The climate prevails on the territory of the Russian plain. Climatic features of the Russian plain

The East European Plain is one of the largest on the planet. Its area exceeds 4 million km2. It is located on the continent of Eurasia (in the eastern part of Europe). On the northwestern side, its borders run along the Scandinavian mountain formations, in the southeast - along the Caucasian, in the southwest - along the Central European massifs (Sudet, etc.) There are more than 10 states on its territory, most of which is occupied by the Russian Federation . It is for this reason that this plain is also called Russian.

East European Plain: climate formation

In any geographic area, the climate is formed due to some factors. First of all, this is the geographical location, relief and neighboring regions with which a certain territory borders.

So, what exactly affects the climate of this plain? To begin with, it is worth highlighting the ocean areas: the Arctic and Atlantic. Due to their air masses, certain temperatures are established and the amount of precipitation is formed. The latter are unevenly distributed, but this is easily explained by the large territory of such an object as the East European Plain.

Mountains have no less impact than the oceans. along its entire length is not the same: in the southern zone it is much larger than in the northern one. Throughout the year, it changes, depending on the change of seasons (more in summer than in winter due to mountain snow peaks). In July, the most high level radiation.

Considering that the plain is located in high and temperate latitudes, it mainly dominates on its territory. It prevails mainly in the eastern part.

Atlantic masses

The air masses of the Atlantic dominate the East European Plain throughout the year. In the winter season, they bring rainfall and warm weather, and in the summer, the air is saturated with coolness. Atlantic winds, moving from west to east, change somewhat. Being above the earth's surface, they become warmer in summer with little moisture, and cold in winter with little rainfall. It is during the cold period that the East European Plain, whose climate directly depends on the oceans, is under the influence of Atlantic cyclones. During this season, their number can reach 12. Moving eastward, they can change dramatically, and this, in turn, brings warming or cooling.

And when Atlantic cyclones come from the southwest, the southern part of the Russian Plain is influenced by subtropical air masses, as a result of which a thaw occurs and in winter the temperature can rise to +5 ... 7 ° С.

Arctic air masses

When the East European Plain is under the influence of the north Atlantic and southwestern Arctic cyclones, the climate here changes significantly, even in the southern part. In its territory comes a sharp cooling. Arctic Air Forces tend to move in a north-west direction. Due to anticyclones, which lead to cooling, the snow lies for a long time, the weather is set to be cloudy with low temperatures. As a rule, they are distributed in the southeastern part of the plain.

winter season

Considering how the East European Plain is located, the climate in the winter season differs in different areas. In this regard, the following temperature statistics are observed:

• Northern regions - winter is not very cold, in January, thermometers show an average of -4 ° C.
• In the western zones of the Russian Federation, the weather conditions are somewhat more severe. The average temperature in January reaches -10 °С.
• The northeastern parts are the coldest. Here on thermometers you can see -20 ° C and more.
• In the southern zones of Russia, there is a temperature deviation in the southeast direction. The average is a revenge of -5 ° C.

Temperature regime of the summer season

In the summer season, the East European Plain is under the influence of solar radiation. The climate at this time depends, directly, on this factor. Here, oceanic air masses are no longer of such importance, and the temperature is distributed in accordance with geographic latitude.

So, let's look at the changes by region:

Precipitation

As mentioned above, most of the East European Plain has a temperate continental climate. And it is characterized by a certain amount of precipitation, which is 600-800 mm / year. Their loss depends on several factors. For example, the movement of air masses from the western parts, the presence of cyclones, the location of the polar and arctic fronts. The highest humidity index is observed between the Valdai and Smolensk-Moscow Uplands. During the year, about 800 mm of precipitation falls in the west, and a little less in the east - no more than 700 mm.

In addition, the relief of this territory has a great influence. On the uplands located in the western parts, precipitation falls by 200 millimeters more than on the lowlands. The rainy season in the southern zones falls on the first month of summer (June), and in the middle lane, as a rule, it is July.

In winter, snow falls in this region and a stable cover is formed. The elevation level may vary, given the natural areas of the East European Plain. For example, in the tundra, the snow thickness reaches 600-700 mm. Here he lies for about seven months. And in the forest zone and forest-steppe, the snow cover reaches a height of up to 500 mm and, as a rule, covers the ground for no more than two months.

Most of the moisture falls on the northern zone of the plain, and evaporation is less. In the middle band, these indicators are compared. As for the southern part, here moisture is much less than evaporation, for this reason drought is often observed in this area.

types and brief characteristics

The natural zones of the East European Plain are quite different. This is explained extremely simply - by the large size of this area. There are 7 zones on its territory. Let's take a look at them.

