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CLIMATE, long-term weather regime in a given area. The weather at any given time is characterized by certain combinations of temperature, humidity, wind direction and speed. In some climates, the weather varies significantly every day or seasonally, while in others it remains constant. Climatic descriptions are based on statistical analysis of average and extreme meteorological characteristics. As a factor in the natural environment, climate influences the geographical distribution of vegetation, soil and water resources and, consequently, land use and the economy. Climate also affects human living conditions and health.

Climatology is the science of climate that studies the reasons for the formation different types climate, their geographical location and the relationship between climate and other natural phenomena. Climatology is closely related to meteorology - a branch of physics that studies short-term states of the atmosphere, i.e. weather.

CLIMATE FORMING FACTORS

Position of the Earth.

When the Earth orbits the Sun, the angle between the polar axis and the perpendicular to the orbital plane remains constant and amounts to 23° 30°. This movement explains the change in the angle of incidence sun rays on the earth's surface at noon at a certain latitude during the year. The greater the angle of incidence of the sun's rays on the Earth in a given place, the more efficiently the Sun heats the surface. Only between the Northern and Southern tropics (from 23° 30° N to 23° 30° S) the sun's rays fall vertically on the Earth at certain times of the year, and here the Sun at noon always rises high above the horizon. Therefore, the tropics are usually warm at any time of the year. At higher latitudes, where the Sun is lower above the horizon, the heating of the earth's surface is less. There are significant seasonal changes in temperature (which does not happen in the tropics), and in winter the angle of incidence of the sun's rays is relatively small and the days are much shorter. At the equator, day and night always have equal duration, while at the poles the day lasts throughout the summer half of the year, and in winter the Sun never rises above the horizon. The length of the polar day only partially compensates for the low position of the Sun above the horizon, and as a result, summers here are cool. During dark winters, the polar regions quickly lose heat and become very cold.

Distribution of land and sea.

Water heats up and cools down more slowly than land. Therefore, the air temperature over the oceans has smaller daily and seasonal changes than over the continents. In coastal areas, where winds blow from the sea, summers are generally cooler and winters warmer than in the interior of continents at the same latitude. The climate of such windward coasts is called maritime. The interior regions of continents in temperate latitudes are characterized by significant differences in summer and winter temperatures. In such cases they speak of a continental climate.

Water areas are the main source of atmospheric moisture. When winds blow from the warm oceans onto land, there is a lot of precipitation. On windward coasts it is usually higher relative humidity and cloudiness and more days with fog than in inland regions.

Atmospheric circulation.

The nature of the pressure field and the rotation of the Earth determine the general circulation of the atmosphere, due to which heat and moisture are constantly redistributed over the earth's surface. Winds blow from areas of high pressure to areas of low pressure. High pressure is usually associated with cold, dense air, while low pressure is usually associated with warm, less dense air. The rotation of the Earth causes air currents to deviate to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deviation is called the “Coriolis effect”.

In both the Northern and Southern Hemispheres, there are three main wind zones in the surface layers of the atmosphere. In the intertropical convergence zone near the equator, the northeast trade wind approaches the southeast. Trade winds originate in subtropical high pressure areas, most developed over the oceans. Air flows moving towards the poles and deflecting under the influence of the Coriolis force form the predominant westerly transport. In the region of the polar fronts of temperate latitudes, westerly transport meets the cold air of high latitudes, forming a zone of baric systems with low pressure in the center (cyclones), moving from west to east. Although air currents in the polar regions are not so pronounced, polar eastern transport is sometimes distinguished. These winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere. Masses of cold air often penetrate into temperate latitudes.

Winds in areas of convergence of air currents form upward flows of air, which cools with height. In this case, cloud formation is possible, often accompanied by precipitation. Therefore, the intertropical convergence zone and frontal zones in the prevailing westerly transport belt receive a lot of precipitation.

Winds blowing higher in the atmosphere close the circulation system in both hemispheres. Air rising in convergence zones rushes into areas of high pressure and sinks there. At the same time, as pressure increases, it heats up, which leads to the formation of a dry climate, especially on land. Such downward air currents determine the climate of the Sahara, located in the subtropical high pressure zone in North Africa.

Seasonal changes in heating and cooling determine the seasonal movements of the main pressure formations and wind systems. Wind zones in summer shift towards the poles, which leads to changes weather conditions at this latitude. Thus, African savannas, covered with herbaceous vegetation with sparsely growing trees, are characterized by rainy summers (due to the influence of the intertropical convergence zone) and dry winters, when a high pressure area with downward air flows moves into this area.

Seasonal changes in the general circulation of the atmosphere are also influenced by the distribution of land and sea. In the summer, when the Asian continent warms up and an area of ​​lower pressure is established over it than over the surrounding oceans, the coastal southern and southeastern regions are affected by moist air currents directed from the sea to the land and bringing heavy rains. In winter, air flows from the cold surface of the continent onto the oceans, and much less rain falls. Such winds, which change direction depending on the season, are called monsoons.

Ocean currents

are formed under the influence of near-surface winds and differences in water density caused by changes in its salinity and temperature. The direction of currents is influenced by the Coriolis force, the shape of sea basins and the contours of the coast. In general, the circulation of ocean currents is similar to the distribution of air currents over the oceans and occurs clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.

Crossing warm currents heading towards the poles, the air becomes warmer and more humid and has a corresponding effect on the climate. Ocean currents moving towards the equator carry cool waters. Passing along the western edges of the continents, they lower the temperature and moisture capacity of the air, and, accordingly, the climate under their influence becomes cooler and drier. Due to moisture condensation near the cold surface of the sea, fog often occurs in such areas.

Relief of the earth's surface.

Large landforms have a significant impact on the climate, which varies depending on the altitude of the area and the interaction of air flows with orographic obstacles. Air temperature usually decreases with height, which leads to the formation of a cooler climate in the mountains and plateaus than in the adjacent lowlands. In addition, hills and mountains form obstacles that force the air to rise and expand. As it expands it cools. This cooling, called adiabatic cooling, often results in moisture condensation and the formation of clouds and precipitation. Most of the precipitation due to the barrier effect of mountains falls on their windward side, while the leeward side remains in the “rain shadow”. Air descending on leeward slopes heats up when compressed, forming a warm, dry wind known as a foehn.

CLIMATE AND LATITUDE

In climate surveys of the Earth, it is advisable to consider latitudinal zones. The distribution of climate zones in the Northern and Southern Hemispheres is symmetrical. To the north and south of the equator there are tropical, subtropical, temperate, subpolar and polar zones. The pressure fields and zones of prevailing winds are also symmetrical. Consequently, most climate types in one hemisphere can be found at similar latitudes in the other hemisphere.

MAIN CLIMATE TYPES

The climate classification provides an orderly system for characterizing climate types, their zoning and mapping. The types of climate that prevail over large areas are called macroclimates. A macroclimatic region must have more or less homogeneous climatic conditions that distinguish it from other regions, although they represent only a generalized characteristic (since there are no two places with an identical climate), more consistent with reality than the identification of climatic regions only on the basis of belonging to a certain latitude -geographical zone.

Ice sheet climate

dominates in Greenland and Antarctica, where average monthly temperatures are below 0° C. During the dark winter season, these regions receive absolutely no solar radiation, although there are twilights and auroras. Even in summer, the sun's rays hit the earth's surface at a slight angle, which reduces the efficiency of heating. Most of the incoming solar radiation is reflected by the ice. In both summer and winter, the higher elevations of the Antarctic Ice Sheet experience low temperatures. The climate of the interior of Antarctica is much colder climate Arctic, because southern mainland is different large sizes and altitudes, and the Arctic Ocean moderates the climate, despite the widespread distribution of pack ice. During short periods of warming in summer, drifting ice sometimes melts.

Precipitation on ice sheets falls in the form of snow or small particles of freezing fog. Inland areas receive only 50–125 mm of rainfall annually, but the coast can receive more than 500 mm. Sometimes cyclones bring clouds and snow to these areas. Snowfalls are often accompanied strong winds, which carry significant masses of snow, blowing it off the rocks. Strong katabatic winds with snowstorms blow from the cold ice sheet, carrying snow to the coasts.

Subpolar climate

manifests itself in tundra areas on the northern outskirts of North America and Eurasia, as well as on the Antarctic Peninsula and adjacent islands. In eastern Canada and Siberia, the southern limit of this climate zone lies well south of the Arctic Circle due to the strong influence of vast land masses. This leads to long and extremely cold winters. Summers are short and cool with average monthly temperatures rarely exceeding +10° C. To some extent long days compensate for the short duration of summer, but in most of the territory the heat received is not enough to completely thaw the soil. Permanently frozen ground, called permafrost, inhibits plant growth and infiltration melt water into the ground. Therefore, in summer, flat areas become swampy. On the coast winter temperatures slightly higher, and summer temperatures slightly lower, than in the interior of the mainland. In summer, when humid air is above cold water or sea ​​ice, fog often occurs on the Arctic coasts.

The annual precipitation usually does not exceed 380 mm. Most of them fall in the form of rain or snow in the summer, during the passage of cyclones. On the coast, the bulk of precipitation can be brought by winter cyclones. But the low temperatures and clear weather of the cold season, characteristic of most areas with a subpolar climate, are unfavorable for significant snow accumulation.

