Berg climate classification

The arctic coast of Eurasia and North America, including coastal islands, has a polar climate north of the July 10℃ isotherm. The annual net radiation here can reach 15-20kcal/cm2, which is roughly consistent with the northern boundary of the forest. The tundra climate zone extends from east to west, and its width changes from north to south at the continental margin. Due to the influence of land contour, topography and coastal current, the southern boundary of this area has obvious deviation from latitude. Due to the approach of cold current, the terrain in northeast Asia is mountainous and the altitude is high, and the southern boundary of tundra climate can reach 60° N；; ; East Siberia is warmer in summer, and the July 10℃ isotherm protrudes northward, which narrows the continental tundra climate. In western Siberia, the southern boundary of the tundra climate is consistent with the Arctic Circle. Because the Taimei Peninsula extends northward, the continental tundra climate extends far northward. Due to the control of the Arctic air mass, it can be cold for more than 8 months in winter and short in summer, and the temperature in the warmest month is below 10℃. Because this area is close to the Arctic Ocean, it is cloudy and cloudy, with weak evaporation and high humidity. The annual precipitation is mostly between 100-250 mm, mostly snowfall. Due to the northeast wind (the wind speed often reaches 16-40 m/s), the snow layer is thin (25-50 cm), and the snow is uneven and permanent. This region is also the region with the largest change in the length of day and night in the Asian continent. There is extreme night in winter, and extreme day and extremely long sunshine in summer bring some warmth to the tundra. Compared with Europe, due to the influence of the North Atlantic warm current, the tundra climate zone is not wide from north to south, and the temperature and precipitation are higher than those on the east coast of Asia at the same latitude. (Also known as sub-frigid continental climate and sub-frigid coniferous forest climate).

South of the tundra climate zone, including western Siberia (except the south), eastern Siberia, kamchatka peninsula, northeastern China, North Korea and northern Japan, northern Canada and northern Alaska, is a continental climate zone in the sub-frigid zone. Its distribution area in Asia is about 700× 104km2. The northern boundary of this area is the hottest month in summer 10℃ isotherm (that is, the southern boundary of tundra climate); The southern boundary is roughly bounded by the annual average temperature of 4℃, and the western part is parallel to the latitude line, which is roughly equivalent to the 50 N line. In the east, it runs along the northern mountains of the Mongolian Plateau, from the south side of Lake Baikal to the northeast along the outer Xing 'an Mountains, and reaches the coast of the Sea of Okhotsk.

This climate zone belongs to continental cold and humid climate. In winter, due to the expansion of polar high pressure, ice air masses can often invade and the climate is very cold. Winter lasts for 6-8 months, and the monthly average coldest temperature is-15 to -30℃, and the absolute lowest temperature is -45 to -50℃. The Yansk-Oymyakon region of Vilho in eastern Siberia is the cold pole of the northern hemisphere. In summer, the temperature rises. The average temperature in July is generally above 10- 12℃, which can reach 18-20℃ in the south, and the daily maximum temperature can rise to 30-35℃. There are only cold and warm seasons throughout the year, and after the warm summer, it enters the severe winter, with a strong continental climate. Although the severe winter in this area is much colder than other areas at the same latitude, the temperature is almost the same in warm summer. The annual precipitation is 300-600 mm, decreasing from west to east, about 300-600 mm in the west, 300-400 mm in the east and 200-300 mm in the northeast. It snows in the cold season, and the snow formed on the ground is thick enough to prevent the soil from freezing deeply and prevent plants from freezing to death. There is little difference between summer rainfall and winter snowfall in the west, but summer rainfall in the east is greater than winter snowfall, so the thickness of winter snowfall also decreases from west to east.

