influence of the Atlantic masses on the climate, a sharper increase in the continentality of the climate in the west-east direction and a constant transformational dynamics that occurs here between the air masses of temperate latitudes and marine tropical masses, which the plains practically do not penetrate into the northern region and do not have a significant impact on the climate.

Marine tropical masses, invading the territory of the southern part of the Russian plain in the winter season, causing periods of sharp warming to positive temperatures with a large amount of precipitation.

In summer, their arrival is also indicated by an increase in humidity and precipitation, but their transformation occurs very quickly, the influence of a high level of solar radiation is great, therefore, for the south of the Russian plain, an alternation of short-term rainy episodes with squally winds and thunderstorms with rather long hot dry periods is typical. The average annual rainfall is estimated to be low.

The irregularity of rainfall in the summer is a problem for agricultural activities here, despite the warm climate and flat terrain, the fields need to find ways to irrigate in case of a drought.

Average temperatures in the selected area: January - from -10 0 C in the north to -5 0 C in the south, July - from +18 0 C in the north to + 24 0 C in the south.

Climatic features of the nature of the Russian Plain

Within the Arctic, subarctic and temperate climatic zones of the northern climatic region of the Russian Plain, typical natural complexes of tundra, forest tundra, taiga and mixed forests successively replace each other.

The tundra is formed in conditions of low average annual temperatures and high humidity with a large amount of precipitation, it extends from the coast of the Barents Sea to the Polar Urals.

The forest-tundra, which replaces the tundra, passes into the so-called forest zone of the Russian plain. It was formed in a warm and humid climate and is conditionally divided into subzones: taiga and mixed forests The taiga zone of the Russian Plain, formed in a milder and more humid temperate climate, differs significantly from the natural zone of the same name located east of the Ural Range: flora and fauna of the European taiga much more diverse and has more similarity with the zone of mixed forests, into which it directly passes, than with the taiga of the West Siberian type, with its peculiar, nowhere else repeated biogeocenosis.

The forest-steppe zone was also formed in conditions of warmth and a sufficient amount of moisture, as evidenced by the abundance of moraine lakes here, which are the remains of the once-giant Valdai glacier that melted.

The steppe zone, located in the southern part of the plain, is characterized by a more pronounced continental climate, especially in summer, but sudden warming in winter and short-term cooling in summer with a large amount of precipitation influenced its formation. There are less droughts here, the flora and fauna are much richer compared to Asian regions.

Thus, on the territory of the Russian Plain, it is possible to conditionally distinguish the Arctic and temperate climatic zones and five climatic natural zones within them.

The East European Plain is located on the territory of the eastern part of Europe, and includes 10 countries at once, but most of it is located in the west of Russia, which is why its second official name is the Russian Plain.

Figure 1. Climate of the Russian Plain. Author24 - online exchange of student papers

The climate of this area directly depends on several key factors:

  • geographical position;
  • the proximity of the ocean;
  • relief.

Radiation plays a central role in the formation of climatic processes in the Russian Plain. Advection is also essential. The continentality of this area increases mainly to the east, and the absence of mountains in the west and north contributes to the rapid penetration of arctic maritime air from temperate latitudes. The transformed air masses reach the Urals, and the air from the Arctic comes from the Kara and Barents Seas.

Researchers and geographers define the Russian Plain as a physical and geographical state, and the basis for its elevation to this rank is:

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  • an elevated, hilly and stratal plain formed on the plate of the ancient East European Platform;
  • continental-Atlantic, insufficiently humid and predominantly temperate climate, which is formed in full under the influence of the Arctic and Atlantic oceans;
  • clearly defined main natural zones, the structures of which were greatly influenced by neighboring territories and flat relief.

Interestingly, when dividing the Russian Plain into large-scale natural complexes, two approaches were taken into account - azonal and zonal. Within the area under consideration, continental air dominates, and the effect of advection is most noticeable in winter than in summer.

