1. Analyze the maps of the atlas (pp. 4-5, 40). Describe the geographical location South America according to the proposed plan.
The hemispheres in which the mainland is located: north, south and west.
Position in relation to the prime meridian: to the west.
Position in relation to the equator: intersects.
Position in relation to the tropics: intersects south of the tropic.
The Amazon Basin is the world's largest river basin, covering an area of approximately 73 million square miles. The second largest river basin, which is the basin of the Zaire River in the African Congo, accounts for less than half. The area's water resources are impressive; the volume of water that flows from the basin to the sea accounts for about 11% of all water flowing down from the continents of the earth. Although there are many rivers in the basin, the most important and famous of them is the Amazon. The Amazon ranges from 1 mile to 5-6 miles wide, and although it is usually only about 20-40 feet deep, there are narrow channels where it can reach 300 feet deep.
Position in relation to the polar circles: does not intersect.
Oceans and seas washing the mainland: Quiet and Atlantic Ocean s, Caribbean.
The names and coordinates of the extreme points of the mainland: sowing. - M. Galinas, y. - M. Frourd, zap. - m. Parinyas, east. - M. Cabo Branco.
The size of the territory and the outlines of the coast in comparison with other continents: S = 17.8 million km 2, the banks are weakly indented; the area is inferior to North America.
The Amazon Basin was once a huge cove before the Andes were pushed along the coast. When mountain range grew, they held back the ocean, and eventually the bay became an inland sea. This sea was finally filled with more erosion. high ground surrounding it, and finally a huge plain was created, crossed by countless waterways. Much of this region is still at sea level and is covered in lush jungle and extensive wetlands. This jungle region contains the largest preserved rainforest in the world.
Position in relation to other continents: removed from Eurasia, Africa, Australia; in the north connects with North America, in the south through the Drake Passage it borders on Antarctica.
The influence of the geographic location of the continent on the formation of nature: the position of most of the continent, except for the extreme south, in low latitudes led to the formation of a warm climate and diverse nature.
Despite the abundance of abundant life, the soil is not very rich; fertile regions are those that receive a fresh layer of river silt when the Amazon floods almost every year. It is where Central America's Panama meets the South American continent, and its location gives it interesting feature coastal areas bordering both the Atlantic and Pacific oceans. It is a country of varied conditions, including coastal, mountainous, jungle and island regions, but in general it can be considered to consist of two main regions based on elevation: the Andes Mountains and the lowlands.
2. Compare the geographic location of Africa and South America and answer the questions.
What are the similarities in their nature?
The presence of equatorial humid forests and a hot climate in most of the territory, there are deserts in tropical latitudes on the coast.
The widest parts of the continents are found in tropical, subequatorial, equatorial and subtropical zones; the deserts on the coasts are the result of the action of the cold current.
The Andes in Colombia can be divided into three different ranges, which run roughly from north to south in parallel with the ridges. The Cordillera East, which is the eastern range, is much higher and many of its peaks are covered with snow all year round. The Cordillera Center, as the name suggests, runs between the Western and Eastern Cordillera.
The lowlands of the east cover two-thirds of Colombia, which is part of the Orinoco and Amazon basins and is therefore well-lined and fertile. Part of this region is covered with rich equatorial rainforest. The northern lowland coastal region also contains several rivers, and Columbia's main river, the Magdalena, begins.
What are the features of the difference between their nature?
The climate of South America is more humid, with less desert areas. In South America, cold air masses flow in the south.
What are the reasons for them?
On the territory of Africa, warm climatic zones are duplicated. South America is influenced by air masses from the Atlantic Ocean. The position of the southern narrow part of the continent in high latitudes and the flatness of the territory contributes to the penetration into the interior of South America of cold air masses.
This is the most northern country South America and can be divided into four main regions. The Guiana Highlands in the southeast makes up almost half of Venezuela's territory and is bordered by Brazil and Guyana. Here is the famous Angel Falls, the highest waterfall in the world. This range is bordered by much of the coastal region of Venezuela and, despite its proximity to both The Caribbean as well as the equator, it has many peaks covered with snow all year round. The Maracaibo Basin, one third of which is covered by Lake Maracaibo, is to the northwest, it is connected to the Caribbean Sea, and although it contains fresh water at one end of the lake, as it approaches the ocean, it becomes more physiological.
3. On the schematic map, designate with numbers: Orinokskaya (1) and La Platskaya (2) lowlands; Brazilian (3) and Guiana (4) Highlands / Parana (5) and Orinoco (6) rivers; lakes Maracaibo (7) and Titicaca (8); archipelago Tierra del Fuego(9); Strait of Magellan (10).
