Section 38. Climatic zones
Remember who distinguish air masses depending on the area of their formation.
Climatic zones. Climatic zones - latitudinal belts earth surface having a relatively homogeneous climate. The belts differ from each other in air temperature and superior air masses, which, according to their properties, determine the main features of the belt's climate. Climatic zones vary from the equator to the poles, i.e. zonal. Distinguish 7 major climatic zones: equatorial, Two tropical, Two moderate and two polar (arctic and Antarctic) - One in each hemisphere. Each of them is dominated by one air mass throughout the year - equatorial, tropical, temperate, arctic (Antarctic), respectively.
Between the major belts in each hemisphere are formed transitional climatic zones: subequatorial, subtropical and subarctic (subantarctic) ... They are called sub-belts - from Latin "sub" means "under", that is, under the main ( ideally, pidtropic, etc.). In transition zones, air masses change with seasons. They come from the neighboring main zones: in summer, air mass reigns south of the main zone, and in winter - in the north. For example, in sub equatorial belt reigns in summer equatorial air- the wet season of the year begins, tropical air comes in in winter - the dry season begins. Therefore, the climate of the subequatorial zone in summer is similar to the climate of the equatorial zone, and in winter - to tropical.
On the map of climatic zones, it is clearly seen that their borders do not run strictly along parallels, but deviate from north to south. This is due to the influence of the third Climate-forming factor - underlying surface: oceans, land, relief, currents, ice sheet.
Within the climatic zones, climatic regions are distinguished with different types of climates: Continental and maritime, a peculiar climate of the western and eastern coasts of the continents.
Rice. Climatic zones
The main types of climate. In different territories under the same influence Climate-forming factors a certain type of climate is formed. The name of the type of climate is determined by the name of the climatic zone (equatorial, subtropical, tropical, temperate climate and others), a subtype of air masses (Marine, continental climate), temperature and humidification features.
Have equatorial belt humid equatorial air masses prevail. Air temperatures are high (24 ... 28 0 С). The updrafts produce powerful cumulonimbus clouds that bring thunderstorms every day. A large amount of precipitation per year (over 2000 mm) is also facilitated by the trade winds, which bring humid oceanic air. Temperature and rainfall remain almost unchanged over the year.
For subequatorial belts seasonal change of air masses is characteristic. The summer monsoon brings equatorial air, the winter monsoon brings continental tropical air. Therefore, in summer it is hot and humid, like in the equatorial zone. And in winter, the temperature decreases slightly (20 0 С, humidity is low, there is no precipitation. Such a climate with humid summers and dry winters is called monsoon... Deciduous forests grow.
Have tropical zones dry tropical air masses predominate. There is high atmospheric pressure and downward air movement. The temperature in summer is very high (35 0 С), in winter it decreases slightly (20 0 С). A very large daily amplitude of fluctuations (30-40 0 С). The tropical air is too dry, so there is generally little rainfall. According to the amount of precipitation in this belt, climatic regions with different types of climate have been formed. Tropical desert climate (almost no precipitation, only abundant dew and thick fogs are formed) formed on west coasts continents, which are washed by cold currents. Tropical wet the climate (there is a lot of precipitation - over 1000 mm per year) dominates on east coasts continents, which are washed by warm currents.
Have subtropical zones the climate is influenced by seasonal change of air masses: tropical in summer, moderate in winter. Continental subtropical the climate is dry, with hot summers and cool winters. On the western coasts of the continents, the climate subtropical Mediterranean with hot, dry summers and mild wet winters. Climate on the eastern coasts monsoon(Summers are hot, humid, winters are cool, dry). Inland climate sharply continental(Cool summers, harsh winters, little rainfall).
Have temperate zones dominated by moderate air masses and westerly winds, cyclones and anticyclones. There are well-defined seasons with positive temperatures in summer and negative in winter. There is a lot of precipitation, but they are unevenly distributed: many in the west of the continents, little in the interior, enough in the east. Various climatic regions have formed in the belt. Continental temperate the type of climate (from moderately continental to sharply continental) is widespread in the interior regions of the continents. On the western coasts of the continents, marine temperate climate, in the east - monsoon.
