On the globe stands out climatic zones. §14. Climatic zones and regions of the Earth. Main natural areas

The climate within the Earth's surface varies zonal. The most modern classification, which explains the reasons for the formation of a particular type of climate, was developed by B.P. Alisov. It is based on the types air masses and their movement.

air masses- These are significant volumes of air with certain properties, the main of which are temperature and moisture content. The properties of air masses are determined by the properties of the surface over which they form. Air masses form the troposphere like lithospheric plates that make up the earth's crust.

Depending on the area of ​​formation, four main types of air masses are distinguished: equatorial, tropical, temperate (polar) and arctic (antarctic). In addition to the area of ​​formation, the nature of the surface (land or sea) over which air accumulates is also important. In accordance with this, the main zonal types of air masses are divided into maritime and continental.

Arctic air masses are formed in high latitudes, above the ice surface of the polar countries. Arctic air is characterized by low temperatures and low moisture content.

moderate air masses clearly divided into marine and continental. Continental temperate air is characterized by low moisture content, high summer and low winter temperatures. Maritime temperate air forms over the oceans. It is cool in summer, moderately cold in winter, and constantly humid.

Continental tropical air formed over tropical deserts. It is hot and dry. Sea air is characterized by lower temperatures and much higher humidity.

equatorial air, forming a zone at the equator both over the sea and over land, has high temperature and humidity.

Air masses constantly move after the sun: in June - to the north, in January - to the south. As a result, territories are formed on the surface of the earth where one type of air mass dominates during the year and where air masses replace each other according to the seasons of the year.

The main feature of the climate zone is the dominance of certain types of air masses. subdivided into main(during the year, one zonal type of air masses dominates) and transitional(air masses change seasonally). The main climatic zones are designated in accordance with the names of the main zonal types of air masses. In transitional belts, the prefix "sub" is added to the name of the air masses.

Main climatic zones: equatorial, tropical, temperate, arctic (antarctic); transitional: subequatorial, subtropical, subarctic.

All climatic zones, except for the equatorial one, are paired, that is, there are both in the Northern and Southern hemispheres.

In the equatorial climate zone all year round equatorial air masses dominate, low pressure prevails. It is humid and hot throughout the year. The seasons of the year are not expressed.

Tropical air masses (hot and dry) dominate throughout the year. tropical zones. Due to the downward movement of air that prevails throughout the year, very little precipitation falls. Summer temperatures higher here than in the equatorial belt. Winds are trade winds.

For temperate zones characterized by the dominance of moderate air masses throughout the year. Westerly air transport prevails. Temperatures are positive in summer and negative in winter. Due to the predominance of low pressure, a lot of precipitation falls, especially on ocean coasts. In winter, precipitation falls in solid form (snow, hail).

In the Arctic (Antarctic) belt Cold and dry arctic air masses dominate throughout the year. Descending air movement is characteristic, north- and south- east winds, predominance of negative temperatures during the year, constant snow cover.

In the subequatorial belt there is a seasonal change of air masses, the seasons of the year are expressed. Summer is hot and humid due to the arrival of equatorial air masses. In winter, tropical air masses dominate, so it is warm but dry.

In sub tropical zone moderate (summer) and arctic (winter) air masses change. Winter is not only severe, but also dry. Summers are much warmer than winters, with more rainfall.

Within the climatic zones are distinguished climatic regions with different types of climates maritime, continental, monsoon. Marine type of climate formed under the influence of sea air masses. It is characterized by a small amplitude of air temperature for the seasons of the year, high cloudiness, and a relatively large amount of precipitation. Continental type of climate formed away from the ocean coast. It is distinguished by a significant annual amplitude of air temperatures, a small amount of precipitation, and a distinct expression of the seasons of the year. Monsoon type of climate It is characterized by the change of winds according to the seasons of the year. At the same time, the wind changes direction with the change of season, which affects the precipitation regime. Rainy summers give way to dry winters.

The largest number of climatic regions is within the temperate and subtropical zones of the Northern Hemisphere.

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Characteristics of climatic zones (table below) is the topic of this article. We will talk about what types of climate exist on our planet, and also consider in detail each of them. To do this, we recall that climate is the weather regime established over the years, which depends on a particular territory, its geographical location.

equatorial belt

This climatic zone is characterized by low pressure, as well as year-round presence of air masses. There are no separate climatic regions within the belt. Concerning temperature regime, it's hot in here. During the year there is a lot of precipitation, moisture in abundance. The weather here changes very drastically during the day. The first half is sultry, and the second begins with heavy rains.

The names of climatic zones are associated with their features. The equatorial belt is located near the equator, therefore it has such a name.