Subarctic climate

also known as “taiga climate” (based on the predominant type of vegetation - coniferous forests). This climate zone covers the temperate latitudes of the Northern Hemisphere - the northern regions of North America and Eurasia, located immediately south of the subpolar climate zone. Sharp seasonal climatic differences appear here due to the position of this climatic zone at fairly high latitudes in internal parts continents. Winters are long and extremely cold, and the further north you go, the shorter the days. Summer is short and cool with long days. In winter, the period with negative temperatures is very long, and in summer the temperature can sometimes exceed +32° C. In Yakutsk, the average temperature in January is –43° C, in July – +19° C, i.e. the annual temperature range reaches 62° C. A milder climate is typical for coastal areas, such as southern Alaska or northern Scandinavia.

Over most of the climate zone under consideration, less than 500 mm of precipitation falls per year, with its maximum amount on the windward coasts and minimum in the interior of Siberia. There is very little snowfall in winter; snowfalls are associated with rare cyclones. Summer is usually wetter, with rain falling mainly when atmospheric fronts. The coasts are often foggy and overcast. In winter, during severe frosts, icy fogs hang over the snow cover.

Humid continental climate with short summers

characteristic of a vast strip of temperate latitudes of the Northern Hemisphere. IN North America it extends from the prairies of south-central Canada to the coast Atlantic Ocean, and in Eurasia covers most of Eastern Europe and some areas Central Siberia. The same type of climate is observed on the Japanese island of Hokkaido and in the south Far East. The main climatic features of these areas are determined by the prevailing westerly transport and the frequent passage of atmospheric fronts. IN harsh winters average air temperatures can drop to –18° C. Summer is short and cool, the frost-free period is less than 150 days. The annual temperature range is not as great as in a subarctic climate. In Moscow, the average temperatures in January are –9° C, in July – +18° C. In this climate zone, there is a constant threat to Agriculture represent spring frosts. In the coastal provinces of Canada, in New England and on about. Hokkaido winters are warmer than inland areas, as easterly winds sometimes bring warmer ocean air.

Annual precipitation ranges from less than 500 mm in the interior of continents to more than 1000 mm on the coasts. In most of the region, precipitation falls mainly in the summer, often with thunderstorms. Winter precipitation, mainly in the form of snow, is associated with the passage of fronts in cyclones. Blizzards are often observed in the rear of a cold front.

Humid continental climate with long summers.

Air temperatures and the length of the summer season increase southward in areas of humid continental climate. This type of climate occurs in the temperate latitude zone of North America from the eastern part of the Great Plains to the Atlantic coast, and in southeastern Europe - in the lower reaches of the Danube. Similar climatic conditions are also expressed in northeastern China and central Japan. Western transport is also predominant here. The average temperature of the warmest month is +22° C (but temperatures can exceed +38° C), summer nights warm. Winters are not as cold as in humid continental climates with short summer, but the temperature sometimes drops below 0° C. The annual temperature range is usually 28° C, as, for example, in Peoria (Illinois, USA), where the average temperature in January is –4° C, and in July – +24° C. On the coast, annual temperature amplitudes decrease.

Most often, in a humid continental climate with long summers, precipitation falls from 500 to 1100 mm per year. The greatest amount of precipitation comes from summer thunderstorms during the growing season. In winter, rain and snowfall are mainly associated with the passage of cyclones and associated fronts.

Temperate maritime climate

characteristic of the western coasts of continents, primarily northwestern Europe, the central part of the Pacific coast of North America, southern Chile, southeastern Australia and New Zealand. The course of air temperature is moderated by the prevailing westerly winds blowing from the oceans. Winters are mild with average temperatures in the coldest month above 0°C, but when arctic air flows reach the coasts, there are also frosts. Summers are generally quite warm; with intrusions of continental air during the day, the temperature can rise for a short time to +38° C. This type of climate with a slight annual amplitude temperatures are the most moderate among climates of temperate latitudes. For example, in Paris the average temperature in January is +3° C, in July – +18° C.

In areas of temperate maritime climate, the average annual precipitation ranges from 500 to 2500 mm. The windward slopes of the coastal mountains are the most humid. Many areas have fairly even rainfall throughout the year, with the exception of the Pacific Northwest coast of the United States, which has very wet winters. Cyclones moving from the oceans bring a lot of precipitation to the western continental margins. In winter, the weather is usually cloudy with light rain and rare short-term snowfalls. Fogs are common on the coasts, especially in summer and autumn.

Humid subtropical climate

characteristic of the eastern coasts of continents north and south of the tropics. The main areas of distribution are the southeastern United States, some southeastern parts of Europe, northern India and Myanmar, eastern China and southern Japan, northeastern Argentina, Uruguay and southern Brazil, the coast of Natal in South Africa and the eastern coast of Australia. Summer in the humid subtropics is long and hot, with temperatures similar to those in the tropics. The average temperature of the warmest month exceeds +27° C, and the maximum – +38° C. Winters are mild, with average monthly temperatures above 0° C, but occasional frosts have a detrimental effect on vegetable and citrus plantations.

In the humid subtropics, average annual precipitation amounts range from 750 to 2000 mm, and the distribution of precipitation across seasons is quite uniform. In winter, rain and rare snowfalls are brought mainly by cyclones. In summer, precipitation falls mainly in the form of thunderstorms associated with powerful inflows of warm and humid oceanic air, characteristic of the monsoon circulation of East Asia. Hurricanes (or typhoons) occur in late summer and fall, especially in the Northern Hemisphere.

Subtropical climate with dry summers

typical of the western coasts of continents north and south of the tropics. In Southern Europe and North Africa, such climatic conditions are typical for the coasts mediterranean sea, which was the reason to call this climate also Mediterranean. The climate is similar in southern California, central Chile, extreme southern Africa and parts of southern Australia. All these areas have hot summers and mild winters. As in the humid subtropics, there are occasional frosts in winter. In inland areas, summer temperatures are significantly higher than on the coasts, and are often the same as in tropical deserts. In general, clear weather prevails. In summer, there are often fogs on the coasts near which ocean currents pass. For example, in San Francisco, summers are cool, foggy, and most warm month- September.

The maximum precipitation is associated with the passage of cyclones in winter, when the prevailing westerly air currents shift towards the equator. The influence of anticyclones and downward air currents under the oceans determine the dryness of the summer season. The average annual precipitation in a subtropical climate ranges from 380 to 900 mm and reaches maximum values ​​on the coasts and mountain slopes. In summer there is usually not enough rainfall for normal tree growth, and therefore a specific type of evergreen shrubby vegetation develops there, known as maquis, chaparral, mali, macchia and fynbos.

Semi-arid climate of temperate latitudes

(synonym - steppe climate) is characteristic mainly of inland areas remote from the oceans - sources of moisture - and usually located in the rain shadow of high mountains. The main areas with a semiarid climate are the intermountain basins and Great Plains of North America and the steppes of central Eurasia. Hot summer and Cold winter due to the inland position in temperate latitudes. At least one winter month has an average temperature below 0° C, and the average temperature of the warmest summer month exceeds +21° C. The temperature regime and the duration of the frost-free period vary significantly depending on the latitude.

The term semiarid is used to describe this climate because it is less dry than the arid climate proper. The average annual precipitation is usually less than 500 mm but more than 250 mm. Since the development of steppe vegetation in conditions of higher temperatures requires more precipitation, the latitudinal-geographical and altitudinal position of the area determine climatic changes. For semiarid climate There are no general patterns of precipitation distribution throughout the year. For example, areas bordering the subtropics with dry summers experience a maximum of precipitation in winter, while areas adjacent to areas of a humid continental climate experience rainfall mainly in summer. Temperate cyclones bring most of the winter's precipitation, which often falls as snow and can be accompanied by strong winds. Summer thunderstorms often include hail. The amount of precipitation varies greatly from year to year.

Arid climate of temperate latitudes

is characteristic mainly of Central Asian deserts, and in the western United States - only small areas in intermountain basins. Temperatures are the same as in areas with a semiarid climate, but precipitation here is insufficient for the existence of a closed natural vegetation cover and average annual amounts usually do not exceed 250 mm. As in semiarid climatic conditions, the amount of precipitation that determines aridity depends on the thermal regime.

Semiarid climate of low latitudes

mostly typical for outskirts tropical deserts(for example, the Sahara and deserts of central Australia), where downdrafts of air in subtropical high pressure zones exclude precipitation. The climate under consideration differs from the semiarid climate of temperate latitudes in its very hot summers and warm winter. Average monthly temperatures are above 0°C, although frosts sometimes occur in winter, especially in areas furthest from the equator and located on high altitudes. The amount of precipitation required for the existence of closed natural herbaceous vegetation is higher here than in temperate latitudes. In the equatorial zone, rain falls mainly in the summer, while on the outer (northern and southern) outskirts of the deserts the maximum precipitation occurs in winter. Precipitation mostly falls in the form of thunderstorms, and in winter the rains are brought by cyclones.

Arid climate of low latitudes.

This is a hot, dry tropical desert climate that extends along the Northern and Southern Tropics and is influenced by subtropical anticyclones for most of the year. Rescue from exhausting summer heat can be found only on coasts washed by cold ocean currents or in the mountains. On the plains, average summer temperatures significantly exceed +32° C, winter temperatures are usually above +10° C.

