Names of thermal zones. Thermal belts. What are thermal belts

Thermal belts

Thermal belts

(temperature belts), zones with certain temperature conditions located along parallels around the globe (sometimes with breaks). They are distinguished in accordance with the established criteria: according to the position on the map of isotherms in some months, according to the number of months of the year from cf. a swarm within certain limits, etc. For example, according to the classification of V. P. Köppen, subtropical, temperate, cold and polar thermal belts.

Geography. Modern illustrated encyclopedia. - M.: Rosman. Under the editorship of prof. A. P. Gorkina. 2006 .


See what "thermal belts" are in other dictionaries:

    thermal belts- Latitudinal belts of the Earth with certain gradations of total solar radiation and air temperature usually distinguish between a hot zone, temperate and polar zones of both hemispheres. Syn.: radiation thermal belts… Geography Dictionary

    radiation-thermal belts- Latitudinal belts of the Earth with certain gradations of total solar radiation and air temperature usually distinguish between a hot zone, temperate and polar zones of both hemispheres. Syn.: thermal belts… Geography Dictionary

    Earth- (Earth) Planet Earth The structure of the Earth, the evolution of life on Earth, animal and vegetable world, Earth in the solar system Contents Contents Section 1. General about the planet earth. Section 2. Earth as a planet. Section 3. Structure of the Earth. Section 4.… … Encyclopedia of the investor

    Earth (from the common Slavic earth floor, bottom), the third planet in order from the Sun solar system, astronomical sign Å or, ♀. I. Introduction Z. ranks fifth in size and mass among major planets, but from the planets so-called. terrestrial group, in ... ...

    I Earth (from the common Slavic earth floor, bottom) is the third planet in the solar system in order from the Sun, the astronomical sign ⊕ or, ♀. I. Introduction Z. occupies the fifth place in size and mass among the large planets, but of the planets t ... Great Soviet Encyclopedia

    system- 4.48 system combination of interacting elements organized to achieve one or more stated objectives Note 1 to entry: A system can be viewed as a product or the services it provides. Note 2 In practice… … Dictionary-reference book of terms of normative and technical documentation

    THEME CARDS- The atlas includes a group of maps of various subjects, consisting of maps natural phenomena and socio-economic: the world, continents, foreign countries, the USSR and its parts. Simultaneous use of general geographical and thematic maps on ... ... Geographic atlas

    I. The subject and structure of physics Physics is a science that studies the simplest and, at the same time, the most general patterns of natural phenomena, the properties and structure of matter, and the laws of its motion. Therefore, the concepts of F. and its laws underlie everything ... ... Great Soviet Encyclopedia

    The largest among the union republics of the CCCP in terms of territory. and the population. Located in the east. parts of Europe and in the north. parts of Asia. Pl. 17.08 million km2. Hac. 145 million people (as of Jan 1, 1987). Capital Moscow. The composition of the RSFSR includes 16 auth. republics, 5 auto ... Geological Encyclopedia


Thermal belts of the Earth

Uneven heating of the earth's surface causes different temperatures air at different latitudes. Latitudinal bands with certain air temperatures are called thermal zones. The belts differ in the amount of heat coming from the Sun. Their stretching depending on the distribution of temperatures is well illustrated by isotherms (from the Greek "iso" - the same, "therma" - heat). These are lines on a map that connect points with the same temperature.

hot belt located along the equator, between the Northern and Southern tropics. It is limited on both sides of the 20 0 C isotherms. It is interesting that the boundaries of the belt coincide with the boundaries of the distribution of palm trees on land and corals in the ocean. Here earth's surface receives the most solar heat. Twice a year (December 22 and June 22) at noon, the sun's rays fall almost vertically (at an angle of 90 0). The air from the surface gets very hot. Therefore, it is hot there throughout the year.

temperate zones(In both hemispheres) are adjacent to the hot belt. They stretched in both hemispheres between the Arctic Circle and the tropic. The sun's rays there fall on the earth's surface with a certain slope. Moreover, the further north, the greater the slope. Therefore, the sun's rays heat the surface less. As a result, the air heats up less. That is why temperate zones are colder than hot ones. The sun is never at its zenith there. Clearly expressed times years: winter, spring, summer, autumn. Moreover, the closer to the Arctic Circle, the longer and colder the winter. The closer to the tropic, the longer and warmer the summer. The temperate zones from the side of the poles are limited by the isotherm of the warm month of 10 0 C. It is the limit of the spread of forests.

cold belts(Northern and southern) of both hemispheres lie between the isotherms 10 0 C and 0 0 C of the warmest month. The sun there in winter for several months does not appear above the horizon. And in the summer, although it does not go beyond the horizon for months, it is very low above the horizon. Its rays only glide over the surface of the Earth and heat it weakly. The Earth's surface not only heats but also cools the air. Therefore, the temperatures there are low. Winters are cold and harsh, while summers are short and cool.