Subarcticі subantarctic belts the seasonal change of air masses is also characteristic: moderate in summer, arctic in winter. Summers are cool (10 0 С) and damp, winters are harsh (-40 0 С), long and with little snow. There is little rainfall - 200 mm per year. Permafrost is widespread - freezing of rocks to a great depth (up to 500 m). Maritime climate with cool summers and mild winters observed around the Arctic Ocean and Antarctica.
Have arctic (antarctic) belt cold and dry arctic (Antarctic) air masses prevail. Air temperatures are negative throughout the year. There is very little rainfall - 100 mm per year.
The climate plays an important role in the living and inanimate nature of the Earth. It determines the distribution of soils, flora and fauna, the state of rivers, lakes, seas, glaciers.
Rice. Arctic belt
Rice. Tropical belt
Rice. Subequatorial belt
Climate map. Climate maps will help you understand the complex formation and placement of climates on Earth. They contain data on the main elements of the climate: the temperature of the warm and cold months (January and July), the direction of the wind, the amount of precipitation. average temperature air is shown by isotherms. Separate numbers indicate low and high temperatures... To show on the map how much and where precipitation falls, places with different annual amount painted over with different colors. The prevailing wind directions are shown with arrows. The climate map can be used to characterize the climate of any territory.
Influenced the climate on a person. Weather and climate affect the living conditions of people. People have learned to adapt to different types of climate. Their dwelling, clothing, footwear, food is the result of such an adaptation. Everyone knows that the dwelling, clothing, footwear of the inhabitants of the Far North are different from where they live and what the inhabitant of the equatorial belt is wearing and wearing. The climate determines not only the need for warmth or coolness, but even the mood.
The harvest and the daily work of builders, pilots, and sailors are associated with the climate. Without knowledge about the climate, it is impossible to choose the right place for dams, reservoirs and airfields, to determine the directions of airlines and sea routes. Weather and climate affect people's health and well-being. For example, people who come to work in the polar regions are sometimes forced to come back, because not everyone's body can adapt to the conditions of the harsh climate with strong winds and frost. Resorts for recreation and treatment have been created in areas with a warm maritime climate.
Climate change. If the weather is marked by variability, then the climate, on the contrary, is persistent. If it does change, then slowly and over a very long time - tens of thousands and millions of years. In the distant geological past, climate change occurred in waves: there was a warming, then a cold snap. Such climate fluctuations are confirmed by the fossil remains of plants and animals that existed under certain conditions, as well as various rocks. For example, coal could form in warm and humid climates. So its deposits in Antarctica indicate that once the climate there was completely different. Due to the cooling of the climate, which took place about a million years ago, an ice age began on Earth. Then large areas of land were covered with glaciers. This period ended only 10-12 thousand years ago.
Questions and tasks
1. Which are the main and transitional climatic zones on Earth?
2. What air masses "pass" in winter and summer into the subtropical and subarctic belts?
3. How does the type of climate change in temperate with a distance from the Atlantic Ocean?
4. What kind of climate indicators can be found on climate maps?
5. What is the influence of climate on human living conditions?
6. Can climate change over geological time?
In latitudinal space - from the equator to the poles - distinguish climatic zones... Each belt has constant climatic indicators throughout the year.
Climatic zones - latitudinal bands the globe with a relatively homogeneous climate.
Allocate seven main climatic zones: equatorial, two tropical, two moderate, two polar (arctic and Antarctic).
Between the main climatic zones there is six transitional: two subequatorial, two subtropical, subarctic and subantarctic(the prefix "sub" means "between"). On transition belts the adjacent main climatic zones are significantly affected.
Let us consider by what indicators the features of the main climatic zones are determined.
- Region atmospheric pressure: Р В - high pressure; NS- low pressure.
- Upward and downward air flows ↓↓.
- Prevailing air masses. (Computer - equatorial, UVM - moderate, AVM - Arctic and Antarctic air masses.)
- Average January temperatures ( t i) and July ( t Il).
- The amplitude of temperature fluctuations throughout the year is At.
- Precipitation amount - O.
