The air is heated by the underlying surface. Olympiad assignments in geography, school stage Olympiad assignments in geography on the topic

Task 1

(10 points) State the traveler's name. He passed through Siberia and Central Asia, Crimea and the Caucasus, Northern China and Central Asia. He studied the sands of the Karakum desert and developed the theory of moving sands. For his first works he was awarded silver and gold medals of the Russian Geographical Society. After an expedition to China, he became known throughout the world as the largest explorer of Asia. The Russian Geographical Society awarded him its highest award - the Great Gold Medal. He is known to many as the author of fascinating science fiction novels.

Who is he? What books of his do you know? Which geographical features named after him?

Answer:

Obruchev. Books "Plutonium", "Sannikov's Land", "Gold Diggers in the Desert", "In the Wilds" Central Asia"A mountain range in Tuva, a mountain in the upper reaches of the Vitim River, one of the peaks in the Russian Altai, and an oasis in Antarctica are named after Obruchev.

Evaluation criteria:Correct definition of a traveler – 2 points. For examples of books by a scientist and a list of geographical objects, 1 point each. Total 10 points.

Task 2

(15 points) The air is heated by the underlying surface; in the mountains, this surface is located closer to the Sun, and, therefore, the influx of solar radiation as it rises should increase and the temperature should increase. However, we know that this does not happen. Why?

Answer:

Firstly, because the air heated near the earth quickly cools when moving away from it, and secondly, because in the upper layers of the atmosphere the air is more rarefied than near the earth. The lower the air density, the less heat is transferred. Figuratively, this can be explained as follows: the higher the air density, the more molecules there are per unit volume, the faster they move and the more often they collide, and such collisions, like any friction, cause the release of heat. Thirdly, the sun's rays on the surface of mountain slopes always fall not vertically, as on the earth's surface, but at an angle. And, in addition, the dense snow caps with which they are covered prevent the mountains from warming up - white snow simply reflects the sun's rays.

Evaluation criteria: Identification of three reasons and their explanation, 5 points each. Total 15 points.

Task 3

(10 points) Name the subject of the Russian Federation that is characterized by the following images.

Evaluation criteria: Total 10 points.

Task 4

About 10 days before the explosion, a small earthquake occurred in the area. This earthquake caused the opening of the deposit natural gas. The presence of gas deposits in this area has been confirmed by research from the Siberian Research Institute of Geology, Geophysics and Mineral Resources, which is confirmed by the institute’s official conclusion. As a result of the release of gas, craters should have formed on the surface. These craters exist in reality; they were discovered by Kulik’s expedition and mistakenly taken for meteorite craters. Emerging into the atmosphere, the gas rose to the upper layers of the atmosphere, mixed with the air and was carried by the wind. In the upper layers of the atmosphere, the gas interacted with ozone. Slow oxidation of the gas occurred, accompanied by a glow.

The gas emission hypothesis does not explain the observation of the fireball and does not fit well with the absence of gas emission channels at the epicenter.

There is an assumption that the Tunguska phenomenon is an explosion of a “spaceship”. 68 years after the Tunguska disaster, a group sent found a piece of the “Martian ship” on the banks of the Vashka River in the Komi Autonomous Soviet Socialist Republic.

Two fishing workers from the village of Ertosh discovered an unusual piece of metal weighing 1.5 kg on the shore.

When he was accidentally hit by a stone, he sprayed a shower of sparks. The unusual alloy contained about 67% cesium, 10% lanthanum, separated from all lanthanum metals, which has not yet been possible to do on Earth, and 8% niobium. The appearance of the fragment led to speculation that it was part of a ring or sphere or cylinder with a diameter of about 1.2 m.

Everything indicated that the alloy was of artificial origin.

The answer to the question was never received: where and in what devices or engines such parts and alloys can be used

Comet.

Soviet astronomer,

Head of the London Observatory, Kew-F. Whipple

No crater. There's no trace celestial body on the ground.

Light phenomena in the night sky different parts planets are possibly caused by the "dust-laden tail of the nucleus of such a small comet." Dust particles scattered in the planet's atmosphere and reflected sunlight

No one had noticed the approach of a celestial body before.

Experiments

Nikola Tesla

In support of this hypothesis, it is reported that at that time Tesla was allegedly seen with a map of Siberia, including the area in which the explosion occurred, and the time of the experiments immediately preceded the “Tunguska Wonder”

There are no documents confirming N. Tesla's experiment. He himself denied his involvement in this event.