In most of this climatic region, the average annual precipitation does not exceed 125 mm. It happens that at many meteorological stations no precipitation is recorded at all for several years in a row. Sometimes the average annual precipitation can reach 380 mm, but this is still only enough for the development of sparse desert vegetation. Occasionally, precipitation occurs in the form of short, strong thunderstorms, but the water drains quickly to form flash floods. The driest areas are along the western coasts of South America and Africa, where cold ocean currents prevent cloud formation and precipitation. These coasts often experience fog, formed by the condensation of moisture in the air over the colder surface of the ocean.

Variably humid tropical climate.

Areas with such a climate are located in tropical sublatitudinal zones, several degrees north and south of the equator. This climate is also called tropical monsoon climate because it prevails in those parts of South Asia that are influenced by the monsoons. Other areas with such a climate are the tropics of Central and South America, Africa and Northern Australia. Average summer temperatures are usually approx. +27° C, and winter – approx. +21° C. The hottest month, as a rule, precedes the summer rainy season.

Average annual precipitation ranges from 750 to 2000 mm. During the summer rainy season, the intertropical convergence zone has a decisive influence on the climate. There are frequent thunderstorms here, sometimes overcast with lingering rains persists for a long time. Winter is dry, as subtropical anticyclones dominate this season. In some areas there is no rain for two or three winter months. In South Asia, the wet season coincides with summer monsoon, which brings moisture from the Indian Ocean, and in winter Asian continental dry air masses spread here.

Humid tropical climate

or tropical rainforest climate, common in equatorial latitudes in the Amazon basins South America and the Congo in Africa, on the Malay Peninsula and on the islands of Southeast Asia. In the humid tropics, the average temperature of any month is at least +17 ° C, usually the average monthly temperature is approx. +26° C. As in the variablely humid tropics, due to the high midday position of the Sun above the horizon and the same day length throughout the year, seasonal temperature fluctuations are small. Humid air, cloudiness and dense vegetation cover prevent night cooling and maintain maximum temperatures. daytime temperatures below +37° С, lower than in higher latitudes.

The average annual precipitation in the humid tropics ranges from 1500 to 2500 mm, and the seasonal distribution is usually fairly even. Precipitation is mainly associated with the Intertropical Convergence Zone, which is located slightly north of the equator. Seasonal shifts of this zone to the north and south in some areas lead to the formation of two maximum precipitation during the year, separated by drier periods. Every day, thousands of thunderstorms roll over the humid tropics. In between, the sun shines in full force.

Highland climates.

In high mountain areas, a significant variety of climatic conditions is due to the latitudinal geographic position, orographic barriers and different exposures of slopes in relation to the Sun and moisture-carrying air flows. Even at the equator in the mountains there are snowfields-migrations. The lower limit of eternal snow descends towards the poles, reaching sea level in the polar regions. Like it, other boundaries of high-altitude thermal belts decrease as they approach high latitudes. Windward slopes of mountain ranges receive more precipitation. On mountain slopes exposed to cold air intrusions, temperatures may drop. In general, the climate of the highlands is characterized by lower temperatures, higher cloudiness, more precipitation and more complex wind patterns than the climate of the plains at the corresponding latitudes. Character seasonal changes Temperatures and precipitation in the highlands are usually the same as in the adjacent plains.

MESO- AND MICROCLIMATES

Territories that are smaller in size than macroclimatic regions also have climatic features that deserve special study and classification. Mesoclimates (from the Greek meso - average) are the climates of areas several square kilometers in size, for example, wide river valleys, intermountain depressions, basins of large lakes or cities. In terms of area of ​​distribution and nature of differences, mesoclimates are intermediate between macroclimates and microclimates. The latter characterize climatic conditions in small areas of the earth's surface. Microclimatic observations are carried out, for example, on city streets or on test plots established within a homogeneous plant community.

EXTREME CLIMATE INDICATORS

Climate characteristics such as temperature and precipitation vary widely between extremes (minimum and maximum). Although they are rarely observed, extremes are just as important as averages for understanding the nature of climate. The warmest climate is the tropics, with the climate of tropical rainforests being hot and humid, and the arid climate of low latitudes being hot and dry. Maximum air temperatures are recorded in tropical deserts. The world's highest temperature - +57.8 ° C - was recorded in Al-Azizia (Libya) on September 13, 1922, and the lowest - -89.2 ° C at the Soviet Vostok station in Antarctica on July 21, 1983.

Rainfall extremes have been recorded in different areas of the world. For example, in 12 months from August 1860 to July 1861, 26,461 mm fell in the town of Cherrapunji (India). The average annual precipitation at this point, one of the rainiest on the planet, is approx. 12,000 mm. There is less data available on the amount of snow that fell. At Paradise Ranger Station national park Mount Rainier (Washington, USA) recorded 28,500 mm of snow during the winter of 1971–1972. Many meteorological stations in the tropics with long observation records have never recorded precipitation at all. There are many such places in the Sahara and on west coast South America.

At extreme wind speeds, measuring instruments (anemometers, anemographs, etc.) often failed. The highest wind speeds in the surface air layer are likely to develop in tornadoes, where it is estimated that they can well exceed 800 km/h. In hurricanes or typhoons, winds sometimes reach speeds of over 320 km/h. Hurricanes are very common in the Caribbean and Western Pacific.

INFLUENCE OF CLIMATE ON BIOTA

Temperature and light regimes and moisture supply, necessary for the development of plants and limiting their geographical distribution, depend on the climate. Most plants cannot grow at temperatures below +5° C, and many species die at subzero temperatures. As temperatures increase, the moisture requirements of plants increase. Light is essential for photosynthesis, as well as for flowering and seed development. Shading the soil by tree crowns in a dense forest suppresses the growth of shorter plants. An important factor is also the wind, which significantly changes the temperature and humidity regime.

The vegetation of each region is an indicator of its climate, since the distribution of plant communities is largely determined by climate. Tundra vegetation in a subpolar climate is formed only by such low-growing forms as lichens, mosses, grasses and low shrubs. The short growing season and widespread permafrost make it difficult for trees to grow everywhere except in river valleys and southern-facing slopes, where the soil thaws to greater depths in the summer. Coniferous forests from spruce, fir, pine and larch, also called taiga, grow in a subarctic climate.

Humid areas of temperate and low latitudes are especially favorable for forest growth. The densest forests are confined to areas of temperate maritime climate and humid tropics. Areas of humid continental and humid subtropical climates are also mostly forested. When there is a dry season, such as in areas of subtropical dry-summer climates or variable-humid tropical climates, plants adapt accordingly, forming either a low-growing or sparse tree layer. Thus, in savannas in a variable humid tropical climate, grasslands with single trees, growing at large distances from one another, predominate.

In semiarid climates of temperate and low latitudes, where everywhere (except river valleys) is too dry for trees to grow, grassy steppe vegetation dominates. The grasses here are low-growing, and there may also be an admixture of subshrubs and subshrubs, such as wormwood in North America. In temperate latitudes, grass steppes in more humid conditions at the borders of their range give way to tallgrass prairies. In arid conditions, plants grow far apart from each other and often have thick bark or fleshy stems and leaves that can store moisture. The driest areas of tropical deserts are completely devoid of vegetation and consist of bare rocky or sandy surfaces.

Climatic altitudinal zonation in the mountains determines the corresponding vertical differentiation of vegetation - from herbaceous communities of foothill plains to forests and alpine meadows.

Many animals are able to adapt to a wide range of climatic conditions. For example, mammals in cold climates or winter have warmer fur. However, the availability of food and water is also important for them, which varies depending on the climate and season. Many animal species are characterized by seasonal migrations from one climatic region to another. For example, in winter, when grasses and shrubs dry out in the variable humid tropical climate of Africa, mass migrations of herbivores and predators occur to more humid areas.

IN natural areas Around the globe, soils, vegetation and climate are closely interrelated. Heat and moisture determine the nature and pace of chemical, physical and biological processes, as a result of which changes rocks on slopes of different steepness and exposure and creates a huge variety of soils. Where the soil is frozen for most of the year, as in the tundra or high in the mountains, soil formation processes are slowed down. In arid conditions, soluble salts are usually found on the soil surface or in near-surface horizons. In humid climates excess moisture seeps down, carrying soluble mineral compounds and clay particles to considerable depths. Some of the most fertile soils are the products of recent accumulation - wind, fluvial or volcanic. Such young soils have not yet been subjected to severe leaching and therefore retain their reserves of nutrients.

The distribution of crops and soil cultivation methods are closely related to climatic conditions. Bananas and rubber trees require plenty of heat and moisture. Date palms grow well only in oases in arid low-latitude areas. Most crops in the arid conditions of temperate and low latitudes require irrigation. The usual type of land use in semiarid climate areas where grasslands are common is pasture farming. Cotton and rice have a longer growing season than spring wheat or potatoes, and all of these crops are susceptible to frost damage. In the mountains, agricultural production is differentiated according to high altitude zones just like natural vegetation. Deep valleys in the humid tropics Latin America are located in the hot zone (tierra caliente) and tropical crops are grown there. At slightly higher altitudes in the temperate zone (tierra templada), the typical crop is coffee. Above is the cold belt (tierra fria), where cereals and potatoes are grown. In an even colder zone (tierra helada), located just below the snow line, on alpine meadows Livestock grazing is possible, and the range of agricultural crops is extremely limited.