4. Complete the table.
South American exploration
| Researcher | Research objectives and results | Research value |
| A. Vespucci | exploring new lands; the coasts of the mainland were explored, a map was compiled | proved that open land not Asia, but "New World" |
| A. Humboldt | study of nature and population; a map of the river basin was compiled. Orinoco, the book "A Journey through the Tropical Regions of the New World" | the northern part of the mainland and Central America (interior regions of Mexico) were explored |
| I.I. Domeyko | study of the Andes; compiled the first geological map of Chile | initiated the study geological structure Andes |
| K.M. Yelsky | exploration of hard-to-reach regions of South America; collected a collection of birds, discovered many new species | data were obtained on the Guiana fauna and on many previously unknown animal species |
5. Analyze the maps of the atlas (pp. 6, 40) and answer the questions.
Not surprisingly, most of the basin is composed of wetlands. Ecuador gets its name from the fact that it straddles the equator. Its eastern and western lowlands are separated by the Andes, which run through the center of the country. The western lowlands on the coast contain tropical rainforest in the north, but it becomes extremely dry in the south. The eastern lowlands are part of the Amazon Basin and are mostly covered rainforest... The rivers Putumayo, Napo and Pastaza run through this area.
Ecuador also claims to be the famous Galapagos Islands, which lie about 650 miles off the coast. These 12 islands are volcanic in origin and some of the volcanoes are still active. The islands are home to many species unique to the world, including perhaps the most famous of them, the Galapagos tortoise.
What are the features of the difference in the relief of the western and eastern parts of South America?
Western part- mountain, East End- flat.
What are the reasons for them?
The relief of the western part was formed on a folded area, the eastern part of the mainland is confined to an ancient platform.
6. Using the atlas maps (pp. 6,12, 40), fill in the table.
Like Ecuador, it is divided by the Andes mountains into two distinct sections. The eastern coastal region is mostly mountainous, and in many places the ocean is bordered by steep cliffs. In the northern part, however, there is a relatively flat area suitable for agriculture. In the east, the lowlands are mostly covered by the dense tropical rainforest of the Amazon Basin. southern part The Andes in Peru contains many volcanoes, some of which are still active, and Lake Titicaca, which Bolivia shares. Lake Titicaca is remarkable that among large lakes without an ocean outlet, Titicaca is the highest in the world.
Tectonic structure, relief and minerals of South America
| Tectonic structure | Corresponding landforms | Minerals | Branches of the economy that can be developed based on their production |
| Ancient South American Platform | Amazonian lowland, Laplat lowland | sedimentary (oil, gas, bauxite) | oil and gas processing, energy |
| Areas of Proterozoic folding | Brazilian highlands | metamorphic and magmatic ( iron ore, bauxite, polymetal | ferrous and non-ferrous metallurgy |
| Areas of Paleozoic folding | eastern part of the Central and Southern Andes, foothills | sedimentary (oil), magmatic (copper ore) | oil refining, non-ferrous metallurgy |
| Cenozoic folding areas | Andes | magmatic and metamorphic (copper and tin ores, polymetal) | non-ferrous metallurgy |
7. Using the thematic map, indicate the differences between the climatic zones of Africa and South America.
The western part of the country, which borders Ecuador and Chile, is covered by the Andean mountains, and like much of this part of the Andes, it contains many active volcanoes... In the southern part of the range, the land becomes drier, and salt marshes are found in many places. This salt Lake only 10 feet deep. In the northern part of the range, the land becomes more habitable, and it is here that Lake Titicaca is discovered, which is shared with Peru.
Bolivia's eastern lowlands are divided into two distinct regions. The southeastern part, called the Gran Chaco, is a semi-arid savanna. The Andes are divided into two branches along the eastern and western edges of the country. The coastline in this area is quite remarkable for outward appearance with numerous fjords. There are many volcanic islands off the coast of Chile, including famous island Easter, which contains some unusual archaeological remains.
In South America, climatic zones do not repeat, tropical belt more narrow, subtropical belt wider, there is a moderate belt.
Explain why, while being shorter from north to south than Africa, South America has more climatic zones.
South America is located in the southern hemisphere and stretches from equatorial to temperate latitudes. Africa is crossed by the equator almost in the middle, and climatic zones are mirrored.
Chile's southern coastal region is temperate zone but in the north it contains the Atacama Desert, which is the longest and driest desert in the world. It is reported that Iquique, Chile, which is located in this region, at one time suffered 14 years without any rain. The dryness of the area is believed to be due to a sudden temperature inversion as clouds move from the cold waters off the coast and collide with the warmth of the continent; this prevents the precipitation of water from the clouds when they reach the coastline.