Evaluation criteria: For each proposed hypothesis, 9 points: only those answers are taken into account that are compiled according to the assignment (hypothesis and its author - 3 points, the presence of arguments confirming it - 3 points, the presence of facts refuting the hypothesis - 3 points). Up to 5 versions are expected. Total up to 45 points.

Total 100 points

Questsschool tour of the Geography Olympiad

7th grade last name, first name_________________________________

When answering questions and completing assignments, do not rush, since the answers are not always obvious and require not only knowledge of the program material, but also general geographical erudition.

Good luck in your work!

1. Determine the geographical coordinates of the city of Cape Town (southern Africa)_________________

2. Convert the numerical scale to a named scale of 1:30000000___________________________

3. “The most, the most” (world records)

4) the highest waterfall_______________________________________________________________

5) the deepest lake_______________________________________________________________

6) the coldest continent_______________________________________________________________

7) the widest strait______________________________________________________________

8) the largest lake_______________________________________________________________

9) the smallest continent_______________________________________________________________

10) the most salty place in the World Ocean_______________________________________________

4 . Explain what the terms mean?

1) Laurasia _________________________________________________________________

2) Passat ______________________________________________________________

3) Meridian __________________________________________________________

4) Azimuth ______________________________________________________________

(for each correct answer 2 points)

5. Are there any points on Earth that require only latitude to locate them? If yes, then name them. ________________________________

(5 points)

6. The name of this object comes from the word “masunu”, which means “big water” in the Indian language. What is this object? _______________________________________

7. From the Tibetan language this name is translated as “goddess - mother of the Earth.” What is it

_____________________________________________________________________________

8. Which concept does the following associations belong to:

1) wave, earthquake, danger, speed, disaster ________________________

2) rocks, rapids, spectacle, roar, water _____________________________________

3) ocean, ice, mountain, danger _____________________________________________

(for each correct answer 2 points)

9. How can we explain the fact that the most abundant rivers in the world flow in the equatorial belt? ______________________________________________________________

(5 points)

10. Student Vanya Stepochkin did not prepare homework not on any subject. He explained to all the teachers that yesterday after school, while walking along the beach, he saw how the wind was carrying a little girl on an inflatable mattress out to the open sea. Naturally, he rushed to save her, but after what happened, he had no time for lessons. All the teachers praised him, except the geography teacher. What made the geography teacher doubt the sincerity of the boy’s words?_________________________________________________

(15 points)

11. Choose the correct statements

1. On south pole colder than in the north
2. The Bering Strait was discovered by Vitus Bering
3. The map is on a larger scale than the topographic plan
4. Azimuth to East means 180 degrees
5. The largest island in the world is Sakhalin
6. The highest peak in the world is called Chomolungma
7. In the south, Eurasia is washed by the Indian Ocean

12. Solve a geographic problem.

An oil driller, a scuba diver, a polar explorer and a penguin argued - who is closer to the center of the Earth? The scuba diver says: “I will sit in the submersible and descend to the bottom of the Mariana Trench, its depth is 11022 m, and I will be closest to the center of the Earth.” The polar explorer says: “I’ll go to North Pole and I will be closest to the center of the Earth.” The driller says: “I will drill a well in the Persian Gulf 14 km deep and I will be closest to the center of the Earth.” Only the penguin doesn’t say anything, he just lives in Antarctica (Antarctica’s altitude is 3000m, altitude ice sheet- 4 km). Which character is closest to the center of the Earth? ________________________________________ (10 points)

13.

(for each correct answer 2 points)

14. The air is heated by the underlying surface; in the mountains, this surface is located closer to the Sun, and, therefore, the influx of solar radiation as it rises should increase and the temperature should increase. However, we know that this does not happen. Why?

______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________(15 points)

15.

1. The navigator who planned, but could not fully accomplish the first thing trip around the world. This journey proved the existence of a single World Ocean and the sphericity of the Earth. ___________________

2. Russian navigator, admiral, honorary member of the St. Petersburg Academy of Sciences, founding member of the Russian Geographical Society, head of the first Russian round-the-world expedition on the ships “Nadezhda” and “Neva”, author of the “Atlas of the South Sea” _____________________________________________

3. Italian traveler, explorer of China and India. The first to describe Asia in more detail was ______________________________

4. Russian navigator, discoverer of Antarctica. Commanded the sloop "Vostok" ______________________________

5. English navigator. He led three expeditions around the world, discovered many islands in Pacific Ocean, found out the island position of New Zealand, discovered the Great Barrier Reef, the east coast of Australia, the Hawaiian Islands ___________________________

(for each correct answer 2 points)

Answers to the tasks of the Olympiad (school tour).

