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 the geographical conditions of a given area, primarily on geographical latitude.

The geographic latitude of the area determines the angle of incidence sun 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. A marine climate is formed over the water surface, which is characterized by: a smooth variation in air temperature, with small daily and annual temperature amplitudes, large cloudiness, uniform and fairly a large number of 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, the Caucasus Mountains trap moist sea winds, and their windward slopes facing the Black Sea receive significantly more precipitation than their leeward slopes. 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.

Districts 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 is the best time of year in the area.

Climatic characteristics are statistical inferences from long-term weather observation series (in temperate latitudes 25-50-year series are used; in the tropics their duration may be shorter), primarily on the following basic meteorological elements: atmospheric pressure, wind speed and direction, temperature and air 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 The climatic indicators included the characteristics of the elements of the heat balance of the earth's surface, such as total solar radiation, radiation balance, 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 transitional zones, air masses change seasonally. 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.

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

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. During the dark winter season, these regions receive absolutely no solar radiation, although there are twilights and auroras. Even in summer, the sun's rays hit 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 is different large sizes and altitudes, 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.

Table 1. Climates of the Earth

Climate type	Climate zone	Average temperature, °C		Mode and amount of atmospheric precipitation, mm	Atmospheric circulation	Territory
Equatorial	Equatorial			During a year. 2000	In areas of low atmospheric pressure, warm and humid equatorial air masses form	Equatorial regions of Africa, South America and Oceania
Tropical monsoon	Subequatorial			Mainly during the summer monsoon, 2000		South and Southeast Asia, Western and Central Africa, Northern Australia
tropical dry	Tropical			During the year, 200		North Africa, Central Australia
Mediterranean	Subtropical			Mainly in winter, 500	In summer there are anticyclones at high atmospheric pressure; in winter - cyclonic activity	Mediterranean, Southern coast of Crimea, South Africa, South Western Australia, Western California
Subtropical dry	Subtropical			During a year. 120	Dry continental air masses	Interiors of continents
Temperate marine	Moderate			During a year. 1000	Western winds	Western parts of Eurasia and North America
Temperate continental	Moderate			During a year. 400	Western winds	Interiors of continents
Moderate monsoon	Moderate			Mainly during the summer monsoon, 560		Eastern edge of Eurasia
Subarctic	Subarctic			During the year, 200	Cyclones predominate	Northern edges of Eurasia and North America
Arctic (Antarctic)	Arctic (Antarctic)			During the year, 100	Anticyclones predominate	The Arctic Ocean and mainland Australia

Subarctic continental climate is formed in the north of the continents (see. climate map atlas). In winter, arctic air prevails here, which forms in the regions high pressure. On eastern regions Canada's arctic air spreads 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.

average temperature in January it 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 the Atlantic coast of 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.

The constant transport of sea air is accompanied by large clouds 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 cyclones are forced to slow down their movement in front of the Cordillera mountain systems. 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 east coast of North America is characterized by monkfish climate, which are expressed in the predominance of winter precipitation and the marine type of annual variation in air temperature: 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. Moderate continental air forming in the area of ​​the anticyclone has low temperature(-0°...-40 °С). 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 the geographical features of the continents. 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 the temperate latitudes of Europe retains its physical properties for a long time, 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 from southern cyclones, also slowly transforms 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, the 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 the snow cover is 30-35 cm, and in Transbaikalia - less than 20 cm. On the plains of Mongolia, in the center of the anticyclonic region, snow cover forms only in individual 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 south-eastern Europe and Central Asia The average air temperature 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 the western and eastern slopes of the Ural Mountains in some places 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 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 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 eastern 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 Mediterranean Sea, which was the reason to call this climate also Mediterranean. Similar climate in southern California, central regions Chile, southernmost 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 are often the same as in tropical deserts. In general, clear weather prevails. In summer, on the coasts near which they pass ocean currents, there are often fogs. 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. Average annual precipitation in sub-conditions tropical 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 the average annual temperature is 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. Humid air, cloud cover and dense vegetation prevent night cooling and keep maximum daytime temperatures below +37 °C, lower than in more recent times. high 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.

Climatic (geographical) zone is a vast strip of the Earth's surface that has a latitudinal direction and similar climatic conditions throughout the entire territory.

