Climatic zones and climatic regions of the Earth. Description, map and characteristics

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

Climate influences living and inanimate nature. Water bodies, soil, vegetation, and animals are closely dependent on climate. Certain 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 reaching the earth's surface; atmospheric circulation; the nature of the underlying surface. At the same time, climate-forming factors themselves depend on geographical conditions of this area, primarily from geographical latitude.

The geographic latitude of the area determines the angle of incidence of the sun's rays, obtaining a certain amount of heat. However, receiving heat from the Sun also depends on proximity to the ocean. In places far from the oceans, there is little precipitation, and the precipitation regime is uneven (more in the warm period than in the cold), cloudiness is low, winters are cold, summers are warm, and the annual temperature range is large. This climate is called continental, as it is typical for places located in the interior of continents. Forms above the water surface maritime climate, which is characterized by: a smooth change in air temperature, with small daily and annual temperature amplitudes, large cloudiness, a uniform and fairly large amount atmospheric precipitation.

The climate is also 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 at approximately the same latitudes as the Scandinavian Peninsula, but is outside the zone of influence of the warm current, is available all year round covered with a thick layer of ice.

A major role in climate formation belongs to relief. You already know that with every kilometer the terrain rises, the air temperature drops by 5-6 °C. Therefore, on the high mountain slopes of the Pamirs the average annual temperature- 1 °C, although it is located just north of the tropics.

The location of mountain ranges greatly influences the climate. For example, Caucasus Mountains They trap moist sea winds, and on their windward slopes facing the Black Sea, much more precipitation falls than on the leeward ones. At the same time, the mountains serve as an obstacle to cold northern winds.

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

Regions of the Far East are under the influence of monsoons. In winter, winds from the interior of the mainland constantly blow here. They are cold and very dry, so there is little precipitation. In summer, on the contrary, 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 best time years in this area.

Climatic characteristics are statistical inferences from long-term weather observation series (in temperate latitudes ah 25-50 year rows are used; in the tropics their duration may be shorter), primarily over the following basic meteorological elements: atmospheric pressure, wind speed and direction, air temperature and humidity, cloudiness and precipitation. The duration of solar radiation, visibility range, and temperature are also taken into account. upper layers soils and reservoirs, evaporation of water from the earth's surface into the atmosphere, height and condition of snow cover, various atmospheric phenomena and ground hydrometeors (dew, ice, fog, thunderstorms, snowstorms, etc.). In the 20th century in number climate indicators included the characteristics of the elements of the heat balance of the earth's surface, such as total solar radiation, radiation balance, the amount of 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.

Climate zones

Long-term average values ​​of meteorological elements (annual, seasonal, monthly, daily, etc.), their sums, frequency, etc. are called climate standards: corresponding values ​​for individual days, months, years, etc. are considered as a deviation from these norms.

Maps with climate indicators are called climatic(temperature distribution map, pressure distribution map, etc.).

Depending on 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 zones there are transitional climatic zones: subequatorial, subtropical, subarctic, subantarctic. In transition 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 zones, and in winter - to 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. 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 Mediterranean, continental and monsoon climates. In mountainous areas it is formed altitudinal zone due to the fact that the air temperature decreases with altitude.

Diversity of Earth's climates

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

Arctic and Antarctic climate zones

Antarctic and Arctic climate dominates in Greenland and Antarctica, where average monthly temperatures are below O °C. Into the dark winter time During the year, these regions receive absolutely no solar radiation, although there are twilights and auroras. Even in summer Sun rays fall onto the earth's surface at a slight angle, which reduces the efficiency of heating. Most of the incoming solar radiation is reflected by the ice. In both summer and winter, the higher elevations of the Antarctic Ice Sheet experience low temperatures. The climate of the interior of Antarctica is much colder than the climate of the Arctic, because southern mainland It is distinguished by its large size and altitude, and the Arctic Ocean moderates the climate, despite the widespread distribution of pack ice. During short periods of warming in summer, drifting ice sometimes melts. Precipitation on ice sheets falls in the form of snow or small particles of freezing fog. Inland areas receive only 50-125 mm of precipitation annually, but the coast can receive more than 500 mm. Sometimes cyclones bring clouds and snow to these areas. Snowfalls are often accompanied strong winds, which carry significant masses of snow, blowing it off the slope. Strong katabatic winds with snowstorms blow from the cold glacial sheet, carrying snow to the coast.

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

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

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

Summer in subarctic belt although short, it is quite warm. The average monthly temperature in July ranges from 12 to 18 °C (daytime maximum is 20-25 °C). During the summer, more than half of the annual 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 compared to the corresponding climate of Asia. Less here Cold winter and colder summers.