Two belts of eternal cold(northern and southern) are surrounded by an isotherm with temperatures of all months below 0 0 C. This is the kingdom of eternal ice.

So, the heating and lighting of each area depends on the position in the thermal zone, that is, on geographical latitude. The closer to the equator, the greater the angle of incidence of the sun's rays, the more the surface heats up and the air temperature rises. Conversely, with distance from the equator to the poles, the angle of incidence of the rays decreases, respectively, the air temperature decreases.

Belts of illumination and their characteristics.

Moderate

Cold

It is located between the tropic and the polar circle inside the hemisphere.

The sun is never at its zenith

During the year, the angle of incidence of the sun's rays varies greatly, therefore, the thermal seasons of the year (summer, autumn, winter, spring) are distinguished. Summer and winter temperatures are very different. For example, at a latitude of 50

summer≈ +20°C

winters≈ -10°C

Located between the northern and southern tropics.

The sun is at its zenith twice a year. All year round the surface warms up very well, there is no difference between summer and winter temperatures, there are no thermal seasons of the year, the average annual t o \u003d + 25 o C. During the year, the duration daylight hours changes slightly. Approximate day=night=12 hours. Twilight is virtually non-existent.

It is located inside the polar circle of each hemisphere.

In winter, the Sun does not rise above the horizon at all - the phenomenon of the Polar Night. In summer, the Sun, on the contrary, does not set below the horizon - the phenomenon of the Polar Day. The angle of incidence of sunlight even in summer is very small, so the heating of the surface is very weak. Summer temperatures usually do not exceed +10°C. In the long polar night, a strong cooling occurs, because. no heat gain at all.

Illumination belts are parts of the Earth's surface bounded by the tropics and the polar circles and differing in illumination conditions.

As a first approximation, it is enough to single out three zones in each hemisphere: 1) tropical, limited by the tropics, 2) temperate, going to the Arctic Circle, and 3) polar. The first is characterized by the presence of the Sun at the zenith at each latitude twice a year (on the tropic one) and a small difference in the length of the day by month. The second is characterized by a large seasonal difference in the height of the Sun and the length of the day. The third is characterized by polar night and polar day, the longitude of which depends on the geographical latitude. North of the Arctic Circle and south of the Antarctic Circle, polar day (summer) and polar night (winter) are observed. The area from the Arctic Circle to the Pole in both hemispheres is called the Arctic.
The polar day is the period when the Sun at high latitudes does not fall below the horizon around the clock. The duration of the polar day is longer, the farther to the pole from the Arctic Circle. In the polar circles, the Sun does not set only on the day of the solstice, at 68 ° latitude the polar day lasts about 40 days, at the North Pole 189 days, at the South it is somewhat less, due to the unequal speed of the Earth's orbit in the winter and summer half-years.
The polar night is the period when the Sun does not rise above the horizon at high latitudes around the clock - a phenomenon opposite to the polar day is observed simultaneously with it at the corresponding latitudes of the other hemisphere. In fact, the polar night is always shorter than the polar day due to the fact that the Sun, when it is not much below the horizon, illuminates the atmosphere and there is no complete darkness (twilight).
However, the division of the Earth into such large belts cannot satisfy practical needs.

On the days of the equinoxes, the height of the midday Sun above the horizon h for different latitudes f is easily determined by the formula: h = 90 ° -f.
So, in St. Petersburg (φ = 60°) on March 21 and September 23 at noon the Sun is at a height of 90°-60° = 30°. It heats the Earth for 12 hours. In the summer of each hemisphere, when the Sun is above the corresponding tropic, its height at noon increases by 23 ° 27 ":
A \u003d 90 ° -f + 23 ° 27 ".
For St. Petersburg, for example, on June 21, the height of the Sun is: 90 ° -60 ° + 23 ° 27 "= 53 ° 27". The day lasts 18.5 hours.

In winter, when the Sun moves to the opposite hemisphere, its height decreases accordingly and reaches a minimum on the days of the solstices. Then it should be reduced by 23°27".
On the Leningrad parallel on December 22, the Sun is at an altitude of 90°-60° -23°27" = 6°33" and illuminates the earth's surface for only 5.5 hours.