- Constant winds - trade winds ( <п ); westerly winds of temperate latitudes ( → sound); northeastern ( / from-to) and southeastern ( \ u-v).
Using the climatic map of the world from the atlas and conventional signs of the main climate indicators, we will characterize the climatic zones.
Equatorial climate zone: NS, Computer, t I =+24 ° С, t Il= + 24 ° С, At = 0 ° C, O= 2000-3000 mm, <п .
In the equatorial climatic zone during the year, there is a low atmospheric pressure and equatorial air masses. January and July temperatures reach + 24 ° С. The amplitude of temperature fluctuations is about 0 ° С, i.e. in the equatorial climatic zone there is no division into seasons. Annual precipitation is 2000-3000 mm. Accordingly, the climate is hot and humid. Trade winds blow from the northeast (Northern Hemisphere) and southeast (Southern Hemisphere).
Tropical climatic zones of both hemispheres — Р В, TVM, t i= +20 ° С, t Il= +30 ° С, At= 10 ° C, O= 100-250 mm, <пф (trade winds are forming). Material from the site
Moderate climatic zones. In both hemispheres, low atmospheric pressure and moderate air masses prevail. There is a large temperature difference between the coldest and warmest months. The seasons are clearly defined. The amount of precipitation depends on the remoteness of the seas and oceans. So, under the influence of westerly winds of temperate latitudes, the largest amount of precipitation falls in the western regions of the continents, the smallest - and in the central, in the eastern part it increases again on the coast of the oceans.
Polar climatic zones (arctic and Antarctic). High pressure. Arctic (Antarctic) cold and dry air masses prevail. Annual air temperatures usually do not exceed 0 ° С. There is very little precipitation (up to 200 mm per year). Katabatic winds are formed here.
On this page material on topics:
An essay on what climatology studies
Climatic zones with conventional signs
Arctic and Antarctic belts high or low pressure
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Climatic zones. 7 class
The climatic zone is a vast territory with more or less homogeneous conditions. Climatic zones are: Basic (7) Transitional (6) Basic climatic zones are zones in which the general nature of air movement throughout the year remains unchanged. Transitional climatic zones are areas where six months are signs of one main belt, and the next six months are signs of another main belt.
The main climatic zones. Equatorial (1) Tropical (2) Moderate (2) Polar (2): Arctic and Antarctic
Intermediate climatic zones Equatorial l Subequatorial Tropical Subtropical Moderate Subpolar Polar
Equatorial climatic zone. There are no seasons. All year round 26-280С Precipitation all year round. More than 2000mm per year. The length of the day during the year is equal to the night. The climate is always warm and very humid
In the equatorial climate, humid equatorial forests grow. MMM
Subequatorial climate On both sides of the equator between 5-15C. There are seasons: the rainy season and the dry season. Hot rainy summers. Dry winters. Here are the SAVANNAS
Savannahs are located in the subequatorial climate.
Tropical climate. Located along the tropics. All year round high pressure area In summer it is very hot up to 40-50gr. With winter up to 15C Little precipitation up to 100mm High daily temperature fluctuations Deserts are characteristic.
In tropical climates, there are usually deserts.
Subtropical climate Located between 30-40 degrees of both latitudes. In summer, the temperature is 25-30C, there is no rain. In winter, up to 15C, rains. Summers are hot and dry, and winters are mild and rainy. The climate is good for health.
Moderate climatic zone. Four seasons Located between 400 and 650 in both latitudes. They are distinguished by a maritime, continental and harsh continental climate. They differ in the amount of precipitation, maximum and minimum temperatures and amplitude. Depending on the temperatures (winter and summer) and precipitation in the temperate zone, there are deciduous, mixed, coniferous (taiga) forests, steppes and deserts.
Temperate deciduous forests.
Taiga - temperate coniferous forests
Temperate zone. Steppe
Moderate climatic zone. Gobi Desert.
Subpolar climate zone Low temperature in winter Summer signs of temperate zone Winter long and cold Summer is cool and windy. Permafrost is characteristic - a thick layer of the earth's crust that does not thaw for hundreds and thousands of years. The tundra is located here.