7th grade

1. 34 S 19E _

2. 1 cm 300 km _

1) Nile

2) Chomolungma

3) -Amazonian

4) -Angel

5-Baikal

6) -Antarctica

7) -Drake

8) -Caspian

9) -Australia

10) Red Sea ( 2 points for each correct answer)

1) Laurasia - ancient continent, 2) Trade wind - wind from 30 latitudes to the equator

3) Meridian - line, conn. north and south pole

4) Azimuth - the angle between the direction to the north and the direction to the object (for each correct answer 2 b)

5. North and south pole(5 points)

6. Amazon River(2 points)

7. Chomolungma (2 points)

1) tsunami, 2) waterfall, 3) iceberg(for each correct answer 2 points)

9. falls the most more precipitation (5 points)

10. The daytime breeze blows from the sea to the land. Not the other way around(15 points)

11. Correct geographical errors

Island Madagascar, Arabian sea, Ladoga lake, mountains Himalayas, river Amazon, Red sea ,

island Greenland (for each correct answer 2 points)

12. _polar explorer(10 points)

13. Indicate the purpose of the devices and instruments listed in the table. Fill in the cells in the table.

Device name	Purpose of the device
	to determine the height difference between points
Hygrometer	To determine air humidity
Luxmeter	To measure illumination
Bathometer	to take a water sample from a given depth of a natural reservoir in order to study its physical and chemical properties, as well as organic and inorganic inclusions contained in it
Seismograph	for detecting and recording all types of seismic waves

(for each correct answer 2 points)

14. firstly, because the air heated near the earth quickly cools when moving away from it, and secondly, because in the upper layers of the atmosphere the air is more rarefied than near the earth. The lower the air density, the less heat is transferred. Figuratively, this can be explained as follows: the higher the air density, the more molecules there are per unit volume, the faster they move and the more often they collide, and such collisions, like any friction, cause the release of heat. Thirdly, the sun's rays on the surface of mountain slopes always fall not vertically, as on the earth's surface, but at an angle. And besides, the mountains are prevented from warming up by the dense snow caps with which they are covered - white snow simply reflects the sun's rays. (15 points)

17. Determine which of the travelers (geographers) we are talking about?

1. Magellan

2. Krusenstern

3. Marco Polo

4. Bellingshausen

5. Cook

1. Vasco da Gama

Video tutorial 2: Atmosphere structure, meaning, study

Lecture: Atmosphere. Composition, structure, circulation. Distribution of heat and moisture on Earth. Weather and climate

Atmosphere

Atmosphere can be called an all-pervading shell. Its gaseous state allows it to fill microscopic holes in the soil; water is dissolved in water; animals, plants and humans cannot exist without air.

The conventional thickness of the shell is 1500 km. Its upper boundaries dissolve in space and are not clearly marked. Atmospheric pressure at sea level at 0 °C is 760 mm. Hg Art. The gas shell consists of 78% nitrogen, 21% oxygen, 1% other gases (ozone, helium, water vapor, carbon dioxide). The density of the air shell changes with increasing altitude: the higher you go, the thinner the air. This is why climbers may experience oxygen deprivation. The earth's surface itself has the highest density.

Composition, structure, circulation

The shell contains layers:

Troposphere, 8-20 km thick. Moreover, the thickness of the troposphere at the poles is less than at the equator. About 80% of the total air mass is concentrated in this small layer. The troposphere tends to heat up from the surface of the earth, so its temperature is higher near the earth itself. With a rise of 1 km. the temperature of the air shell decreases by 6°C. Active movement occurs in the troposphere air masses in vertical and horizontal direction. It is this shell that is the weather “factory”. Cyclones and anticyclones form in it, westerly and easterly winds. It contains all the water vapor that condenses and is shed by rain or snow. This layer of the atmosphere contains impurities: smoke, ash, dust, soot, everything we breathe. The layer bordering the stratosphere is called the tropopause. This is where the temperature drop ends.