The subequatorial belt is characterized by a change in air masses, which occurs seasonally. Equatorial air masses predominate in summer, while tropical air masses prevail in winter. The weather conditions in summer fully correspond to the equatorial type of climate, while the weather in winter resembles the conditions of the tropical zone. Winters are dry and slightly colder than summers.

tropical belt

As we already know, the names of climatic zones are associated with their location. This type of climate is characterized by tropical air masses throughout the year. The air is continental. real weather the tropical zone is high pressure and temperature, a large temperature difference not only during the year, but also during the day. Water is scarce in this climate. It is very hot and dry here, and dry winds often occur. There is almost no rain. The weather is usually dry and sunny.

However, the tropical belt is deceptive. The eastern shores of the continents, which are washed by warm currents, are also in this zone, but have a different climate. Tropical marine air, heavy rainfall, monsoons. Climatic conditions are similar to the equatorial climate.

Subtropical zones are characterized by a change in air masses. The climate is tropical in summer and temperate in winter. Pressure surges in summer and winter are quite high. The pressure is low in winter and high in summer. Despite the strong difference in temperature and precipitation throughout the year, the thermometer is above zero all year round. Sometimes the temperature can even drop to negative values. During such periods, snow falls. In the flat areas, it melts quickly, but in the mountains it can lie for several months. As for the winds, the trade winds rule in winter and the trade winds in summer.

Temperate zone

The temperature of climatic zones largely depends on the air masses that prevail over the territory. IN temperate zone, as the name implies, temperate climate. But not always. Sometimes tropical or arctic air masses invade. The temperate climate is characterized big difference th temperature. Summers are hot and winters are cold and long. Relatively low pressure, cyclonicity, instability weather conditions in winter. Blow all year round westerly winds, sometimes there are trade winds in summer, and northeasterly winds in winter. Massive snow cover every winter.

Arctic and Antarctic belts

In the characteristics of climatic zones in the table, you can see what temperatures prevail in these zones. The features of these belts are low temperatures all year round, strong winds and cold summers. There are very few rainfalls.

Subarctic and subantarctic belts

These belts are distinguished by the fact that a temperate climate prevails here in summer. Because of this, there is a large amplitude of temperature fluctuations. There is a lot of permafrost in these belts. In winter, northeast and southeast winds prevail, and in summer - west winds. Belts have 2 climatic regions, about them below.

Territories of climatic zones

Each zone is characteristic of a certain territory. Natural and climatic zones have been formed on the planet for a long time, so it is safe to identify certain areas in which the climate of the zone is pronounced.

The equatorial climate is typical for Oceania, the countries of South America and Africa. Subequatorial climate is characteristic of Northern Australia and South-East Asia. The central part of Australia and North Africa is a tropical zone. The subtropics are typical for interior areas continents. A temperate climate prevails in the western part and eastern outskirts of Eurasia. belt prevails in North America and northern Eurasia. arctic and ant arctic belt and are characteristic of Australia and the waters of the Northern Arctic Ocean.

Table of climatic zones

The table shows the characteristics of the zones.

Climatic regions of the belts

Subtropical belts have three climatic regions:

1. Mediterranean climate. It prevails in the northern hemisphere, on the southern and western coasts of the continents. In summer there is a continental climate, and in winter - continental and maritime air masses. Summers are dry and warm, while winters are relatively cool and wet. Humidification is insufficient.
2. Monsoon climate. Distributed on the eastern shores of the continents. Summer monsoons cause intense heat and a lot of precipitation, and the winter monsoons are cool and dry. Humidity in this area is moderate. Precipitation is typical for the winter season.
3. Marine climate. Distributed on the continents of the southern hemisphere. Characterized by maritime air masses. Summer and winter are warm. There is enough moisture, it is distributed evenly throughout the year.

The temperate zone consists of 5 climatic regions:

1. moderate It prevails on the western coasts of the continents. The weather is formed under the influence of warm currents and westerly winds. Winters are quite mild and summers are warm. There is a lot of precipitation throughout the year. Winter is characterized by heavy and frequent snowfalls. More than enough moisture. The geography of the climate zone contributes to the instability of the weather.
2. Continental temperate climate. Characterized warm summer and cold winter. Arctic air masses sometimes provoke a sharp cooling, and tropical air masses - warming. There are few precipitations, they are uniform (cyclonal and frontal).
3. Continental climate. Distributed only in the northern hemisphere. Moderate air masses prevail here throughout the year. Sometimes arctic air masses appear (in this area their invasion is also possible in summer). In the warm season, there is more precipitation, but in general they are insignificant. A small amount of snow and the predominance of low temperatures contribute to the existence of permafrost.
4. Sharply continental climate. It is typical for the interior regions of North America and Eurasia. The territory is practically isolated from the influence of the seas and oceans and is located in the center high pressure. Sometimes summers are hot, winters are always frosty. Lots of permafrost. The type of weather is anticyclonic. Little precipitation, little moisture.
5. Monsoon climate. Distributed on the eastern side of the continents. It is characterized by seasonality of air masses. Summers are humid and warm, while winters are dry and cool. Summer precipitation is more numerous, excessive moisture.