The difference between climate zones is expressed in the prevailing air masses and air temperature. The main climate characteristics are determined based on these parameters. Climatic zones change in the direction from the equator to the poles. The climatic zones were classified by the Soviet climatologist B.P. Alisov. This was done in 1956, and now this classification is used in the Russian Federation and other countries. B.P. Alisov identified 2 types of belts - basic and transitional.

Main belts:

• arctic;
• northern temperate;
• northern tropical;
• equatorial;
• southern tropical;
• southern temperate;
• Antarctic;

These geographical zones are dominated by air masses of the same name.

The equatorial belt is located between the two tropical ones. It receives a lot of heat and rainfall throughout the year. The average monthly temperature is +23...+28 °C. The radiation balance reaches 90 kcal/sq. cm per year. Precipitation up to 3000 mm per year; on windward slopes this figure reaches 10,000 mm per year. The equatorial belt receives excess moisture due to the fact that the evaporation rate is lower than the monthly precipitation amount.

Tropical zones are located north and south of the equatorial zone. They cross every continent except Antarctica. Tropical zones are most pronounced between the 20th and 32nd parallels of both hemispheres. The tropical climate is formed by air masses of the same name, with anticyclonic circulation and high atmospheric pressure. IN tropical zones throughout the year there is low cloudiness and humidity, with little precipitation. Trade winds predominate among the winds. During the summer average monthly temperature in the tropics it is +30...+35 °C. In winter, the average monthly temperature is above +10 °C. Annual precipitation is 40-200 mm. However, in island regions, windward slopes can receive 2000 mm per year or more. In Hawaii, up to 13,000 mm falls per year. Cold currents make the western coasts of continents cooler compared to the eastern and southern ones. On the western outskirts the air humidity is higher.

The northern temperate zone is located within the 42nd and 64th parallels, and the southern one - between the 41st and 58th. These are the biggest geographical zones by area. The land occupies only a few percent of the southern temperate zone. In the northern part of the planet, the temperate zone has a large area. The climate in temperate zones is characterized by significant differences in average monthly temperature. In temperate latitudes, winter is much colder than in the equatorial zone or the tropics. Here, daily temperature changes are more pronounced. Air masses are transported mainly in a westerly direction. Cyclones are more active than anticyclones. On the outskirts of continents, humidity and precipitation are higher. 650-2000 mm of precipitation falls annually. The windward oceanic slopes receive 5000-8000 mm of precipitation per year.

In the Northern Hemisphere, the polar climate zone is called the Arctic, and in the southern hemisphere, the Antarctic. The Arctic belt occupies the territory north of the 70th parallel. sh., Antarctic - south of the 65th parallel south. w. Both zones have a polar night and a polar day. Permafrost and snow cover reflect large amounts of sunlight. This is one of the reasons for the low air temperature. High in the polar zones Atmosphere pressure. Eastern winds of the same name predominate. The Pole of Cold is located in Antarctica. In summer the average temperature is -30...-35 °C, and in winter -70 °C. At the Antarctic station "Vostok" it drops to -87...-90 °C, and on the coast of Antarctica the average monthly temperature is in the range of -1...-5 °C in summer time and within -18...-22 °C in winter. Similar climatic conditions are observed over the Greenland ice sheet, but are warmer by an average of 15 °C. The Atlantic regions of the Arctic are warmer - up to +5 °C in summer, with the invasion of warm air masses. In the summer season at the North Pole, temperatures reach 0...+2 °C, and the absolute maximum temperature is +5 °C. In winter, the air temperature in the ocean area averages about -20 °C. The American Arctic sector is characterized by a colder climate. In the European part of the Arctic, less than 350 mm of precipitation falls per year, and in the American and Asian sectors it is 160-250 mm.

Transition belts

Between the main belts there are six transition belts. They are characterized by seasonal changes in the prevailing air masses. They alternate between summer and winter. The names of these belts have the prefix “sub”. This means location under the main climate zone.

Transition belts:

• subarctic belt;
• northern subtropical;
• northern subequatorial;
• southern subequatorial;
• southern subtropical;
• subantarctic.