It has also been suggested that the steep rise of the Andean Mountains on the coast is contributing to this effect. The Andes Mountains separate western Argentina from Chile, and in the south, known as the Tierra de Fuego, the area is still partially covered by glaciers. Most of Argentina is a region of lowlands and plains. The northern part of the lowland, called Chaco, is the hottest region in Argentina. In the northwestern part of Argentina, near the Paraguayan and Brazilian borders, there are the wonderful Iguassa Falls.
8. Complete the table using atlas maps (p. 9, 41) and material study guide(§ 46).
Characteristics of the climatic zones of South America
| Climatic zone | Geographical position | Prevailing air masses | Average temperatures | Average annual quantity precipitation | ||
| in winter | summer | in winter | summer | |||
| Equatorial | Amazonian lowland, northwest coast | equatorial | + 27 ° C | 5000 mm | ||
| Sub-equatorial | Oriana, Guinean Highlands, most of the Brazilian | tropical | equatorial | + 30 ° C | 1100 mm | |
| Tropical | 20-30 ° S | tropical | + 30 ° C | mus. 1000 mm, cont. 25 mm | ||
| Subtropical | 30-40 ° S | moderate | tropical | + 10 ° C | + 20 ° C | 300-2000 mm |
| Moderate | south of 40 ° S | moderate | + 5 ° C | + 15 ° C | 300-2000 mm | |
9. Determine what influence on the formation of the natural and climatic conditions of South America have:
They are 5 miles wide and 269 feet high. Most of the low-lying plains are called Pampa, which are humid in the east and semi-arid in the west. The southern Highlands of Patagonia, which begins below the Colorado River, is a dry and mostly uninhabited plateau region. On Tierra del Fuego there is the southernmost extension of the Andes. They mostly freeze and there are many glacial lakes. Where mountains descend into the sea, glaciers shape them so that the coast has a fjord-like appearance.
The Falkland Islands are at east coast Argentina. It is a group of 200 islands made up of hills and peat valleys, although there are several low mountains to the north of the main islands. The sea around the Falkland Islands is quite shallow and for this reason they are believed to lie on the extension of the continental shelf.
- a) movement of air masses: the air masses of the Pacific and Atlantic oceans bring precipitation, the Antarctic air has a cooling effect.
- b) features of the placement of landforms: the barrier for air masses from the west is the Andes, which are stretched submeridionally, therefore the coasts are humid, and central part the mainland is dry.
- c) warm currents: contribute to the condensation of air coming from the Pacific and Atlantic oceans and the saturation of air masses with moisture.
- d) cold currents: prevent condensation and cause the formation of deserts on the western coast in tropical latitudes.
10. Determine which ocean basin most rivers in South America belong to.
About half of the country is part of the Gran Chaco, a large plain west of the Paraguay River, which also extends into Bolivia and Argentina. To the east of the Paraguay River lies another plain covered with forests and seasonal swamps. This region becomes a flat plateau country in the easternmost part of Paraguay, much of which is covered with evergreen and deciduous forests. Indian tribes of Guiana.
London. Unknown people in an unknown country. Keller, Franz. Amazon and Madeira rivers. Columbia Encyclopedia, 6th ed. It is politically divided into 12 independent countries: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela, and overseas department French Guiana.
To the Atlantic basin.
What are the reasons for this fact?
Located in the west of the watershed - the Andes mountain range.
11. What changes in natural and climatic conditions temperate zone South America could cause extinction of the Andes mountain range? Provide evidence to support your hypothesis.
The climate will be maritime not only on the western coasts, but also on the rest of the territory, because in the temperate latitudes, the western transfer dominates and with the disappearance of the Andes there will be no obstacles.
Topographically, the continent is divided into three sections: the South American cordillera, the inland lowlands, and the continental shield. The continental shield to the east, which is divided into two unequal sections along the Amazonian geosyncline, contains the continent's oldest cliffs. Geological studies in South America supported the theory of continental drift and showed that up to 135 million years ago, South America was annexed to Africa, based on tectonic correspondence, a connection was established between Brazil and Gabon.
The length of the middle of the continent is a series of lowlands running south from the northern lions, through the selva of the great Amazon basin and the Gran Chaco, to Pampa from Argentina. Parallel with Pacific coast are great corals made up of Andean ridges and high intermontane valleys and plateaus. Akankagua in Argentina is highest point in the Western Hemisphere. The Andes region is seismically active and prone to earthquakes. Volcanoes are present, but mostly inactive.