The subarctic and subantarctic belts have two areas:

• continental climate (severe, but short winter, little precipitation, swampy territory);
• oceanic climate (fogs, a lot of precipitation, mild winters and cool summers).

The characteristic of climatic zones in the table does not include two areas of the Arctic and Antarctic zones:

• continental (little precipitation, the temperature is below zero all year round);
• oceanic climate (cyclones, little precipitation, negative temperatures).

The temperature in the oceanic climate can rise to +5 during the polar day.

Summing up, let's say that the characteristics of climatic zones (in the table) are necessary for every educated person.

Climatic zones and regions The lands stretch in the latitudinal direction in accordance with the zoning of the climate. The main climatic zones are distinguished on the basis of the predominance of air masses certain type. In each hemisphere - Northern and Southern - there is one tropical, one temperate and one polar (Arctic or Antarctic) zone. The equatorial belt is one for both hemispheres.

Between the main climatic zones are transitional zones - three in each hemisphere - subequatorial, subtropical And subarctic (subantarctic).

In transitional climatic zones, air masses change according to the seasons of the year.

Together with the Sun, air masses move north and south in summer and winter. Transitional belts do not have their own air masses. In summer, masses come here from the neighboring main belt, closer to the equator (Fig. 34, A), and in winter - from the more “polar” neighboring belt (Fig. 34, B).

In the Northern Hemisphere, equatorial air masses come to the subequatorial belt in summer, and hot weather with rains sets in. In winter, tropical air comes from the north, it becomes hot and dry.

In the subtropical zone, tropical air "hosts" in summer (hot and dry), and in winter air comes from temperate latitudes - the temperature drops, it rains. For example, a type of climate with hot, dry summers and cool, rainy winters is called mediterranean. There are other types of sub tropical climate A.

In the subarctic zone in summer - the air of temperate latitudes, and in winter, long and severe - arctic.

When talking about the climate of any territory, they most often use the words: warm, cold, wet, dry. Indeed, the conditions for providing heat and moisture are very diverse and depend on combinations of climate-forming factors. The boundaries of climatic zones do not run strictly along parallels. In addition, within the belts, there are areas With different types climate (Fig. 33). This is the result of different remoteness of territories from the oceans and seas, as well as, to some extent, the action of atmospheric circulation and ocean currents. material from the site

In the tropical, subtropical and temperate zones there are areas maritime And continental climate. Climate areas are also distinguished Western And east coasts of the continents. For example, on the eastern coast of Eurasia, in the subtropical zone, there is a monsoon climate with hot, humid summers and cold, dry winters. And on the western coast of Eurasia in the subtropics, the Mediterranean climate. Despite its name, it exists on other continents, including the Southern Hemisphere.

It should also be noted that cold currents pass along the western coasts from high latitudes to low latitudes. They cool and dry the climate. Along the eastern coasts, on the contrary, warm currents flow from low latitudes to high latitudes, contributing to an increase in temperature and humidity in the adjacent territories.

Total for the globe seven main and six transitional climatic zones. Various combinations climate-forming factors determine the presence of areas within climatic zones. The main one is remoteness (proximity) from the ocean.

Definition 1

climate zone- This is a latitudinal strip on the surface of the Earth, with a relatively uniform climate.

Climatic zones differ from each other air temperature And dominating air masses. In accordance with their properties, the main features of the climate are determined. Change of climatic zones on the planet occurs zonal, i.e. from equator to the poles. The classification of climatic 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 singles out basic and transitional climatic zones.

There are seven main climatic zones:

• equatorial belt;
• Two tropical belts;
• Two temperate belts;
• Two polar belts arctic and antarctic.