Subequatorial climate zones are located north and south of the main equatorial zone. As a result of the seasonal movement of the belts, dry air from the tropics comes in in winter, and in the summer season there is more humid equatorial air. Accordingly, summers in subequatorial climates are humid and winters are dry. At the same time, the amount of precipitation per year reaches 1400-1500 mm. Mountain slopes receive significantly more - 6000-10000 mm. The difference between winter and summer temperatures is small, but unlike the equatorial zone, it exists. In summer, the air temperature is within +22...+30 °C. Subequatorial belts pass through Northern Australia, Central and South America, Hindustan, Indochina, and Central Africa.

Subtropical zones are located in both hemispheres, within the 30th and 40th parallels. In the Northern Hemisphere, the subtropics are bordered on the south by the tropics, and on the northern side by the temperate zone, and in the Southern Hemisphere these zones are located in reverse order. The thermal regime changes twice a year. The climate here is temperate in winter and tropical in summer. Frosts are possible in subtropical zones. In the subtropics, ocean waters differ high salinity and high temperature (in summer).

The subarctic zone is located between the northern temperate and arctic zones. Arctic and temperate air masses displace each other throughout the year. The belt is located in Northern Canada, Alaska, Russia, the southern edge of Greenland and the Scandinavian Peninsula. Within the borders of Russia, it stretches from the north of Western Siberia to the eastern coast.

The subantarctic belt is located in Southern Hemisphere, and passes through some Antarctic islands and the northern part of the Antarctic Peninsula. The warm period here is short, and the temperature never rises above +20 °C. With the end of summer, cold air masses reduce temperatures below 0 °C. For most of the year it has negative values, which is also typical for the subarctic zone. 250-550 mm of precipitation falls here annually.

Climate-forming factors

The planet's climate is influenced by various factors - both external and internal. External factors mainly influence the amount of incoming radiation and its distribution across seasons, hemispheres and continents.

These factors include the position of the earth's axis and the parameters of the earth's orbit:

Current distance to the Sun. Thanks to this indicator, the amount of solar energy received is determined.
• Earth's orbital eccentricity. This characteristic influences seasonal changes.
• The tilt of the earth's axis.

Internal factors:

• The presence of active volcanoes that can provoke the onset of a volcanic winter or other climate changes.
• Configuration of oceans and continents.
• Air masses.
• Albedo of the atmosphere and surface of the Earth.
• Proximity of seas and oceans.
• Human life activity.
• The nature of the underlying surface.
• Heat flows.

They appeared back 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 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. On climate this belt The trade winds also have an influence, bringing an abundance of precipitation here. The equatorial climate type is formed over the northern regions; on the coast of the Gulf of Guinea, over the basin and headwaters, including the coast 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 climate zones (in the Northern and Southern Hemisphere) over the following areas.

In this type of climate, the state of the atmosphere over the continent and the ocean is different, therefore a distinction is made between continental and oceanic tropical climates.

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 and can be carried 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 the territories (from 40-45° northern 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°C). 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 often than in coastal areas, so summers here are warm (+17-26°C), and winters are cold (-10-24°C) with a stable multi-month temperature. 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, dominant in the east of Eurasia to Korea and in the north, in the northeast, is characterized by a change in stable winds (monsoons) over the seasons, which affects the amount and regime of precipitation. It blows here in winter cold wind from the continent, so 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. The soils dry out after the summer rains, so in the subequatorial climate, unlike in the subequatorial climate, swamps are rare. The territory is favorable for human settlement, which is why many centers of civilization are located here -,. According to N.I. , this is where many varieties originated cultivated plants. The northern subequatorial belt includes: South America (Isthmus of Panama); Africa (Sahel belt); Asia (India, all of Indochina, Southern China, ). The southern subequatorial belt includes: South America (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 summers (from +30 to +50°C) and relatively cold winters with precipitation, no stable snow cover is 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, is cold and dry, and summer is 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 the summer makes it possible to develop lush. 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.

On Earth, it determines the nature of many features of nature. Climatic conditions also greatly influence life, economic activity people, their health and even biological characteristics. At the same time, the climates of individual territories do not exist in isolation. They are parts of a single atmospheric process for the entire planet.

Climate classification

Earth's climates, which have similar features, are combined into certain types, which replace each other in the direction from the equator to the poles. In each hemisphere there are 7 climatic zones, of which 4 are main and 3 are transitional. This division is based on the distribution of air masses around the globe with different properties and characteristics of air movement in them.