The north-south width of this climate zone is not consistent everywhere, and the difference between east and west is larger than that of tundra climate zone. If we compare the sub-frigid climate of Eurasia and North America, the sub-frigid climate of Eurasia is narrow in the west and wide in the east, while that of North America is wide in the west and narrow in the east. The main reason for this difference lies in the role of topography and ocean currents. Europe is flat, and there are no tall mountains to stop the moist air mass from moving eastward. The warm current in the North Atlantic strengthens the influence of the ocean on the climate, thus pushing the southern boundary of the sub-frigid climate in Europe to a high latitude. However, from here to the east, it goes directly to the east of Asia. On the one hand, due to the enhancement of continental degree and the effect of cold ocean currents, the southern boundary of the sub-frigid climate is south of Europe. In the whole North Asia, the climate zone is widest in the middle, the tundra in the east extends southward, the cold current in the east is Leng Hai, the cold pole in the northern hemisphere, and the width is obviously reduced due to the influence of the outer Xing 'an Mountains. The difference between the east and the west of the sub-cold zone is also obvious. As far as the Eurasian continent is concerned, to the west of 60 E, that is, to the west of the North and South Urals, due to the influence of the Atlantic Ocean, the continental nature weakens from east to west, and the precipitation increases from east to west. Between the East Urals Mountains and the western slope of the Pacific Coast Mountains, it is mainly controlled by the cyclone activities and anticyclone activities related to the Arctic. Continency increases from west to east, and precipitation decreases from west to east. For example, the monthly average temperature 1 in East Siberia is -20 to -40℃, and in July it is 18-20℃, with annual precipitation of 200-400 mm and snow thickness of 50-80. As for the climate in the Far East of the Soviet Union and the northern part of Heilongjiang Province in China, it has always been influenced by monsoon circulation. The annual precipitation is generally 500-700 mm, and the thickness of snow is only 10-20cm. The east coast of Eurasia, south of sub-frigid zone, north of Qinling-Huaihe River, east of temperate semi-arid and arid zone, including Northeast China, North China, Korea, Japan and south of Soviet Far East, belongs to temperate monsoon climate zone. The northern boundary of this area is the southern boundary of the sub-cold zone, with the annual average temperature of 4℃ isotherm as the boundary; The southern boundary is based on the average temperature of 9.5℃ in eight months of the year, and it is the northern boundary of the subtropical climate zone. In China, this boundary is roughly equivalent to the Qinling-Huaihe line, and is also roughly consistent with the zonality. The western boundary of temperate monsoon climate extends along the northeast of Daxing 'anling to the eastern end of Waixing 'anling. Here, the boundaries between sub-frigid coniferous forest climate, temperate monsoon climate and temperate continental arid and semi-arid climate are relatively close. The land and sea distribution and topographic structure of East Asia have a great influence on the range of temperate monsoon climate, such as the northeast-southwest mountainous areas, which can prevent the deepening of monsoon forces.

This climate zone is hot in Leng Xia in winter, rainy in summer and dry in winter, with four distinct seasons. In winter, influenced by the strong Siberian high, a strong northwest land breeze blows, which is very cold, and the temperature in 1 month reaches -20℃. Cold waves frequently hit the mainland, freezing the soil. There is snow in the north, but the thickness of snow is very small. Except for precipitation in western Japan, most areas are sunny and dry in winter. The southeast sea breeze blows in summer, bringing a lot of water vapor from the ocean and forming a lot of precipitation. The annual precipitation is above 600- 1000mm, and it can reach above 1000mm on the windward slope of Shandong (such as the southeast slope of Changbai Mountain). The annual precipitation in the plain area is also 500-700 mm, and 60-70% of the annual precipitation is concentrated in summer, forming rain heat. In addition, there are some differences within this climate zone: for example, the continental part of this region has a continental temperate monsoon climate, and its northern winter Leng Xia is long, which is the northern edge of the East Asian summer monsoon; Leng Xia is hot in winter in the south, which belongs to warm summer type, and the continental monsoon climate in North China has always been warm temperate zone; As for the Japanese archipelago, most of them belong to the maritime monsoon climate, which is mild and humid. The precipitation on the windward slope of the mountain is over 2000 mm, and the south of the temperate monsoon climate zone, mainly including the central part of China and the southern part of the Japanese archipelago, belongs to the subtropical monsoon climate. The northern boundary of this area is Qinling-Huaihe Line, the southern boundary is Nanling Mountains, and the western boundary is the eastern edge of Qinghai-Tibet Plateau (105 E). In this area, Leng Xia has a hot climate and abundant precipitation in winter. The monthly average temperature of the whole year is higher than 9.5℃ for at least 8 months, but the absolute minimum temperature can be reduced to below-10 to -20℃, and the average maximum temperature is above 34℃. In winter, it is in front of the southward extension of continental high, and the southern branch jet passes through at high altitude, with frequent cyclones and more clouds and rain, and the precipitation accounts for about 10% of the whole year. In summer, with the northward advance of the ocean monsoon and the northward retreat of the polar front, the Meiyu area in this area also advances from south to north. Meiyu period generally lasts for 20-30 days, and Meiyu precipitation accounts for about 70% of the total precipitation in June and July in this area. 9. There is typhoon and rainstorm along the coast in 10; It can be seen that the precipitation in subtropical monsoon climate is much richer than that in temperate monsoon climate. For example, the annual precipitation in the plain area in the middle and lower reaches of the Yangtze River is about 1 1,000mm, and it can reach 2,529mm in Guling area with the same wind direction.