East European Plain and West Siberian Plain: Comparison

The Russian and West Siberian plains have a number of common features. For example, their geographical location. They are both located on the Eurasian continent. They are influenced by the Arctic Ocean. The territory of both plains has such natural zones as forest, steppe and forest-steppe. There are no deserts and semi-deserts in the West Siberian Plain. The prevailing Arctic air masses have almost the same effect on both geographic areas. They also border on mountains, which directly affect the formation of the climate.

The East European Plain and the West Siberian Plain also have differences. These include the fact that although they are located on the same mainland, they are located in different parts: the first is in Europe, the second is in Asia. They also differ in relief - the West Siberian is considered one of the lowest, so some of its sections are swampy. If we take the territory of these plains as a whole, then in the latter the flora is somewhat poorer than that of the East European.

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

Climate influences living and non-living nature. In close dependence on the climate are water bodies, soil, vegetation, animals. Individual sectors of the economy, primarily agriculture, are also very dependent on climate.

The climate is formed as a result of the interaction of many factors: the amount of solar radiation entering the earth's surface; atmospheric circulation; the nature of the underlying surface. At the same time, climate-forming factors themselves depend on the geographical conditions of a given area, primarily on geographical 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, obtaining heat from the Sun also depends on the proximity of the ocean. In places far from the oceans, there is little precipitation, and the mode of precipitation is uneven (in the warm period more than in the cold), cloudiness is low, winters are cold, summers are warm, and the annual temperature amplitude is large. Such a climate is called continental, as it is typical of places located in the depths 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 amplitudes, high cloudiness, a uniform and fairly large amount of precipitation.

The climate is greatly influenced by sea ​​currents. Warm currents warm the atmosphere in the areas where they flow. 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 approximately at the same latitudes as the Scandinavian Peninsula, but is outside the zone of influence of the warm current, all year round covered with a thick layer of ice.

plays an important role in shaping the climate relief. You already know that with the rise of the terrain for each kilometer, the air temperature drops by 5-6 ° C. Therefore, on the alpine slopes of the Pamirs, the average annual temperature is 1 ° C, although it is located just 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 their windward slopes facing the Black Sea receive much more precipitation than their leeward slopes. At the same time, the mountains serve as an obstacle to the cold northern winds.

There is a dependence of climate and prevailing winds. On the territory of the East European Plain, for almost the entire year, westerly winds prevail, coming from Atlantic Ocean therefore, winters in this area are relatively mild.

Districts Far East are under the influence of the 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, the winds bring a lot of moisture from the Pacific Ocean. In autumn, when the wind from the ocean subsides, the weather is usually sunny and calm. This is the best time of the year in the area.

Climate characteristics are statistical inferences from long-term weather records (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 soil and water bodies, the evaporation of water from the earth's surface into the atmosphere, the height and condition of the snow cover, various atmospheric phenomena and ground-based hydrometeors (dew, ice, fog, thunderstorms, snowstorms, etc.) . In the XX century. The climatic indicators included characteristics of the elements of the heat balance of the earth's surface, such as total solar radiation, radiation balance, heat exchange between the earth's surface and the atmosphere, and heat consumption for evaporation. 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 average values ​​of meteorological elements (annual, seasonal, monthly, daily, etc.), their sums, frequencies, etc. are called climate standards: the corresponding values ​​for individual days, months, years, etc. are considered as a deviation 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, climatic zones.

The main climatic zones are:

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

Between the main belts there are transitional climatic zones: subequatorial, subtropical, subarctic, subantarctic. In transitional zones, air masses change with the 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 atmospheric pressure belts over the globe following the Sun: in summer - to the north, in winter - to the south.

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

Diversity of Earth's climates

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

Arctic and Antarctic climate zones

Antarctic and arctic climate dominates in Greenland and Antarctica, where the average monthly temperatures are below 0 °C. During the dark winter season, these regions receive absolutely no solar radiation, although there are twilight and auroras. Even in summer, the sun's rays fall on the earth's surface at a slight angle, which reduces the heating efficiency. Most of the incoming solar radiation is reflected by the ice. In both summer and winter, low temperatures prevail in the elevated regions of the Antarctic Ice Sheet. The climate of the interior of Antarctica is much colder than the climate of the Arctic, since the southern mainland is large and high, and the Arctic Ocean moderates the climate, despite the wide distribution of pack ice. In summer, during short periods of warming, drift ice sometimes melts. Precipitation on ice sheets falls in the form of snow or small particles of ice mist. Inland 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 snowstorms blow from the cold glacial sheet, bringing snow to the coast.