Climate influences the health and living conditions of people as well as their economic activities. The human body loses heat through radiation, conduction, convection and evaporation of moisture from the surface of the body. If these losses are too great in cold weather or too small in hot weather, the person experiences discomfort and may get sick. Low relative humidity and high wind speed enhance the cooling effect. Weather changes lead to stress, worsen appetite, disrupt biorhythms and reduce the human body's resistance to disease. Climate also influences the habitat of pathogens that cause disease, resulting in seasonal and regional disease outbreaks. Epidemics of pneumonia and influenza in temperate latitudes often occur in winter. Malaria is common in the tropics and subtropics, where there are conditions for the breeding of malaria mosquitoes. Diseases caused by poor nutrition are indirectly related to climate, since in food products, produced in a particular region, may lack some nutrients as a result of climate influences on plant growth and soil composition.

CLIMATE CHANGE

Rocks, plant fossils, landforms, and glacial deposits contain information about significant fluctuations in average temperatures and precipitation over geological time. Climate change can also be studied by analyzing tree rings, alluvial deposits, ocean and lake bottom sediments, and organic peatland deposits. Over the past few million years, there has been a general cooling of the climate, and now, judging by the continuous reduction of the polar ice sheets, we seem to be at the end of the ice age.

Climate change over a historical period can sometimes be reconstructed from information about famines, floods, abandoned settlements, and migrations of peoples. Continuous series of air temperature measurements are available only for weather stations located primarily in the Northern Hemisphere. They span only a little over one century. These data indicate that over the past 100 years, the average temperature on the globe has increased by almost 0.5 ° C. This change did not occur smoothly, but spasmodically - sharp warmings were replaced by relatively stable stages.

Experts from different fields of knowledge have proposed numerous hypotheses to explain the reasons climate change. Some believe that climate cycles are determined by periodic fluctuations in solar activity with an interval of approx. 11 years. Annual and seasonal temperatures could be affected by changes in the shape of the Earth's orbit, resulting in changes in the distance between the Sun and Earth. Currently, the Earth is closest to the Sun in January, but approximately 10,500 years ago it was closest to the Sun in July. According to another hypothesis, depending on the angle of inclination of the earth's axis, the amount of solar radiation entering the earth changed, which affected the general circulation of the atmosphere. It is also possible that the Earth's polar axis occupied a different position. If the geographic poles were located at the latitude of the modern equator, then, accordingly, the climate zones shifted.

So-called geographical theories explain long-term climate fluctuations by movements earth's crust and changes in the position of continents and oceans. In light of global plate tectonics, continents have moved throughout geological time. As a result, their position in relation to the oceans, as well as in latitude, changed. During the process of mountain building, mountain systems with cooler and possibly wetter climates were formed.

Air pollution also contributes to climate change. Large masses of dust and gases released into the atmosphere during volcanic eruptions occasionally became an obstacle to solar radiation and led to cooling of the earth's surface. An increase in the concentration of certain gases in the atmosphere exacerbates the overall warming trend.

Greenhouse effect.

Like the glass roof of a greenhouse, many gases pass most of the heat and light energy of the Sun to the Earth's surface, but prevent the rapid return of the heat radiated by it to the surrounding space. The main gases causing the "greenhouse" effect are water vapor and carbon dioxide, as well as methane, fluorocarbons and nitrogen oxides. Without the greenhouse effect, the temperature of the earth's surface would drop so much that the entire planet would be covered in ice. However, an excessive increase in the greenhouse effect can also be catastrophic.

Since the beginning of the Industrial Revolution, the amount of greenhouse gases (mainly carbon dioxide) in the atmosphere has increased due to economic activity humans and especially the burning of fossil fuels. Many scientists now believe that the rise in average global temperatures after 1850 occurred primarily as a result of increases in atmospheric carbon dioxide and other anthropogenic greenhouse gases. If current trends in fossil fuel use continue into the 21st century, average global temperatures could rise by 2.5 to 8°C by 2075. If fossil fuels are used at a faster rate than at present, such temperature increases could occur as early as by 2030.

Predicted rise in temperature could lead to melting polar ice and most mountain glaciers, causing sea levels to rise by 30–120 cm. All this could also affect changing weather conditions on Earth, with possible consequences such as prolonged droughts in the world's leading agricultural regions.

However global warming As a consequence, the greenhouse effect can be slowed down if carbon dioxide emissions from burning fossil fuels are reduced. Such a reduction would require restrictions on its use throughout the world, more efficient energy consumption and increased use of alternative energy sources (for example, water, solar, wind, hydrogen, etc.).

Literature:

Pogosyan Kh.P. General atmospheric circulation. L., 1952
Blutgen I. Geography of climates, vol. 1–2. M., 1972–1973
Vitvitsky G.N. Zoning of the Earth's climate. M., 1980
Yasamanov N.A. Ancient climates of the Earth. L., 1985
Climate fluctuations over the last millennium. L., 1988
Khromov S.P., Petrosyants M.A. Meteorology and climatology. M., 1994



Typical for a given region of the Earth, like average weather over many years. The term “climate” was introduced into scientific use 2200 years ago by the ancient Greek astronomer Hipparchus and means “slope” (“klimatos”) in Greek. The scientist had in mind the inclination of the earth's surface to the sun's rays, the difference in which was already considered the main reason for the differences in weather in . Later, climate was called the average state in a certain region of the Earth, which is characterized by features that are practically unchanged over one generation, that is, about 30-40 years. These features include the amplitude of temperature fluctuations, .

There are macroclimate and microclimate:

Macroclimate(Greek makros - large) - the climate of the largest territories, this is the climate of the Earth as a whole, as well as large regions of land and water areas of oceans or seas. In the macroclimate, the level and patterns of atmospheric circulation are determined;

Microclimate(Greek mikros - small) - part of the local climate. The microclimate mainly depends on differences in soils, spring-autumn frosts, and the timing of melting of snow and ice on reservoirs. Taking into account the microclimate is essential for the placement of crops, for the construction of cities, laying roads, for any human economic activity, as well as for his health.

The description of the climate is compiled from observations of the weather over many years. It includes average long-term indicators and monthly quantities, frequency various types weather. But a description of the climate will be incomplete if it does not include deviations from the average. Typically, the description includes information about the highest and lowest temperatures, the highest and lowest amounts of precipitation over the entire period of observation.

It changes not only in space, but also in time. A huge amount of facts on this problem is provided by paleoclimatology - the science of ancient climates. Research has shown that the geological past of the Earth is an alternation of eras of seas and eras of land. This alternation is associated with slow oscillations, during which the ocean area either decreased or increased. In the era of increasing area, the sun's rays are absorbed by water and heat the Earth, which also heats the atmosphere. General warming will inevitably cause the spread of heat-loving plants and animals. Spreading warm climate“eternal spring” in the era of the sea is also explained by an increase in CO2 concentration, which causes the phenomenon. Thanks to him, the warming increases.

With the onset of the land era, the picture changes. This is due to the fact that land, unlike water, reflects the sun's rays more, which means it heats up less. This leads to less warming of the atmosphere, and inevitably the climate will become colder.

Many scientists consider space to be one of the important causes of the Earth. For example, quite strong evidence of solar-terrestrial connections is given. With an increase in solar activity, changes in solar radiation are associated, and the frequency of occurrence increases. A decrease in solar activity can lead to droughts.

The Earth's climate has a large number of patterns and is formed under the influence of many factors. At the same time, it is fair to attribute to it a variety of phenomena in the atmosphere. The climatic state of our planet largely determines the state of the natural environment and human activities, especially economic ones.

The Earth's climatic conditions are formed by three large-scale geophysical processes of a cyclic type:

• Heat turnover- heat exchange between earth's surface and atmosphere.
• Moisture circulation- the intensity of water evaporation into the atmosphere and its correlation with the level of precipitation.
• General atmospheric circulation- a set of air currents over the Earth. The state of the troposphere is determined by the distribution features air masses, for which cyclones and anticyclones are responsible. Atmospheric circulation occurs due to the unequal distribution of atmospheric pressure, which is caused by the division of the planet into land and water bodies, as well as uneven access to ultraviolet light. The intensity of sunlight is determined not only by geographical features, but also by the proximity of the ocean and the frequency of precipitation.

Climate should be distinguished from weather, which represents the state of the environment at the current moment. However, weather characteristics are often the object of study of climatology or even the most important factors in changing the Earth's climate. The level of heat plays a special role in the development of the earth's climate, as well as weather conditions. The climate is also affected sea ​​currents and relief features, in particular the proximity of mountain ranges. An equally important role belongs to the prevailing winds: warm or cold.

In the study of the Earth's climate, careful attention is paid to such meteorological phenomena, How Atmosphere pressure, relative humidity, wind parameters, temperature indicators, precipitation. They also try to take solar radiation into account when compiling a general planetary picture.