The cyclonic functional manifests itself most actively in winter along the entire Arctic front, which is often located in the north of the plain, but often shifts to the Black Sea coast. In the summer half of the year, three zones of cyclone activity are formed at once. The first zone is observed across the Arctic front, the second zone acts on polar-frontal occlusions, and the third zone occupies a whole strip from the Crimea to the Middle Volga.

Northern climatic region

The northern climatic region is located not far from the northern zone of high atmospheric pressure, therefore, it is characterized by the dominance of western wet winds throughout the year. The western transformation of air masses prevailing in this zone increases due to the systematic recurrence of cyclones of the polar and arctic fronts.

Remark 1

In the formation of climatic phenomena in the Northern region, the Arctic air plays a huge role, which is gradually transformed when moving south. Sometimes at the height of summer, hot tropical air comes in from the south.

It should be noted that sometimes continental tropical air can form in the south of the Northern Region, which acts under the influence of polar air. However, such a phenomenon can only be observed in anticyclonic weather, so the last time the transformation of polar air masses was recorded in 1936 near Moscow.

Winters in this climate zone are snowy and cold. In the northeast, the average January temperature reaches -15-20°C, and the snow cover, which is 70 cm high, pleases local residents up to 220 days a year. Winters are much milder in the south-western region: the average air temperature in winter does not fall below -10 °, and the duration of the white ice sheet is reduced to 4 months a year.

The entire territory of the Northern Region belongs to the subarctic, arctic and temperate climatic zones. These natural zones with forest-tundra and tundra climate types cover the coast of the Barents Sea and the islands of the Arctic. The temperate belt here has two types of terrain - taiga and mixed forests.

Southern climatic region

The southern climatic region extends along the southern band of high atmospheric pressure. The direction of air masses in this area is not stable, since the westerly winds prevailing in the warm season transform into southeast cold winds in winter.

Remark 2

Under conditions of constant anticyclones, the processes of movement of air masses intensify, as a result of which the western moist air is quickly transformed into temperate continental.

In summer, all processes of transformation of the polar air in the territory of the Southern Region end with the formation of a tropical climate.

From the side of the Mediterranean Sea tropical sea air gradually enters in a transformed form. The systematic recurrence of temperate tropical cyclones in summer sharply distinguishes the southern region of the Russian Plain from the northern one, where tropical air masses are observed only as exceptions.

The absence of sharp contrasts between the polar and continental tropical air is explained by the passivity of the cyclones that originate here and the low humidity of the moving air masses, which ultimately does not provide the required amount of precipitation.

Such a ratio of moisture and heat in the south of the Russian Plain is an unfavorable element for agriculture, which needs stable moisture. A prolonged absence of precipitation automatically causes drought - one of the most peculiar and characteristic phenomena of the southern climatic region.

Climatic features of the nature of the Russian Plain

On the Russian Plain, one can observe such natural zones: forest-tundra and tundra, forest-steppe, forest, steppe, semi-desert and desert. The tundra and forest-tundra zones are moderately cold and humid climatic processes and occupy the entire coast of the Barents Sea. The tundra completely covers the Kanin Peninsula, and then its border goes to the Polar Urals and Naryan-Mar.

The forest-steppe in the zone of the Russian Plain is characterized by humid and warm weather, since it is simultaneously affected by the non-freezing part of the Barents Sea and the Atlantic Ocean. In winter, a minimum of passing cyclones can be observed here. This is clearly reflected in the division of the annual amount of all precipitation that formed the permafrost (from 0° to -3°), which has now been transformed into glacial, marine, deltaic, river and lake deposits.

Definition 1

The forest zone is a moderately humid and warm zone of the Russian Plain, which extends south of the forest tundra with a strip of 1000-1200 km.

