Detailed explanation of geographical and climatic characteristics of grade one in junior high school
geographical and climatic characteristics of the first grade: low-latitude climate on land
The low-latitude climate is mainly controlled by equatorial air mass and tropical air mass, with high temperature all year round and the lowest monthly average temperature above 15℃. The main circulation systems that affect the climate are intertropical convergence zone, trade winds, equatorial westerly winds, tropical cyclones and subtropical high. The seasonal movement of these systems leads to the seasonal variation of precipitation.
The low latitude climatic zones on land include equatorial zone and tropical zone. It consists of five climate types: equatorial rainy climate, tropical marine climate, tropical monsoon climate, tropical dry and wet season climate and tropical drought and semi-drought. Except for tropical drought and semi-arid climate, it is distributed to the south and north latitude of 3? In addition, other climate types occur in the south and north latitude of 25? Within. Specifically, the land low latitude climate zone includes:
1. The equatorial rainy climate
is also called tropical rain forest climate, which is mainly distributed in the south and north latitudes on both sides of the equator at 5? 1? Within the scope of, including the Amazon Plain in South America, the Congo Basin and the Gulf of Guinea coast in Africa, and most of the Malay Archipelago in Asia. It is located in the low latitude, the source of equatorial air mass, and at the same time in the equatorial low pressure zone, where the trade winds of the northern and southern hemispheres converge and rise, and there are many convective rains. It is summer all year round, with an average temperature of 25? At 28℃, the daily range is slightly larger than that in annual range. The average annual precipitation is more than 2 mm, and the minimum monthly precipitation is more than 6 mm. The zonal soil is tropical rain forest latosol.
2. Tropical dry and wet season climate
, also known as savanna climate, is mainly distributed in the periphery of the equatorial rainy climate zone, generally reaching 15? About, can also be extended to 25? About. Including the Sudan grassland in Africa, the Ethiopian Plateau, the northern part of the East African Plateau and the South African Plateau, the Brazilian Plateau and the Orinoco Plain in South America, the Pacific coast of Central America and the northern part of Australia. The climate is characterized by high temperature all year round, and there are obvious dry and wet seasons. In dry season, controlled by trade winds, tropical continental air masses prevail, which are dry and lack of rain; In the rainy season, it is controlled by the equatorial low pressure zone, and when the equatorial airflow convergence zone moves, it is wet and rainy. The vegetation soil type is tropical savanna red-brown soil.
3. The tropical arid and semi-arid climate
is mainly distributed in the inland and west on both sides of the Tropic of Cancer, roughly between the south and the north latitude of 15? 3? Between Typical tropical arid climate zones include Sahara Desert in Africa, kalahari desert and namib desert, Arabian Desert in West Asia, thar desert in South Asia, deserts in western and central Australia and Atacama Desert on the west coast of South America. Under the control of subtropical high and trade winds all the year round, tropical continental air masses prevail and the climate is hot and dry. For example, the world? Hot pole? And? Dry pole? They all appear in this type of area. Berbera, the northern part of Somalia Peninsula in Africa, once recorded an extreme maximum temperature of 63℃, becoming the world's largest? Hot pole? ; The average annual rainfall of Atacama Desert in northern Chile in South America is close to (measured in Aarika City is .7 mm), and it never rains during the 91 years from 1845 to 1936, so it is called the world? Dry pole? . As for the tropical semi-arid climate, it is distributed at the outer edge of the arid climate zone, and it transits to the tropical dry and wet season climate zone and the subtropical summer dry climate zone respectively. The vegetation soil type is tropical desert (or desert grassland) desert soil.