Temperate climate zone

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

Permanent transfer sea ​​air is accompanied by heavy cloudiness and causes long springs, in contrast to the interior of the continental regions of Eurasia.

Winter in temperate zone It's warm on the western coasts. The warming influence of the oceans is enhanced by warm sea ​​currents, washing the western shores of the continents. The average temperature in January is positive and varies across the territory from north to south from 0 to 6 °C. When arctic air invades, it can drop (on the Scandinavian coast to -25 °C, and on the French coast - to -17 °C). As tropical air spreads northward, the temperature rises sharply (for example, it often reaches 10 °C). In winter, on the western coast of Scandinavia, large positive temperature deviations from the average latitude (by 20 °C) are observed. The temperature anomaly on the Pacific coast of North America is smaller and amounts to no more than 12 °C.

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

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

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

Temperate climate of the eastern coasts of the continents has monsoon features and is accompanied by a seasonal change in winds: in winter, northwestern currents predominate, in summer - southeastern ones. It is well expressed on the eastern coast of Eurasia.

In winter, with the north-west 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. There is little precipitation in the southern coastal areas. 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 heavy snow cover, especially in Kamchatka, where it maximum height reaches 2 m.

In summer, temperate sea air spreads along the Eurasian coast with a southeast wind. Summers are warm, with an average July temperature of 14 to 18 °C. Frequent precipitation is caused by cyclonic activity. Their annual quantity is 600-1000 mm, with most of them falling in summer. Fogs are common at this time of 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 marine type annual progress air temperatures: the minimum occurs in February, and the maximum in August, when the ocean is 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 the snowdrifts reaches 2.5 m. With a southerly wind, there is often black ice. Therefore, some streets in some cities in eastern Canada have iron railings for pedestrians. Summer is cool and rainy. Annual precipitation 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 in 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. During the winter months, with a negative radiation balance, the earth's surface cools. The cooling effect of the land surface on the surface layers of air is especially great in Asia, where in winter a powerful Asian anticyclone forms and partly cloudy, windless 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 midwinter, the continental air in the lower layers becomes even colder than the Arctic air. This very cold air of the Asian anticyclone extends to Western Siberia, Kazakhstan, and the 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 continent, as in Asia, but, on the contrary, decreases somewhat due to the frequent passage of cyclones. Continental temperate air in North America has a higher temperature than continental temperate air in Asia.

The formation of a continental temperate climate is significantly influenced by geographical features continental territories. In North America, the Cordillera mountain ranges are a natural boundary separating the maritime coastline from the continental inland areas. In Eurasia, a temperate continental climate is formed over a vast expanse of land, from approximately 20 to 120° E. d. Unlike North America, Europe is open to the free penetration of sea air from the Atlantic deep into its interior. This is facilitated not only by the westerly transport of air masses, which dominates in temperate latitudes, but also by the flat nature of the relief, highly rugged coastlines and deep penetration of the Baltic and North Seas into the land. Therefore, a temperate climate of a lesser degree of continentality is formed over Europe compared to Asia.

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

The fact that Eurasia and North America face the Arctic basin as a broad front contributes to the deep penetration of cold air masses onto the continents throughout the year. Intense 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 the high speed of its movement, high moisture content and continuous low clouds.

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

During 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 depth of the snow cover depends on the duration of its occurrence and the amount of precipitation. In Europe, stable snow cover on flat areas forms east of Warsaw, its maximum height reaches 90 cm in the northeastern regions of Europe and Western Siberia. In the center of the Russian Plain, the height of snow cover is 30-35 cm, and in Transbaikalia - less than 20 cm. On the plains of Mongolia, in the center of the anticyclonic region, snow cover forms only in some years. The lack of snow, along with low winter air temperatures, causes the presence of permafrost, which is not observed anywhere else on the globe at these latitudes.

In North America, snow cover is negligible on the Great Plains. To the east of the plains, tropical air increasingly begins to take part in frontal processes; it aggravates frontal processes, which causes heavy snowfalls. In the Montreal area, 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 the arid regions of southeastern Europe and Central Asia average temperature air in July reaches 24-28 °C.

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

In the temperate zone, the annual precipitation on the flat continental areas varies from 300 to 800 mm; on the windward slopes of the Alps more than 2000 mm falls. Most of the precipitation falls in 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 decreases from north to south due to a decrease in the frequency of cyclones and an increase in dry air in this direction. In North America, a decrease in precipitation across the territory is observed, on the contrary, towards the west. Why do you think?