The described conditions of illumination of the globe, due to the inclination of the earth's axis, represent the radiative, associated with the sun's rays, the basis for the change of seasons.

In the formation of the weather, and thus the seasons, not only solar radiation, but also very many telluric (terrestrial) factors, therefore, in reality, both the seasons and their change are a complex phenomenon.



Uneven heating of the earth's surface causes different air temperatures at different latitudes. Latitudinal bands with certain air temperatures are called thermal zones. The belts differ in the amount of heat coming from the Sun. Their stretching depending on the distribution of temperatures is well illustrated by isotherms (from the Greek "iso" - the same, "therma" - heat). These are lines on a map that connect points with the same temperature.

The hot belt is located along the equator, between the Northern and Southern tropics. It is limited on both sides of the 20 0С isotherms. Interestingly, the boundaries of the belt coincide with the boundaries of the distribution of palm trees on land and corals in the ocean. Here the earth's surface receives the greatest solar heat. Twice a year (December 22 and June 22) at noon, the sun's rays fall almost vertically (at an angle of 900). The air from the surface gets very hot. Therefore, it is hot there throughout the year.

The temperate zones (in both hemispheres) adjoin the hot zone. They stretched in both hemispheres between the Arctic Circle and the tropic. The sun's rays there fall on the earth's surface with a certain slope. Moreover, the further north, the greater the slope. Therefore, the sun's rays heat the surface less. As a result, the air heats up less. That is why temperate zones are colder than hot ones. The sun is never at its zenith there. Clearly defined seasons: winter, spring, summer, autumn. Moreover, the closer to the Arctic Circle, the longer and colder the winter. The closer to the tropic, the longer and warmer the summer. The temperate zones from the side of the poles are limited by the isotherm of the warm month of 10 0C. It is the limit of the distribution of forests.

The cold zones (Northern and Southern) of both hemispheres lie between the isotherms of 10 0С and 0 0С of the warmest month. The sun there in winter for several months does not appear above the horizon. And in the summer, although it does not go beyond the horizon for months, it is very low above the horizon. Its rays only glide over the surface of the Earth and heat it weakly. The Earth's surface not only heats but also cools the air. Therefore, the temperatures there are low. Winters are cold and harsh, while summers are short and cool.

Two belts of eternal cold (northern and southern) are surrounded by an isotherm with temperatures of all months below 0 0C. This is the realm of eternal ice.

So, the heating and lighting of each locality depends on the position in the thermal zone, that is, on the geographical latitude. The closer to the equator, the greater the angle of incidence of the sun's rays, the more the surface heats up and the air temperature rises. Conversely, with distance from the equator to the poles, the angle of incidence of the rays decreases, respectively, the air temperature decreases.

It is important to remember that the lines of the tropics and polar circles outside the thermal zones are taken conditionally. Since in reality the air temperature is also determined by a number of other conditions.

26 question. Adiabatic processes in the atmosphere.

Suggested answer:

Processes in which there is no heat exchange with environment, called adiabatic. It was also found there that during adiabatic expansion, the gas is cooled, since in this case work is done against the forces of external pressure, as a result of which internal energy gas decreases. The air in the updraft expands as it rises into areas of less and less pressure. This process occurs practically without heat exchange with the surrounding layers of air, which also rise and also cool. Therefore, the expansion of air in the upward flow can be considered adiabatic. So, the rise of air in the atmosphere is accompanied by its cooling. Calculations and measurements show that an increase in air by 100 is accompanied by a cooling of approximately 1.

Manifestations of the action of adiabatic processes in the atmosphere are very numerous and varied. Let, for example, an air flow on its way meet a high mountain range and be forced to climb its slopes upwards. The upward movement of air is accompanied by its cooling. Therefore, the climate of the mountainous countries is always colder than the climate of the nearest plains, and on high altitudes eternal frost prevails. On the mountains, starting from a certain height (in the Caucasus, for example, from a height of 3000-3200 m), the snow no longer has time to melt in the summer and accumulates year after year in the form of powerful snowfields and glaciers.

As the air mass descends, it compresses and heats up as it compresses. If the air flow, having crossed the mountain range, descends, it heats up again. This is how a hair dryer arises - a warm wind, well known in all mountainous countries - in the Caucasus, in Central Asia, in Switzerland. The adiabatic cooling process proceeds in a special way during humid air. When the air reaches its dew point during its gradual cooling, water vapor begins to condense in it. This is how the smallest drops of water are formed, which make up a fog or a cloud. During condensation, the heat of vaporization is released, which slows down further cooling of the air. Therefore, the rising air stream will cool more slowly when the vapor condenses than when the air is completely dry. An adiabatic process in which steam condenses simultaneously is called wet adiabatic.