In the main belts, one air mass is formed throughout the year. In the equatorial zone - equatorial, in the tropical - tropical, in the temperate - air of temperate latitudes, in the Arctic (Antarctic) - arctic (Antarctic). In the transitional zones located between the main ones, in different seasons years alternately set from the adjacent main belts. Here, conditions change seasonally: in summer they are the same as in the neighboring warmer zone, in winter they are the same as in the neighboring colder zone. Along with the change in air masses in the transition zones, the weather also changes. For example, in the subequatorial zone, hot and rainy weather prevails in summer, and cooler and drier weather in winter.

The climate within the belts is heterogeneous. Therefore, the belts are divided into climatic regions. Above the oceans, where sea air masses are formed, there are areas of oceanic climates, and above the continents - continental climates. In many climatic zones on the western and eastern coasts of the continents, special types of climate are formed, differing from both continental and oceanic. The reason for this is the interaction of marine and continental air masses, as well as the presence of ocean currents.

Hot ones include and. These territories constantly receive significant amount heat due to the high angle of incidence of sunlight.

In the equatorial belt, the equatorial air mass dominates throughout the year. The heated air constantly rises in conditions, which leads to the formation of rain clouds. There is heavy rainfall here every day, often with . The amount of precipitation is 1000-3000 mm per year. This is more than the amount of moisture that can evaporate. The equatorial zone has one season of the year: always hot and humid.

In tropical zones, a tropical air mass dominates throughout the year. In it, air descends from the upper layers of the troposphere to the earth's surface. As it descends, it heats up, and even over the oceans no clouds form. Clear weather prevails, in which the sun's rays strongly heat the surface. Therefore, on land the average in summer is higher than in the equatorial zone (up to +35 ° WITH). Winter temperatures lower than in summer due to a decrease in the angle of incidence of sunlight. Due to the lack of clouds, there is very little rainfall throughout the year, so tropical deserts are common on land. These are the hottest areas of the Earth, where temperature records are recorded. The exception is the eastern shores of the continents, which are washed by warm currents and are influenced by trade winds blowing from the oceans. Therefore, there is a lot of rainfall here.

The territory of subequatorial (transitional) belts is occupied by a humid equatorial air mass in summer, and dry tropical air in winter. Therefore, there are hot and rainy summers and dry and also hot - due to the high position of the Sun - winter.

Temperate climate zones

They occupy about 1/4 of the Earth's surface. They have sharper seasonal differences in temperature and precipitation than hot zones. This is due to a significant decrease in the angle of incidence of sunlight and increased complexity of circulation. They contain air of temperate latitudes all year round, but there are frequent intrusions of arctic and tropical air.

The Southern Hemisphere is dominated by an oceanic temperate climate with cool summers (from +12 to +14 °C), mild winters (from +4 to +6 °C) and heavy precipitation (about 1000 mm per year). In the Northern Hemisphere, large areas are occupied by continental temperate and. Its main feature is pronounced temperature changes across the seasons.

On the western shores of the continents it arrives all year round. wet air From the oceans brought by the western temperate latitudes, a lot of precipitation falls here (1000 mm per year). Summers are cool (up to + 16 °C) and humid, and winters are wet and warm (from 0 to +5 °C). Moving from west to east into the interior of the continents, the climate becomes more continental: the amount of precipitation decreases, summer temperatures increase, and winter temperatures decrease.

A monsoon climate is formed on the eastern shores of the continents: summer monsoons bring heavy precipitation from the oceans, and winter monsoons, blowing from the continents to the oceans, are associated with frosty and drier weather.

The subtropical transition zones receive air from temperate latitudes in winter, and tropical air in summer. The continental subtropical climate is characterized by hot (up to +30 °C) dry summers and cool (0 to +5 °C) and somewhat wetter winters. There is less precipitation per year than can evaporate, so deserts and deserts predominate. There is a lot of precipitation on the coasts of the continents, and on the western shores it is rainy in winter due to westerly winds from the oceans, and on the eastern shores it is rainy in summer due to the monsoons.

Cold climate zones

IN earth's surface during the polar day it receives little solar heat, and during the polar night it does not heat up at all. Therefore, the Arctic and Antarctic air masses are very cold and contain little. The Antarctic continental climate is the most severe: exceptionally frosty winter and cold summers with negative temperatures. Therefore, it is covered by a powerful glacier. In the Northern Hemisphere, the climate is similar, and above it is Arctic. It is warmer than Antarctic waters, since ocean waters, even covered with ice, provide additional heat.