The forest zone of the East European Plain is conventionally divided by researchers into two subzones: mixed forests and taiga. The taiga of the Russian Plain is very different from the Siberian one, since its geographical position is determined by the history of the development of this territory. The proximity to the Atlantic Ocean and the warmest zone of the Arctic determined the growth of a powerful multiple ice cover and a temperate continental climate, which contributes to the spread of animals and European plants over the plain.

Taking into account all the features of the radiation regime and the universal circulation of the atmosphere, it is necessary to distinguish two main climatic zones on the territory of the Russian Plain - temperate and subarctic, and within their boundaries - five climatic zones. In all areas, an increase in the continentality of the climate from west to east is observed. Differences in the climate of the East European area directly affect the nature of vegetation and the presence of pronounced soil zoning.

The climate of the Russian Plain is decisively influenced by two circumstances: the geographical position and the flat relief.

The Russian Plain, more than any other part of the USSR, is under the influence of the Atlantic Ocean and its warm Gulf Stream. Marine polar air, which is formed over the Atlantic, enters the Russian Plain still little transformed. Its properties largely determine the main features of the climate of the Russian Plain. The air is humid, relatively warm in winter and cool in summer. That is why the Russian Plain is better moistened than the more eastern regions of the USSR, the winter on it is not severe, and the summer is hot.

The plain does not know East Siberian frosts; the average January temperature in its coldest place - in the northeast - is close to -20 °, and in the west it is only -5.-4 °. The average July temperature in most of the plain is below 20°C and rises to 25°C only in the southeast.

The sharp increase in the continentality of the climate in the eastern, southeastern third of the Russian Plain is due to the rapid drop in the frequency of polar sea air here, which loses its properties when moving east. In January, the frequency of sea polar air in the region of Leningrad and Western Ukraine is 12 days, while near Stalingrad and Ufa it decreases to three days; in July, polar sea air in the Baltics is observed for 12 days, and in Rostov and Kuibyshev only one day (Fedorov and Baranov, 1949). In the southeast of the Russian Plain, the role of continental air is increasing; for example, in January the frequency of continental polar air in the southeast is 24 days, while in the northwest it is only 12 days.

The flat relief creates favorable conditions for the free exchange of air masses in remote areas. Arctic air from time to time in the form of cold waves breaks through to the southern borders of the Russian Plain, and in summer, in July, continental tropical air moves north to the Arkhangelsk region on some days. The Ural Range does not serve as an obstacle to the penetration of continental polar air of Siberian origin into the Russian Plain. Close contact and interpenetration of qualitatively different air masses causes instability on the Russian Plain of climatic phenomena, frequent change of one type of weather by another. How sharp a change in the weather is due to a change in air masses can be judged by the following example. On December 27, 1932, in Kazan, with arctic air, very frosty weather was observed, with air temperatures down to -40 °, in the morning of the next day, when the arctic air was pushed aside by polar air, a sharp warming set in, and the air temperature rose to 0 ° (Khromov, 1937) .

The same factor - the flat terrain and the absence of mountain obstacles in the west - makes the Russian Plain easily accessible for cyclones to penetrate its territory. Cyclones from the Arctic and Polar fronts come here from the Atlantic Ocean. The frequency and activity of western cyclones on the Russian Plain decreases sharply when moving to the east, which is especially noticeable in the Cis-Urals, east of 50° E. e. In the east of the plain, due to the increase in the continentality of the climate, the contrasts between the main air masses in winter and summer are smoothed out, the frontal zones are eroded, which creates unfavorable conditions for cyclonic activity.

Despite the generally uniform relief of the Russian Plain, there are still uplands and lowlands on it, which cause, although not sharp, but quite noticeable differentiation of climatic conditions. Summers are cooler in the uplands than in the lowlands; the western slopes of the uplands receive more precipitation than the eastern slopes and the lowlands shaded by them. In summer, on the uplands of the southern half of the Russian Plain, the frequency of rainy weather types almost doubles, while the frequency of dry weather types decreases at the same time.