27 Question. Temperature inversion. The role of inversion processes in the formation of frosts, fogs, difficult environmental situations.

Suggested answer:

Inversion in meteorology means the anomalous nature of the change in any parameter in the atmosphere with increasing altitude. Most often this applies to temperature inversion, that is, to an increase in temperature with height in a certain layer of the atmosphere instead of the usual decrease.

For freezing, a clear and quiet night is needed, when the effective radiation from the soil surface is large, and the turbulence is small, and the air cooled from the soil is not transferred to higher layers, but is subjected to prolonged cooling. Such clear and calm weather is usually observed during internal parts areas of high atmospheric pressure, anticyclones.

A strong nighttime cooling of the air near the earth's surface leads to the fact that the temperature rises with height. In other words, during freezing, a surface temperature inversion takes place.

Frost occurs more often in lowlands than in high places or on slopes, since in concave landforms the nighttime drop in temperature is increased. In low places, cold air stagnates more and cools for a longer time.

The power of surface inversions is tens of meters. The power of inversions in the free atmosphere reaches hundreds of meters. Temperature inversion prevents the development of vertical air movements, contributes to the formation of haze, fog, smog, clouds, mirages. The inversion is highly dependent on local terrain features.

Under the inversion, the intensity of turbulent transport is sharply weakened, which can lead to the accumulation of condensed water vapor (fog), pollution, etc.

The meteorological factors that create an intense accumulation of impurities in the surface air layer include wind speed, the dangerous value of which depends on the emission parameters, elevated inversion located above the sources, and fogs.

28 Question. Formation conditions, types of frosts and their impact on agricultural production.

Uneven heating of the earth's surface causes different air temperatures at different latitudes. Latitudinal bands with certain air temperatures are called thermal zones. The belts differ in the amount of heat coming from the Sun. Their stretching depending on the distribution of temperatures is well illustrated by isotherms (from the Greek "iso" - the same, "therma" - heat). These are lines on a map that connect points with the same temperature.

The hot belt is located along the equator, between the Northern and Southern tropics. It is limited on both sides of the 20 0С isotherms. Interestingly, the boundaries of the belt coincide with the boundaries of the distribution of palm trees on land and corals in the ocean. Here the earth's surface receives the greatest solar heat. Twice a year (December 22 and June 22) at noon, the sun's rays fall almost vertically (at an angle of 900). The air from the surface gets very hot. Therefore, it is hot there throughout the year.

The temperate zones (in both hemispheres) adjoin the hot zone. They stretched in both hemispheres between the Arctic Circle and the tropic. The sun's rays there fall on the earth's surface with a certain slope. Moreover, the further north, the greater the slope. Therefore, the sun's rays heat the surface less. As a result, the air heats up less. That is why temperate zones are colder than hot ones. The sun is never at its zenith there. Clearly defined seasons: winter, spring, summer, autumn. Moreover, the closer to the Arctic Circle, the longer and colder the winter. The closer to the tropic, the longer and warmer the summer. The temperate zones from the side of the poles are limited by the isotherm of the warm month of 10 0C. It is the limit of the distribution of forests.

The cold zones (Northern and Southern) of both hemispheres lie between the isotherms of 10 0С and 0 0С of the warmest month. The sun there in winter for several months does not appear above the horizon. And in the summer, although it does not go beyond the horizon for months, it is very low above the horizon. Its rays only glide over the surface of the Earth and heat it weakly. The Earth's surface not only heats but also cools the air. Therefore, the temperatures there are low. Winters are cold and harsh, while summers are short and cool.

Two belts of eternal cold (northern and southern) are surrounded by an isotherm with temperatures of all months below 0 0C. This is the realm of eternal ice.

So, the heating and lighting of each locality depends on the position in the thermal zone, that is, on the geographical latitude. The closer to the equator, the greater the angle of incidence of the sun's rays, the more the surface heats up and the air temperature rises. Conversely, with distance from the equator to the poles, the angle of incidence of the rays decreases, respectively, the air temperature decreases.

It is important to remember that the lines of the tropics and polar circles outside the thermal zones are taken conditionally. Since in reality the air temperature is also determined by a number of other conditions (see the article main and transitional climatic zones).