Approximate boundaries stratosphere 11-55 km. Up to 25 km. Minor changes in temperature occur, and above it it begins to rise from -56 ° C to 0 ° C at an altitude of 40 km. For another 15 kilometers the temperature does not change; this layer is called the stratopause. The stratosphere contains ozone (O3), a protective barrier for the Earth. Thanks to the presence of the ozone layer, harmful ultraviolet rays do not penetrate the surface of the earth. Recently, anthropogenic activities have led to the destruction of this layer and the formation of “ozone holes.” Scientists claim that the cause of the “holes” is the increased concentration free radicals and freon. Under the influence of solar radiation, gas molecules are destroyed, this process is accompanied by a glow (northern lights).

From 50-55 km. the next layer begins - mesosphere, which rises to 80-90 km. In this layer the temperature decreases, at an altitude of 80 km it is -90°C. In the troposphere, the temperature again rises to several hundred degrees. Thermosphere extends up to 800 km. Upper limits exosphere are not detected, since the gas dissipates and partially escapes into outer space.

Heat and moisture

The distribution of solar heat on the planet depends on the latitude of the place. The equator and the tropics receive more solar energy, since the angle of incidence of the sun's rays is about 90°. The closer to the poles, the angle of incidence of the rays decreases, and accordingly the amount of heat also decreases. sun rays, passing through the air shell, do not heat it. Only when it hits the ground, solar heat is absorbed by the surface of the earth, and then the air is heated from the underlying surface. The same thing happens in the ocean, except that the water heats up more slowly than the land and cools down more slowly. Therefore, the proximity of seas and oceans influences the formation of climate. In summer, sea air brings us coolness and precipitation, in winter it warms, since the surface of the ocean has not yet spent its heat accumulated over the summer, and the earth's surface has quickly cooled. Marine air masses form above the surface of the water, therefore they are saturated with water vapor. Moving over land, air masses lose moisture, bringing precipitation. Continental air masses form above the surface of the earth, as a rule, they are dry. The presence of continental air masses in summer brings hot weather, in winter - clear frosty.

Weather and climate

Weather– the state of the troposphere in a given place for a certain period of time.

Climate– long-term weather regime characteristic of a given area.

The weather can change during the day. Climate is a more constant characteristic. Each physical-geographical region is characterized by certain type climate. The climate is formed as a result of the interaction and mutual influence of several factors: the latitude of the place, the prevailing air masses, the topography of the underlying surface, the presence of underwater currents, the presence or absence of water bodies.

On earth's surface there are low and high belts atmospheric pressure. Equatorial and temperate zones low pressure, at the poles and in the tropics the pressure is high. Air masses move from an area of ​​high pressure to an area of ​​low pressure. But since our Earth rotates, these directions deviate, in the northern hemisphere to the right, in the southern hemisphere to the left. From tropical zone Trade winds blow to the equator, westerly winds blow from the tropical zone to the temperate zone, and polar eastern winds blow from the poles to the temperate zone. But in each zone, land areas alternate with water areas. Depending on whether the air mass has formed over land or ocean, it may bring heavy rain or a clear, sunny surface. The amount of moisture in air masses is affected by the topography of the underlying surface. Over flat areas, moisture-saturated air masses pass without obstacles. But if there are mountains on the way, it’s hard humid air cannot move through the mountains, and is forced to lose part, or even all, of the moisture on the mountain slope. East Coast Africa has a mountainous surface (the Drakensberg Mountains). The air masses that form over the Indian Ocean are saturated with moisture, but they lose all the water on the coast, and a hot, dry wind comes inland. That's why most South Africa occupied by deserts.

The rays of the Sun, as already mentioned, passing through the atmosphere, experience some changes and give off some of the heat to the atmosphere. But this heat, distributed throughout the entire atmosphere, has a very small effect in terms of heating. On temperature conditions the lower layers of the atmosphere are mainly influenced by the temperature of the earth's surface. The lower layers of the atmosphere are heated from the heated surface of land and water, and cooled from the cooled surface. Thus, the main source of heating and cooling of the lower layers of the atmosphere is precisely earth's surface. However, the term “earth’s surface” in this case (i.e., when considering processes occurring in the atmosphere) is sometimes more convenient to replace with the term underlying surface. With the term earth's surface, we most often associate the idea of ​​the shape of the surface, taking into account land and sea, while the term underlying surface denotes the earth's surface with all its inherent properties that are important for the atmosphere (shape, nature of rocks, color, temperature, humidity, vegetation cover and etc.).

The circumstances we have noted force us, first of all, to focus our attention on the temperature conditions of the earth's surface, or, more precisely, the underlying surface.