Table 1. Climates of the Earth

Climate type	Climate zone	Average temperature, ° С		Mode and amount of atmospheric precipitation, mm	Atmospheric circulation	Territory
Equatorial	Equatorial			During a year. 2000	Warm and humid equatorial air masses form in the area of ​​low atmospheric pressure.	Equatorial regions of Africa, South America and Oceania
tropical monsoon	Subequatorial			Mostly during the summer monsoon, 2000		South and Southeast Asia, West and Central Africa, Northern Australia
tropical dry	Tropical			During the year, 200		North Africa, Central Australia
Mediterranean	Subtropical			Mainly in winter, 500	In summer - anticyclones at high atmospheric pressure; winter - cyclonic activity	Mediterranean, Southern coast of Crimea, South Africa, Southwestern Australia, Western California
subtropical dry	Subtropical			During a year. 120	Dry continental air masses	Inland parts of the continents
temperate maritime	Moderate			During a year. 1000	westerly winds	Western parts of Eurasia and North America
temperate continental	Moderate			During a year. 400	westerly winds	Inland parts of the continents
moderate monsoon	Moderate			Mostly during the summer monsoon, 560		Eastern margin of Eurasia
Subarctic	Subarctic			During the year, 200	Cyclones prevail	Northern margins of Eurasia and North America
Arctic (Antarctic)	Arctic (Antarctic)			During the year, 100	Anticyclones predominate	The water area of ​​the Arctic Ocean and mainland Australia

subarctic continental climate is formed in the north of the continents (see the climate map of the atlas). In winter, arctic air prevails here, which is formed in areas of high pressure. In the eastern regions of Canada, Arctic air is distributed from the Arctic.

Continental subarctic climate in Asia, it is characterized by the largest annual amplitude of air temperature on the globe (60-65 ° С). The continentality of the climate here reaches its limit.

The average temperature in January varies across the territory from -28 to -50 °C, and in the lowlands and hollows, due to air stagnation, its temperature is even lower. In Oymyakon (Yakutia) a record for northern hemisphere negative air temperature (-71 °С). The air is very dry.

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

The climate of the subarctic zone of North America is less continental than the corresponding climate of Asia. It has less cold winters and colder summers.

temperate climate zone

The temperate 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 Cordilleras are a natural boundary separating the coast with a maritime type of climate from the inland regions. The European coast, except for Scandinavia, is open to the free access of temperate maritime air.

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

winter in temperate zone warm on the western coasts. The warming effect 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 °C. Intrusions of arctic air can lower it (on the Scandinavian coast down to -25°C, and on the French coast down to -17°C). With the spread of tropical air to the north, the temperature rises sharply (for example, it often reaches 10 ° C). In winter, on the western coast of Scandinavia, there are large positive temperature deviations from the average latitude (by 20 ° C). The temperature anomaly on the Pacific coast of North America is smaller and does not exceed 12 °С.

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

Even during the day, the air temperature rarely exceeds 30 °C. Cloudy and rainy weather is typical for all seasons due to frequent cyclones. There are especially many cloudy days on the western coast of North America, where cyclones are forced to slow down in front of the Cordillera mountain systems. In connection with this, the weather regime in the south of Alaska is characterized by great uniformity, where there are no seasons in our understanding. Eternal autumn reigns there, and only plants remind of the onset of winter or summer. Annual rainfall 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 excessive moisture, coniferous forests. The lack of summer heat reduces the upper limit of the forest in the mountains to 500-700 m above sea level.

The temperate climate of the eastern coasts of the continents It has monsoonal features and is accompanied by a seasonal change of winds: in winter, northwestern flows predominate, in summer - southeast. It is well expressed on the eastern coast of Eurasia.

In winter, with a northwest wind, cold continental temperate air spreads to 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. In the southern regions of the coast, there is little rainfall. The north of the Amur region, Sakhalin and Kamchatka often fall under the influence of 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, temperate sea air spreads on the coast of Eurasia. Summers are warm, with an average July temperature of 14 to 18 °C. Precipitation is frequent due to cyclonic activity. Their annual amount is 600-1000 mm, and most of it falls in the summer. Fog is frequent at this time of the year.

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

The Canadian anticyclone, unlike the Asian one, is unstable. It forms far from the coast and is often interrupted by cyclones. Winter here is mild, snowy, wet and windy. In snowy winters, the height of snowdrifts reaches 2.5 m. With a southerly wind, icy conditions often occur. Therefore, some streets in some cities in eastern Canada have iron railings for pedestrians. Summers are cool and rainy. The annual rainfall is 1000 mm.

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

A feature of the temperate continental climate is the large annual amplitude of air temperature, which can reach 50-60 °C. In the winter months, with a negative radiation balance, the earth's surface cools down. 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 formed in the area of ​​the anticyclone has a 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 here are less severe, 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 is warmer than continental temperate air in Asia.