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

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

Subtropical climate zone

Continental sub tropical 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 some places, in the northeast of China -5...-10°C. The average temperature of the warmest month ranges from 25-30 °C, with daily maximums exceeding 40-45 °C.

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

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

In North America, the continental arid subtropical climate is formed in closed plateaus and in intermountain basins located between the Coast 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. A temperature of +56.7 °C was recorded in Death Valley!

Humid subtropical climate characteristic of the eastern coasts of continents north and south of the tropics. The main areas of distribution are the southeastern United States, some southeastern parts 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 temperatures similar to those in the tropics. The average temperature of the warmest month exceeds +27 °C, and the maximum is +38 °C. 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, average annual precipitation amounts range from 750 to 2000 mm, and the distribution of precipitation across seasons is quite uniform. In winter, rain 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, characteristic of the monsoon circulation East Asia. Hurricanes (or typhoons) occur in late summer and fall, especially in the Northern Hemisphere.

Subtropical climate with dry summers, typical for the western coasts of continents north and south of the tropics. In Southern Europe and North Africa Such climatic conditions are typical for the coasts of the Mediterranean Sea, which was the reason for calling this climate also Mediterranean. The climate is similar in southern California, central Chile, extreme southern Africa and parts of southern Australia. All these areas have hot summers and mild winters. As in the humid subtropics, there are occasional frosts in winter. In inland areas, summer temperatures are significantly higher than on the coasts, and often the same as in tropical deserts. In general, clear weather prevails. In summer, there are often fogs on the coasts near which ocean currents pass. For example, in San Francisco, summers are cool and 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 downdrafts of air over the oceans cause the dry summer season. The average annual precipitation in a subtropical climate ranges from 380 to 900 mm and reaches maximum values ​​on the coasts and mountain slopes. In summer there is usually not enough rainfall for normal tree growth, and therefore a specific type of evergreen shrubby vegetation develops there, known as maquis, chaparral, mali, macchia and fynbos.

Equatorial climate zone

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

Very varied. The first climate classifications appeared in the 70s of the 19th century and were of a descriptive nature. According to the classification of Moscow State University professor B.P. Alisov, there are 7 types of climates on Earth, which make up climatic zones. 4 of them are basic, and 3 are transitional. The main types include:

Equatorial climate zone . This type of climate is characterized by the dominance of equatorial climates throughout the year. On the days of the spring (March 21) and autumn (September 21) equinox, the Sun is at its zenith above the equator and greatly heats the Earth. The air temperature in this climate zone is constant (+24-28°C). At sea, temperature fluctuations can generally be less than 1°. The annual amount of precipitation is significant (up to 3000 mm); on the windward slopes of the mountains, precipitation can fall up to 6000 mm. The amount of precipitation here exceeds evaporation, so in the equatorial climate they are swampy, and dense and tall trees grow on them. The climate of this zone is also influenced by the trade winds, which bring an abundance of precipitation here. The equatorial climate type is formed over northern regions; on the coast of the Gulf of Guinea, over the basin and headwaters, including the shores of Lake Victoria in Africa; over most of the Indonesian archipelago and adjacent parts and Pacific Oceans in Asia.
Tropical climate zone. This type of climate forms two tropical climatic zones (in the North and Southern Hemisphere) over the following territories.

In this type of climate, the state of the atmosphere over the continent and the ocean is different, therefore a continental tropical climate and an oceanic tropical climate are distinguished.

Continental climate zone: the region dominates over a significant territory, so very little precipitation falls here (from 100-250 mm). The mainland tropical climate is characterized by very hot summers (+35-40°C). In winter, the temperature is much lower (+10-15°C). There are large daily temperature fluctuations (up to 40 °C). The absence of clouds in the sky leads to the formation of clear and cold nights (clouds could trap heat coming from the Earth). Sharp daily and seasonal temperature changes contribute, which produces a lot of sand and dust. They are picked up by winds and can be transported over considerable distances. These dusty sandstorms are a great danger for a traveler in.

Mainland tropical climates The western and eastern coasts of the continents are very different from each other. Cold currents pass along the western coasts of South America and Africa, so the climate here is characterized by relatively low air temperatures (+18-20°C) and low precipitation (less than 100 mm). Warm currents pass along the eastern coasts of these continents, so temperatures here are higher and there is more precipitation.