Heat balance on the underlying surface. The temperature of the underlying surface is determined by the ratio of heat inflow and outflow. The incoming and outgoing balance of heat on the earth's surface during the daytime consists of the following quantities: incoming - heat coming from direct and diffuse solar radiation; consumption - a) reflection of part of the solar radiation from the earth's surface, b) evaporation, c) earth radiation, d) heat transfer to adjacent layers of air, e) heat transfer deep into the soil.

At night, the components of the incoming and outgoing heat balance on the underlying surface change. There is no solar radiation at night; heat can come from the air (if its temperature is higher than the temperature of the earth's surface) and from the lower layers of the soil. Instead of evaporation, there may be condensation of water vapor on the soil surface; The heat generated during this process is absorbed by the earth's surface.

If the heat balance is positive (heat inflow is greater than heat outflow), then the temperature of the underlying surface increases; if the balance is negative (income is less than consumption), then the temperature decreases.

The heating conditions of the land surface and the water surface are very different. Let us first dwell on the conditions for heating sushi.

Heating the sushi. The land surface is not uniform. In some places there are vast expanses of steppes, meadows and arable lands, in others there are forests and swamps, and in others there are deserts almost devoid of vegetation. It is clear that the conditions for heating the earth's surface in each of the cases we have presented are far from the same. Most easily they will be where the earth's surface is not covered with vegetation. We will focus on these simplest cases first.

To measure the temperature of the surface layer of soil, a conventional mercury thermometer is used. The thermometer is placed in an unshaded place, but so that the lower half of the reservoir with mercury is in the thickness of the soil. If the soil is covered with grass, then the grass must be cut (otherwise the area of ​​soil being examined will be shaded). However, it must be said that this method cannot be considered completely accurate. To obtain more accurate data, electric thermometers are used.

Measuring soil temperature at a depth of 20-40 cm produce soil mercury thermometers. To measure deeper layers (from 0.1 to 3, and sometimes more meters), so-called exhaust thermometers. These are essentially the same mercury thermometers, but only placed in an ebonite tube, which is buried in the ground to the required depth (Fig. 34).

During the daytime, especially in summer, the soil surface becomes very hot and cools down very much during the night. Typically, the maximum temperature occurs around 13:00, and the minimum occurs before sunrise. The difference between the highest and lowest temperatures is called amplitude daily fluctuations. IN summer time the amplitude is significantly greater than in winter. So, for example, for Tbilisi in July it reaches 30°, and in January 10°. In the annual variation of soil surface temperature, the maximum is usually observed in July and the minimum in January. From the top heated layer of soil, the heat is partly transferred to the air, and partly to layers located deeper. At night the process is reversed. The depth to which daily temperature fluctuations penetrate depends on the thermal conductivity of the soil. But in general it is small and ranges from approximately 70 to 100 cm. In this case, the daily amplitude decreases very quickly with depth. So, if on the soil surface the daily amplitude is 16°, then at a depth of 12 cm it is already only 8°, at a depth of 24 cm - 4°, and at a depth of 48 cm-1°. From the above it is clear that the heat absorbed by the soil accumulates mainly in its upper layer, the thickness of which is measured in centimeters. But this top layer of soil is precisely the main source of heat on which temperature depends

layer of air adjacent to the soil.

Annual fluctuations penetrate much deeper. IN temperate latitudes, where the annual amplitude is especially large, temperature fluctuations die out at a depth of 20-30 m.

The transfer of temperatures into the Earth occurs rather slowly. On average, for every meter of depth, temperature fluctuations lag by 20-30 days. Thus, the highest temperatures observed on the Earth's surface in July are at a depth of 5 m will be in December or January, and the lowest in July.

Influence of vegetation and snow cover. Vegetation cover shades the earth's surface and thereby reduces the flow of heat to the soil. At night, on the contrary, the vegetation cover protects the soil from radiation emission. In addition, the vegetation cover evaporates water, which also consumes part of the radiant energy of the Sun. As a result, soils covered with vegetation heat up less during the day. This is especially noticeable in the forest, where in summer the soil is much colder than in the field.

An even greater influence is exerted by snow cover, which, due to its low thermal conductivity, protects the soil from excessive winter cooling. From observations made in Lesnoy (near Leningrad), it turned out that soil devoid of snow cover is on average 7° colder in February than soil covered with snow (data derived from 15 years of observations). In some years in winter the temperature difference reached 20-30°. From the same observations, it turned out that soils devoid of snow cover froze to 1.35 m depth, while under snow cover freezing is no deeper than 40 cm.