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted on http://www.allbest.ru/

1. Thermal belts of the Earth

Uneven heating of the earth's surface causes different air temperatures at different latitudes. Latitudinal bands with certain air temperatures are called thermal zones. The belts differ in the amount of heat coming from the Sun. Their stretching depending on the distribution of temperatures is well illustrated by isotherms (from the Greek "iso" - the same, "therma" - heat). These are lines on a map that connect points with the same temperature.

The hot belt is located along the equator, between the Northern and Southern tropics. It is limited on both sides of the 20 0С isotherms. Interestingly, the boundaries of the belt coincide with the boundaries of the distribution of palm trees on land and corals in the ocean. Here the earth's surface receives the greatest solar heat. Twice a year (December 22 and June 22) at noon, the sun's rays fall almost vertically (at an angle of 900). The air from the surface gets very hot. Therefore, it is hot there throughout the year.

The temperate zones (in both hemispheres) adjoin the hot zone. They stretched in both hemispheres between the Arctic Circle and the tropic. The sun's rays there fall on the earth's surface with a certain slope. Moreover, the further north, the greater the slope. Therefore, the sun's rays heat the surface less. As a result, the air heats up less. That is why temperate zones are colder than hot ones. The sun is never at its zenith there. Clearly defined seasons: winter, spring, summer, autumn. Moreover, the closer to the Arctic Circle, the longer and colder the winter. The closer to the tropic, the longer and warmer the summer. The temperate zones from the side of the poles are limited by the isotherm of the warm month of 10 0C. It is the limit of the distribution of forests.

The cold zones (Northern and Southern) of both hemispheres lie between the isotherms of 10 0С and 0 0С of the warmest month. The sun there in winter for several months does not appear above the horizon. And in the summer, although it does not go beyond the horizon for months, it is very low above the horizon. Its rays only glide over the surface of the Earth and heat it weakly. The Earth's surface not only heats but also cools the air. Therefore, the temperatures there are low. Winters are cold and harsh, while summers are short and cool.

Two belts of eternal cold (northern and southern) are surrounded by an isotherm with temperatures of all months below 0 0C. This is the realm of eternal ice.

So, the heating and lighting of each locality depends on the position in the thermal zone, that is, on the geographical latitude. The closer to the equator, the greater the angle of incidence of the sun's rays, the more the surface heats up and the air temperature rises. Conversely, with distance from the equator to the poles, the angle of incidence of the rays decreases, respectively, the air temperature decreases.

It is important to remember that the lines of the tropics and polar circles outside the thermal zones are taken conditionally. Since in reality the air temperature is also determined by a number of other conditions (see the article main and transitional climatic zones).

1.1 Roast

Equatorial belt - zone low pressure, ascending currents of air, weak winds. Temperatures are high throughout the year (about +28 °C), air humidity is high. There is a lot of precipitation - about 2000 mm. seasonal fluctuations average monthly temperatures and little rainfall.

Subequatorial belts are characterized by seasonal change air masses: summer monsoon brings hot and humid equatorial air, dry continental tropical air dominates in winter. Such a climate with wet summers and dry winters is called monsoonal.

Tropical zones are characterized by an arid (dry) climate, they have the greatest deserts in the world: Sahara, Arabian, Australian. The air temperature ranges from +20 °c in summer to +15 °c in winter.

1.2 Moderate

In subtropical zones, air masses change from tropical in summer to moderate in winter, and temperatures are above zero throughout the year. However, short-term drops in temperature to negative values and even snowfall. On the plains, the snow melts quickly, and in the mountains it can lie for several months. In the inland areas, the climate is arid, with hot (about +30 °C) dry summers, cool (0...+5 °C), relatively humid (200-250 mm) winters. Change of air masses and frequent passage atmospheric fronts defines unsettled weather. Due to insufficient moisture, landscapes of deserts, semi-deserts, and dry steppes predominate here. Special sharply continental climate with cool summers, harsh winter and insignificant rainfall stands out the largest and highest (4-5 km) highlands of the world Tibet with high-mountainous deserts.

In the Southern Hemisphere, where there are no large continents, and only a narrow part of the South America, the island of Tasmania and South New Zealand, the climate is oceanic mild with warm winter and cool summers with uniform heavy (about 1000 mm) precipitation. And only in Patagonia the climate is transitional to continental, and moisture is insufficient.