The formation of a continental temperate climate is significantly influenced by the geographical features of the territory of the continents. In North America, the Cordillera mountain ranges are a natural boundary separating the coast with a maritime climate from the inland regions with a continental climate. In Eurasia, a temperate continental climate is formed over a vast expanse of land, approximately from 20 to 120 ° E. e. Unlike North America, Europe is open to free penetration of sea air from the Atlantic deep into the interior. This is facilitated not only by the western transport of air masses, which prevails in temperate latitudes, but also by the flat nature of the relief, the strong indentation of the 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 compared to Asia.

In winter, the Atlantic sea air moving over the cold land surface of the temperate latitudes of Europe retains its physical properties for a long time, and its influence extends to the whole of Europe. In winter, as the Atlantic influence weakens, the air temperature decreases from west to east. In Berlin it is 0 °С in January, -3 °С in Warsaw, -11 °С in Moscow. At the same time, the isotherms over Europe have a meridional orientation.

The orientation of Eurasia and North America with a wide front to the Arctic basin contributes to the deep penetration of cold air masses onto the continents throughout the year. Intensive meridional transport of air masses is especially characteristic of North America, where arctic and tropical air often replace each other.

Tropical air entering the plains of North America with southern cyclones is also slowly transformed due to its high speed of movement, high moisture content and continuous low cloudiness.

In winter, the result of intense meridional circulation of air masses are the so-called "jumps" of temperatures, their large daily 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, they fall in the form of snow, a snow cover is formed, which protects the soil from deep freezing and creates a supply of moisture in the spring. The height 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 territory is formed 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 it is less than 20 cm. On the plains of Mongolia, in the center of the anticyclonic region, snow cover forms only in some years. The absence of snow along with the low winter air temperature causes the presence of permafrost, which is no longer observed anywhere on the globe under these latitudes.

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

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

In North America, continental air is somewhat colder in summer than in Asia and Europe. This is due to the smaller extent of the mainland in latitude, the large indentation of its northern part with bays and fjords, the abundance of large lakes, and the more intense development of cyclonic activity compared to the inland regions of Eurasia.

In the temperate zone, the annual amount of precipitation on the flat territory of the continents varies from 300 to 800 mm; on the windward slopes of the Alps, more than 2000 mm falls. Most of the precipitation falls in the summer, which is primarily due to 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, the Carpathians, the Altai, the Sayans, the Cordillera, the Rocky Mountains, and others. In the mountainous regions, the 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 often turns out to be lower than in the mountains.

The influence of mountains on precipitation is great. Precipitation increases on the windward slopes and at some distance in front of them, and weakens on the leeward slopes. For example, differences in annual precipitation between the western and eastern slopes of the Ural Mountains in places reach 300 mm. In mountains with height, precipitation increases to a certain critical level. In the Alps level most precipitation falls at altitudes 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°C. The average temperature of the warmest month is in the range of 25-30°C, while daily highs can exceed 40-45°C.

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 °C.

Sharply continental climate in the subtropical zone for the high-mountainous regions of the Pamirs and Tibet, whose height 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 in intermountain basins located between the Coastal and Rocky Ranges. 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 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 in South Africa and the east coast of Australia. Summer in the humid subtropics is 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 the humid subtropics, the average annual precipitation ranges from 750 to 2000 mm, the distribution of precipitation over the seasons is quite uniform. In winter, rains and rare snowfalls are brought mainly by cyclones. In summer, precipitation falls mainly in the form of thunderstorms associated with powerful inflows of warm and humid oceanic air, which are characteristic of the monsoonal circulation of East Asia. Hurricanes (or typhoons) appear in late summer and autumn, especially in the Northern Hemisphere.

subtropical climate with dry summers is 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 is in southern California, the central regions of Chile, in the extreme south of Africa and in a number of areas in southern Australia. All these regions have hot summers and mild winters. As in the humid subtropics, there are occasional frosts in winter. In inland areas, summer temperatures are much higher than on the coasts, and often the same as in tropical deserts. In general, clear weather prevails. In summer, on the coasts near which ocean currents pass, there are often fogs. 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. The influence of anticyclones and downward air currents over the oceans determine the dryness of the summer season. The average annual precipitation in a subtropical climate varies from 380 to 900 mm and reaches maximum values ​​on the coasts and mountain slopes. In the 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 i, macchia and fynbosh.