12. Complete the table using the material in the tutorial (§ 47).
Comparative characteristics of the Amazon I Parana rivers
13. Complete the South American Natural Zones Schematic Map using thematic maps and pictures.
- Natural area: humid equatorial forest
- Soils: red-yellow ferralite
- Plants: 4
- Animals: 1, 2
- Natural area: savannas and woodlands
- Soils: red and red-brown
- Plants: 1
- Animals: 3, 4
- Natural area: deserts and semi-deserts
- Soils: brown, gray-brown
- Plants: cacti
- Animals: 3, lizards
- Natural area: pampa
- Soils: reddish black
- Plants: thorny herbs
- Animals: llama, pampas cat
14. Indicate the features of the difference between placement natural areas to Africa and South America.
Chile is home to the barren Atacama Desert. There are few good natural harbors on the South American coast. Great river systems continent lowered into the Atlantic Ocean and the Caribbean Sea, from north to south - the Magdalena, Orinoco, Amazon and Paraguay-Parana systems. Only short streams enter the Pacific Ocean. Excluding Lake Maracaibo, which is actually a hand Caribbean, Lake Titicaca, on the border of Peru and Bolivia, is the largest of the continent's lakes. South America covers every climatic zone- tropical rainy, desert, high alpine and vegetation.
A large territory is occupied by areas of altitudinal zonation, variable-humid forests, deserts have received little development, there is a zone of steppes and mixed forests.
What are the reasons for them?
The mainland lies almost entirely in the southern hemisphere; South America - more wet continent what is associated with a digital computer; the position of the southern part of the continent in temperate latitudes; the presence of the Andes mountain range.
Native peoples make up a significant portion of the continent's Andean population, especially in Bolivia, Ecuador, Peru and Paraguay. In other parts of South America, the population is generally mestizo, although Chile, Argentina, Uruguay and Brazil are mostly Europeans.
With the exception of Brazil and Ecuador, the national capitals have largest population and are the economic, cultural and political centers of the countries. Squatter settlements multiplied around urban areas like poor and unskilled herds to cities; unemployment is widespread. Outside the cities, the continent's population density is very low, with huge parts of the interior virtually uninhabited; most people live 200 miles off the coast.
15. List the signs of adaptation of a representative of the flora of the savannas of South America to habitat conditions.
Crown shape (umbrella), waxy coating on leaves, low moisture content in leaves and trunks, light bark, hard foliage.
16. List the signs of adaptation of representatives of the fauna of the savannas of South America to habitat.
Small size, dense integuments (an armadillo has a shell, for example), light color, activity in the dark.
17. Which of the following assessments of the state and importance of humid equatorial forests for nature and economy do you consider correct? Which ones do you think are of the utmost importance? Justify the answer.
A... Reduction of forests occurs only in certain states of the Brazilian Amazon, along with deforestation, they are being rapidly restored in protected zones.
B... The humid equatorial forests of the Amazon are an important source of oxygen, and their conservation is essential for the whole world.
B... V equatorial forests there are many valuable tree species whose timber is exported abroad.
The correct point is B, because Amazonian forests are truly unique. Point A is controversial, because the rate and volume of reforestation are not comparable to the rate of felling. Point B is also controversial, since wood is really valuable, but it is much more profitable to export finished products from this wood.
18. It is known that there is a real danger of extinction of the humid equatorial forests of the Amazonian lowland. State the possible consequences of this for:
- a) Brazilian farms: the country's economy will receive significant damage for solving environmental problems, and will be deprived of significant income from the sale of valuable varieties of wood.
- b) the indigenous population of the Amazonian lowland: the indigenous population will be deprived of their habitat, forced to move to other parts of the mainland and will gradually disappear.
- c) nature and population of the whole world: Amazonian lowlands with their wet forests is the lungs of the planet; their disappearance will affect ecological state nature on a global scale.
19. Which of the assessments of the Trans-Amazonian Railway do you consider correct? Which ones do you think are of the utmost importance? Justify the answer.
A... The Trans-Amazonian Railway is helping to improve connectivity between different regions in Brazil.
B... The construction of the Trans-Amazonian Railway contributes to the early destruction of the Amazon forests.
B... The construction of the Trans-Amazonian Railway justifies the damage done to the nature of the mainland, as it links Brazil with the countries of the Pacific coast.
Estimates B and C will be correct. The construction of the Trans-Amazonian Railway plays an important role for the economies of South America. Since these countries are developing countries, the issue of ecology is not at all in the first place, but the main one is the ecological criterion, therefore the primary assessment is V.