The great length of the Russian Plain from north to south causes sharp climatic differences between its northern and southern parts. These climatic differences are so significant that one should speak of the existence of two climatic regions on the Russian Plain - northern and southern.

Northern climatic region It is located to the north of the band of high atmospheric pressure (Voyeikov axis) and therefore is characterized by the predominance of humid western winds throughout the year. The prevailing western transport of air masses in the region is intensified due to the frequent recurrence of cyclones of the Arctic and Polar fronts. Most often cyclones are observed between 55-60° N. sh. This band with increased cyclonic activity is the most humid part of the Russian Plain: the annual amount of precipitation in its west reaches 600-700 mm, in the east 500-600 mm.

In the formation of the climate of the Northern region, in addition to the polar air, a very important role is played by the arctic air, which is gradually transformed when moving south. Occasionally, at the height of summer, strongly heated tropical air comes in from the south.

In some years, in the south of the region, during anticyclonic weather, local continental tropical air can form due to the transformation of polar air. Such a case of transformation of polar air into tropical air was noted, for example, in 1936 near Moscow.

Winter in this climatic region, with the exception of the southwest, is cold and snowy. In the northeast, its average temperature in January is -15, -20 °, snow cover 70 cm high lies up to 220 days a year. The winter is much milder in the south-west of the region: the average January temperature does not fall below -10 ° here, the duration of the snow cover is reduced to 3-4 months a year, and its average long-term height drops to 30 cm or less.

Summer throughout the region is cool or even cold. The average temperature of the warmest month - July - in the south does not reach 20°, and in the north, on the coast of the Barents Sea, it is only 10°. The heat balance of the climatic region is characterized by high heat costs for the evaporation of moisture. In the Polyarny, on the Murmansk coast, the radiation balance is 7 kcal / cm 2, and the annual heat consumption for evaporation is 5 kcal / cm 2. The corresponding figures for Leningrad are 23 and 18 kcal/cm2.

Low air temperatures with a significant amount of precipitation cause high cloudiness in the north of the Russian Plain in summer. The frequency of overcast skies in July on the coast of the Barents Sea reaches 70%, in the south of the region about 45%. The relative humidity of the air is also high: in May at 1 pm, even in the south of the region, it does not fall below 50%, and on the coast of the Barents Sea it exceeds 70%. .

More precipitation falls in the Northern Region than can be evaporated under given temperature conditions. This circumstance is of great landscape-forming importance, since the nature of vegetation and the direction of soil and geomorphological processes are connected with the balance of moisture.

In the south of the Northern climatic region, the moisture balance approaches neutral (atmospheric precipitation is equal to the evaporation rate). The change in the moisture balance from positive to negative means an important climatic boundary separating the Northern and Southern climatic regions of the Russian Plain.

The territory of the Northern region belongs to the arctic, subarctic and temperate climatic zones. The Arctic and subarctic belts with tundra and forest-tundra climate types cover the islands of the Arctic and the continental coast of the Barents Sea. The temperate zone is represented by two types of climate - taiga and mixed forests. Their characteristics are given in the description of the physiographic zones and regions of the Russian Plain.

Southern climatic region lies in the band of high atmospheric pressure (Voyeikov axis) and to the south of it. The direction of the wind on its territory is not constant, the westerly winds prevailing in summer are replaced by cold and dry easterly winds in the southeast in winter. Cyclonic activity and the western transport associated with it in the south of the Russian Plain are weakening. Instead, the frequency of anticyclones of Siberian origin in winter and Azores in summer increases. Under the conditions of stable anticyclones, the processes of transformation of air masses intensify, as a result of which humid western air is quickly transformed into continental air.

In summer, the processes of transformation of polar air in the southern region end with the formation of continental tropical air. From the side of the Mediterranean, the sea tropical air enters, always to some extent already transformed. The frequent recurrence of tropical air in summer sharply distinguishes this climatic region of the Russian Plain from the Northern one, where tropical air is observed only as a rare exception. time become a cyclone-forming region. However, the cyclones that originate here are not very active and do not produce a large amount of precipitation, which is explained by the absence of sharp contrasts between the continental tropical and continental polar air, as well as the low humidity of these air masses.