In a word, subtropical monsoon climate is a transitional zone between temperate monsoon climate (Leng Xia is hot in winter, summer rain is dry in winter, and rain and heat are in the same season) and tropical monsoon climate (no winter all year round, dry and wet seasons, and hot before rain). South Asia and Southeast Asia, including the Indian Peninsula, the middle and lower reaches of Ganges River and Brahmaputra River Basin, Indochina Peninsula and Philippine Islands, belong to tropical monsoon climate, with 6-20 N being the most typical. The air mass that dominates the climate in this area is the equatorial air mass in wet season (June-September). Under the joint action of Tagg low pressure and equatorial westerly wind, the southwest monsoon blows, and the wind force is stronger than the East Asian summer monsoon, bringing wet and rainy weather. For example, 80% or even 90% of the annual precipitation in South Asia (western India) falls in the summer monsoon period. The dry season (11-April) is a tropical air mass, and the northeast monsoon prevails, belonging to the tropical trade wind, accompanied by dry weather. Before the establishment of the southwest monsoon, that is, before the arrival of the rainy season, the Indian Peninsula and Indochina Peninsula (except Laos and northern Vietnam) were the hottest periods-the hot season (usually from March to May, the hottest in May), and the hottest monthly average temperature was 25-30℃. The northern boundary of this area is equivalent to the position of tropical wind in summer, which is roughly consistent with the most Leng Yue average temperature 18℃. The alternation of winter and summer monsoon, the division of dry and wet seasons every year, the hottest month before warm season, the strong summer monsoon, abundant precipitation but great changes, etc. , are the same characteristics of tropical monsoon climate zone.

In particular, the rainy season in this climate zone is closely related to the establishment of the southwest monsoon in this region. The beginning of the rainy season is the day when the southwest monsoon is established, and the end of the rainy season is the day when the southwest monsoon retreats. For example, the rainy season began in Myanmar in mid-May, Sri Lanka in late May, and the southern tip of Indian Peninsula in early June, and then rapidly advanced northward until the southwest monsoon was established in the whole inland of South Asia at the end of June and reached Pakistan in mid-July. Then the southwest monsoon reached its peak. The formation process of southwest monsoon varies from place to place. In India, it is explosive, but in Vietnam and Thailand, it is not as explosive as in India. For example, in April and May, the precipitation in Bangkok was 12 1 and 147mm, and in Mumbai it was 3 and 16mm, but in June, the precipitation in Bangkok was 2 18mm. The southwest monsoon began to retreat in September 1, and the northeast monsoon appeared in mid-June. 1 1 At the beginning of the month, the northeast monsoon moved to the south of Indian Peninsula, 1 moved to Madras, and 1 appeared in the middle of Sri Lanka at the beginning of the month. In the tropical monsoon climate zone, the annual precipitation is 1, 000- 1, 500 mm, and the windward side of the mountains can reach more than 2000 mm. tropical monsoon forest grows here, but in the leeward side and the inner plain lowlands, the precipitation is obviously reduced, and the trees are sparse, showing a tropical grassland landscape. The similarity between tropical monsoon climate and tropical grassland climate is that summer precipitation is related to intertropical convergence zone, and the precipitation in the driest month is less than 50mm；; The difference is that the change of wind direction in prairie climate in a year is not as opposite as that in tropical monsoon climate.