Equatorial climate zone

Equatorial type of climate distributed in equatorial latitudes in the Amazon basin in South America and the Congo in Africa, on the Malay Peninsula and on the islands South-East Asia. Usually the average annual temperature is about +26 °C. Due to the high noon position of the Sun above the horizon and the same length of the day throughout the year, seasonal temperature fluctuations are small. Moist air, cloudiness and dense vegetation prevent nighttime cooling and maintain maximum daytime temperatures below +37 °C, lower than at higher latitudes. The average annual rainfall in the humid tropics ranges from 1500 to 3000 mm and is usually evenly distributed over the seasons. Precipitation is mainly associated with the intratropical convergence zone, which is located slightly north of the equator. Seasonal shifts of this zone to the north and south in some areas lead to the formation of two precipitation maxima during the year, separated by drier periods. Every day, thousands of thunderstorms roll over the humid tropics. In the intervals between them, the sun shines in full force.

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. forests;
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 changed significantly as a result of economic activity person. 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 animal world The Russian plain was heavily depleted. 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 (south of 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 Egoryevskoye 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).

The relief of the Russian Plain is more diverse in the northwest, in the region of the last glacier. The main terminal moraine belt enters here from the southwest. It stretches to Lake Onega and further - to the lower reaches of the Northern Dvina and to the Mezen Bay. It is characterized by a hilly-morainic relief with many lakes. The heights of the Valdai, Veps and other uplands of the main belt in the Carboniferous Plateau reach 300 m.

To the west of the main belt, moraine ridges are located in the form of discontinuous hills; characteristic are kams and flat low-lying plains - Volkhovsko-Ilmenskaya and others. During the retreat of the glacier, huge dammed lakes formed in these areas. The deepest sections of the ancient lake basins are now occupied by large lakes - Ilmen, Chudskoye and Pskovskoye. A flat limestone Ordovician plateau stretches along the Gulf of Finland and Lake Ladoga, on which karst is developed.

A different relief was formed in the area between the main terminal moraine belt and Timan. The landforms created here by the early glaciations are eroded. Interfluve plateaus have a flat and undulating surface. Spacious lowlands with river valleys of the Northern Dvina and other rivers, dividing the plateau, merge in the north with the coastal lowland. The ancient Timan ridge is poorly expressed in the relief: it consists of several flat ridges - "stones" with hilly remnants of hard rocks. The northwestern extension of Timan is the low and flat Pae Range on the Kanin Peninsula. In the southeast, Timan comes close to the spurs of the Urals - Polyudov stone. The Pechora basin between the Timan and the Urals is characterized by undulating, in places hilly plains, dissected by lowlands with river valleys. On the Bolshezemelskaya and Malozemelskaya plains there are moraine hills and ridges - Musyurs.

The relief of the Polar and Northern Urals is extremely diverse. Mountain ranges and massifs are separated there by deep tectonic depressions and river valleys. Glaciation in the Urals was accompanied by the formation of pointed ridges, troughs, the accumulation of moraine and water-glacial deposits in valleys and at the foot of mountains, and the smoothing of slopes.

The highest peaks of the Northern Urals are characterized by sharp (alpine) forms: narrow ridges, peaks. As a result of frosty weathering, placers (kurums) of large stone blocks and rock fragments near the peaks and on the slopes of high ridges are very typical for the Ural Mountains. There are no sharp fluctuations in elevation on the western slope of the Urals, the summit surfaces are wavy in nature, descending, the mountains are replaced in the foothills by wide quartzite uplands - parmas.

The climate features of the European North are primarily due to the position of the region in the temperate and cold zones in the north-west of Eurasia and the large extent of the region from south to north, as well as from east to west on both sides of the Arctic Circle.

From south to north, according to the seasons of the year, the conditions of illumination and heating of the earth's surface by the sun's rays change especially strongly in the European North - the length of the day and the height of the sun above the horizon, which determine the influx of solar energy (radiation). The midday height of the sun above the horizon on the southern edge of the European North reaches on the day of the summer solstice, June 22, almost 58 °, and the duration of the day is 18 hours. To the north of here, the sun's height decreases, and the length of the day increases, the nights become shorter. Approximately from the latitude of Leningrad, the sun hides behind the horizon shallowly and for a short time, so that the evening dawn merges with the morning one, and white nights reign from late April to mid-August.

At the Arctic Circle on June 22, the day lasts around the clock. Under 70 ° with. sh. the sun does not set from May 20 to July 23, and on Franz Josef Land - over four months. During this period of the polar day, the sun here, not rising high above the horizon, "walks in a circle."

The polar day and beyond the polar circle are preceded by bright, twilight nights; at 70° N sh. they start already on March 30, and after the polar day they continue until September 12.

With the end of bright nights, the days become shorter and the height of the midday sun decreases. In the middle of winter, even in the south of the region, the sun rises only to 11 °, and the day lasts only 6 hours and 30 minutes.

At the Arctic Circle and north of it, the sun does not appear above the horizon at all.