Atmospheric precipitation in the southern region falls 500-300 mm per year, i.e. less than in the northern; their number rapidly decreases in the southeast direction, where moist western air hardly penetrates.

Winter is shorter and somewhat warmer than in the north of the Russian Plain. The snow cover is thin and lies for a short time - 2-3 months in the southwest, 4-5 months in the northeast of the climatic region. Thaws and black ice are often observed, which adversely affects the overwintering of crops and hinders the work of transport.

Summers are long and warm, and hot in the southeast; the average July temperature is 20-25°. With a high frequency of anticyclones, cloudiness is not great in summer, very often it is sunny with cumulus clouds in the middle of the day. In July, the frequency of the cloudy sky in the north is 40%, in the south 25%.

High summer temperatures, combined with low precipitation, result in low relative humidity. In May at 1 pm it does not exceed 50% even in the north of the region, and in the southeast it falls below 40%.

Precipitation in the Southern region falls much less than the amount of moisture that can evaporate under given temperature conditions. In the north of the region, the moisture balance is close to neutral, i.e., the annual amount of precipitation and evaporation are approximately equal, and in the southeast of the region, evaporation is three to four times higher than the amount of precipitation.

The ratio of heat and moisture, which is unfavorable for agriculture, is exacerbated in the south of the Russian Plain by the extreme instability of moisture. Annual and monthly amounts of precipitation fluctuate sharply, wet years alternate with dry ones. In Buguruslan, for example, according to observations over 38 years, the average annual precipitation is 349 mm, the maximum annual precipitation is 556 mm, and the minimum is 144 mm. In most of the Southern Region, according to long-term data, June is the wettest month; there are, however, such years when even in June in places not a drop of rain falls.

Prolonged absence of precipitation causes drought - one of the most characteristic phenomena of the Southern climatic region. Drought can be spring, summer or autumn. About one year out of three is dry. The frequency and intensity of droughts increase in the southeast direction. Crops are severely affected by droughts, yields are sharply reduced. For example, in 1821 in the steppe Trans-Volga, according to E. A. Eversmann (1840), “almost not a drop of rain fell for a whole summer, there was not even dew at all for six weeks in a row. In almost the entire province, bread withered before flowering, was abandoned on the vine, and there was no harvest at all.

Sometimes dry years follow one after another, which is especially detrimental to vegetation. Such are the well-known droughts of 1891-1892 and 1920-1921, accompanied by crop failure and famine in many provinces of southern Russia.

In addition to droughts, dry winds have an adverse effect on vegetation. These are hot and dry winds blowing at high speed. High temperatures and low relative humidity persist during dry winds and at night. Sultry dry winds, if they blow without interruption for several days, burn crops and foliage of trees. At the same time, vegetation suffers especially strongly in cases where there is little moisture in the soil, which happens during droughts.

Many researchers explained the high temperature and low humidity of dry winds by the fact that these winds allegedly come to the Russian Plain from the southeast, from the dry deserts and semi-deserts of the Caspian Sea. Other researchers attached exceptional importance to descending air movements in anticyclones, at which the temperature of the air masses rises and the relative humidity falls. Studies of the last decade have shown that dry winds are observed not only with winds blowing from the southeast, but also from other places. Moreover, dry winds very often develop under the conditions of an arctic air mass penetrating the south of the Russian Plain from the north and undergoing continental transformation. And although dry winds blow on the outskirts of anticyclones, their high temperature and low relative humidity, as it turns out, are due not to downward air movements, but to local continental transformation of air masses.