Due to the influence of location, area and topography related to land and ocean, there are some differences within the tropical monsoon climate zone, which can be mainly divided into continental type and ocean type. The former is located in the South Asian subcontinent and Indian zhina Peninsula. Because the coastal mountains block the sea breeze, and the bases of Indian Peninsula and Indochina Peninsula are close to the vast mainland, the temperature can reach 20℃ throughout the year, and the dry season is longer than the warm season, and the hot season is prominent. The latter is located on the coast of Philippine Islands and Indochina Peninsula, where there is abundant precipitation in both winter monsoon and summer monsoon, and the annual range and diurnal range are smaller than those of Indian Peninsula, especially in dry season.

Compared with the monsoon climate in Southeast Asia, the tropical monsoon climate in the South Asian subcontinent has its own characteristics in * * * *:

1) On the basis of dry and wet seasons, there is also a prominent hot season (March-May). For example, the average temperature in Madras from April to August exceeds 30℃. The highest temperature in Alba reaches 50.6℃.

2) The establishment of southwest monsoon is about 1 month later than that of Indochina Peninsula.

3) The rainfall changes greatly. For example, the annual precipitation in the Indus-Ganges lowlands ranges from 150 mm to 1500 mm (tropical rainforest climate).

This area is located in the southern part of Malay Archipelago and Malay Peninsula, close to the equator. Controlled by equatorial air mass or denatured tropical air mass all year round, it is hot and rainy all year round. The temperature is often 24-28℃, and the lowest temperature at night is mostly above 16℃. The annual temperature is lower than that of Amazon Plain and Congo Basin of the same type, generally lower than 65438 0.5℃, and the highest temperature is not more than 3℃. The annual precipitation is more than 2000 mm, and there is no sultry feeling due to the adjustment of sea breeze.

This climate zone is located between Asia and Europe, Australia and the Pacific Ocean and the Indian Ocean, and it is also a broken mountain range, island or peninsula surrounded by warm sea water. This special land and sea location and topographic factors make this climate area have more complicated monsoon maritime characteristics than the same type of Amazon Plain and Congo Basin, except for high temperature, rainy, hot and humid. This is mainly reflected in the relationship between the temporal and spatial distribution of precipitation and monsoon in this area.

There are two rain peaks in the equatorial rainforest climate zone in general years, which appear when the direct point of the sun passes through the zenith and intertropical convergence zone twice, namely the vernal equinox and the autumnal equinox. However, the rain peaks in this climate area do not necessarily appear in the vernal equinox and autumn equinox, but often appear in the period when the monsoon prevails. The regional distribution of precipitation is complicated, generally it is rainy on the side facing the northeast trade wind and northwest monsoon, rainy in the west of the island and less in the east.

Due to the north-south opposition between the Eurasian continent and the Australian continent, the north-south displacement of intertropical convergence zone between the subtropical high in the eastern hemisphere can reach 30 degrees latitude from June to July, which not only forms a tropical monsoon climate zone in Asia, but also makes the islands between Asia and Australia deeply controlled by the intertropical convergence zone moving north and south with the seasons and the perennial equatorial westerly wind. In June+10, 5438, the northeast monsoon from the Asian continent and the northeast trade wind from the east of the Philippines, whose leading edge can reach the equator. The southeast trade winds in the southern hemisphere can reach about 12 s, and the equatorial westerly belt is located south of the equator. At this time, intertropical convergence zone in the north passes through the central Sumatra Island near the equator, southern kalimantan island and the northwest Sulawesi Island, and the airflow convergence rises obviously. In addition, near 12 S (west section) to 15 S (east section), it is the convergence zone of northwest monsoon and southeast trade wind, equatorial westerly wind and southeast trade wind, so it is rainy in the west of the islands than in the east. In July, the equatorial westerly airflow obviously moved northward and expanded, and the southern convergence zone also moved northward. At this time, except Sumatra island in the equatorial region, the southeast monsoon from Australia and the south wind turning to the equator are affected by the convergence with the southwest monsoon. In April and June of the transitional season 10, the equatorial westerly line is in the equatorial belt, and the northern convergence belt moves to the middle of Malay Peninsula near 4° N and the northern part of Kalimantan, and the southern convergence belt moves to 5° S to cross the Indonesian archipelago. At this time, the equatorial region is affected by the north-south convergence zone and the equatorial westerly wind.