4. Tropical monsoon climate
is mainly distributed in Indochina Peninsula, Indian Peninsula and Philippine Islands in Asia. In the season when the sun's altitude angle is large, the equatorial trough extends northward to 3? Left and right, coupled with the influence of land and sea thermal factors, a thermal depression is formed in the northwest of the South Asian subcontinent. At this time, the southwest monsoon blowing from the Indian Ocean, that is, the summer monsoon, prevails, and the rainy season is formed due to the heavy precipitation. In the season when the sun's altitude angle is small, the equatorial trough moves southward, and coupled with the thermal difference between land and sea, weak high pressure develops in the northwest of the subcontinent. At this time, the northeast monsoon, that is, the winter monsoon, prevails, resulting in a thousand seasons due to less precipitation. In addition, some areas can be subdivided into cool season and hot season. The climate in this area is long in summer without winter, the annual average temperature is above 2℃, and the annual average precipitation is generally 1 5? 2 mm, or even more.
5. Tropical maritime climate
is mainly distributed in the south and north latitude of 1? 25? The east coast of the trade wind zone and several islands in the tropical ocean include the east coast of Central America and the West Indies, the narrow strip along the east coast of Brazil Plateau in South America, the eastern part of Madagascar Island in Africa, the coastal area of Queensland, Australia, and the Hawaiian Islands in the Pacific Ocean. These areas are located on the windward coast of the trade winds, and tropical marine air masses prevail all year round. In addition, the trade winds rise when they encounter coastal mountains after landing, so they form a high-temperature and rainy climate with maritime characteristics. The type of vegetation soil formed here is the same as that in equatorial rainy climate, and it is tropical rain forest latosol.
geographical and climatic characteristics of the first day: land mid-latitude climate
The mid-latitude zone is a zone where tropical air mass and polar air mass intersect, and the main circulation systems that affect the climate are polar front, prevailing westerly wind, temperate cyclone and anticyclone, subtropical high and tropical cyclone, etc., and the weather changes aperiodically and the precipitation changes seasonally. The mid-latitude climate zone on land is an area where cold and warm currents compete with each other, and the seasonal and non-periodic changes of temperature and precipitation are remarkable. According to the heat situation, the mid-latitude climate zone on land can be divided into temperate zone and subtropical zone. Because the global continent is most severely divided by the ocean in the mid-latitude region, there are often different climatic phenomena and characteristics on the east and west sides of the continent and within the continent, which show the dry-wet zone and thus affect the regional differentiation of the natural environment.
1. land temperate climate
the land temperate zone is mainly distributed in 35? ～6? N area, the southern hemisphere because only a small land extends to 4? South of n, so the temperate zone is not large. Due to the influence of ocean division, there is obvious east-west differentiation in temperate regions. Generally, there is a temperate continental humid climate or temperate monsoon climate on the east coast of the mainland, a temperate maritime climate on the west coast of the mainland, and a temperate continental arid and semi-arid climate in the interior between them.
(1) temperate continental humid climate
mainly distributed in 35? ～55? N between the east of North America and the east of Eurasian temperate maritime climate zone, that is, the east of Eurasian temperate maritime climate zone and North America 1? About 4 east of w? ～6? N areas, etc. The temperature and precipitation of this climate are somewhat similar to those of temperate monsoon climate, but the seasonal changes of wind direction and wind force are not as obvious as those of temperate monsoon climate. In terms of causes, its cold and dry winter is not caused by the continental monsoon, but by the deep westerly wind blowing from the ocean, which has undergone continental degeneration, so the temperature is low and the precipitation is less; There is convective rain in summer, but the concentration of summer rain is not as significant as that of temperate monsoon climate.
(2) temperate maritime climate
is mainly distributed at 4? 6? The western part of the continent, including the western and southern Scandinavia in Europe, most of western and central Europe, the Pacific coast west of Cordillera Mountain in North America and Canada, the area west of Andes Mountain in southern Chile in South America and Tasmania and New Zealand in Australia. The westerly and temperate ocean air masses prevail here all year round, and warm currents pass along the coast, thus forming the climate characteristics of warm winter and cool summer, small annual range, precipitation all year round and a little more rainfall in autumn and winter. In addition, there are more rainy days, more clouds and less sunshine here.