The degree of damage that can be caused by drought and dry winds of cultivated vegetation depends on the level of agricultural technology and special reclamation measures aimed at weakening them. In tsarist Russia, with low agricultural technology, droughts and dry winds often caused the complete destruction of crops, which entailed terrible famine in the countryside. In the Soviet years, after the collectivization of agriculture, the level of agricultural technology rose sharply, agriculture began to suffer much less from droughts and dry winds, and the threat of famine was completely eliminated in the countryside.

Among the special measures taken to mitigate droughts and dry winds, special attention should be paid to snow retention and the creation of shelterbelts and state forest belts. These activities contribute to the accumulation of moisture in the soil, and the forest belts also weaken the wind speed during dry winds, reduce the temperature and increase the relative humidity of the air.

Large-scale steppe afforestation, together with the construction of ponds and reservoirs, in the coming years will lead to some weakening of the continental climate of the southern regions of the Russian Plain: an increase in precipitation and a slight decrease in summer air temperatures. As climatologists suggest, due to increased evaporation in the east of the forest-steppe, the amount of precipitation during the warm season will increase by 30-40 mm; in the west, there will also be an increase in precipitation (by 5-10% in relation to existing values), but not due to an increase in evaporation, but due to increased vertical air movements over forest belts (Budyko, Drozdov et al., 1952). In semi-deserts and deserts, due to the low relative humidity of the air, changes in the amount of precipitation are expected to be very insignificant.

Four types of climate are expressed on the territory of the Southern climatic region: forest-steppe, steppe, semi-desert and desert.

- Source-

Milkov, F.N. Physical geography of the USSR / F.N. Milkov [and d.b.]. - M .: State publishing house of geographical literature, 1958. - 351 p.

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Physical geography of Russia and the USSR
European part: Arctic, Russian Plain, Caucasus, Urals

REGIONAL NATURE REVIEWS IN RUSSIA

Chapters of the section "REGIONAL REVIEWS OF THE NATURE OF RUSSIA"

  • Natural areas of Russia
  • East European (Russian) Plain
    • Climate

EAST EUROPEAN (RUSSIAN) PLAIN

See photos of the nature of the East European Plain: Curonian Spit, Moscow Region, Kerzhensky Reserve and the Middle Volga in the Nature of the World section of our site.

Climate

The climate of the East European Plain is influenced by its position in temperate and high latitudes, as well as neighboring territories (Western Europe and North Asia) and the Atlantic and Arctic Oceans. The total solar radiation per year in the north of the plain, in the Pechora basin, reaches 2700 mJ / m 2 (65 kcal / cm 2), and in the south, in the Caspian lowland, 4800-5050 mJ / m 2 (115-120 kcal / cm 2 ). The distribution of radiation over the territory of the plain changes dramatically with the seasons. In winter, radiation is much less than in summer, and more than 60% of it is reflected by the snow cover. In January, the total solar radiation at the latitude Kaliningrad - Moscow - Perm is 50 mJ / m 2 (about 1 kcal / cm 2), and in the southeast of the Caspian lowland about 120 mJ / m 2 (3 kcal / cm 2). The radiation reaches its greatest value in summer and in July, its total values ​​in the north of the plain are about 550 mJ / m 2 (13 kcal / cm 2), and in the south - 700 mJ / m 2 (17 kcal / cm 2).

All year round the East European Plain is dominated by western air mass transport. Atlantic air brings coolness and rainfall in summer, and warmth and rainfall in winter. When moving east, it transforms: in summer it becomes warmer and drier in the surface layer, and colder in winter, but also loses moisture. During the cold season, 8 to 12 cyclones come from different parts of the Atlantic to the East European Plain. When they move to the east or northeast, there is a sharp change in air masses, contributing to either warming or cooling. With the arrival of southwestern cyclones - Atlantic-Mediterranean - (and there are up to six of them in a season), the warm air of subtropical latitudes invades the south of the plain. Then in January the air temperature can rise to 5°-7°C and, of course, thaws come.