Soil freezing and permafrost . The question of the depth of soil freezing is of great importance practical significance. Suffice it to recall the construction of water pipelines, reservoirs and other similar structures. In the central zone of the European part of the USSR, the freezing depth ranges from 1 to 1.5 m, in the southern regions - from 40 to 50 cm. IN Eastern Siberia, where winters are colder and snow cover is very small, the freezing depth reaches several meters. Under these conditions for summer period the soil has time to thaw only from the surface, and deeper remains a permanently frozen horizon, known as permafrost. The area where permafrost occurs is huge. In the USSR (mainly in Siberia) it occupies over 9 million. km 2. Warming of the water surface. The heat capacity of water is twice the heat capacity of the rocks that make up the land. This means that under the same conditions, over a certain period of time, the surface of the land will have time to heat up twice as much as the surface of the water. In addition, water evaporates when heated, which also costs a lot of money.

amount of thermal energy. And finally, it is necessary to note one more very important reason, which slows down heating: this is stirring upper layers water due to waves and convection currents (up to a depth of 100 and even 200 m).

From all that has been said, it is clear that the surface of the water heats up much more slowly than the surface of the land. As a result, the daily and annual amplitudes of sea surface temperatures are many times smaller than the daily and annual amplitudes of the land surface.

However, due to its greater heat capacity and deeper heating, the water surface accumulates much more heat than the land surface. As a result, the average surface temperature of the oceans, according to calculations, exceeds the average air temperature by only globe by 3°. From all that has been said, it is clear that the conditions for heating the air above the sea surface are significantly different from the conditions on land. Briefly these differences can be described as follows:

1) in areas with a large daily amplitude ( tropical zone) at night the sea temperature is higher than the land temperature, during the day the opposite is true;

2) in areas with a large annual amplitude (temperate and polar zones), the sea surface is warmer in autumn and winter, and colder in summer and spring, than the land surface;

3) the sea surface receives less heat than the land surface, but retains it longer and spends it more evenly. As a result, the sea surface is on average warmer than the land surface.

Methods and instruments for measuring air temperature. Temperatureair is usually measured using mercury thermometers. In cold countries, where the air temperature drops below the freezing point of mercury (mercury freezes at - 39°), alcohol thermometers are used.

When measuring air temperature, thermometers must be placed V protection to protect them from direct solar radiation and from terrestrial radiation. In the USSR, for these purposes we use a psychrometric (louvered) wooden booth (Fig. 35), which is installed at a height of 2 m from the soil surface. All four walls of this booth are made of a double row of inclined slats in the form of blinds, the roof is double, the bottom consists of three boards located on different heights. This arrangement of the psychrometric booth protects thermometers from direct solar radiation and at the same time allows air to freely penetrate into it. To reduce the heating of the booth, it is painted in white. The doors of the booth open to the north so that the sun's rays do not fall on the thermometers when readings.

In meteorology, thermometers of various designs and purposes are known. Of these, the most common are: psychrometric thermometer, sling thermometer, maximum and minimum thermometers.

is the main one currently accepted for determining air temperature during urgent observation hours. This is a mercury thermometer (Fig. 36) with an insert scale, the division value of which is 0°.2. When determining air temperature with a psychrometric thermometer, it is installed in a vertical position. In areas with low air temperatures, in addition to a mercury psychrometric thermometer, a similar alcohol thermometer is used at temperatures below 20°.

In expeditionary conditions, they are used to determine air temperature. sling thermometer(Fig. 37). This instrument is a small mercury thermometer with a stick type scale; divisions on the scale are marked at 0°.5. OK, a cord is tied to the upper end of the thermometer, with the help of which, when measuring temperature, the thermometer is quickly rotated above the head so that its mercury reservoir comes into contact with large masses of air and is less heated by solar radiation. After rotating the sling thermometer for 1-2 minutes. The temperature is measured, and the device must be placed in the shade so that it is not exposed to direct solar radiation.

serves to determine the highest temperature observed during any elapsed period of time. Unlike conventional mercury thermometers, the maximum thermometer (Fig. 38) has a glass pin soldered into the bottom of the mercury reservoir, the upper end of which slightly enters the capillary vessel, greatly narrowing its opening. When the air temperature rises, the mercury in the tank expands and rushes into the capillary vessel. Its narrowed opening is not a big obstacle. The column of mercury in the capillary vessel will rise as the air temperature rises. When the temperature begins to decrease, the mercury in the reservoir will begin to shrink and will break away from the mercury column in the capillary vessel due to the presence of a glass pin. After each reading, shake the thermometer, as is done with a medical thermometer. When making observations, the maximum thermometer is placed horizontally, since the capillary of this thermometer is relatively wide and the mercury in it in an inclined position can move regardless of the temperature. The maximum thermometer scale division value is 0°.5.