(3) temperate monsoon climate
is mainly distributed in 35? 55? N or so in East Asia, including the area north of the Qinling-Huaihe line in eastern China, the Korean Peninsula, the northern part of Japan and the southern part of the Russian Far East. The climate causes are similar to the subtropical monsoon climate. Winter is controlled by temperate continental air mass, which is cold and dry, and the temperature difference between north and south is great; In summer, it is warm, hot and rainy due to the influence of temperate ocean air mass or denatured tropical ocean air mass, and the temperature difference between north and south is small. In addition, the distinct seasons and the remarkable aperiodic change of weather are also the main characteristics of temperate monsoon climate. Because the climate characteristics of the above temperate climate types are mainly humid (the North China Plain and the Northeast Plain in China are semi-humid), the temperate broad-leaved forest landscape (the North China Plain and the Northeast Plain in China are forest and grassland landscapes) is generally developed, but there are also some differences. There are more kinds of broad-leaved trees in East Asia than in Europe, including Quercus mongolica, Quercus liaotungensis and miscellaneous trees such as Acer, Tilia and Betula. In western Europe, pure forests composed of single tree species are often formed, such as beech forests and oak forests. The broad-leaved forest landscape in North America (including the south of the Great Lakes, to the Appalachian Mountains, the Mississippi River Basin and the Atlantic coastal lowlands) is dominated by American beech and sugar maple. Colored brown soil and gray brown soil are mainly developed in the whole temperate moist broad-leaved forest belt, while cinnamon soil and black soil are developed in the semi-humid forest grassland belt.
(4) temperate continental arid and semi-arid climate
Also known as temperate desert and temperate grassland climate, it is mainly distributed in the hinterland of Asia and North America, Patagonia Plateau and pampas in South America. This kind of climate zone in Asia and North America is far away from the sea, deep inland, surrounded by mountains and plateaus, and it is difficult for humid ocean air to reach. Temperate continental air masses prevail all year round, thus forming a temperate continental arid and semi-arid climate with hot Leng Xia in winter and little rain. Generally speaking, the average annual precipitation in arid climate is below 25 mm, while that in semi-arid climate is 25? 5 mm。 This kind of climate zone in South America is located on the east coast of the continental westerly belt, which is the rain shadow area of the westerly belt, and there are tall Andes on the west coast. After the westerly wind passes over the mountain, it sinks, which is adiabatic and warm, dry and rainy, and there is a cold current along the coast, so the air is stable and the precipitation is scarce. Vegetation is sparse in temperate continental arid climate, and the vegetation land type is temperate desert soil; The vegetation soil type in temperate continental semi-arid climate zone is temperate grassland chestnut soil.
2. Terrestrial subtropical climate
Terrestrial subtropics are mainly distributed at latitude 25? 4? The area between. Due to the subtropical high and the location of land and sea, the east coast of the mainland generally has a subtropical humid climate or a subtropical monsoon climate; The west coast of the mainland has a subtropical summer and dry climate (Mediterranean climate); There is a subtropical continental arid and semi-arid climate between them.
(1) Subtropical humid climate
is mainly distributed in 25? 35? N zone and the southeast margin of Brazil Plateau in South America, east of the middle and lower reaches of parana river and east of pampas. In addition, it is also distributed on the southeast coast of Africa and the southeast coast of Australia, but the area is small. Its main characteristics are that the temperature difference between winter and summer is smaller than that in subtropical monsoon climate zone, and the precipitation distribution in a year is also more uniform than that in monsoon climate zone. These areas are similar to the subtropical monsoon climate zone in East Asia in latitude and land-sea position (east coast of the mainland), but because the continental area and adjacent ocean area are small, the thermal difference between land and sea is not as prominent as the latter, so a typical monsoon climate has not formed.
(2) Subtropical monsoon climate
is distributed in subtropical eastern Asia, mainly including the area south of Qinling-Huaihe River in eastern China, the area north of tropical monsoon climate zone, southern Japan and the southern tip of Korean Peninsula. The change of air pressure configuration caused by different sea and land temperatures in winter and summer is the main reason for the climate in this area. In winter, the Asian continent is controlled by high pressure, which blows the northwest wind from land to sea, that is, the winter wind, with less precipitation; In summer, the Asian continent is controlled by the low pressure, which blows the southeast wind from the ocean to the land, that is, the summer monsoon, with more precipitation.