The duration of the polar night, as well as the polar day, is not the same in different latitudes (at the Arctic Circle - 24 hours, at 70 ° N - 64 days, on Franz Josef Land - more than 130 days). In the winter months, the influx of solar heat in the European North is small everywhere, and where the polar night reigns, its flow completely stops.

In general, for the year at the southern border of the European North, the influx of solar energy by "/h, on the coast of the Barents Sea is almost half and in the Far North in the Arctic almost 2 times less than in the south of the Russian Plain, off the coast of the Black Sea.

Atmospheric circulation has a great influence on the climate. In the European North, these influences are very pronounced due to the position of the territory in the north-west of Eurasia - in the zone of active cyclonic activity and frequent changes in air masses, different in their place of formation, temperature and humidity.

Throughout the year, western air currents prevail here. Cyclones move mainly from the North Atlantic to the Barents Sea. Cyclonic activity is especially intense in autumn and winter. In winter, the entry of warm and humid Atlantic air is accompanied by warming, snowfalls, and during thaws, sometimes rain. In summer, when cool air comes in from the west, temperatures drop, cloudiness increases, and heavy rains fall. Moving over land further to the east, humid Atlantic air is converted into continental air (it cools in winter and warms up in summer).

From the northeast, from the side of the Kara Sea, less often from the northwest or from the north, Arctic air invades the territory of the European North. Arctic air coming from the northeast forms above the ice. This "Kara" Arctic air is much colder and drier than the Arctic air coming from the northwest and passing a long way over the relatively warm waters of the ocean. The intrusion of arctic air occurs more often in summer, but it brings strong drops in air temperature in winter, especially in the second half and at the end of winter. With the advent of arctic air, frosty weather sets in in winter, and cool in summer.

Moving inland, the Arctic air warms up and transforms into continental air. In winter from the east, and in summer from the southeast, continental air from temperate latitudes enters the European North. In winter it is very cold and dry, in summer it is dry and warm.

Spreading, it brings clear, frosty weather in winter, dry and warm in summer.

Sometimes in summer, from the southwest, maritime subtropical air, warm and very humid, spreads to the territory of the European North. It covers mainly only the southwestern regions. With the advent of this air, heavy rains fall, but then, usually for a short time, clear, warm or even hot weather sets in. Even more rarely, and only in summer, continental dry and hot tropical air comes from Central Asia and other southeastern regions.

It brings briefly very warm, dry, windless weather.

Huge masses of heat coming with the Atlantic air cause a positive temperature anomaly characteristic of the European North (the average air temperatures here are higher than the average for these latitudes).

Frequent changes in air masses, as well as cyclones, cause unstable weather typical of the European North.

The winds here are also changeable. In the northern strip of this region, northern winds dominate in summer, and southern and southwestern winds dominate in winter.

The coldest month almost everywhere in the European North is January (in the southwest and extreme northwest - February). The lowest average January temperatures (-22°) are observed in the northeast of the mainland of the European North and on the eastern side of Novaya Zemlya, the highest (-6°) and slightly higher - in the southwestern regions and under the warming influence of the sea in the far north -west, in the coastal strip of the Kola Peninsula.

The absolute minimum temperature in areas far from the sea reaches -55° in the European North and is below -35, -40° everywhere.

The warmest month in the European North is July. The average July temperatures are highest in the south (+18, +19°), the lowest - in the northeast of the continental part of the European North (+8°). Temperatures are even lower on the islands of Novaya Zemlya (+5°) and on Franz Josef Land (0°). The highest (maximum) daily temperatures (above +36°) were observed in July in different parts of the European North.

The duration of the period with stable temperatures above +5°, which determine the timing of sowing and harvesting crops, within the temperate zone varies in the European North from 180-150 days in the south, to 110-80 days in the north. The possibilities of growing agricultural plants also depend on the availability of heat during the growing season.

The indicator of security is the sum of stable average temperatures above 10 °. In the southern regions of the European North, the sums of temperatures above +10° reach almost 2000°, which is sufficient for ripening even late varieties of wheat, potatoes, tomatoes, and flax for fiber. In the northern zone, the sum of temperatures drops to 750-500 °, however, it makes it possible to grow potatoes, vegetables and some grains.

Atlantic air coming from the west brings not only heat, but also a lot of moisture. The annual amount of precipitation on the plains of the European North reaches an average of 500 - 700 mm, in the extreme northeast - only 300 mm, in the mountains of the Urals - more than 800 mm.

Rains and snowfalls are frequent - up to 160 - 200 days a year. Rains are predominantly heavy, drizzling. Summer showers are rare. Although precipitation occurs most often in autumn and winter, most of it occurs during the warm season.