It can be seen that the equatorial region of Asia is dominated by westerly winds, and the south of the equator is mainly controlled by southeast trade winds (June-August) and northwest monsoon (65438+February-February), while the north of the equator is influenced by southwest monsoon and northeast monsoon. Coupled with the topographic effect of mountainous islands, the regional distribution difference of precipitation increases. The north side of the equator facing the northeast monsoon is rainy, such as Gualatinganu on the east coast of Malay Peninsula, with an annual precipitation of 3,093 mm, of which the precipitation in February is over 600mm, while it is only 130mm in summer. The annual precipitation in Sandakan on the northeast coast of kalimantan island is 3650mm and 65,438 respectively. South of the equator, the rainy side facing the northwest monsoon, such as Wurong Pandang in the southwest of Sulawesi, faces the northwest monsoon and the southeast trade wind. The annual precipitation is 2878mm, and the northwest wind is 597 mm and 676mm in February, 65438+and 65438+ 10, respectively. The southeast wind prevails in July, August and September, and the precipitation is reduced to 36 and 10. The area near the equator is rainy in the monsoon transition season, and the precipitation on the west coast is more than that on the east coast. For example, the annual precipitation in Badong, west of Sumatra Island, is more than 4000mm, while the eastern plain is only 2573 mm Even if it is close to the equator, it becomes a semi-arid area on the equator because of the winter and summer monsoon. For example, the annual precipitation in Barrobo, Sulawesi Island is only 550 mm In addition, the equatorial rain forest area in Asia is also one of the areas with the most convective rainstorms. Bogor, for example, is located in the mountainous plateau basin where the leeward of the island is blocked, and there are 332 days of thunderstorms every year, which is called "Leidu". (temperate grassland climate)

It is located in the temperate inland of Asia, bordering Daxing 'anling and Taihang Mountains in the east, with a coniferous forest climate in southern Xinjiang in the north, a temperate desert climate in the south, and a grassland belt in southern Eastern Europe in the west, including southern Siberia, Kazakh hills in Central Asia, Mongolian grasslands, Inner Mongolia, the middle reaches of the Yellow River and the great plains in central North America. It is a transitional zone between humid climate and dry climate, extending from east to west, and is the main part of temperate grassland belt in Eurasia. The main feature of this kind of climate is that it is rarely affected by ocean moisture because it is located inland or blocked by mountains. The annual precipitation is mostly 250-450 mm, mainly in summer, with heavy rain and large rainfall changes. The evaporation may be greater than the precipitation, and the dryness is between 1.5-3.99. The climate is continental, and it is very cold in winter. 1 month, the average temperature is mostly between-5 and-20℃, and it is hot in summer, and the average temperature in July is higher than 20℃. The annual temperature is mostly 36-37℃. Turgay, Central Asia, Soviet Union, 1 monthly average temperature-17.8℃, July 23.7℃, annual average temperature 3.7℃, annual precipitation 249mm, including 79mm in summer, 52mm in winter, and growing period 160- 190 days. Another example is Ulaanbaatar, Mongolia, which is also an obvious summer rain type. 84% of the annual precipitation (208mm) falls in the three months of summer. (temperate desert, temperate semi-desert climate)