In the Northern Hemisphere, on the contrary, vast land masses dominate and a whole spectrum of climates differing in degree of continentality is developed. From west to east - from temperate to sharply continental climate - daily and seasonal temperature amplitudes increase, and annual precipitation decreases from 700-600 mm to 300 mm and even to 200-100 mm in the Middle and Central Asia. More precipitation falls in summer than in winter, and this difference is more significant in the center of the continents, especially in Eastern Siberia, due to a very dry anticyclonic winter.

IN temperate zone distinguish the northern part with cool summers and relatively severe winters and the southern part with warm summer and relatively mild winters. July temperatures vary from -4...-10 °c to +12 °c in the north and up to +30 °c in the south, January temperatures from -5 °c in the west to -25...- 30 °c in the center of the continents, in Yakutia even below -40 °c.

1.2 Cold

The subarctic and subantarctic belts are characterized by a seasonal change of air masses: in the summer of the MT, in the winter of the AB. In the north of Eurasia and North America, the climate is continental and sharply continental with cool, damp summers with temperatures below +10...+12 °C and long, severe (up to -40...-50 °C) winters with little snow and large annual temperature ranges. . In the area of ​​the city of Oymyakon there is a cold pole of the Northern Hemisphere and the entire planet - (-78 ° C). Such conditions contribute to the maintenance of ubiquitous permafrost. There is little precipitation (200-100 mm), however, due to low temperatures, moisture is excessive. The tundra and forest-tundra prevailing here are heavily swamped.

The maritime climate of the northern and southern coasts is characterized by cool (+3...+5 °c) damp summers, relatively mild (-10...-15 °c) winters, floating sea and continental ice, constant fogs with significant low temperatures rainfall (up to 500 mm). Tundra is widespread along the coasts of the continents and on the islands.

In the Arctic (Greenland and the islands of the Canadian archipelago) and Antarctic belts(Antarctica), dominated continental climate. These are the coldest regions of the Earth - the thermometer does not rise above zero all year, and at the inland Antarctic station "Vostok" an absolute minimum temperature of -89.2 ° C was recorded (but the station "Vostok" is located at an altitude of 3488 m). Rainfall is less than 100 mm. Here you can hardly see anything other than icy deserts. The Arctic has an oceanic climate. Negative temperatures prevail, but during the polar day it can get warmer up to +5 °C. Precipitation is also low, the islands are characterized by tundra.

2.Air masses

Large air masses in the troposphere, commensurate in size with the mainland or ocean and having more or less the same properties (temperature, humidity, transparency, dust content, etc. - approx. from geoglobus.ru), are called air masses. They extend upwards for several kilometers, reaching the boundaries of the troposphere.

Air masses move from one region of the globe to another, determining the climate and weather in a given area. Each air mass has properties characteristic of the area over which it formed.

Moving to other territories, it carries with it its own weather regime. But passing over a territory with different properties, the air masses gradually change, transform, acquiring new qualities.

Depending on the regions of formation, four types of air masses are distinguished: arctic (in the southern hemisphere - antarctic), temperate, tropical and equatorial. All types are divided into subtypes with their own characteristic properties. Continental air masses form over the continents, and oceanic air masses form over the oceans. Shifting along with atmospheric pressure belts throughout the year, air masses occupy not only the permanent belts of their stay, but seasonally dominate in neighboring, transitional climatic zones. In the process of general circulation of the atmosphere, air masses of all types are interconnected.

Air masses that move from a colder earth's surface to a warmer one and which have a lower temperature than the surrounding air are called cold air masses. They bring cooling, but they themselves warm up from below from the warm earth's surface, while powerful cumulus clouds form and heavy rains fall. Particularly severe cold snaps occur in temperate latitudes during the invasion of cold masses from the Arctic and Antarctica - approx. from geoglobus.ru. Cold air masses sometimes reach the southern regions of Europe and even North Africa, but are most often delayed by the mountain ranges of the Alps. In Asia, arctic air is freely distributed over vast territories, up to the mountain ranges of southern Siberia. IN North America mountain ranges are located meridianally, so cold Arctic air masses penetrate to the Gulf of Mexico.

Masses of air that have a higher temperature than the surrounding air and come to a colder earth's surface are called warm air masses. They bring warming, and they themselves are cooled from below, thus forming stratus clouds and fogs. In summer, warm tropical air masses from North Africa sometimes penetrate to the northern regions of Europe and significantly increase the temperature (sometimes up to +30 ° C).

Local, or neutral, air mass is called the mass located in thermal equilibrium with its environment, that is, day after day, retaining its properties. The changing air mass can be both warm and cold, and upon completion of the transformation, it becomes local.

Where air masses meet different types, atmospheric fronts are formed.