Climate-forming factors

1. Astronomical factors: the brightness of the Sun, the relationship between the Sun and the Earth, features of orbits, the density of matter in space. These factors influence the level of solar radiation on our planet, daily weather changes, and the spread of heat between the hemispheres.
2. Geographical factors: the weight and parameters of the Earth, gravity, air components, atmospheric mass, ocean currents, the nature of the earth's topography, sea level, etc. These features determine the level of heat received in accordance with the weather season, continent and hemisphere of the earth.

The Industrial Revolution led to the inclusion of active human activity in the list of climate-forming factors. However, all characteristics of the Earth's climate are largely influenced by the energy of the Sun and the angle of incidence of ultraviolet rays.

Types of Earth's climate

There are many classifications of the planet's climate zones. Various researchers take the separation as a basis, both individual characteristics and the general circulation of the atmosphere or the geographical component. Most often, the basis for identifying a separate type of climate is the solar climate - the influx of solar radiation. The proximity of bodies of water and the relationship between land and sea are also important.

The simplest classification identifies 4 basic zones in each earth’s hemisphere:

• equatorial;
• tropical;
• moderate;
• polar.

There are transitional areas between the main zones. They have the same names, but with the prefix “sub”. The first two climates, together with the transitions, can be called hot. In the equatorial region there is a lot of precipitation. Temperate climates have more pronounced seasonal differences, especially in the case of temperature. As for the cold climate zone, these are the most severe conditions caused by the lack of solar heat and water vapor.

This division takes into account atmospheric circulation. Based on the predominance of air masses, it is easier to divide the climate into oceanic, continental, and also the climate of the eastern or western coasts. Some researchers additionally define continental, maritime and monsoon climates. Often in climatology there are descriptions of mountainous, arid, nival and humid climates.

Ozone layer

This concept refers to a layer of the stratosphere with elevated levels of ozone, which is formed due to the influence of sunlight on molecular oxygen. Thanks to the absorption of ultraviolet radiation by atmospheric ozone, the living world is protected from combustion and widespread cancer. Without the ozone layer, which appeared 500 million years ago, the first organisms would not have been able to emerge from the water.

Since the second half of the 20th century, it has been customary to talk about the problem of the “ozone hole” - a local decrease in ozone concentration in the atmosphere. The main factor of this change is anthropogenic in nature. The ozone hole can lead to increased mortality of living organisms.

Global climate changes on Earth

(Promotion average temperature air over the last century, since the 1900s)

Some scientists view large-scale climate transformations as a natural process. Others believe that this is a harbinger of a global catastrophe. Such changes mean a strong warming of air masses, an increase in the level of aridity and a softening of winters. We are also talking about frequent hurricanes, typhoons, floods and droughts. The cause of climate change is the instability of the Sun, which leads to magnetic storms. Changes in the earth's orbit, the outlines of the oceans and continents, and volcanic eruptions also play a role. The greenhouse effect is also often associated with destructive human activities, namely: atmospheric pollution, deforestation, plowing land, burning fuel.

Global warming

(Climate change towards warming in the second half of the 20th century)

An increase in the average temperature of the Earth has been recorded since the second half of the 20th century. Scientists believe that the reason for this is high level greenhouse gases due to human activity. A consequence of the increase in global temperature is a change in precipitation, the growth of deserts, an increase in extreme weather phenomena, extinction of some biological species, rising sea levels. The worst thing is that in the Arctic this leads to shrinking glaciers. All together, this can radically change the habitat of various animals and plants, shift the boundaries of natural areas and cause serious problems with agriculture and human immunity.

The country is located in middle and high latitudes, which is why there is a clear division into seasons. Atlantic air affects the European part. The weather there is milder than in the east. The polar ones receive the least sun, the maximum value is reached in the Western Ciscaucasia.

The country's territory lies in four main climatic zones. Each of them has its own temperature and precipitation rates. There is a transition from east to west monsoon climate to continental. The central part is characterized by a clear distinction between the seasons. In the south, the thermometer rarely drops below 0˚C in winter.

Climatic zones and regions of Russia

Map of climatic zones and regions of Russia/Source: smart-poliv.ru

Air masses play a decisive role in the division into belts. Within their boundaries are climatic regions. They differ from each other in temperature, amount of heat and moisture. Below is a brief description of the climatic zones of Russia, as well as the areas they include.

Arctic belt

It includes the coast of the Arctic Ocean. In winter, severe frost prevails, the average January temperature exceeds -30˚C. The western part is slightly warmer due to the air from the Atlantic. In winter, the polar night sets in.

The sun shines in summer, but due to the low angle of incidence of the sun's rays and the reflective properties of snow, heat does not linger at the surface. A lot of solar energy is spent on melting snow and ice, so the summer temperature regime approaches zero. The Arctic zone is characterized by a small amount of precipitation, the bulk of which falls in the form of snow. The following climatic regions are distinguished:

• Intra-Arctic;
• Siberian;
• Pacific;
• Atlantic.

The Siberian region is considered the most severe; the Atlantic region is mild but windy.

Subarctic belt

It includes the territories of the Russian and West Siberian Plains, located mainly in forest-tundra. Winter temperatures increase from west to east. Summer rates average +10˚C, and even higher near the southern borders. Even in the warm season there is a threat of frost. There is little precipitation, the main share comes from rain and wet snow. Due to this, waterlogging occurs in the soil. The following areas are distinguished in this climate zone:

• Siberian;
• Pacific;
• Atlantic.

The lowest temperatures in the country were recorded in the Siberian region. The climate of the other two is softened by cyclones.

Temperate zone

This applies to most of territory of Russia. Winters are snowy, sunlight is reflected from the surface, causing the air to become very cool. In summer, the amount of light and heat increases. In the temperate zone there is a significant contrast between cold winter and warm summer. There are four main types of climate:

1) Moderate continental falls on the western part of the country. Winters are not particularly cold due to the Atlantic air, and thaws occur frequently. The average summer temperature is +24˚C. The influence of cyclones causes significant amounts of precipitation in the summer.

2) Continental climate affects the territory of Western Siberia. Throughout the year, both arctic and tropical air penetrates into this zone. Winters are cold and dry, summers are hot. The influence of cyclones is weakening, so there is little precipitation.

3) Sharply continental climate dominates in Central Siberia. The entire territory experiences very cold winters with little snow. Winter temperatures can reach -40˚C. In summer, the air warms up to +25˚C. Precipitation is scarce and falls as rain.

4) Monsoon climate type prevails in the eastern part of the belt. In winter, continental air dominates here, and in summer - sea. Winter is snowy and cold. January figures are -30˚C. Summers are warm but humid, with frequent showers. The average July temperature exceeds +20˚C.

The following climatic regions are located within the temperate zone:

• Atlantic-Arctic;
• Atlantic-continental European (forest);
• Continental West Siberian northern and central;
• Continental East Siberian;
• Far Eastern monsoon;
• Pacific;
• Atlantic-continental European (steppe);
• Continental West Siberian southern;
• Continental Eastern European;
• Mountain region of the Greater Caucasus;
• Mountain region of Altai and Sayan.

Subtropical climate

It includes a small area of ​​the Black Sea coast. The Caucasus Mountains do not allow air flow from the east, so the Russian subtropics are warm in winter. Summer is hot and long. Snow and rain fall all year round, there are no dry periods. In the subtropics of the Russian Federation, only one region is distinguished - the Black Sea region.

Climatic zones of Russia

Map of climatic zones of Russia/Source: meridian-workwear.com

A climatic zone is a territory in which the same climatic conditions prevail. The division arose due to uneven heating of the Earth's surface by the sun. There are four climatic zones in Russia:

• The first includes the southern regions of the country;
• the second includes the regions of the west, north-west, as well as the Primorsky Territory;
• the third includes Siberia and the Far East;
• The fourth includes the Far North and Yakutia.

Along with them, there is a special zone that includes Chukotka and territories beyond the Arctic Circle.

Climate of Russian regions

Krasnodar region

The minimum January temperature is 0˚C, the soil does not freeze. The fallen snow melts quickly. Most of the precipitation falls in the spring, causing numerous floods. Summer temperatures average 30˚C, drought begins in the second half. Autumn is warm and long.

central Russia

Winter begins at the end of November and lasts until mid-March. Depending on the region, January temperatures range from -12˚C to -25˚C. A lot of snow falls, which melts only with the onset of thaws. Extremely low temperatures occur in January. February is remembered for its winds, often hurricane-force. Heavy snowfalls in the last few years have occurred at the beginning of March.

Nature comes to life in April, but positive temperatures are set only next month. In some regions, the threat of frost occurs in early June. Summer is warm and lasts 3 months. Cyclones bring thunderstorms and showers. Night frosts occur as early as September. This month has a lot of rainfall. In October, a sharp cold snap occurs, foliage flies off the trees, it rains, sleet can fall.

Karelia

The climate is influenced by 3 neighboring seas, the weather is very changeable throughout the year. The minimum January temperature is -8˚C. There is a lot of snow falling. February weather is changeable: cold snaps are followed by thaws. Spring comes in April, the air warms up to +10˚С during the day. Summer is short; truly warm days occur only in June and July. September is dry and sunny, but frosts are already occurring in some areas. Finally cold weather installed in October.

Siberia

One of the largest and coldest regions of Russia. Winter has little snow, but very cold. In remote areas, the thermometer shows more than -40˚C. Snowfalls and winds occur infrequently. The snow melts in April, and the region gets warm only in June. Summer temperatures are +20˚С, there is little precipitation. Calendar autumn begins in September, the air cools quickly. By October the rains give way to snow.