The Lan Tu Plain in the Soviet Union, the inland basin in the northwest of China, the western part of Inner Mongolia and the southeastern part of Mongolia, because they live inland, have little precipitation, the annual precipitation is generally below 250mm, the climate is dry, the temperature changes extremely, and the annual amplitude and daily range are very large. For example, in the temperate desert of Central Asia in the Soviet Union, the monthly temperature is-1 5℃ to-10℃, the temperature is 25-30℃ in July, and the annual precipitation is 100-200mm. The annual precipitation in Turpan, Xinjiang, China is only 22.7mm, with little snowfall in winter and high annual relative sunshine percentage (60-70%), and it is hot in Leng Xia in winter and the temperature changes sharply, which are the main differences between the climate in this area and the tropical arid climate. For example, although Turpan is located at 43 N, the average monthly temperature in summer from June to August is above 30℃, with the extreme maximum temperature reaching 47.8℃ and the extreme maximum ground temperature reaching 75℃. It is the hottest place in China, known as the "volcanic island", and annual range also reaches 43.5℃, which is higher than annual range (18.9℃) in the tropical dry early climate zone of Aswan. (Tropical desert climate, tropical semi-desert climate)

This area is located on the southern edge of Arabian Peninsula and Iranian Plateau, and is an eastward extension of the desert belt in North Africa. Due to the influence of subtropical high and northeast trade winds, the climate is very dry and hot. The hottest month temperature is 30-39℃, the Leng Yue temperature is 10-25℃, the absolute maximum temperature is above 55℃, sometimes it drops to 0℃ at night, the annual temperature difference is generally below 18℃, and the daily temperature difference sometimes reaches 35-40℃. Due to the lack of humid southwest monsoon, the precipitation in this area is scarce, and some have not dropped a drop of rain in the desert for many years (but there is also a record of a rainstorm with a precipitation of tens of millimeters), so tropical deserts are widely distributed. The main difference between tropical desert and temperate desert is that the former is hot in summer and not cold in winter, which is a typical dry-hot climate. Sandstorms often occur with high temperature and very dry air (relative humidity is 10%).

Generally speaking, the arid climate, that is, the desert climate, is dominated by non-zonality. Although temperate, subtropical and tropical semi-arid climates can be divided from north to south in temperature, except for a few cases, they are continuous in regional distribution and difficult to distinguish. The global arid areas are mainly distributed in the northern hemisphere10-50 n and the southern hemisphere15-50 s. The equatorial arid areas are mainly located in Peru coast in South America, northeast Brazil, Kenya, Ethiopia and Somalia in East Africa. The most widely distributed arid area in the world is the west coast of North Africa-Sahara-Arabian Peninsula-Iran-Central Asia, which is 13000km long from east to west. Subtropical and tropical deserts can be collectively referred to as hot deserts. Their common characteristics are strong sunshine, with annual sunshine hours of 3500-4000 h, relative humidity below 50%, annual average temperature above 18℃, and surface temperature above 25℃ in some places up to 80℃, but as low as 0℃ at night. The average temperature in Leng Yue is not lower than 10℃, and the annual variation is not high, which is around 18℃. The daily range is quite large, reaching 35-40℃, with little precipitation, generally less than 250mm, and less than 100mm in some places, even without dripping for several years, and sandstorms often occur. Temperate desert is cold desert, which is characterized by very cold winter, with extreme temperature difference of 90℃, average temperature of 3-10℃ in Leng Yue, and temperature of shady place of 50℃ in summer. In the northern hemisphere, temperate deserts are related to vast land area and being far away from the ocean, while subtropical and tropical deserts are controlled by subtropical high belts. (Mediterranean climate)

Compared with the monsoon region at the same latitude on the east coast of the mainland, the climate characteristics in this region are obviously different. It belongs to the subtropical climate on the west coast of the mainland, with abundant sunshine in summer, hot and dry, and mild and rainy in winter. Vegetation communities are hard-leaved evergreen shrubs and forests. Suitable for developing grape, olive and citrus horticulture. The Asia minor peninsula (except inland), the Mediterranean coast, the western edge of the Iranian plateau, the California coast of North America, the central Chile and the southwest coast of Australia all belong to this climate. In the Pamir Plateau, Qinghai-Tibet Plateau and other alpine regions, climate factors such as temperature and precipitation change vertically with the terrain, forming an alpine climate. For example, although the Qinghai-Tibet Plateau is at the same latitude as the Iranian Plateau, it has a cold desert, alpine meadow and alpine grassland landscape because of its high terrain, low temperature and severe winter. Because of its high and steep terrain, Himalayan Mountain has also formed a typical subtropical and alpine vertical climate zone structure from the foothills subtropical to alpine ice and snow areas.