Moderate air masses form in temperate latitudes. Those that form over the continent are characterized by low temperature and low moisture content in winter and bring clear and frosty weather. In summer, continental temperate air masses are dry and hot. Moderate air masses formed over the ocean are warm and humid. In winter they bring thaws, and in summer - cold snap and precipitation.

Arctic and Antarctic air masses form over the ice surface of polar latitudes. They are characterized low temperature and a small amount of moisture. They significantly lower the temperature of the areas they invade. In summer, moving to the center of Eurasia, these air masses gradually heat up, dry out even more and become the cause of dry winds in southern regions West Siberian lowland.

Tropical air masses are hot at any time of the year. The marine subtype of tropical air masses is characterized by high humidity, while the continental subtype is dry and dusty. Over the oceans in the tropics, the trade winds dominate all year - approx. from geoglobus.ru. The air masses formed in these areas are characterized by moderately high temperatures from +20 to +27 °С in summer and cool temperatures up to +10 +15 °С in winter. In the districts tropical deserts Extremely dry air masses form over the continents with average temperatures of +26 +40 °C.

Equatorial air masses are formed in equatorial latitudes. They possess high temperature and high humidity, regardless of where they formed - over the mainland or over the ocean. The average temperatures of equatorial air masses in all months of the year range from +24 to +28 °С. Since evaporation is high in these areas, the absolute humidity is also high, and relative humidity even in the driest months of the year above 70%.

3. Precipitation

thermal belt air atmospheric

Their education

Precipitation is any moisture that has fallen from the atmosphere onto the earth's surface. These include rain, snow, hail, dew, frost. Precipitation can fall both from clouds (rain, snow, hail) and from the air (dew, frost).

The main condition for education precipitation is cooling warm air, leading to the condensation of the vapor contained in it.

When warm air rises and cools, clouds are formed, consisting of water droplets. Colliding in a cloud, the drops are connected, their mass increases. The bottom of the cloud turns blue and it rains. At negative air temperatures, water droplets in the clouds freeze and turn into snowflakes. Snowflakes stick together into flakes and fall to the ground. During a snowfall, they can melt a little, and then it snows. It happens that air currents repeatedly lower and raise frozen drops, at which time ice layers grow on them. Finally, the drops become so heavy that they fall to the ground like hail. Sometimes hailstones reach the size of a chicken egg.

IN summer time in clear weather, the earth's surface cools. It cools the surface layers of air. Water vapor begins to condense on cold objects - leaves, grass, stones. This is how dew forms. If the surface temperature was negative, then the water droplets freeze, forming frost. Dew usually falls in summer, frost in spring and autumn. At the same time, both dew and frost can form only in clear weather. If the sky is covered with clouds, then the earth's surface cools slightly and cannot cool the air.

According to the method of formation, convective, frontal and orographic precipitation are distinguished. The general condition for the formation of precipitation is the upward movement of air and its cooling. In the first case, the reason for the rise of air is its heating from warm surface(convection). Such precipitation falls all year round in the hot zone and in summer in temperate latitudes. If warm air rises when it interacts with colder air, then frontal precipitation is formed. They are more characteristic of temperate and cold zones, where warm and cold air masses are more common. The reason for the rise of warm air may be its collision with the mountains. In this case, orographic precipitation is formed. They are characteristic of the windward slopes of mountains, and the amount of precipitation on the slopes is greater than on the adjacent parts of the plains.

The amount of precipitation is measured in millimeters. On average, about 1100 mm of precipitation falls on the earth's surface per year.

Distribution of precipitation on the globe. Atmospheric precipitation on the planet is unevenly distributed. It depends on the geographical location of the area and the prevailing winds. The largest number precipitation falls in equatorial (over 2,000 mm) and temperate (over 800 mm) latitudes. Little precipitation (200 mm) falls in tropical and polar latitudes. However, this distribution is disturbed by the nature of the earth's surface: more precipitation falls over the oceans than over land. In the mountains, much more precipitation "accepts" those slopes facing prevailing winds. So, in Ukraine, the windward slopes of the Carpathians receive 1500 mm per year, and the leeward slopes - half as much as -750 mm per year.

I have a record high annual rainfall on Earth in the village of Cherrapunji, at the foot of the Himalayas - 23,000 mm. And the rainiest place on the planet is the Hawaiian Islands, where 335 days a year it happens with rain, which brings 12,000 mm of water. The record dry places where precipitation does not fall for years are the Atacama desert in South America (1 mm per year) and the Sahara in Africa (5 mm per year).