Snow cover within the European North is long, on average 120 days, and in the northeast even 250 days. In the mountains of the Kola Peninsula and the Urals, snow spots remain for several years.

The northern island of Novaya Zemlya, the islands of Franz Josef Land and Victoria Land are almost entirely covered with a thick layer of ice and snow. There are also small glaciers in the Urals.

In the western regions of the European North, due to thaws, the snow is compacted and the thickness of the snow cover is less (30 cm) than in the east (70 - 100 cm).

Due to the considerable thickness of the snow cover, the soils of the European North do not freeze deeply and not strongly, the temperatures of frozen soils are usually only slightly below 0 °. Nevertheless, in the Far North, a layer of permafrost lies already at an insignificant depth. It is more widespread in the east, where the continentality of the climate increases, and less in the west, but nowhere does it form a continuous shell.

A characteristic feature of the climate of the European North is the constant high relative humidity of the air (average 75 - 90%). At low air temperatures and high humidity, evaporation is low everywhere.

Differences in the climate of the European North are reflected in the timing of the onset, duration and temperatures of the seasons.

Winter is the time of the year with daily air temperatures below -5°, stable snow cover.

It begins first in the northeast (at the end of October), and later in the southwest (on average, in the first half of November); winter in the west, and especially in the southwest, is usually mild, with thaws, cloudy, less often frosty, in the east it is more stable, cold and clear, and beyond the Arctic Circle it is dark and twilight, with strong winds and frequent blizzards, with storms at sea . In the extreme northeast, there are up to 100 days with snowstorms. Winds and blizzards are also common in other parts of the European North during intrusions of arctic air masses, when mild cyclonic weather often changes to a thaw, anticyclonic clear, sunny, bright from shining snow, windless and cold weather.

But it doesn’t happen year after year: some winters were with long frosty weather, others with frequent thaws.

Spring begins in the European North almost everywhere in March, in the Far North - in April, and in the northeast - even at the end of April. In March (to the north - in April), announcing the onset of spring, rooks are the first to arrive, in the Far North - snow bunting. In April, a bear leaves its den, waterfowl arrive, and a stork comes to the south-west. In April (to the north - in early May), the first butterflies fly out - urticaria, snowdrops bloom - blueberry, anemone; in the southwest at the beginning of May (in the east - at the end) the first cuckoo is heard, the birch begins to turn green (in the Far North in June), the first song of the nightingale is heard; in the south-west in May (to the north - in June), bird cherry, lilac bloom, winter rye begins to ear. In spring, the influence of the Atlantic weakens, cloudiness decreases, the day becomes longer, the sun rises higher, shines brighter.

With the heating of surface air during the day above zero degrees, there are thaws, and at night it freezes and the snow freezes, an ice crust forms on it - crust. Arctic air intrusions become more frequent, especially in May. In this regard, there are returns of cold weather, when frosts are possible.

The northern spring is protracted and proceeds in different ways. There were years when in Leningrad, for example, on May 1, people went to a festive demonstration in summer clothes, but it happened that on that day the temperature dropped below 0 ° C or a gale was blowing, it was sleet and raining.

Only in June (south of 65 ° N) and July (north of this parallel) does summer come, moderately warm or cool. At this time, lilac blossoms in the southwestern regions of the European North.

The real, full summer comes later, in the second half of June - early July, when the average daily temperatures rise above -15 °, blueberries and raspberries ripen, the number of edible mushrooms increases in the forests, and haymaking takes place. But north of the 65th parallel, summer is very cool and there is no period with temperatures above 15 ° at all.

In the extreme northeast and on the polar islands, the average air temperature in all summer months is below -\-10 °.

The entry of warm air from the south sometimes raises the temperature to +30. + 35 ° (even on Novaya Zemlya it is above + 20 degrees). On the contrary, the entry of arctic air greatly lowers the temperature (to -2°, in the northeast to -5°).

Frosts are possible almost everywhere in June and August, and in the east, in the northern strip, even in July. Cyclones in summer come more often than in spring, cloudiness increases (especially in the second half), the amount of precipitation increases, there are thunderstorms and showers.

A sign of autumn - yellowing of birch leaves - everywhere in the European north is already noticeable at the end of August. But autumn really comes in September. Arctic air comes less often in autumn, but it gets colder; cyclonic activity intensifies, cloudiness increases. During the period of golden autumn, in September and in the first half of October, with the entry of warm air, "Indian summer" is briefly established - dry, sunny, warm weather.

In deep autumn, until the first snow, the days quickly shorten, cloudiness increases even more, rainy weather happens more often, the departure of waterfowl ends, and rooks fly away. Drizzling rains are replaced by snowfalls, and before the beginning of winter, during the "pre-winter" period, in November, snow cover appears and disappears again.