To determine the lowest temperature over a certain period of time, it is used minimal thermometer(Fig. 39). The minimum thermometer is an alcohol thermometer. Its scale is divided into 0°.5. When taking measurements, the minimum thermometer, as well as the maximum, is installed in a horizontal position. In the capillary vessel of a minimum thermometer, a small pin made of dark glass and with thickened ends is placed inside the alcohol. As the temperature decreases, the column of alcohol shortens and the surface film of alcohol will move the pin

tick to the tank. If the temperature then begins to rise, the column of alcohol will lengthen, and the pin will remain in place, fixing the minimum temperature.

To continuously record changes in air temperature during the day, recorders - thermographs - are used.

Currently, two types of thermographs are used in meteorology: bimetallic and manometric. Most widespread thermometers with a bimetallic receiver are used.

(Fig. 40) has a bimetallic (double) plate as a temperature receiver. This plate consists of two thin dissimilar metal plates soldered together, each with a different temperature coefficient of expansion. One end of the bimetallic strip is fixedly fixed in the device, the other is free. When the air temperature changes, the metal plates will be deformed differently and, therefore, the free end of the bimetallic plate will bend in one direction or another. And these movements of the bimetallic plate are transmitted through a system of levers to the arrow to which the pen is attached. The pen, moving up and down, draws a curved line of temperature change on a paper tape wound on a drum rotating around an axis using a clock mechanism.

U manometric thermographs The temperature receiver is a curved brass tube filled with liquid or gas. Otherwise they are similar to bimetallic thermographs. When the temperature rises, the volume of liquid (gas) increases, and when it decreases, it decreases. A change in the volume of liquid (gas) deforms the walls of the tube, and this, in turn, is transmitted through a system of levers to the arrow with the feather.

Vertical distribution of temperatures in the atmosphere. Heating of the atmosphere, as we have already said, occurs in two main ways. The first is the direct absorption of solar and terrestrial radiation, the second is the transfer of heat from the heated earth's surface. The first path was sufficiently covered in the chapter on solar radiation. Let's take the second path.

Heat is transferred from the earth's surface to the upper layers of the atmosphere in three ways: molecular thermal conductivity, thermal convection and through turbulent air mixing. The molecular thermal conductivity of air is very small, so this method of heating the atmosphere does not play a big role. The greatest importance in this regard is thermal convection and turbulence in the atmosphere.

The lower layers of air, heating up, expand, reduce their density and rise upward. The resulting vertical (convection) currents transfer heat to the upper layers of the atmosphere. However, this transfer (convection) is not easy. Rising warm air, entering conditions of lower atmospheric pressure, expands. The expansion process requires energy, causing the air to cool. It is known from physics that the temperature of the rising air mass when rising for every 100 m decreases by approximately 1°.

However, the conclusion we have given applies only to dry or moist but unsaturated air. When saturated air cools, it condenses water vapor; in this case, heat is released (latent heat of vaporization), and this heat increases the air temperature. As a result, when air saturated with moisture rises for every 100 m the temperature drops not by 1°, but by approximately 0°.6.

When air descends, the reverse process occurs. Here for every 100 m lowering, the air temperature rises by 1°. The degree of air humidity in this case does not play a role, because as the temperature rises, the air moves away from saturation.

If we take into account that air humidity is subject to strong fluctuations, then the complexity of the conditions for heating the lower layers of the atmosphere becomes obvious. In general, as already mentioned in its place, in the troposphere there is a gradual decrease in air temperature with height. And at the upper boundary of the troposphere, the air temperature is 60-65° lower than the air temperature at the Earth's surface.

The daily variation of air temperature amplitude decreases quite quickly with height. Daily amplitude at an altitude of 2000 m expressed only in tenths of a degree. As for annual fluctuations, they are much greater. Observations have shown that they decrease to a height of 3 km. Above 3 km an increase is observed, which increases to 7-8 km height, and then decreases again to approximately 15 km.