20. Make up “ Business Cards»Specified states.
ARGENTINA
Capital: Buenos Aires
Population: 40 million
Form of government: republic
VENEZUELA
Capital: Caracas
Population: 26 million
Form of government: republic
State language: Spanish
Mainstream religion: Catholicism
BRAZIL
Capital: Brasilia
Population: 190 million
Form of government: republic
State language: Portuguese
Mainstream religion: Catholicism
21. Analyze the thematic map (p. 42 of the atlase). List the factors that influenced the distribution of the population of South America.
The location of the relief was influenced by natural (relief, climate) and environmental (development, infrastructure) factors. The maximum population density is typical for the coastal lowlands of the Atlantic and Pacific oceans, the Caribbean Sea, and the Laplat lowland. Central areas the mainland and the Andes are rarely inhabited.
Note. Use the following to populate the table legend: "-" - has little or no development: "+" - has been developed, but has mainly internal development: "++" - is a branch of international specialization.
23. Answer the questions.
What are the features of similarity in the economy of the countries of South America? What are the reasons for them?
Agriculture, extractive industries, and the low development of science-intensive industries play a significant role.
What are the features of the differences in the economy of the countries of South America?
The level of development of countries, favorable conditions for agriculture, the wealth of mineral raw materials.
What are the reasons for them?
Various industries of specialization, the Brazilian economy is more developed in a sectoral plan.
24. Imagine a situation: the water level in the Parana River has risen sharply. What are the consequences of this?
Environmental consequences: flooding of adjacent territories, change in connection with this natural conditions.
Socio-economic consequences: dams of numerous hydroelectric power plants that are built on the river will be damaged; their destruction can damage human settlements.
Climatic factors.
a. geographic location, configuration, dismemberment.
b. ocean currents
v. relief
Air circulation in July and January.
Distribution of temperatures, precipitation.
Climatic factors.
a. Geographical position, configuration, division of the continent.
Most of South America is located in the equatorial, tropical and subtropical zones. The southern tropic crosses the mainland where it begins to narrow. The mainland lies mainly in the southern hemisphere.
The location of the most extensive part of the continent in equatorial and tropical latitudes leads to the receipt of a significant amount solar radiation- 140-160 kcal / cm per year. Only south of 40 S lat. the total radiation is reduced to 80-120 kcal. The same factor mainly explains the high indicators of the radiation balance, reaching almost 60-85 kcal. Even in Patagonia, the radiation balance is about 40 kcal, i.e. it is in the same conditions as the south of the European part of Russia.
V equatorial latitudes due to the high heating of the continent throughout the year, there is a constant rise of air masses and the formation of an area of reduced pressure, where the trade wind air masses rush from the Atlantic. Hence the predominance of a powerful east-west transport in equatorial latitudes. In subtropical and temperate latitudes, the area of the continent decreases, and therefore, even in winter, continental anticyclones are almost not formed. But over both oceans, subtropical maxima are always very clearly expressed and serve as areas of outflow of trade wind air masses. The east of the continent in the tropical and subtropical zones is affected by the western periphery of the Atlantic highs. In the west, the influence of the eastern periphery of the Pacific anticyclone is strong, with a predominance of southerly air currents. In the circulation of temperate latitudes, where the size of the land is small, the west-east transfer of air masses is expressed with active cyclonic activity on the polar front.
b. Ocean currents.
The warm Brazilian current warms and increases the moisture content of the trade wind air masses that irrigate the eastern part of the Brazilian Highlands. The cold Falkland Current enhances the aridity of Patagonia lying on the ocean coast, and the cold Peruvian Current greatly contributes to the formation of a huge desert belt in the west of the mainland. v.Relief is an important factor in the formation of the climate.
The orographic features of South America contribute to the meridional transport of air masses over the mainland. The Andes, like the Himalayas, are the most important climatic division. The high barrier of the Andes, stretching along the entire western edge of the mainland, limits the influence The Pacific... On the contrary, almost the entire continent is left to the influence of air masses coming from the Atlantic. Continental air masses are formed only in the southern summer in the Gran Chaco region (continental tropical air) and are poorly observed in the winter on the plains of Patagonia (continental air of temperate latitudes).
Air circulation.
July. In July, all baric systems are displaced To north. The northeastern trade wind, coming to the coast of the continent from the southeastern periphery of the Azores maximum, consists of warm, moist sea air masses. These winds and cyclonic rains on the tropical front are responsible for the summer rainy season in northern Colombia and Venezuela and in Guiana. Equatorial humid air from the Amazon spreads to Llanos. The latter is formed in the Amazon due to the Atlantic trade wind air masses. Intense inland convection causes daily afternoon showers associated with cooling of air masses in the high layers of the atmosphere. In the Eastern Amazon, the effect of the southeastern trade wind from the Brazilian Highlands manifests itself in a decrease in rainfall at this time of the year.