Yakutia

The average monthly temperature in January is -35˚C; in the Verkhoyansk region the air cools down to -60˚C. The cold season lasts at least seven months. There is little precipitation, daylight hours last 5 hours. The polar night begins above the Arctic Circle. Spring is short, begins in May, summer lasts 2 months. During white nights the sun does not set for 20 hours. Already in August, rapid cooling begins. By October, the rivers are covered with ice and the snow stops melting.

Far East

The climate is varied, ranging from continental to monsoon. The approximate winter temperature is -24˚C and there is a lot of snow. On spring time there is little rainfall. Summer is hot, with high humidity; August is considered a period of prolonged rains. Fogs dominate the Kuril Islands, and white nights begin in Magadan. The beginning of autumn is warm but rainy. The thermometer in mid-October shows -14˚C. In a month, winter frosts arrive.

Most of the country lies in the temperate zone, separate territories have their own climatic characteristics. The heat deficit is felt in almost all zones. Climate has a serious impact on human activity, and it must be taken into account when conducting agriculture, construction, and transport.

2.1. Natural processes in the hydrosphere

2.2. Natural systems in the hydrosphere

2.2.1. Water in the atmosphere

2.2.2. surface water

2.2.3. The groundwater

2.3. Freshwater reserves and their distribution

2.3.1. Freshwater reserves

2.3.2. Placement of fresh water reserves

2.4. Anthropogenic processes in the hydrosphere

2.4.1. Construction of reservoirs and their impact on the environment

2.4.2. Ecological consequences of the Volga reservoirs

2.4.3. Wastewater and its formation

2.4.4. Land surface water pollution

2.4.5. Groundwater pollution on land

2.4.6. Ocean Pollution

2.4.7. Geographical features of sea pollution

Control questions

Chapter 3. Geocosmos

3.1. Atmosphere

3.1.1. Composition and structure of the atmosphere

3.1.2. Natural processes in the atmosphere

3.1.3. Climate formation

Climate-forming factors

Climate-forming processes

3.1.4. Natural atmospheric systems

Types of climates around the globe

3.1.5. Anthropogenic processes in the atmosphere

3.1.6. Anthropogenic climate change and its causes

3.1.7. Ecological consequences of anthropogenic ozone loss in the stratosphere

3.1.8. Anthropogenic impact on near-Earth space

3.2. Ionosphere

3.2.1. Natural processes in the ionosphere

3.2.2. Anthropogenic electromagnetic impacts on the ionosphere

3.2.3. Anthropogenic formation of the space debris sphere

3.3. Magnetosphere

3.3.1. Natural processes in the magnetosphere

3.3.2. Anthropogenic impact on the magnetosphere

3.4. Spread of technogenic impact beyond geospace

Control questions

Chapter 4. Biosphere

4.1. Basic properties and functions of the biosphere

4.1.1. Biosphere and space energy

4.1.2. Functions of the biosphere in the development of the Earth

4.1.3. Relationships between living organisms in the biosphere

4.2. Soils (pedosphere)

4.2.1. Factors and processes of soil formation

4.2.2. Natural types of soil formation and soils

4.2.2. Land fund and land resources of the world and Russia

4.2.3. Anthropogenic impact on soils

4.3. Vegetation

4.3.1. Phytomass reserves and production

The meaning of forests

4.3.2. Natural processes in plant communities

4.3.3. Exchange of matter and energy in plant communities

4.3.4. The importance of animals in plant life

4.3.5. Natural vegetation systems

4.3.6. Anthropogenic processes in plant communities

4.4. Animal world

4.4.1. Natural connections of the animal world with vegetation in biocenoses

4.4.2. Natural systems in the animal world

4.4.3. Anthropogenic impact on fauna

Direct human impact on the animal world

Indirect human impact on animals

4.4.4. Anthropogenic degradation of the animal world

Control questions

Chapter 5. Landscapes

5.1. Natural processes of formation, functioning and development of landscapes

5.1.1. Structural and functional connections of the landscape

5.1.2. Landscape energy

5.1.3. Moisture circulation in the landscape

5.1.4. Biogeochemical cycle

5.1.5. Abiotic migration of matter

5.1.6. Landscape development and age

5.2. Natural landscape belts and zones

5.2.1. Natural landscape belts and land zones

5.2.2. Natural Landscape Zones of the Oceans

5.3. Anthropogenic changes in natural land landscapes

Control questions

Chapter 6

6.1. The growth of the world population in a historical aspect

6.2. Demographic "explosion": causes and consequences

6.3. Maximum load on the natural environment

6.4. Population Growth Limiters

6.5. Migration

6.6. Modern tendencies

6.7. Conflicts and overpopulation

6.8. Global predictive models and scenarios for the future development of mankind

Control questions

Control questions

Conclusion

Literature

Content

Chapter 1. Lithosphere

Chapter 2. Hydrosphere

Chapter 3. Geocosmos

Chapter 4. Biosphere

Chapter 5. Landscapes

Chapter 6

Geoecology

Types of climates around the globe

In accordance with the climate classification of B.P. Alisov, in various climatic zones on the land the following main types of climate are formed ( Fig.10).

Fig. 10. Climate zones Lands:

1 - equatorial; 2 - subequatorial; 3 - tropical; 4 - subtropical; 5 - moderate; 6 - subarctic; 7 - subantarctic; 8 - arctic; 9 - Antarctic

Equatorial belt located in equatorial latitudes, reaching 8° latitude in places. Total solar radiation 100–160 kcal/cm 2 year, radiation balance 60–70 kcal/cm 2 year.

Equatorial hot humid climate occupies the western and central parts of the continents and the islands of the Indian Ocean and the Malay Archipelago in the equatorial belt. Average monthly temperatures are +25 – +28° all year round, seasonal variations are 1–3°. Monsoon circulation: in January the winds are northerly, in July - southerly. Annual precipitation is usually 1000–3000 mm (sometimes more), with uniform precipitation throughout the year. Excessive moisture. Constantly high temperatures and high air humidity make this type of climate extremely difficult for a person, especially for a European. There is the possibility of year-round tropical farming with the cultivation of two crops per year.

WITH at bequato R ial belts located in the subequatorial latitudes of both hemispheres, sometimes reaching 20 ° latitude, as well as in equatorial latitudes on the eastern margins of the continents. Total solar radiation 140–170 kcal/cm 2 year. Radiation balance 70–80 kcal/cm 2 year. Due to the seasonal movement of intertropical baric depression from one hemisphere to another following the zenithal position of the Sun, seasonal changes in air masses, winds and weather are observed. In the winter of each hemisphere, KTV prevails, winds of the trade wind direction towards the equator, and anticyclonic weather. In the summer of each hemisphere, computers dominate, winds (equatorial monsoon) are in the opposite direction from the equator, and cyclonic weather.

Subequatorial climate with sufficient moisture adjacent directly to equatorial climate and occupies most of the subequatorial belts, except for regions adjacent to tropical climates. Average temperatures in winter are +20 – +24°, in summer - +24 – +29°, seasonal fluctuations are within 4–5°. The annual precipitation is usually 500–2000 mm (maximum in Cherrapunji). The dry winter season is associated with the dominance of continental tropical air, the wet summer season is usually associated with the equatorial monsoon and the passage of cyclones along the VTK line and lasts more than six months. The exception is the eastern slopes of the Hindustan and Indochina peninsulas and northeast Sri Lanka, where the maximum precipitation is in winter, due to the saturation with moisture of the winter continental monsoon over the South China Sea and the Bay of Bengal. On average, moisture per year ranges from close to sufficient to excessive, but is distributed very unevenly over the seasons. The climate is favorable for growing tropical crops.

Subequatorial climate with insufficient moistureeniya adjacent to tropical climates: in South America - Caatinga, in Africa - the Sahelips of Somalia, in Asia - the west of the Indo-Gangetic Lowland and the north-west of Hindustan, in Australia - the south coast of the Gulf of Carpentaria and Arnhem Land. Average temperatures in winter + 15 ° - + 24 °, in summer temperatures are especially high in the northern hemisphere (due to the vast area of ​​continents in these latitudes) +27 – +32°, slightly lower in the south - +25 – +30°; seasonal fluctuations are 6–12°. Here, for most of the year (up to 10 months), cold weather and anticyclonic weather prevail. Annual precipitation is 250–700 mm. The dry winter season is due to the dominance of tropical air; The wet summer season is associated with the equatorial monsoon and lasts less than six months, in some places only 2 months. Humidification is insufficient throughout. The climate makes it possible to grow tropical crops after measures to improve soil fertility and with additional irrigation.

T R optically e belts located in tropical latitudes, reaching in places 30–35° latitude; and on the western edges of South America and Africa in the southern hemisphere, the tropical belt pinches out, because here, due to cold ocean currents, the intertropical baric depression is located north of the equator all year round and the southern subtropical climate zone reaches the equator. Tropical air masses and trade wind circulation dominate year-round. Total solar radiation reaches its maximum on the planet: 180–220 kcal/cm 2 year. Radiation balance 60–70 kcal/cm 2 year.