Tundra. Subpolar climate.
Polar climate. Arctic .. Very cold Most pronounced in Greenland. In summer, on polar days, it is warmer to minus 10-150. Little precipitation and low evaporation. In the Arctic, there is water under the ice, except for the islands. There are few animals in the Arctic desert. Polar bears live here.
Antarctic climatic zone. The coldest belt on Earth In 1983, -89.20C was recorded - this is the cold pole. The mainland is under the snow. The climate is very dry. Central Antarctica has the driest place on Earth - there is no precipitation. Of the animals, flightless birds - penguins - live on the ocean coast. There are polar days and nights and the northern lights.
Antarctica
Thank you for your attention! Were used by: www.ecosystema.ruwww.google.com
Remember
What do you know from your Grade 6 Geography course about the conditions that determine climate?
The climate is determined by the latitude of the area (the angle of incidence of the sun's rays), the nature of the underlying surface, and the general circulation of the atmosphere.
This i know
1. List the main climate-forming factors. What is the most important factor?
The main climate-forming factors are latitude, general atmospheric circulation and the nature of the underlying surface. The most important factor is the geographical latitude of the area.
2. Explain how the underlying surface affects the climate of the area?
First, different temperature conditions and humidity are formed over the surface of the oceans and land. More humidity over the oceans, less temperature fluctuations. On land, the climate changes with distance from the coasts inland. At the same time, temperature fluctuations increase, cloudiness and precipitation decrease. The climate is influenced by currents. The cold currents off the coast make the coastal climate cool and very dry. Warm currents make the climate milder. The relief and the absolute height of the area play an important role in the formation of the climate.
3. Give examples of the influence of remoteness from the oceans on the climate of the territory.
A striking example of the influence of remoteness from the oceans on climate is the difference between the climate of the coasts and inland regions of Eurasia. The coasts of the continents have a mild climate with warm summers and mild winters with frequent thaws. Up to 800 mm of precipitation falls here. The interior regions are characterized by dry hot summers and very frosty winters with little snow.
4. What is the difference between the main climatic zone and the transitional one?
In the main climatic zone, one air mass dominates throughout the year. In the transition zones, two air masses replace each other.
That i can
5. On the map "Climatic zones and regions of the Earth", name the main and transitional climatic zones.
Transition belts have the prefix "sub-" in the name.
6. Determine the type of climate by the combination of signs: January temperature -10 ... -150C, July + 20 ... + 250C. precipitation occurs throughout the year, but with a summer maximum. Annual precipitation is 250-300 mm. On which continents is this type of climate represented?
This is a temperate continental type of climate. It is represented in Eurasia, North America.
7. Using the climate diagram (see Figure 35), determine the type of climate.
The climate is characterized by small temperature fluctuations. The air temperature does not drop below 10 0С in winter, summer temperatures - + 20 ... + 250С. Precipitation has a winter maximum. Such characteristics can be possessed by a subtropical Mediterranean type of climate.
8. Fill in the table
This is interesting to me
9. In what climatic zone would you like to go on vacation in the summer? What kind of clothing will you especially need when traveling?
For a summer vacation, I would go to the subtropical Mediterranean climatic zone. 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.
During the trip, you will need light clothing made from natural fabrics that would not leave exposed skin, beachwear and hats.
EARTH CLIMATE BELTS
Due to the uneven heating of our planet by the Sun and the distribution of atmospheric precipitation over the earth's surface, the Earth's climates are very diverse. The first classifications of climates appeared in the 70s of the 19th century and were descriptive. According to the classification of Moscow State University professor B. P7 Alisov, there are 7 types of climates on Earth that make up climatic zones. 4 of them are basic, and 3 are transitional. The main types are:
Equatorial. This type of climate is characterized by the dominance of equatorial air masses throughout the year. On the days of the spring (March 21) and autumn (September 21) equinox, the Sun is at its zenith above the equator and heats the Earth greatly. The air temperature in this climatic zone is constant (+ 24-28 ° С). 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 the soils in the equatorial climate are swampy, and dense and tall humid forests grow on them. The climate of this zone is also influenced by the trade winds, which bring here an abundance of precipitation. The equatorial type of climate is formed over the northern regions of South America; on the coast of the Gulf of Guinea, over the Congo Basin and the upper Nile, including the shores of Lake Victoria in Africa; over most of the Indonesian archipelago and the adjacent Indian and Pacific oceans in Asia.