The distribution of precipitation on Earth depends on a number of reasons:

a) from the placement of high and low pressure belts. At the equator and in temperate latitudes, where areas of low pressure are formed, there is a lot of precipitation. In these areas, the air heated from the Earth becomes light and rises, where it meets the colder layers of the atmosphere, cools, and the water vapor turns into water droplets and falls to the Earth in the form of precipitation. In the tropics (30th latitudes) and polar latitudes, where areas high pressure, descending air currents predominate. Cold air descending from upper layers troposphere contains little moisture. When lowered, it shrinks, heats up and becomes even drier. Therefore, in the areas high blood pressure little precipitation falls over the tropics and near the poles;

b) the distribution of precipitation also depends on the geographical latitude. There is a lot of precipitation at the equator and in temperate latitudes. However, the earth's surface at the equator warms up more than at temperate latitudes, so the updrafts at the equator are much more powerful than at temperate latitudes, and therefore, stronger and more abundant precipitation;

c) the distribution of precipitation depends on the position of the terrain relative to the World Ocean, since it is from there that the main share of water vapor comes. For example, less precipitation falls in Eastern Siberia than in the East European Plain, since Eastern Siberia removed from the oceans;

d) the distribution of precipitation depends on the proximity of the area to ocean currents: warm currents contribute to precipitation on the coasts, and cold ones hinder. Cold currents pass along the western coasts of South America, Africa and Australia, which led to the formation of deserts on the coasts; e) the distribution of precipitation also depends on the relief. On the slopes mountain ranges facing moist winds from the ocean, noticeably more moisture falls than on the opposite ones - this is clearly seen in the Cordillera of America, on the eastern slopes of the mountains Far East, on the southern spurs of the Himalayas. Mountains prevent the movement of moist air masses, and the plain contributes to this.

Hosted on Allbest.ru

Similar Documents

    Analysis of the rules for drawing the boundaries of time zones, their number on the surface of the Earth. The study of the essence of standard time - the local average time of the axial meridian of the belt, common throughout the entire belt. Decree, summer and ship time.

    abstract, added 06/01/2010

    Geographical position equatorial belt earth, his distinctive features, the annual course of temperature and precipitation. The flora and fauna of this belt, wealth species composition. Specificity climatic conditions and economically useful plants.

    presentation, added 01/18/2011

    The main types of precipitation and their characteristics. Types of daily and annual course precipitation. Geographical distribution of precipitation. Snow cover on the Earth's surface. Atmospheric humidification as the degree of supply of moisture to the area.

    presentation, added 05/28/2015

    Composition and structure of the Earth's atmosphere. Atmosphere value for geographical envelope. Essence and characteristic properties of weather. Classification of climates and characteristics of species climatic zones. General atmospheric circulation and factors affecting it.

    abstract, added 01/28/2011

    The concept of volcanism is a set of processes associated with the appearance of magma on the surface of the Earth. Features of the structure of the volcano and types volcanic eruptions. Definition of the main volcanic belts. The role of volcanism in the transformation of relief and climate.

    term paper, added 02/10/2011

    Definition of the concept "atmosphere", characteristics of interrelated phenomena and processes that form the weather. Energy exchange in the lower and upper layers atmosphere. The structure of the atmospheric layers of the Earth. The main regularities of the circulation of air masses in the atmosphere.

    term paper, added 12/12/2011

    The total length of the territory of Dagestan and physiographic zones. Characteristics of the climate is temperate continental, arid. Diversity of vegetation and climatic zones of Dagestan. Description of the main rivers and lakes, their location and significance.

    abstract, added 02/07/2010

    The concept of the lithosphere, hypotheses of the origin of the Earth and the essence of Schmidt-Fesenkov's assumptions. Stages of education earth's crust and its structure. Characteristics of the boundary regions between lithospheric plates, the formation and significance of seismic belts on Earth.

    presentation, added 10/27/2011

    Elements that make up the atmosphere: nitrogen, oxygen, carbon dioxide and water vapor. Consideration of the protective functions of the ozone layer in the stratosphere. Characteristics of cirrus separate, thin and filamentous clouds. Description of stratus and cumulus air masses.

    presentation, added 02.10.2011

    Hypotheses of the formation of planets and ways to solve the problem of the origin of the Earth. The theory of the structure of the earth's crust and the doctrine of lithospheric plates. Causes of diversity and patterns of placement large forms on the surface of the earth. Features of the topography of the ocean floor.



If you find an error, please select a piece of text and press Ctrl+Enter.