Tropical climateereg deserts is formed on the western edges of continents under the influence of cold ocean currents. Average winter temperatures are +10 – +20°, summer - +16 – +28°, seasonal temperature fluctuations are 6–8°. Tropical sea cool air is carried throughout the year by trade winds blowing along the coast. Annual precipitation is low due to trade wind inversion - 50–250 mm and only in places up to 400 mm. Precipitation falls mainly in the form of rain and fog. Humidification is severely insufficient. Opportunities for tropical farming exist only in oases with artificial irrigation and systematic work to increase soil fertility.

ClAndtropical continental desert mat is typical for the interior regions of continents and is distinguished by the most pronounced features of continentality within the tropical zones. Average winter temperatures are +10 – +24°, summer temperatures are +29 – +38° in the northern hemisphere, +24 – +32° in the southern hemisphere; seasonal temperature fluctuations in the northern hemisphere are 16–19°, in the southern hemisphere - 8–14°; daily fluctuations often reach 30°. The whole year is dominated by dry KTV, carried by trade winds. Annual precipitation is 50–250 mm. Precipitation falls sporadically, extremely unevenly: in some areas there may be no rain for several years, and then there is a downpour. There are often cases when raindrops do not reach the ground, evaporating in the air when approaching the hot surface of a rocky or sandy desert. Humidification is severely insufficient. Due to extremely high summer temperatures and dryness, this type of climate is extremely unfavorable for agriculture: tropical farming is possible only in oases on abundantly and systematically irrigated lands.

The climate is tropicaleskiy wet confined to the eastern margins of the continents. Formed under the influence of warm ocean currents. Average winter temperatures are +12 – +24°, summer - +20 – +29°, seasonal temperature fluctuations are 4–17°. The heated MTV, brought from the ocean by trade winds, dominates all year round. The annual precipitation is 500–3000 mm, with the eastern windward slopes receiving approximately twice as much precipitation as the western leeward ones. Precipitation falls all year round with a summer maximum. There is sufficient moisture, only in some places on the leeward slopes it is somewhat insufficient. The climate is favorable for tropical agriculture, but the combination of high temperatures and high air humidity makes it difficult for humans to tolerate.

Subtropical e belt are located beyond the tropical belts in subtropical latitudes, reaching 42–45° latitude. Everywhere there is a seasonal change in air masses: in winter moderate air masses dominate, in summer - tropical ones. Total solar radiation is in the range of 120–170 kcal/cm 2 year. The radiation balance is usually 50–60 kcal/cm 2 year, only in some places it decreases to 45 kcal (in South America) or increases to 70 kcal (in Florida).

Subtropical WedeMediterranean climate is formed on the western outskirts of the continent and adjacent islands. Average winter temperatures under the influence of the MU invasion are uniform: +4 – +12°, frosts occur, but rare and short-lived; summer temperatures in the northern hemisphere are +16 – +26° and in the southern - +16 – +20°, only in Australia reach +24 °; seasonal temperature fluctuations 12–14°. There is a seasonal change in air masses, winds and weather. In the winter of each hemisphere, ISW, westerly transport winds and cyclonic weather dominate; in summer - KTV, trade winds and anticyclonic weather. Annual precipitation is 500–2000 mm. Precipitation is distributed extremely unevenly: the western windward slopes usually receive twice as much precipitation as the eastern leeward ones. The periods alternate: wet winter (due to ISW and the passage of cyclones along the polar front) and dry summer (due to the predominance of CTV). Precipitation falls more often in the form of rain, in winter occasionally - in the form of snow, moreover, a stable snow cover is not formed and after a few days the snow melts. There is sufficient moisture on the western slopes and insufficient on the eastern slopes. This climate is the most comfortable for living on the planet. It is favorable for agriculture, especially subtropical (irrigation is sometimes required on leeward slopes), and is also very favorable for human habitation. This contributed to the fact that it was in the areas of this type of climate that the most ancient civilizations arose and a large number of the population had long been concentrated. Currently, there are many resorts located in areas with a Mediterranean climate.

Subtropical continentenal arid climate confined to the interior regions of continents in subtropical zones. Average winter temperatures in the northern hemisphere are often negative -8 - +4°, in the southern - +4 - +10°; summer temperatures in the northern hemisphere are +20 - +32° and in the southern - +20 - +24°; seasonal temperature fluctuations in the northern hemisphere are about 28 °, in the south - 14–16°. Continental air masses dominate throughout the year: moderate in winter, tropical in summer. Annual precipitation in the northern hemisphere is 50–500 mm, in the southern hemisphere - 200–500 mm. Humidification is insufficient, especially severely insufficient in the northern hemisphere. In this climate, agriculture is possible only with artificial irrigation; grazing is also possible.

Subtropicalequalerno wetmonsoonalclimate characteristic of the eastern outskirts of continents in subtropical zones. Formed under the influence of warm ocean currents. Average temperatures in winter in the northern hemisphere are -8 - +12° and in the southern - +6 - +10°, in summer in the northern hemisphere +20 - +28° and in the southern - +18 - +24°; Seasonal temperature fluctuations in the northern hemisphere are 16–28° and in the southern hemisphere - 12–14°. There is a seasonal change in air masses and winds during year-round cyclonic weather: in winter, the dominant air force, brought by the winds of the western directions, in the summer, the heated MTV, brought by the winds of the eastern directions. Annual precipitation is 800–1500 mm, in some places up to 2000 mm. At the same time, precipitation falls throughout the year: in winter due to the passage of cyclones along the polar front, in summer it is brought by oceanic monsoons formed from winds in the trade wind direction. In winter, precipitation in the form of snow predominates in the northern hemisphere; in the southern hemisphere, winter snowfalls are very rare. In the northern hemisphere, snow cover can form for several weeks to several months (especially in inland regions), while in the southern hemisphere, snow cover, as a rule, does not form. There is sufficient moisture, but on the eastern slopes it is somewhat excessive. This type of climate is favorable for human habitation and economic activity, however, in some regions, winter frosts limit the spread of subtropical agriculture.

Ume R military belts are located beyond the subtropical zones in both hemispheres, reaching in places 58–67° N latitude. in the northern hemisphere and 60–70° S. - in the south. The total solar radiation is usually in the range of 60–120 kcal/cm 2 year and only over the northern part of Central Asia, due to the prevalence of anticyclonic weather there, it reaches 140–160 kcal/cm 2 year. The annual radiation balance in the northern hemisphere is 25–50 kcal/cm2 and 40–50 kcal/cm2 in the southern hemisphere due to the predominance of land areas adjacent to the subtropical belt. Moderate air masses prevail all year round.

Diedenautical maritime climate is formed on the western edges of continents and adjacent islands under the influence of warm ocean currents and only in South America - the cold Peruvian Current. Winters are mild: average temperatures are +4 – +8°, ​​summers are cool: average temperatures are +8 – +16°, seasonal temperature fluctuations are 4–8°. MUW and westerly winds prevail all year round, the air is characterized by high relative and moderate absolute humidity, and fogs are frequent. The windward slopes of western exposure receive especially much precipitation: 1000–3000 mm/year; on the eastern leeward slopes, precipitation falls 700–1000 mm. The number of cloudy days per year is very high; precipitation falls throughout the year with a summer maximum associated with the passage of cyclones along the polar front. Moisture is excessive on the western slopes and sufficient on the eastern slopes. The mildness and humidity of the climate are favorable for vegetable gardening and meadow farming, and in connection with this, dairy farming. There are conditions for year-round marine fishing.

Temperate climate, laneerunning fromseato continental, is formed in areas directly adjacent to areas of temperate marine climate from the east. Winter is moderately cold: in the northern hemisphere 0 – -16°, there are thaws, in the southern hemisphere - 0 – +6°; summer is not hot: in the northern hemisphere +12 – +24°, in the southern hemisphere - +9 – +20°; seasonal temperature fluctuations in the northern hemisphere are 12–40°, in the southern hemisphere - 9–14°. This transitional climate is formed when the influence of westerly transport weakens as air moves eastward; as a result, the air cools in winter and loses moisture, and warms up more in summer. Precipitation is 300–1000 mm/year; the maximum precipitation is associated with the passage of cyclones along the polar front: at higher latitudes in summer, at lower latitudes in spring and autumn. Due to significant differences in temperature and precipitation, moisture varies from excessive to insufficient. In general, this type of climate is quite favorable for human habitation: agriculture with crops growing for a short growing season and livestock raising, especially dairy, are possible.

Temperate continental climate is formed in the interior regions of continents only in the northern hemisphere. Winter is the coldest in temperate zones, long, with persistent frosts: average temperatures in North America are -4 – -26°, in Eurasia - -16 – -40°; summers are hottest in temperate zones: average temperatures +16 – +26°, in some places up to +30°; seasonal temperature fluctuations in North America are 30–42°, in Eurasia - 32–56°. The more severe winter in Eurasia is due to the larger size of the continent in these latitudes and the vast spaces occupied by permafrost. The CSW dominates all year round; in winter, stable winter anticyclones with anticyclonic weather are established over the territory of these regions. Annual precipitation is often in the range of 400–1000 mm, only in Central Asia it decreases to less than 200 mm. Precipitation falls unevenly throughout the year; the maximum is usually confined to the warm season and is associated with the passage of cyclones along the polar front. Humidification is heterogeneous: there are areas with sufficient and unstable moisture, and there are also arid areas. Human living conditions are quite diverse: logging, forestry and fishing are possible; Agriculture and livestock breeding opportunities are limited.