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

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

Tropical climate zones. One tropical belt is located in Northern hemisphere of the planet, the second - in Southern hemisphere. Tropical belts cross all continents except Antarctica and are well expressed in the oceans between the $20$ and $30$ parallels of both hemispheres. The climate of the tropics 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 rainfall. By the prevailing winds are trade winds. Summer average monthly air temperatures are + $30$-$35$ degrees, winter temperatures are not lower than +$10$ degrees. Daily and annual amplitudes are quite high. Annual precipitation is 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, in the Hawaiian Islands about $13,000 mm falls. On the western coasts of the continents, the climate will be cooler due to cold ocean currents. There will be higher air humidity, an even temperature course and frequent fogs.

temperate climatic zones. One temperate zone is located in Northern hemisphere, between $40$ and $65$ parallel, the other - in Southern 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, the opposite is true. There $98\%$ falls on ocean. In temperate zones, there is a clear seasonality of the climate. It is expressed in a large difference between summer and winter temperatures. Moreover, in the Northern Hemisphere, the annual and daily amplitude is much higher than in the Southern. The western transport of air masses of temperate latitudes dominates here, and intense cyclonic activity is observed. To the margins 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 belts are characterized by polar nights and polar days. Eternal ice and snows radiate a huge amount of solar heat, which is the cause of very cold air. Atmospheric pressure is high all year round and easterly winds prevail. Located in Antarctica pole of cold planets. IN summer period the average air temperature is $30$ degrees, and the winter temperature is $70$. 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. over the Greenland ice sheet Arctic climatic conditions similar but softer. In the Atlantic regions Arctic and up to the Pole, the summer temperature is about $0$ degrees, and with warm air intrusion, 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. Most of the 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 are zones transitional belts. They are $6$ and are characterized by a seasonal change in the prevailing air masses, i.e. In summer, one air mass dominates there, and in winter, another. The prefix " sub", which in Latin means " under”, i.e., a belt located under the main.

Transition belts include:

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

Subequatorial climate zone. These belts are located south and north of the equatorial. As a result of the shift of climatic zones according to the seasons of the year, humid equatorial air comes here in summer, and dry tropical air comes in winter. Summer for subequatorial belts 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 is even more - $6,000-$10,000 mm per year. The difference between summer and winter temperatures is small, but the difference with the equatorial belt is felt. Summer temperatures range from $22$-$30$ degrees. In addition to the oceans, the subequatorial belt passes through South America, Central Africa, Hindustan, Indochina, and North Australia.

Subtropical climatic zones. They are located within $30$-$40$ degrees of the Northern and Southern hemispheres. From the south, the subtropics border on the tropical zone, and on the north with the temperate zone in the Northern Hemisphere. In the Southern Hemisphere, north of the subtropics is the tropical zone, and the temperate zone to the south. Thermal regimes alternate in half a year - a moderate regime is observed in winter, and a tropical regime in summer. Frosts are already possible for the subtropics. Within the ocean belts are characterized by high temperature and high salinity of water.

Subarctic climate zone. This transitional belt is closest to North Pole Earth. Moderate and arctic air masses alternate during 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 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 a short summer with temperatures below + $20$ degrees. Cold air masses in winter reduce the temperature to negative values. And it stays below freezing most of the year. The same is true for the subarctic zone. There are few precipitations and they are reduced from $500$-$250$ mm and below.

climate-forming factors

On the formation of the planet's climate big influence render external and internal factors. Most of the external factors have an impact on the total amount of incoming solar radiation, its distribution by seasons of the year, by hemispheres and continents.

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

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

Internal factors include:

• The configuration of the oceans and continents and their relative position;
• The presence of active volcanoes that can change the climate up to the 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 in them;
• The nature of the underlying surface;
• Human economic activity;
• Heat flows of the planet.

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

Climate influences living and inanimate nature. are closely related to climate water bodies, soil, vegetation, animals. Separate sectors of the economy, especially Agriculture are also highly dependent on climate.

The climate is formed as a result of the interaction of many factors: the amount of solar radiation entering the earth's surface; atmospheric circulation; the nature of the underlying surface. At the same time, climate-forming factors themselves depend on geographical conditions the area, especially geographic latitude.

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

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

plays an important role in shaping the climate relief. You already know that with the rise of the terrain for each kilometer, the air temperature drops by 5-6 ° C. Therefore, on the high slopes of the Pamirs, the average annual temperature- 1 ° C, although it is located a little north of the tropic.

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

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

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

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

Climatic zones

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

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

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

The main climatic zones are:

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

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

Climatic zones are divided into climatic regions. So, for example, in the tropical zone of Africa, areas of tropical dry and tropical humid climate are distinguished, and in Eurasia, the subtropical zone is divided into areas of the Mediterranean, continental and monsoon climate. In the mountainous areas is formed altitudinal zonality because the air temperature decreases with altitude.