Oceanic tropical climate similar to the equatorial one, but differs from it in smaller and more stable winds. Summer over the oceans is not so hot (+20-27°C), and winter is cool (+10-15°C). Precipitation falls mainly in summer (up to 50 mm). Moderate. There is a significant influence of westerly winds, bringing precipitation throughout the year. Summer in this climate zone is moderately warm (from +10°C to +25-28°C). Winter is cold (from +4°С to -50°С). Annual precipitation ranges from 1000 mm to 3000 mm on the outskirts of the continent and up to 100 mm in the interior. The differences between the seasons of the year are clearly visible. This type of climate also forms two zones in the Northern and Southern Hemispheres and is formed over areas of temperate latitudes (from 40-45° northern and southern latitudes to the polar circles). A region is formed above these territories low pressure, active cyclonic activity. Temperate climates are divided into two subtypes:

1. nautical, which dominates in the western parts of North America and South America, is formed under the direct influence of westerly winds from the ocean to the mainland, therefore it is characterized by cool summers (+ 15-20 ° C) and warm winter(from +5°С). Precipitation brought by westerly winds falls all year round (from 500 mm to 1000 mm, in the mountains up to 6000 mm);
2. continental, dominant in the central regions of the continents, differs from it. Cyclones penetrate here less frequently than in coastal areas, so summers here are warm (+17-26°C), and winters are cold (-10-24°C) with stable snow cover for many months. Due to the significant extent of Eurasia from west to east, the most pronounced continental climate is observed in Yakutia, where average January temperatures can drop to -40°C and there is little precipitation. This happens because the interior of the continent is not exposed to the same influence of the oceans as the coasts, where moist winds not only bring precipitation, but also mitigate the heat in summer and frost in winter.

The monsoon subtype of temperate climate, dominant in the east of Eurasia to Korea and in the north, northeast, is characterized by a change in stable winds (monsoons) over the seasons, which affects the amount and regime of precipitation. In winter, a cold wind blows from the continent, so the winter is clear and cold (-20-27°C). In summer, winds bring warm, rainy weather. In Kamchatka, precipitation falls from 1600 to 2000 mm.

In all subtypes of temperate climates, only moderate air masses dominate.

Polar climate type. Above 70° north and 65° south latitudes, a polar climate prevails, forming two zones: and. Polar air masses prevail here all year round. The sun does not appear at all for several months (polar night) and does not go below the horizon for several months (polar day). Snow and ice emit more heat than they receive, so the air is very cool and does not melt all year round. Throughout the year, a high pressure area dominates over these areas, so the winds are weak and there are almost no clouds. There is very little precipitation, the air is saturated with small ice needles. As they settle, they provide a total of only 100 mm of precipitation per year. The average summer temperature does not exceed 0°C, and winter -20-40°C. Long drizzle is typical for summer.

Equatorial, tropical, temperate, polar climate types are considered the main ones, since within their zones the air masses characteristic of them dominate throughout the year. Between the main climatic zones there are transitional ones, which have the prefix “sub” (Latin for “under”) in their names. In transitional climate zones, air masses change seasonally. They come here from neighboring belts. This is explained by the fact that as a result of the movement of the Earth around its axis, climatic zones shift either to the north or to the south.

There are three additional climate types:

Subequatorial climate. In summer, this belt is dominated by equatorial air masses, and in winter by tropical ones.

Summer: a lot of precipitation (1000-3000 mm), average +30°C. Even in the spring the sun reaches its zenith and burns mercilessly.

Winter is cooler than summer (+14°C). There is little precipitation. Soils dry out after summer rains, so in the subequatorial climate, unlike the equatorial climate, swamps are rarely found. The territory is favorable for human settlement, which is why many centers of civilization are located here - Indochina. According to N.I. , it is from here that many varieties of cultivated plants originated. The northern subequatorial belt includes: South America (Isthmus of Panama); Africa (Sahel belt); Asia (India, all of Indochina, South China, ). The southern subequatorial belt includes: South America (Amazonian lowland); Africa (centre and east of the continent); (northern coast of the mainland).

Subtropical climate. Here in summer tropical air masses dominate, and in winter air masses of temperate latitudes invade here, carrying precipitation. This determines the following weather in these areas: hot, dry summer(from +30 to +50°C) and a relatively cold winter with precipitation, a stable snow cover is not formed. Annual precipitation is about 500 mm. Inside the continents in subtropical latitudes there is little precipitation even in winter. The climate here is dominated by dry subtropics with hot summers (up to +50°C) and unstable winters, when frosts down to -20°C are possible. Precipitation in these areas is 120 mm or less. In the western parts of the continents it dominates, which is characterized by hot, partly cloudy summers without precipitation and cool, windy and rainy winters. The Mediterranean climate receives more precipitation than the dry subtropics. The annual precipitation here is 450-600 mm. The Mediterranean climate is extremely favorable for human life, which is why the most famous summer resorts are located here. Valuable subtropical crops are grown here: citrus fruits, grapes, olives.