In the southern hemisphere, the southeastern trade wind from the northern periphery of the South Atlantic high pressure region approaches the northeastern bulge of Brazil. But, further, as a result of the strike of the coastline to the northwest, it only slides along the coast, without significantly affecting the climate.
The winds of the western periphery of the South Atlantic anticyclone, moving counterclockwise from northeast to southwest, consist of masses of warm tropical air and capture not only the coast of eastern Brazil, but, bypassing the central part of the highlands with relatively high winter pressure, penetrate to the south - west inland to the eastern foothills of the Andes, where they come into contact with the air masses of temperate latitudes, forming a polar front.
The entire western coast, slopes of the Andes and intermontane plateaus from 30 S lat. to the equator in winter are under the influence of the eastern periphery of the Pacific maximum. The southerly and southeasterly winds are composed of masses of tropical sea air... These relatively cold and heavy masses are only saturated in the lower layers. In the same direction at these latitudes along west coast The cold Peruvian current runs through South America. These phenomena lead to a decrease in the relative humidity of the air. All west between 30 S. turns out to be sharply arid and abnormally cooled. But, north of the equator, where the southeastern trade wind, changing direction, turns into a southwestern monsoon, warm, moisture-saturated Pacific equatorial masses, approaching at an angle to the Andes, abundantly irrigate western Colombia, which receives precipitation and convective rains at these latitudes.
In temperate latitudes, the winter continental anticyclone in Patagonia is weakly expressed due to a sharp narrowing of the continent in temperate latitudes. Air masses of temperate latitudes come to the mainland and from the Pacific Ocean, where there is a constant westerly transport. This Pacific sea air brings huge amounts of rainfall to southern Chile in winter. Middle subtropical Chile also falls into the sphere of moderate circulation due to the displacement of the Pacific anticyclone to the north. Westerly and south-westerly winds irrigate the territory up to 30 S latitude. These rains have a frontal character with the interaction of temperate and tropical air masses.
THUS, in July, the northern edge of the mainland, the eastern coast of Brazil, the western Amazon, southern and central Chile, and western Colombia receive the most moisture.
In January all baric centers occupy their extreme southern position. The Azores anticyclone is as close as possible to the equator, causing the introduction of the North Atlantic sea air masses in the form of a northeastern trade wind, which penetrates into the area of reduced pressure over the Amazon lowland and the lowland of Paraguay to the eastern slopes of the Andes, where it transforms over land into continental tropical air, also warm and wet. Rising currents of air saturated with moisture give daily rains. Corresponding to the standing of the sun at its zenith, precipitation maxima are observed twice - in spring and autumn.
Moist equatorial air from the northeast also captures the northern, northwestern and western parts of the Brazilian Highlands, including the Parana Basin and the Gran Chaco region, reaching La Plata, causing the summer rainy season here. The northern edge of the continent is experiencing a winter drought at this time of year, as humid equatorial air masses move south. The South Atlantic Anticyclone (its western periphery) irrigates the southeastern coast of Brazil (northeastern in July) and northeastern Argentina and has a monsoon character.
In temperate latitudes, the western transport of Pacific air masses occurs at higher latitudes than in winter and in a somewhat weakened form, although southern Chile also receives a large amount of precipitation in summer. But the plains of Patagonia remain in "dry shadow" throughout the year. The influence of the eastern periphery of the Pacific anticyclone with cold southerly winds in the west of the mainland already affects the subtropical middle of Chile, where dry weather sets in in summer. The entire central part of the west coast is characterized by a lack of rainfall - which is why the Atacama Desert is located here. North of the Gulf of Guayaquil, western Ecuador receives summer rains due to the penetration of equatorial masses from the north.
They, together with the southwestern equatorial monsoon, irrigate western Colombia in January.
THEREFORE, heavy rainfall occurs in January in the Amazonian Lowland, but the east is more irrigated than in July. The entire subequatorial belt experiences abundant moisture in the east. southern hemisphere up to 20 0 S, while the north of the mainland is arid. Summer-autumn frontal rains are typical for southeastern Brazil and northeastern Argentina, southern Chile, as well as western Colombia, are still the "wet corners" of the mainland, but central Chile is experiencing a dry period and, conversely, the coast of Ecuador is wet. Between 28-5 0 S in the west, there is practically no precipitation in summer and winter.