But in other years already in September (and in some areas in the north and east in August) there were frosts up to -6 ° in the southwest and -18 ° in the east.

The climate is one of the most important physical and geographical characteristics of the territory. Climate is a long-term weather pattern characteristic of a particular area on Earth. In this case, the multi-year regime is understood as the totality of all weather conditions in a given area over a period of several decades; typical annual change of these conditions and possible deviations from it in individual years; weather combinations characteristic of its various anomalies (droughts, rainy periods, cooling, etc.).

The climate of the East European Plain is influenced by its position in temperate and high latitudes, as well as by the connection of the territory (Western Europe and North Asia) and water areas (the Atlantic and Arctic Oceans) (Appendix 4).

The Russian Plain is located in temperate and high latitudes, where seasonal differences in the arrival of solar radiation are especially large. 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. The radiation balance in winter, with the exception of the extreme southern regions, is negative. It falls in the direction from the southwest to the northeast and depends mainly on the amount of cloudiness. In summer, the radiation balance is positive everywhere. It reaches its greatest value in July in the south of Ukraine, in the Crimea and the Sea of ​​Azov. The total solar radiation increases from north to south from 66 to 130 kcal/cm2 per year. In January, the total solar radiation at the latitude of Kaliningrad-Moscow-Perm is 50, and the Ciscaucasia and the southeast of the Caspian lowland is about 150 MJ/m 2 .

All year round, the western transfer of air masses dominates over the East European Plain, and the Atlantic air of temperate latitudes brings coolness and precipitation in summer, and warmth and precipitation in winter. When moving to the 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, from 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, 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. Anticyclones often recur in the southeast of the plain, due to the influence of the Asian High.

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 distribution of precipitation over the territory of the Russian Plain is primarily dependent on circulation factors. Cyclonic activity is observed mainly in the west, in the area of ​​the Barents Sea. On the mainland, atmospheric pressure is distributed in such a way that Arctic and Atlantic air flows into the plain, with which large clouds and significant precipitation are associated. The western transfer of air masses prevailing here is intensified due to the frequent recurrence of cyclones of the Arctic and Polar fronts. Especially often cyclones move from west to east between 55-60°N. sh. (Baltic, Valdai, upper reaches of the Dnieper). This strip is the most humid part of the Russian Plain: the annual amount of precipitation here reaches 600-700 mm. in the west and 500-600 mm in the east.

Winter cyclonic precipitation forms a snow cover with a height of 60-70 cm, which lies up to 220 days a year, to the south-west, the duration of the snow cover is reduced to 3-4 months a year, and its average long-term height is reduced to 10-20 cm. As we move deeper into the mainland, cyclonic activity and the associated western transport in the south of the East European Plain weakens. Instead, the frequency of anticyclones 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. Because of this, precipitation in the southern part of the plain falls 500-300 mm per year, and their amount rapidly decreases in the southeast direction to 200 mm. and sometimes less. The snow cover is thin and lies for a short time: 2-3 months in the southwest. Relief influences the increase in annual precipitation. For example, in the Donetsk ridge falls 450 mm. precipitation, and in the surrounding steppe - 400 mm. The difference in the annual amount of precipitation between the Volga Upland and the low-lying Trans-Volga region is about 100 mm. In the southern half of the plain, the maximum precipitation occurs in June, and in the middle lane - in July. The southern half is characterized by the lowest, and the northern half by the highest relative humidity. The moisture index in the north of the territory is more than 0.60, and in the south 0.10.

Precipitation practically falls from all air masses, but most of it is associated with the Atlantic air of temperate latitudes. Tropical air brings a lot of moisture to the southwest. Precipitation is mainly due to the circulation of air masses on the Arctic and Polar fronts, and only 10% of them are produced by intramass processes in the summer.

The degree of moistening of the territory is determined by the ratio of heat and moisture. It is expressed in different quantities:

• a) moisture coefficient. On the East European Plain, it reaches values ​​from 0.55 (the Crimean plains) to 1.33 or more (in the Pechora lowland);
• b) dryness index - 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 moisture from the upper reaches of the Dniester, Don and the mouth of the Kama, the amount of precipitation is approximately equal to evaporation, and the further south from this zone, the more and more evaporation exceeds precipitation (from 100 to 700 mm), i.e. insufficient moisture sets in.

Differences in the climate of the East European Plain affect the nature of the vegetation and the presence of a fairly clearly expressed soil-vegetation zonality.

B.P. Alisov, taking into account the radiation balance and atmospheric circulation (transport of air masses, their transformation, cyclonic activity), distinguishes three climatic regions in the European part:

• 1) northern Atlantic-Arctic;
• 2) the middle Atlantic-continental region;
• 3) southern continental region.