The subtropical climate of the eastern coasts of the continents is monsoon. Winter here compared to other climates subtropical zone cold and dry, and summers are hot (+25°C) and humid (800 mm). This is explained by the influence of the monsoons, which blow from land to sea in winter, and from sea to land in summer, bringing precipitation in summer. The monsoon subtropical climate is well defined only in the Northern Hemisphere, especially on the east coast of Asia. Heavy rainfall in summer time give the opportunity to develop magnificently. The fertile soils here support the life of more than a billion people.

Subpolar climate. In summer, humid air masses come here from temperate latitudes, so summers are cool (from +5 to +10°C) and about 300 mm of precipitation falls (in the northeast of Yakutia 100 mm). As elsewhere, precipitation increases on windward slopes. Despite the small amount of precipitation, the moisture does not have time to evaporate completely, therefore, in the north of Eurasia and North America, small lakes are scattered in the subpolar zone, and large areas are swampy. In winter, the weather in this climate is influenced by Arctic and Antarctic air masses, so there are long, cold winters, temperatures can reach -50°C. Subpolar climate zones are located only on the northern edges of Eurasia and North America and in the Antarctic waters.

The cycle of heat, moisture and general circulation of the atmosphere form the weather and climate in the geographic envelope. Types of air masses, features of their circulation in different latitudes create conditions for the formation of Earth's climates. The dominance of one air mass throughout the year determines the boundaries of climate zones.

Climate zones- these are territories that encircle the Earth in a continuous or intermittent strip; They differ from each other in temperature, atmospheric pressure, amount and regime of precipitation, prevailing air masses and winds. The symmetrical distribution of climate zones relative to the equator is a manifestation of the law geographical zonation. There are main and transitional climatic zones. The names of the main climatic zones are given according to the dominant air masses and the latitudes in which they are formed.

There are 13 climatic zones: seven main and six transitional. The boundaries of each zone are determined by the summer and winter positions of climate fronts.

There are seven main climatic zones: equatorial, two tropical, two temperate and two polar (Arctic and Antarctic). In each of the climatic zones, one air mass dominates throughout the year - equatorial, tropical, temperate, arctic (Antarctic), respectively.

Between the main zones in each hemisphere, transitional climate zones are formed: two subequatorial, two subtropical and two subpolar (subarctic and subantarctic). In transition zones, seasonal changes in air masses occur. They come from neighboring main belts: in summer the air mass is from the southern main belt, and in winter from the northern one. The proximity of oceans, warm and cold currents, and topography influence climatic differences within zones: climatic regions with different types climate.

Characteristics of climate zones

The equatorial belt formed in the region of the equator as an intermittent strip, where equatorial air masses predominate. Average monthly temperatures range from +26 to +28 C. Precipitation falls 1500-3000 mm evenly throughout the year. The equatorial belt is the wettest part of the earth's surface (the Congo River basin, the coast of the Gulf of Guinea in Africa, the Amazon River basin in South America, the Sunda Islands).

There are continental and oceanic climate types, but the difference between them is small.

The subequatorial belts, which encircle the equatorial belt from the north and south, are characterized by monsoon air circulation. A feature of the belts is the seasonal change of air masses. In summer, equatorial air dominates, in winter - tropical. There are two seasons: wet summer and dry winter. In summer, the climate differs slightly from the equatorial one: high humidity, abundance of precipitation. During the winter season, hot, dry weather sets in, grasses burn out, and trees shed their leaves. The average air temperature in all months ranges from +20 to +30 °C. The annual precipitation is 1000-2000 mm, with maximum precipitation falling in summer.

Tropical zones are between 20 and 30 C. and Yu. w. on both sides of the tropics, where trade winds prevail. (Remember why in tropical latitudes the air sinks and prevails high pressure.) Tropical air masses with high temperatures dominate here throughout the year. The average temperature of the warmest month is +30...+35 C, the coldest month is not lower than +10 C. In the center of the continents the climate is tropical continental (desert). Cloud cover is insignificant, precipitation in most parts is less than 250 mm per year. Low precipitation causes the formation greatest deserts world - the Sahara and Kalahari in Africa, the deserts of the Arabian Peninsula, Australia. In the eastern parts of the continents, which are influenced warm currents and trade winds blowing from the ocean, intensified by monsoons in the summer season, a tropical humid climate is formed. The average monthly temperature in summer is +26 C, in winter +22 C. The average annual precipitation is 1500 mm.