Temperature distribution.
In July the entire Amazon lowland and the western part of the Brazilian Highlands are very hot, are mainly influenced by equatorial air masses and lie within the + 25 0 isotherm. On the territory of subtropical and temperate latitudes, the deep penetration of sea air masses of temperate latitudes affects the rapid drop in temperatures, and the isotherms, following from east to west, change from + 18 0 at Asuncion to +2 0 in the south of Tierra del Fuego. But on the high plateaus of Patagonia, negative temperatures down to -5 0 are established. Invasions from the south of temperate air masses cause irregular frosts throughout the central and eastern Brazilian Highlands, in the Chaco and northern Argentina. In the southern Pampa, frosts can last for 2-3 months, in northeastern Patagonia - for 5-6 months, in the central - up to 9 months, and in the southwestern part it is possible even in summer, in winter the temperature sometimes drops to -30 ...
Cold air and sea currents from south to north along the western coast of South America cause the isotherms to abruptly deflect northward and squeeze them into a tight bundle in western Peru. For example, the July isotherm +20 0 from the latitude of Copiapo (27 0 S) rises along the coast almost to Guayaquil (5 0 S).
In the Andes, the temperature decreases with height, and frosts occur on the high plateaus not only in winter, but also in summer. At an altitude of 2000 m under 40 0 S in the Andes, absolute minimum – 40 0 .
In january e the entire northern half of the mainland in the east to the Andes and 20 0 S lat. lies inside the isotherm +25 0. In the region of Gran Chaco, Mato Grosso and western Bolivia, on both sides of the tropic, a closed ring of the +28 0 isotherm forms.
The warming of the continent and in temperate latitudes causes a bend to the south in the steppes of Argentina and Patagonia, a decrease in temperature to +10 in the south of Tierra del Fuego.
An anomalous jump of isotherms to the north and their compression into a bundle on the west coast is observed.
Climatic zones and regions.
EQUATORIAL - constantly hot and humid climate includes the western part of the Amazonian Plain with the adjacent lower eastern slopes of the Andes. The large heating of the continent at these latitudes causes the development of baric depression and intramass ascending air currents coming here Atlantic masses are transformed into equatorial. Moisture is evaporated by gile forests and waters and returned to the ground in afternoon convective rains. A uniform course of temperatures and very small annual and daily amplitudes are typical. Precipitation decreases from June to October and increases in quantity on the mountain slopes.
SUBEQUATORIAL.
a) subequatorial seasonally humid climate forms north and south of the equatorial climate region and includes the lowlands and plains of Orinoco and Magdalena, coastal regions of Venezuela, the Guiana Highlands, most of the Brazilian Highlands, except for the east and south, and the east of the Amazon. It is characterized by the contrasts of the rainy and dry seasons, caused by the change of summer equatorial air masses to winter tropical ones. When approaching the equator, the long dry period gradually breaks up into two short ones, interspersed with long rainy ones.
b) the north is characterized by sharp dryness Venezuela and the northeastern Brazilian Highlands. The central parts of the latter have a very large amplitude of daily and especially extreme temperatures. With significant annual precipitation, sometimes not a drop of rain falls in the winter months.
v) the climate of the eastern slopes of the Guiana Highlands and the Guiana Lowland, although it is characterized by subequatorial circulation, is closer to the equatorial type in terms of precipitation and temperature regime. The rainy winter season there is caused by the action of the humid northeastern trade wind, the spring and summer - by the equatorial monsoon, while in the autumn a dry period is expressed due to the penetration of the southeastern trade wind.
TROPICAL BELT.
a) tropical trade wind humid climate the western periphery of oceanic anticyclones is characteristic of the east of the Brazilian Highlands. Abundant rainfall is due to both the Atlantic trade winds and cyclonic rains on the polar fronts, and the relief. The southern part of the highlands is characterized by winter invasions of cold air masses from the south, causing a drop in temperatures with small amplitudes.
b) T ropy continental seasonally humid climate the area of Gran Chaco. It is very similar to the climate of the subequatorial monsoons, but differs from it in more different temperature ranges. Precipitation caused by g. transformed equatorial air masses and humid trade winds.
v) T ropy tradewind climate the eastern periphery of oceanic anticyclones (coastal desert climate or “garoua” climate) from 4 0 30 / to 28 0 S lat. in Peru and northern Chile. Sharply arid under the influence of the eastern periphery of the anticyclone and constant southeastern trade winds. Annual precipitation is less than 30 mm. Small annual amplitudes of comparatively low temperatures and large diurnal, high relative air humidity and abnormal cooling of the coastal strip cause strong cloudiness in winter.