Diversity of Earth's climates

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

Arctic and Antarctic climate zones

Antarctic and arctic climate dominates in Greenland and Antarctica, where the average monthly temperatures are below 0 °C. Into the dark winter time During the year, these regions receive absolutely no solar radiation, although there are twilights and auroras. Even in summer, the sun's rays fall on the earth's surface at a slight angle, which reduces the heating efficiency. Most of the incoming solar radiation is reflected by the ice. In both summer and winter, low temperatures prevail in the elevated regions of the Antarctic Ice Sheet. The climate of the interior of Antarctica is much colder than the climate of the Arctic, because southern mainland is different large sizes and heights, and the Arctic Ocean moderates the climate, despite the wide distribution of pack ice. In summer, during short periods of warming, drift ice sometimes melts. Precipitation on ice sheets falls in the form of snow or small particles of ice mist. Inland regions receive only 50-125 mm of precipitation annually, but more than 500 mm can fall on the coast. Sometimes cyclones bring clouds and snow to these areas. Snowfalls are often accompanied strong winds, which carry significant masses of snow, blowing it off the slope. Strong katabatic winds with snowstorms blow from the cold glacial sheet, bringing snow to the coast.

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

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

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

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

The climate of the subarctic zone of North America is less continental than the corresponding climate of Asia. Here less Cold winter and colder summers.

temperate climate zone

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

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

winter in temperate zone warm on the western coasts. The warming effect of the oceans is enhanced by warm sea currents washing the western shores of the continents. The average temperature in January is positive and varies across the territory from north to south from 0 to 6 °C. Intrusions of arctic air can lower it (on the Scandinavian coast down to -25°C, and on the French coast down to -17°C). With the spread of tropical air to the north, the temperature rises sharply (for example, it often reaches 10 ° C). In winter, on the western coast of Scandinavia, there are large positive temperature deviations from the average latitude (by 20 ° C). The temperature anomaly on the Pacific coast of North America is smaller and does not exceed 12 °С.

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

Even during the day, the air temperature rarely exceeds 30 °C. Cloudy and rainy weather is typical for all seasons due to frequent cyclones. Especially a lot cloudy days happens on the west coast of North America, where before mountain systems Cordillera cyclones are forced to slow down their movement. In connection with this, the weather regime in the south of Alaska is characterized by great uniformity, where there are no seasons in our understanding. Eternal autumn reigns there, and only plants remind of the onset of winter or summer. Annual rainfall ranges from 600 to 1000 mm, and on the slopes of mountain ranges - from 2000 to 6000 mm.

In conditions of sufficient moisture on the coasts developed broadleaf forests, and in conditions of excess - coniferous. The lack of summer heat reduces upper bound forests in the mountains up to 500-700 m above sea level.

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

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

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

Unlike Eurasia, East Coast North America is characterized sea ​​features climate, which are expressed in the predominance of winter precipitation and marine type annual course air temperatures: the minimum occurs in February, and the maximum occurs in August, when the ocean is at its warmest.

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

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

A feature of the temperate continental climate is the large annual amplitude of air temperature, which can reach 50-60 °C. IN 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 a powerful Asian anticyclone forms in winter and cloudy, calm weather prevails. The temperate continental air formed 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 the middle of winter, continental air in lower layers becomes even colder than the arctic. This very cold air of the Asian anticyclone spreads to Western Siberia, Kazakhstan, southeastern regions of Europe.

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

On the formation of the continental temperate climate have a significant impact geographical features continental territories. In North America, the Cordillera mountain ranges are a natural boundary separating the coast with a maritime climate from the inland regions with a continental climate. In Eurasia, a temperate continental climate is formed over a vast expanse of land, approximately from 20 to 120 ° E. e. Unlike North America, Europe is open to free penetration of sea air from the Atlantic deep into the interior. This is facilitated not only by the western transfer of air masses, which prevails in temperate latitudes, but also by the flat nature of the relief, the strong indentation of the coasts and the deep penetration into the land of the Baltic and North Seas. Therefore, a temperate climate is forming over Europe. lesser degree continentality compared to Asia.

In winter, the Atlantic sea air, moving over the cold land surface of the temperate latitudes of Europe, retains its physical properties 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 °С in January, -3 °С in Warsaw, -11 °С in Moscow. At the same time, the isotherms over Europe have a meridional orientation.

The orientation of Eurasia and North America with a wide front to the Arctic Basin contributes to the deep penetration of cold air masses onto the continents throughout the year. 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 its high speed of movement, high moisture content and continuous low cloud cover.

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

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

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

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

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

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

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

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

Subtropical climate zone

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

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

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

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

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

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

Equatorial climate zone

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