Moderatemonsoonalclimate is formed on the eastern edge of Eurasia. Winter is cold: average temperatures are -10 - -32 °, summer is not hot: average temperatures are +12 - + 24 °; seasonal temperature fluctuations are 34–44°. There is a seasonal change in air masses, winds, and weather: in winter, KUV, northwestern winds, and anticyclonic weather prevail; in summer - SW, south-easterly winds and cyclonic weather. Annual precipitation is 500–1200 mm with a pronounced summer maximum. In winter, a slight snow cover forms. Humidification is sufficient and somewhat excessive (on the eastern slopes), the continentality of the climate increases from east to west. The climate is favorable for human habitation: agriculture and various animal husbandry, forestry and crafts are possible.

Temperate climate with cold and snowy winters is formed on the northeastern margins of the continents of the northern hemisphere within the temperate zone under the influence of cold ocean currents. Winter is cold and long: average temperatures are -8 – -28°; summers are relatively short and cool: average temperatures +8 – +16°; seasonal temperature fluctuations are 24–36°. In winter, KUV dominates, sometimes KAV breaks through; MUV penetrates in summer. Annual precipitation is 400–1000 mm. Precipitation falls throughout the year: in winter, heavy snowfalls are generated by the invasion of cyclones along the Arctic front, a long and stable snow cover exceeds 1 m; in summer, precipitation is brought by the oceanic monsoon and is associated with cyclones along the polar front. Excessive moisture. The climate is difficult for human habitation and economic activity: there are conditions for the development of reindeer herding, breeding sled dogs, and fishing; farming opportunities are limited by a short growing season.

Suba R ktic belt located beyond the temperate zone in subarctic latitudes and reaches 65–75° N latitude. Total solar radiation 60–90 kcal/cm 2 year. Radiation balance +15 – +25 kcal/cm 2 year. Seasonal change of air masses: arctic air masses dominate in winter, moderate in summer.

Subarcticmaritime climate confined to the marginal regions of continents in the subarctic zone. Winter is long, but moderately severe: average temperatures are -14 - -30 °, only in Western Europe warm currents soften the winter to -2 °; summer is short and cool: average temperatures +4 – +12°; seasonal temperature fluctuations are 26–34°. Seasonal change of air masses: Arctic predominantly sea air in winter, moderate sea air in summer. The annual amount of precipitation is 250–600 mm, and on the windward slopes of the coastal mountains - up to 1000–1100 mm. Precipitation falls throughout the year. Winter precipitation is associated with the passage of cyclones along the Arctic front, which bring snowfalls and snowstorms. In summer, precipitation is associated with the penetration of ISW - it falls in the form of rain, but there are also snowfalls, dense fogs are often observed, especially in coastal areas. There is sufficient moisture, but on the coasts it is excessive. The conditions for human habitation are rather harsh: the development of agriculture is limited to a cool short summer with a corresponding short growing season.

Subarcticcontinuenal climate is formed in the interior regions of continents in the subarctic zone. In winter, long, severe and persistent frosts: average temperatures -24 - -50 °; summer is cool and short: average temperatures +8 – +14°; seasonal temperature fluctuations are 38–58°, and in some years they can reach 100°. In winter, the KAW dominates, which spreads in different directions from the winter continental anticyclones (Canadian and Siberian); in summer, the CSW and its inherent westerly transport predominate. Precipitation is 200–600 mm per year, the summer maximum of precipitation is clearly pronounced due to the penetration of the ISW into the mainland at this time; winter with little snow. Sufficient hydration. The conditions for human habitation are very harsh: farming at low summer temperatures and a short growing season is difficult, there are opportunities for forestry and crafts.

Subantarctic belt is located beyond the southern temperate zone and reaches 63–73° S. latitude. Total solar radiation 65–75 kcal/cm 2 year. Radiation balance +20 – +30kcal/cm 2 year. Seasonal change of air masses: Antarctic air dominates in winter, moderate in summer.

Subantarcticmaritime climate occupies the entire sub-Antarctic belt, with land only on the Antarctic Peninsula and on individual islands. Winter is long and moderately severe: average temperatures are -8 – -12°; summer is short, very cool and damp: average temperatures are +2 – +4°; seasonal temperature fluctuations are 10–12°. Seasonal changes in air masses and winds are pronounced: in winter, the KAV flows from Antarctica its inherent eastern transport winds, while the CAV, as it passes over the ocean, warms up a little and transforms into a MAV; in the summer, MUV and western transport winds dominate. Annual precipitation is 500–700 mm with a winter maximum associated with the passage of cyclones along the Antarctic front. Excessive moisture. Conditions for human habitation are harsh; there is an opportunity for the development of seasonal marine fisheries.

Arctic belt located in northern subpolar latitudes. Total solar radiation 60–80 kcal/cm 2 year. Radiation balance +5 – +15 kcal/cm 2 year. Arctic air masses dominate year-round.

Arctic climate with relatively mild winters confined to regions arctic belt, subject to the softening influence of the relatively warm waters of the Atlantic and Pacific oceans: in North America - the coast of the Beaufort Sea, the north of Baffin Island and the coast of Greenland; in Eurasia - on the islands from Spitsbergen to Northland and on the mainland from Yamal to western Taimyr. Winter is long and relatively mild: average temperatures are -16 – -32°; summer is short, average temperatures 0 – +8°; seasonal temperature fluctuations are 24–32°. Arctic, predominantly maritime air masses dominate all year round, with sea air having a moderating effect. The annual precipitation is 150–600 mm at the summer maximum associated with the passage of cyclones along the Arctic front. Sufficient and excessive hydration. The climate for human habitation is unfavorable due to its severity and constancy of low temperatures; there is the possibility of seasonal fisheries.

Arctic climate with cold winters occupies the rest of the Arctic belt, except for the interior of Greenland, is influenced by the cold waters of the Arctic Ocean. Winter is long and harsh: average temperatures are -32 – -38°; summer is short and cold: average temperatures 0 – +8°; seasonal temperature fluctuations are 38–40°. KAV dominates all year round. Annual precipitation is 50–250 mm. Sufficient hydration. Conditions for human habitation are extreme due to constantly low temperatures. Life is possible only if there are stable external ties to provide food, fuel, clothing, etc. Seasonal marine fisheries are possible.

Arctic climate with the coldest winters stands out in the interior of Greenland, is formed under the year-round influence of the Greenland ice sheet and the Greenland anticyclone. Winter lasts almost the whole year and is severe: average temperatures are -36 – -49°; in summer, there are no stable positive temperatures: average temperatures are 0 - -14 °; seasonal temperature fluctuations are 35–46°. Year-round dominance of CAV and winds spreading in all directions. Sufficient hydration. Climatic conditions for human habitation are the most extreme on the planet due to constant very low temperatures in the absence of local sources of heat and food. Life is possible only if there are stable external ties to provide food, fuel, clothing, etc. There are no opportunities for fishing.

Antarctic belt is located in the southern subpolar latitudes, mainly on the continent of Antarctica, and the climate is formed under the dominant influence of the Antarctic ice sheet and the Antarctic belt of relatively high pressure. Total solar radiation 75–120 kcal/cm 2 year. Due to the year-round dominance of continental Antarctic air, dry and transparent over the ice sheet, and the repeated reflection of solar rays during the polar day in summer from the surface of ice, snow and clouds, the value of total solar radiation in the interior regions of Antarctica reaches the value of total radiation in the subtropical zone. However, the radiation balance is -5 – -10 kcal/cm 2 year, and it is negative all year, which is due to the large albedo of the ice sheet surface (up to 90% of solar radiation is reflected). Exceptions are small oases that are freed from snow in summer. Antarctic air masses dominate year-round.

Antarctic climate with relatively mild winters forms over the marginal waters of the Antarctic continent. Winter is long and somewhat softened by Antarctic waters: average temperatures are -10 – -35°; summers are short and cold: average temperatures are -4 – -20°, only in oases are summer temperatures of the ground air layer positive; seasonal temperature fluctuations are 6–15°. The Antarctic sea air has a moderating effect on the climate, especially in summer, penetrating with cyclones along the Antarctic front. Annual precipitation of 100–300 mm with a summer maximum is associated with cyclonic activity along the Antarctic front. Precipitation in the form of snow predominates all year round. Excessive moisture. The climate for human habitation is unfavorable due to its severity and constant low temperatures; it is possible to conduct seasonal fishing.

Antarctic climate with the coldest winters confined to the interior regions of the Antarctic continent. Temperatures are negative all year round, there are no thaws: average winter temperatures are -45 - -72 °, summer - -25 - -35 °; seasonal temperature fluctuations are 20–37°. Continental Antarctic air dominates all year round, winds spread from the anticyclonic center of the periphery, southeast direction prevails. The annual precipitation is 40–100 mm, precipitation falls in the form of ice needles and hoarfrost, less often in the form of snow. Anticyclonic, partly cloudy weather prevails throughout the year. Sufficient hydration. Living conditions for humans are similar to the Arctic climate with cold winters.

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