Tropical. This type of climate forms two tropical climatic zones (in the Northern and Southern Hemisphere) over the following territories.
In this type of climate, the state of the atmosphere over the mainland and the ocean is different, therefore, a continental tropical climate and an oceanic tropical climate are distinguished.
Mainland: a large area is dominated by an area of high pressure, therefore very little precipitation falls here (from 100-250 mm). The continental tropical climate is characterized by very hot summers (+ 35-40 ° С). In winter, the temperature is much lower (+ 10-15 ° С). Daily temperature fluctuations are great (up to 40 ° C). The absence of clouds in the sky leads to the formation of clear and cold nights (clouds could trap the heat coming from the Earth). Sharp daily and seasonal temperature drops contribute to the destruction of rocks, which gives a lot of sand and dust. They are picked up by the winds and can be carried over considerable distances. These dusty sandstorms are a great danger to the traveler in the desert.
The continental tropical climates of the western and eastern coasts of the continents are very different from each other. Cold currents pass along the western shores of South America, Africa and Australia, so the climate here is characterized by a relatively low air temperature (+ 18-20 ° C) and low precipitation (less than 100 mm). Warm currents run along the eastern coasts of these continents, so temperatures are higher here and more precipitation falls.
The tropical oceanic climate is similar to the equatorial one, but differs from it in less cloudiness and steady winds. Summer over the oceans is not so hot (+ 20-27 ° С), and winters are cool (+ 10-15 ° С). Precipitation falls mainly in summer (up to 50 mm).
Moderate. A significant influence of westerly winds is observed, bringing precipitation throughout the year. Summer in this climatic zone is moderately warm (from + 10 ° С to + 25-28 ° С). Winter is cold (from + 4 ° С to -50 ° С). Annual precipitation ranges from 1000 mm to 3000 mm on the outskirts of the mainland and up to 100 mm in the interior. The differences between the seasons of the year are clearly manifested. This type of climate also forms two belts in the Northern and Southern Hemispheres and is formed over the territories of temperate latitudes (from 40-45 ° north and south latitude to the polar circles). Above these territories, an area of low pressure, active cyclonic activity is formed. The temperate climate is classified into two subtypes:
- marine, which dominates in the western parts of North America, South America, Eurasia, is formed under the direct influence of westerly winds from the ocean to the mainland, therefore it is distinguished by cool summers (+ 15-20 ° С) and warm winters (from + 5 ° С). Precipitation brought by westerly winds falls all year round (from 500 mm to 1000 mm, in the mountains up to 6000 mm);
- continental, dominant in the central regions of the continents, differs from it. Cyclones penetrate here less often than in coastal areas, so summers are warm (+ 17-26 ° С), and winters are cold (-10-24 ° С) with a stable snow cover for many months. Due to the considerable length of Eurasia from west to east, the most striking continental climate is observed in Yakutia, where average January temperatures can drop to -40 ° C and little precipitation falls. This is because the inland areas of the mainland are not affected by the oceans as much as the coasts, where humid winds not only bring precipitation, but also soften the heat in summer and frost in winter. The monsoon subtype of the temperate climate, prevailing in the east of Eurasia from Kamchatka to Korea and in the north of Japan, in the northeast of China, is characterized by a change in steady winds (monsoons) by seasons, which affects the amount and mode of precipitation. In winter, a cold wind blows here from the continent, so winters are clear and cold (-20-27 ° С). In summer, winds from the Pacific Ocean bring warm rainy weather. In Kamchatka, Sakhalin falls from 1600 to 2000 mm of precipitation.
In all subtypes of the temperate climate, only moderate air masses dominate.