Subtropical zones (25-40 N and S latitude) are formed under the influence of tropical air masses in summer and temperate air masses in winter. The western parts of the continents have a Mediterranean climate: summers are dry, hot, the average temperature of the warmest month is +30 C, and winters are wet and warm (up to +5...+10 C), but short-term frosts are possible. On eastern coasts continents is formed subtropical monsoon climate with hot (+25 C) rainy summers and cool (+8 C) dry winters. The amount of precipitation is 1000-1500 mm. Snow rarely falls.

In the central parts of the continents, the climate is subtropical continental, with hot (+30 C) and dry summers and relatively cold winters (+6...+8 C) with low precipitation (300 mm). The subtropical humid climate is characterized by more uniform temperatures and precipitation. In summer +20 C, in winter +12 C, precipitation is 800-1000 mm. (Use the climate map to determine the differences in the climates of the subtropical zones.)

Temperate zones stretch in temperate latitudes from 40 s. and Yu. w. almost to the polar circles. Temperate air masses dominate here throughout the year, but arctic and tropical air masses can penetrate. In the Northern Hemisphere in the western continents, westerly winds and cyclonic activity predominate; in the east there are monsoons. As you move deeper into the territory, the annual amplitude of air temperature increases (the coldest month is from +4...+6 °C to –48 °C, and the warmest month is from +12 °C to +30 °C).

In the Southern Hemisphere, the climate is mainly oceanic. There are 5 types of climate in the Northern Hemisphere: maritime, moderate continental, continental, sharply continental, and monsoon.

The maritime climate is formed under the influence of westerly winds blowing from the ocean (Northern and Central Europe, western North America, Patagonian Andes of South America). In summer temperatures are about +15…+17 °C, in winter - +5 °C. Precipitation falls throughout the year and reaches 1000-2000 mm per year. In the Southern Hemisphere, the temperate zone is dominated by an oceanic climate with mild summers, mild winters, heavy rainfall, westerly winds, and unstable weather (“roaring” forties latitudes).

Continental climate is characteristic of the interior regions of large continents. In Eurasia, a moderate continental, continental, sharply continental climate is formed, in North America - moderate continental and continental. On average, July temperatures vary from +10 °C in the north to +24 °C in the south. In a temperate continental climate, the January temperature drops from west to east from –5° to –10 °C, in a sharply continental climate - to –35…–40 °C, and in Yakutia below –40 °C. The annual precipitation in a temperate continental climate is approximately 500-600 mm, in a sharply continental climate - about 300-400 mm. In winter, as you move eastward, the duration of stable snow cover increases from 4 to 9 months, and the annual temperature range also increases.

The monsoon climate is best expressed in Eurasia. In summer, a stable monsoon from the ocean prevails, the temperature is +18...+22 °C, in winter - –25 °C. At the end of summer - beginning of autumn, typhoons from the sea with gusty winds and heavy precipitation are frequent. Winters are relatively dry as the winter monsoon blows inland. Precipitation in the form of rain predominates in summer (800-1200 mm).

The subpolar zones (subarctic and subantarctic) are located north and south of the temperate zone. They are characterized by seasonal changes in air masses: moderate air masses dominate in summer, and arctic (Antarctic) air masses dominate in winter. Continental subarctic climate is characteristic of the northern margins of North America and Eurasia. Summer is relatively warm (+5…+10 °C) and short. Winter is severe (up to –55 °C). Here is the pole of cold in Oymyakon and Verkhoyansk (–71 °C).

Small amount of precipitation - 200 mm. Permafrost and excessive moisture are widespread, and large areas are swamped. The oceanic climate in the Northern Hemisphere is formed in the Greenland and Norwegian Seas, in the Southern Hemisphere - around Antarctica. Cyclonic activity is widespread throughout the year. Cool summer (+3…+5 °C), floating sea and continental ice, relatively mild winter (–10…–15 °C). Winter precipitation is up to 500 mm, fog is constant.

The polar zones (Arctic and Antarctic) are located around the poles. Continental climate prevails in Antarctica, Greenland, and the islands of the Canadian Arctic archipelago. There are negative temperatures all year round.

Oceanic climate is observed mainly in the Arctic. Temperatures here are negative, but during the polar day they can reach +2 °C. Precipitation - 100-150 mm (Fig. 16).

Climatic zones differ from each other in air temperature, atmospheric pressure, air masses and precipitation. The climate of the temperate zone from west to east changes from maritime to moderate continental, continental, sharply continental, and monsoon.

There are several climate zones on the globe. Let's remember what we mean by the word “climate”. Climate is a long-term interaction and mutual influence of temperature, humidity, air flows, and solar heat in a certain area. Division general climate Earth into different climatic zones is determined by the position of one or another part of the Earth relative to the equator and is largely based on the fact that vegetable world climatic zones differ significantly from each other. Different types plants needed different quantities moisture and solar heat. Therefore, it is often possible to determine from vegetation alone how much solar heat this part of the Earth receives and how much precipitation falls here.