In the subarctic and subantarctic zones, the Arctic (Antarctic) air mass dominates in winter, and air of temperate latitudes in summer. Summers are cool, short and humid, winters are long, harsh and with little snow.

The amount of solar radiation decreases from the equator to the poles, and air masses are formed along thermal zones, i.e. depending on latitude. Latitude also determines the climatic zone - huge territories within which the main climate indicators practically do not change. Climatic zones were defined by the Russian climatologist B.P. Alisov. Their definition is based on the dominant types of air masses, from which the climatic zones received their name.

Climatic zones are divided into main and transitional. Where the influence of one type of air mass predominates throughout the year, the main climatic zones have formed. There are only seven of them: equatorial, two tropical, two temperate, Arctic and Antarctic. Four types of air masses correspond to the seven main climatic zones.

In the equatorial climate zone, low atmospheric pressure and equatorial air masses predominate. The sun here is high above the horizon, which contributes to high temperatures air, and due to the predominance of rising air currents and the influence of moist oceanic air masses that come with the trade winds, a lot of precipitation (1000-3500 mm) falls in this belt.

Tropical zones are dominated by tropical air masses, high pressure and low air masses. Tropical air masses are always dry, because the air that comes from the equator in the tropics at an altitude of 10-12 km already contains little moisture. As it descends, it heats up and becomes even drier. Therefore, it does not rain here often. The air temperature is high. Such climatic conditions contributed to the creation of zones here tropical deserts and semi-deserts.

The temperate climate zone is influenced by westerly winds and moderate air masses. There are clearly defined four seasons here. The amount of precipitation depends on the distance of the territory from the ocean. Thus, the most precipitation falls in the western part of Eurasia. They are brought by westerly winds from the Atlantic Ocean. The further you go to the east, the less precipitation, i.e. the continental climate increases. In the far east, under the influence of the ocean, the amount of precipitation increases again.

The Arctic and Antarctic climate zones are areas of high pressure that are influenced by katabatic winds. The air temperature rarely rises above 0⁰C. The climatic conditions in both zones are very similar - it is always cold and dry here. Precipitation falls less than 200 mm for the whole year.

Territories where air masses change seasonally twice a year belong to transitional climatic zones. In the names of transitional zones the prefix “sub” appears, which means “under”, i.e. under the main belt. Transitional climatic zones are located between the main zones. There are only six of them: two subequatorial, two subtropical, subarctic and subantarctic.

Thus, the subarctic zone is located between the Arctic and temperate, the subtropical - between temperate and tropical, the subequatorial - between tropical and equatorial belts. In transitional zones, the weather is determined by air masses that come from neighboring main zones and change with the seasons. For example, the climate of the subtropical zone in summer is similar to the climate of the tropical zone, and in winter - to the climate of the temperate zone. And the climate of the subequatorial zone in summer has characteristics of an equatorial climate, and in winter - of a tropical climate. In the subarctic zone, the weather in summer is determined by moderate air masses, and in summer by arctic ones.

Thus, climate zones are located zonally and this is due to the influence of solar radiation. Thus, the type of climate on Earth varies zonally. Climate type is understood as a constant set of climatic indicators characteristic of a certain period of time and certain territory. But the earth's surface is heterogeneous, therefore, different types of climate can form within climate zones.

The boundaries of climate zones do not always coincide with the direction of the parallels. And in some places they deviate significantly to the north or south. This is primarily due to the nature of the underlying surface. Therefore, within the same climate zone, different types of climate can form. They differ from each other in the amount of precipitation, the seasonality of its distribution and the annual amplitudes of temperature fluctuations. For example, in the temperate zone of Eurasia there are maritime, continental and monsoon climates. Therefore, individual climatic zones are also divided into climatic regions.

Thus, 13 climatic zones are conventionally distinguished on Earth: 7 of them are main and 6 are transitional. The determination of climate zones is based on the air masses that dominate the region throughout the year. Individual climatic zones (temperate, subtropical, tropical) are also divided into climatic regions. Climatic regions are formed under the influence of the underlying surface within the boundaries of one climate zone.