Polar type of climate. Above 70 ° northern and 65 ° southern latitudes, a polar climate prevails, forming two belts: Arctic and Antarctic. Polar air masses prevail here throughout the year. The sun does not appear at all for several months (polar night) and for several months does not go beyond the horizon (polar day). Snow and ice emit more heat than they receive, so the air is very cooled, the snow cover does not melt all year round. Throughout the year, a high pressure area dominates over these territories, so the winds are weak, there are almost no clouds. Very little precipitation falls, the air is saturated with small ice needles. When they settle, they add up to only 100 mm of precipitation per year. The average summer temperature does not exceed 0 ° C, and the winter temperature does not exceed -20-40 ° C. Prolonged drizzle is typical for summer.
Equatorial, tropical, temperate, polar types of climate are considered to be the main ones, since within their belts the air masses characteristic of them dominate throughout the year. Between the main climatic zones there are transitional zones with the prefix "sub" (Latin "under") in the name. In transitional climatic zones, air masses change with seasons. They come here from neighboring belts. This is due to the fact that as a result of the movement of the Earth around its axis, there is a shift of climatic zones to the north, then to the south.
There are three additional types of climate:
Subequatorial climate. Equatorial air masses dominate in this belt in summer, and tropical air masses in winter.
Summer: a lot of precipitation (1000-3000 mm), the average air temperature is + 30 ° С. The sun reaches its zenith in spring and beats down mercilessly.
Winter is cooler than summer (+ 14 ° С). Little precipitation falls. Soils dry out after summer rains, therefore, in the subequatorial climate, in contrast to the equatorial, swamps are rarely found. The territory is favorable for human settlement, therefore it is here that many centers of the emergence of civilization are located - India, Indochina, Ethiopia. According to N.I. Vavilov, it is from here that many varieties of cultivated plants originated. The northern subequatorial belt includes: South America (Isthmus of Panama, Venezuela, Guinea); Africa (Sahel belt); Asia (India, Bangladesh, Myanmar, all of Indochina, South China, the Philippines). The southern subequatorial belt includes: South America (Amazonian lowland, Brazil); Africa (center and east of the mainland); Australia (northern coast of the mainland).
Subtropical climate. Here in summer, tropical air masses dominate, and in winter, air masses of temperate latitudes, carrying precipitation, invade here. Such circulation of air masses determines the following weather in these areas: hot, dry summers (from +30 to + 50 ° С) and relatively cold winters with precipitation, no stable snow cover is formed. Annual precipitation is about 500 mm. Inside the continents, in subtropical latitudes, precipitation is low even in winter. The climate of dry subtropics prevails here with hot summers (up to + 50 ° С) and unstable winters, when frosts down to -20 ° С are possible. In these areas, precipitation is 120 mm or less. In the western parts of the continents, the Mediterranean climate prevails, which is characterized by hot, slightly cloudy summers without precipitation and cool, windy and rainy winters. More precipitation falls in the Mediterranean climate than in the dry subtropics. The annual amount of 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. Winters here are cold and dry compared to other climates of the subtropical zone, while summers are hot (+ 25 ° C) and humid (800 mm). This is due to the influence of monsoons blowing from land to sea in winter and from sea to land in summer and bringing precipitation in summer. The monsoon subtropical climate is well expressed only in the Northern Hemisphere, especially on the east coast of Asia. Abundant rainfall in summer makes it possible to develop lush vegetation. On fertile soils, agriculture is developed here, supporting the lives of more than a billion people.
Subpolar climate. In summer, humid air masses come here from temperate latitudes, so the summer is cool (from +5 to + 10 ° С) and about 300 mm of precipitation falls (in the north-east 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, in the subpolar belt, shallow lakes are scattered, significant areas are swampy. In winter, the weather in this climate is influenced by the Arctic and Antarctic air masses, so there are long, cold winters, the temperature can reach -50 ° C. Subpolar climatic zones are located only on the northern outskirts of Eurasia and North America and in Antarctic waters.
If you look at the map, you will notice that the boundaries of the climatic zones do not pass strictly along the parallels, but deviate either to the north or to the south. This is due to the fact that the formation of climatic zones is influenced not only by the uneven heating of the Earth and the geography of atmospheric precipitation, but also by other climate-forming factors: relief, ocean currents, glaciers and others.