Conventionally, there are five main climatic zones, which are divided into several derivatives climatic zones. Let's list these zones: tropical, subtropical, temperate, Arctic or Antarctic, and finally, highland.

Tropical climate zones extend from 20" to 30" north latitude and from 20" to 30" south latitude. The lush evergreen rainforests (those closest to the equator) are warm and humid all year round. There is a lot of rainfall here. In the tropics, zones of dry and humid climates are distinguished: dry tropical savannas, where due to lack of moisture the vegetation is noticeably scarce, even drier tropical steppes and, finally, hot and devoid of vegetation tropical deserts.

From 30" to 40" northern and southern latitudes, a subtropical climate prevails. This zone has either a Mediterranean climate with hot, dry summers and warm, wet winters, or a subtropical climate with hot summers and warm

in winter. There is a lot of rainfall here almost throughout the year, so the flora is especially rich and diverse.

The temperate climate zone is located from 40" to 60" northern and southern latitudes, and it is far from uniform. Here you can distinguish a maritime climate (west coast of North America), cool steppe or humid continental climate. Moreover, all zones differ from each other in both average annual precipitation and characteristic vegetation.

The Antarctic, or Arctic, climate zone extends from 60" northern and southern latitudes to the Earth's poles. Winters here are very cold and summers are cool. Let's list several climatic zones of the Antarctic zone. This is primarily the taiga zone with very harsh, cold winters; zone the tundra, where only moss, low-growing shrubs and dwarf trees grow; and the polar climate zone, where winter lasts almost all year round.

The alpine climate zone covers regions located at high altitudes above sea level, that is, high mountain areas globe, regardless of their location relative to the equator.

Definition 1

Climate zone is a latitudinal strip on the Earth’s surface with a relatively uniform climate.

Climate zones differ from each other air temperature And dominant air masses. In accordance with their properties, the main features of the climate are determined. Climate zones on the planet are changing zonally, i.e. from equator to poles. The classification of climate zones, which is used in Russia and in most countries of the world, was created by a Soviet climatologist B.P. Alisov in $1956$ He highlights basic and transitional climatic zones.

There are seven main climatic zones:

• Equatorial belt;
• Two tropical zones;
• Two temperate zones;
• Two polar belts - Arctic and Antarctic.

In these climatic zones, only air masses with the same names dominate throughout the year.

Equatorial climate zone located on both sides of the equator. The territory and water area of ​​the belt receives a large amount of heat throughout the year, and average monthly temperatures are $24$-$28$ degrees. On land, the radiation balance reaches $90$ kcal/cm2. in year. Annual precipitation is up to $3000$ mm per year, and on the windward slopes - up to $10,000$ mm. There is excessive moisture here because the amount of precipitation is much greater than evaporation.

Tropical climate zones. One tropical zone is located in Northern hemisphere of the planet, the second - in South hemispheres. Tropical zones cross all continents except Antarctica and are well expressed in the oceans between the $20$ and $30$ parallels of both hemispheres. The formation of the tropical climate is influenced by tropical air masses, with their characteristic high atmospheric pressure and anticyclonic circulation. There is very little cloud cover throughout the year, relative humidity and annual precipitation. The prevailing winds are trade winds. Summer average monthly air temperatures are +$30$-$35$ degrees, winter temperatures are not lower than +$10$ degrees. The daily and annual amplitudes are quite high. Annual precipitation ranges from $50$-$200$ mm. The exception is the eastern outskirts of the continents, and on the islands the windward slopes of the mountains receive up to $2000$ mm or more. For example, about $13,000 mm falls in the Hawaiian Islands. On the western coasts of the continents the climate will be cooler, which is associated with cold ocean currents. There will be higher air humidity, an even temperature change and frequent fogs.

Temperate climate zones. One temperate zone is located in Northern hemisphere, between $40$ and $65$ parallel, the other - in South between $42$ and $58$ parallel. These are the largest climatic zones in terms of area. One of the differences between these belts is that in the Northern Hemisphere the belt occupies more than half sushi, while in the Southern Hemisphere it is the opposite. There $98\%$ comes from ocean. In temperate zones there is a clear seasonality of climate. It is expressed in big difference between summer and winter temperatures. Moreover, in the Northern Hemisphere, the annual and daily amplitude is significantly higher than in the Southern Hemisphere. The western transport of air masses of temperate latitudes dominates here, and intense cyclonic activity is observed. Towards the outskirts of the continents, the amount of precipitation increases, and the annual amount is $800$-$2000$ mm. On the windward oceanic slopes their number increases and reaches $5000$-$8000$ mm.