Evergreen broad-leaved forest is the main vegetation in subtropical humid climate and monsoon climate, and the corresponding soil types are red soil and yellow soil.
(3) Subtropical summer and dry climate
Also known as Mediterranean climate, it is mainly distributed at 3? -4? On the west coast of the mainland, the Mediterranean region has the largest summer and dry climate range and the most obvious characteristics. In addition, it also includes the Pacific coast of the southwestern United States, central Chile, the southern tip of Africa and the southern tip of Australia. The planetary wind system on the west coast of subtropical continent is normally distributed, and the climate here is controlled by the seasonal alternation of subtropical high pressure zone and westerly wind zone. In summer, this area is controlled by the subtropical high pressure belt, dominated by downdraft, and the climate is hot and dry; Winter is controlled by westerlies, where temperate ocean air masses prevail, cyclones are active and precipitation is high. Therefore, hot and dry summer and mild and rainy winter are the main features of Mediterranean climate. This type of climate zone mainly forms evergreen hardwood forest belt, mainly evergreen shrub forest and brown soil.
(4) Subtropical continental arid and semi-arid climate
Mainly distributed in the interior of subtropical continent, including Iranian Plateau and Anatolia Plateau in West Asia, inland plateau in the western United States and Granchako in South America. The formation of arid climate is due to the fact that it is far from the sea in the inland or blocked by mountains, and it is difficult to reach the humid ocean airflow, and it is located in the subtropical zone, so it is hot in summer and mild in winter. Semi-arid climate belongs to the transitional type from arid climate to other climate. The vegetation here belongs to desert grassland, usually with xerophytes and gramineous plants, and the soil belongs to semi-desert light brown soil.
geographical and climatic characteristics of the first grade: land high-latitude climate
The land high-latitude climate zone mainly includes 5? The sub-frigid zone north of N and the terrestrial frigid zone in the Arctic Circle, as well as the Antarctic continent in the southern hemisphere. The Arctic Ocean and the Antarctic ice sheet are the sources of glacial air mass and Antarctic air mass respectively, while Siberia and Canada are the sources of polar continental air mass in Asia and North America respectively. There is a cyclone moving from west to east on the ice front where the ice air mass meets the polar air mass. The temperature here is low, including the world cold pole and the northern hemisphere cold pole. The main climate types are sub-frigid continental climate, polar long cold climate and polar ice sheet climate. The characteristics of several climatic zones are as follows:
1. Sub-frigid continental climate
Also known as sub-frigid coniferous forest climate, generally distributed in 5? 7? N, and the west coast of the mainland is at 6? 7? N, including most of North Asia, northern Europe, Alaska in North America and north-central Canada. The climate here is mainly influenced by the polar ocean air mass and the polar continental air mass, and it is the source of the polar continental air mass. In winter, there are many opportunities for ice air masses to invade; In warm seasons, tropical continental air masses can also penetrate. The climate is characterized by strong continental nature, long and cold winters, short warm seasons, high annual range temperature, little precipitation, concentrated in warm seasons, and weak evaporation, belonging to a cold and humid environment. Vilho Yansk and Oymyakon in the northeast of Siberia have an average temperature of -5℃ in January and an absolute minimum temperature of -73℃, making them the cold poles in the northern hemisphere. The absolute annual range in Jansk, Vilho, once reached 11.8℃, making it the highest temperature in annual range.
2. The polar long cold climate
, also known as tundra climate, is mainly distributed along the Arctic Ocean coast and islands in Eurasia and North America, with a latitude of about 7? 75? N, which is located within the Arctic Circle, so the phenomenon of extreme day and night is obvious. The climate is characterized by winter all year round, with only 1? The average temperature for 4 months is ? IO~C, precipitation is scarce, which mostly belongs to the precipitation on the glacial front, mostly snowfall, with many clouds and weak evaporation.
3. The climate of polar ice sheet
is mainly distributed in Antarctic continent, Arctic Ocean and Greenland.