The arrival of cyclones from the North Atlantic and the Southwestern Arctic to the Russian Plain is associated with the intrusion of cold air. It enters the rear of the cyclone, and then the arctic air penetrates far to the south of the plain. Arctic air enters freely over the entire surface and along the eastern periphery of anticyclones moving slowly from the northwest. Anticyclones often recur in the southeast of the plain, due to the influence of the Asian High. They contribute to the intrusion of cold continental air masses of temperate latitudes, the development of radiative cooling in cloudy weather, low air temperatures, and the formation of a thin, stable snow cover.

In the warm period of the year, from April, cyclonic activity proceeds along the lines of the Arctic and Polar fronts, shifting to the north. Cyclonic weather is most typical for the northwest of the plain, so cool sea air from temperate latitudes often comes to these areas from the Atlantic. It lowers the temperature, but at the same time it heats up from the underlying surface and is additionally saturated with moisture due to evaporation from the moistened surface.

Cyclones contribute to the transfer of cold air, sometimes arctic, from the north to more southern latitudes and cause cooling, and sometimes frost on the soil. The southwestern cyclones (6-12 per season) are associated with the invasion of the plain of humid warm tropical air, which penetrates even into the forest zone. Very warm but dry air is formed in the cores of the spur of the Azores High. It can contribute to the formation of arid types of weather and droughts in the southeast.

The position of the January isotherms in the northern half of the East European Plain is submeridional, which is associated with greater frequency in the western regions of the Atlantic air and its lesser transformation. The average January temperature in the Kaliningrad region is -4°С, in the western part of the compact territory of Russia it is about -10°С, and in the northeast -20°С. In the southern part of the country, the isotherms deviate to the southeast, amounting to -5 ... -6 ° С in the region of the lower reaches of the Don and Volga.

In summer, almost everywhere on the plain, the most important factor in the distribution of temperature is solar radiation, so isotherms, in contrast to winter, are located mainly in accordance with geographic latitude. In the extreme north of the plain, the average temperature in July rises to 8°C, which is associated with the transformation of the air coming from the Arctic. The average July isotherm of 20°C goes through Voronezh to Cheboksary, approximately coinciding with the border between forest and forest-steppe, and the isotherm of 24°C crosses the Caspian lowland.

The distribution of precipitation over the territory of the East European Plain is primarily dependent on circulation factors (western transport of air masses, the position of the Arctic and polar fronts, and cyclonic activity). Especially many cyclones move from west to east between 55-60°N. (Valdai and Smolensk-Moscow Uplands). This strip is the most humid part of the Russian Plain: the annual precipitation here reaches 700-800 mm in the west and 600-700 mm in the east.

The relief has an important influence on the increase in the annual total precipitation: on the western slopes of the uplands, precipitation is 150-200 mm more than on the lowlands lying behind them. In the southern part of the plain, the maximum precipitation occurs in June, and in the middle lane - in July.

In winter, a snow cover forms. In the north-east of the plain, its height reaches 60-70 cm, and the duration of occurrence is up to 220 days a year. In the south, the height of the snow cover decreases to 10-20 cm, and the duration of occurrence is up to 60 days.

The degree of moistening of the territory is determined by the ratio of heat and moisture. It is expressed by various values: a) the coefficient of moisture, which in the East European Plain varies from 0.35 in the Caspian lowland to 1.33 or more in the Pechora lowland; b) dryness index, which varies from 3 in the deserts of the Caspian lowland to 0.45 in the tundra of the Pechora lowland; c) the average annual difference in precipitation and evaporation (mm). In the northern part of the plain, moisture is excessive, since precipitation exceeds evaporation by 200 mm or more. In the zone of transitional moistening from the upper reaches of the Dniester and Don rivers and the mouth of the Kama, the amount of precipitation is approximately equal to evaporation, and the further south from this zone, the more evaporation exceeds precipitation (from 100 to 700 mm), i.e. moisture becomes inadequate.