SUBTROPICAL BELT.
a) subtropical evenly humid and warm climate distributed in Uruguay, between the Parana-Uruguay and the eastern Pampa. In summer, humidification occurs due to moisture brought from the northeast by the masses of Atlantic tropical air (monsoon winds), during the rest of the year, especially in autumn and spring, due to cyclonic rains on the polar fronts. Summers are hot, winters are mild, but invasions from the south of temperate air can cause a sharp drop in temperature and even snow fall.
b) subtropical continental arid climate to the west and south of the previous one, i.e. in the western and south-western Pampa and in the Precordillera area up to 41 0 S lat. With distance from the Atlantic Ocean and closer to temperate latitudes, the amount of precipitation decreases, and it falls in the form of summer showers; the temperature amplitudes increase and frosts can be within five months,
With) subtropical Mediterranean »From 28 0 to 37 0 30 / S with a pronounced seasonality, especially in the course of precipitation. In summer (from November to March) the region is captured by the eastern periphery of the Pacific anticyclone and is devoid of precipitation; in winter (May-August) it is included in the sphere of moderate circulation and is irrigated by cyclonic rains on the polar front. The Peruvian current causes low temperatures for a given latitude in the coastal strip, especially summer and low annual temperatures.
TEMPERATE ZONE.
a) temperate dry semi-desert climate dominates the plains and plateaus of Patagonia. It is characterized by an extremely small amount of precipitation, sharp temperature ranges, very strong westerly and southerly winds, causing temperatures to drop to -32 0 -35 0 in winter. The Andes barrier does not allow wet westerly winds to pass to the east, they do not come from the Atlantic due to westerly transport in these latitudes, while the flat relief is favorable for the invasion of cold southerly winds. Frosts last for six to seven months,
b) temperate oceanic cool and humid climate south of 42 0 30 / S .. Throughout the year, westerly winds of moderate circulation, as well as from the southern periphery of the anticyclone and intense cyclonic activity, bring a huge amount of moisture to southern Chile, the fall of which is facilitated by the rise of sea air masses along the western slopes of the Andes ... The course of temperatures is very even, the amplitudes are small, but the absence of a warm current causes a lack of heat and summer temperatures for a given latitude are very low. Cold and rainy weather with strong westerly winds prevails.
In the Andes. According to the climatic regime, the outer slopes of the Andean system generally belong to neighboring regions, but taking into account the altitudinal zonality, there is a decrease in temperatures with altitude. The inner slopes of the Andean ridges and valleys are characterized by greater aridity and continentality compared to the outer slopes. Ridge strips of high sierras with eternal snow and ice have a high-altitude climate, dry in the center of the mainland and more humid in the north and especially in the south.
Features of glaciation
Despite the presence in South America of one of the most powerful mountain systems world with many peaks exceeding 6000 m, modern glaciation on the mainland is relatively weak.
The Andes of Colombia, Ecuador and northern Peru lie in equatorial and subequatorial latitudes, where the average monthly temperatures at an altitude of 3000 m are +10 0, and heavy rainfall, although it occasionally falls in the form of snow, can maintain constant snow cover only at altitudes above 4600-4800 m Further to the south - in the Central Andes - winter temperatures decrease, but the continentality of the climate causes high summer and especially spring temperatures. Orographic isolation of the continent, fenced off by high ridges from the influence of humid air cause extreme dryness. Such a combination of climatic factors, despite the significant heights, cannot contribute to the development of glaciation and the snow border in Pune rises to the highest position in the world -6000-6300 m.
Favorable conditions are created in the south - in the Chilean-Argentine Andes and especially in the Patagonian ones. Here, the Andes reach great heights, which, together with the increasing flow of moisture to the south in the cyclones of the polar front, quickly reduce the snow line and give rise to valley glaciers. The ridges and peaks in Patagonia do not exceed 3500-4000 m, but in temperate latitudes at such an altitude, negative temperatures are observed during the whole year. Constant westerly winds bring a huge amount of moisture, and the mountains are covered with a thick layer of snow and ice, and the snow line goes down to 1200-1000 m.
One zonal phenomenon should be noted that is characteristic of the highlands and on other continents in the equatorial, tropical and subtropical latitudes. On firn fields, one can observe the characteristic phenomenon of “repentant snows”. Under the combined ablative action of insolation, wind, rain, erosion of melt water and some other reasons, regular rows are formed, usually oriented from east to west. These firn pyramids are elongated and inclined towards the sun and have a height of 5-6 m. They resemble kneeling figures, hence the name.