Polar climate zones(Arctic and Antarctic). In the Northern Hemisphere arctic the belt begins north of the $70$ parallel, and Antarctic south of the $65$ parallel. Both zones are characterized by polar nights and polar days. Eternal ice and snow emit enormous amounts of solar heat, causing the air to become very chilled. Atmospheric pressure is high all year round and dominates easterly winds. Located in Antarctica pole of cold planets. In summer, the average air temperature is $30$ degrees, and in winter -$70$. At the Russian polar station " East"The temperature drops to -$88.3 degrees. On the Antarctic coast, average monthly summer temperatures range from -$1$ to -$5$ degrees, and winter temperatures from -$18$ to -$20$ degrees. Above the Greenland ice sheet in Arctic climatic conditions are similar, but milder. In the Atlantic regions Arctic and to the pole, the summer temperature is about $0$ degrees, and with warm air invasion it rises to +$5$. Average winter temperatures are around -$20$ degrees. American The Arctic sector is more severe with temperatures of -$50$ degrees in winter and -$10$ degrees in summer. Largest quantity precipitation falls on European sector of the Arctic, where $300$-$350$ mm falls, and in Asian and American sector from $160$-$250$ mm.

Transitional climatic zones.

Between the main climatic zones there are zones transition zones. There are $6$ and they are characterized by seasonal changes in the prevailing air masses, i.e. In summer, one air mass dominates there, and in winter, another. The names of all transition zones are appended with the prefix “ sub", which translated from Latin means " under", i.e., a belt located under main.

Transitional belts include:

• Two subequatorial belts;
• Two subtropical zones;
• Subarctic belt;
• Subantarctic belt.

Subequatorial climate zone. These belts are located south and north of the equatorial one. As a result of the shift in climatic zones according to the seasons of the year, humid equatorial air comes here in the summer, winter period comes the dry tropical. Summer for subequatorial belts it will be wet, A winter is dry. Despite this, the average annual precipitation is excessive and reaches $1500$ mm per year. On the slopes of the mountains, precipitation falls even more - $6000$-$10000$ mm per year. The difference between summer and winter temperatures is small, but the difference with equatorial belt is felt. Summer temperatures range from $22$-$30$ degrees. Beyond the oceans subequatorial belt passes through South America, Central Africa, Hindustan, Indochina, Northern Australia.

Subtropical climate zones. They are located within $30$-$40$ degrees of the Northern and Southern Hemispheres. In the south, the subtropics border on the tropical zone, and in the north on the temperate zone in the Northern Hemisphere. In the Southern Hemisphere, there is a tropical zone to the north of the subtropics, and a temperate zone to the south. Thermal regimes alternate in half a year - in winter there is a moderate regime, and in summer - tropical. For the subtropics, frosts are already possible. Within the ocean, the belts are characterized by high temperatures and high salinity of water.

Subarctic climate zone. This transitional belt is closest to North Pole Earth. Temperate and arctic air masses replace each other throughout the year. The belt occupies Northern Canada, Alaska, the southern tip of Greenland, northern Iceland and the Scandinavian Peninsula. Within Russia it passes through the northern part of Western and Central Siberia, as well as the Far East.

Subantarctic climate zone. Located in the Southern Hemisphere, this belt occupies a number of Antarctic islands and the northern tip of the Antarctic Peninsula. The belt is characterized by short summers with temperatures below + $20$ degrees. Cold air masses in winter reduce temperatures to negative values. And it stays below zero for most of the year. The same is typical for the subarctic zone. There is little precipitation and it decreases from $500$-$250$ mm and below.

Climate-forming factors

On the formation of the planet's climate big influence provide external and internal factors. Most external factors influence the total amount of incoming solar radiation and its distribution across seasons, hemispheres and continents.

TO external factors The parameters of the earth's orbit and the earth's axis include:

• Distance between the Sun and Earth. It determines the amount of solar energy received;
• The inclination of the rotation of the earth's axis to the orbital plane, which determines seasonal changes;
• Earth's orbital eccentricity. Affects heat distribution and seasonal changes.

TO internal factors relate:

• Configuration of oceans and continents and their relative positions;
• The presence of active volcanoes that can change the climate until a volcanic winter;
• Albedo of the Earth's atmosphere and its surface;
• Air masses;
• The proximity of oceans and seas that moderate the climate, with the exception of cold currents;
• The nature of the underlying surface;
• Human economic activity;
• Heat flows of the planet.