Temperature inversion. There are cases when the lower ground layers of air may turn out to be colder than those lying above. This phenomenon is called temperature inversion; A sharp temperature inversion is expressed where there is no wind during cold periods. In countries with long cold winter Temperature inversions are a common occurrence in winter. It is especially pronounced in Eastern Siberia, where, thanks to the dominant high blood pressure and when there is no wind, the temperature of the supercooled air at the bottom of the valleys is extremely low. As an example, we can point to the Verkhoyansk or Oymyakon depressions, where the air temperature drops to -60 and even -70°, while on the slopes of the surrounding mountains it is much higher.

The origin of temperature inversions varies. They can be formed as a result of the flow of cooled air from mountain slopes into closed basins, due to strong radiation of the earth's surface (radiative inversion), during the advection of warm air, usually in early spring, over the snow cover (snow inversion), when cold air masses attack warm ones ( frontal inversion), due to turbulent mixing of air (turbulence inversion), with the adiabatic lowering of air masses that have a stable stratification (compression inversion).

Frost. During the transitional seasons of the year in spring and autumn, when the air temperature is above 0°, frosts are often observed on the soil surface in the morning hours. Based on their origin, frosts are divided into two types: radiation and advection.

Radiation freezes are formed as a result of cooling of the underlying surface at night due to terrestrial radiation or due to the flow of cold air with a temperature below 0° from the slopes of elevations into depressions. The occurrence of radiation frosts is facilitated by the absence of clouds at night, low air humidity and windless weather.

Advective frost arise as a result of the invasion of a particular territory by cold air masses (Arctic or continental polar masses). In these cases, frosts are more stable character and cover large areas.

Frosts, especially in late spring, often cause great harm agriculture, since often low temperatures observed during frosts, destroy agricultural plants. Since the main cause of frosts is the cooling of the underlying surface by the earth's radiation, the fight against them goes along the line of artificially reducing the radiation of the earth's surface. The amount of such radiation can be reduced by creating smoke (by burning straw, manure, pine needles and other combustible material), artificially humidifying the air and creating fog. To protect valuable crops from frost, direct heating of plants is sometimes used in various ways or build canopies from canvas, straw and reed mats and other materials; Such canopies reduce the cooling of the earth's surface and prevent the occurrence of frost.

Daily cycle air temperature. At night, the Earth's surface radiates heat all the time and gradually cools. Along with the earth's surface, the lower layer of air also cools. In winter, the moment of greatest cooling usually occurs shortly before sunrise. When the sun rises, the rays fall on the earth's surface at very sharp corners and they hardly heat it up, especially since the Earth continues to radiate heat into space. As the Sun rises higher and higher, the angle of incidence of the rays increases, and the arrival of solar heat becomes greater than the expenditure of heat emitted by the Earth. From this moment on, the temperature of the Earth's surface, and then the air temperature, begins to rise. And the higher the Sun rises, the steeper the rays fall and the higher the temperature of the earth's surface and air rises.

After noon, the heat influx from the Sun begins to decrease, but the air temperature continues to rise, because the loss of solar radiation is compensated by the emission of heat from the earth's surface. However, this cannot continue for long, and a moment comes when terrestrial radiation can no longer cover the decline solar radiation. This moment in our latitudes occurs around two in the winter, and around three in the summer in the afternoon. After this point, a gradual drop in temperature begins, until sunrise the next morning. This daily temperature variation is very clearly visible in the diagram (Fig. 41).

In different zones of the globe, the daily variation of air temperatures is very different. At sea, as already mentioned, the daily amplitude is very small. In desert countries, where the soils are not covered with vegetation, during the day the Earth's surface heats up to 60-80°, and at night it cools down to 0°; daily amplitudes reach 60 degrees or more.

Annual variation of air temperatures. The earth's surface in the northern hemisphere receives the greatest amount of solar heat at the end of June. In July, solar radiation decreases, but this decrease is made up by still quite strong solar radiation and radiation from the highly heated earth's surface. As a result, the air temperature in July is higher than in June. On seashore and on the islands the highest air temperatures are observed not in July, but in August. This is explained

the fact that the water surface takes longer to heat up and consumes its heat more slowly. Approximately the same thing happens in winter months. The earth's surface receives the least amount of solar heat at the end of December, and the lowest air temperatures are observed in January, when the increasing influx of solar heat cannot yet cover the heat consumption resulting from the earth's radiation. Thus, the most warm month for sushi July is the coldest month.

The annual variation of air temperature for different parts of the globe is very different (Fig. 42). First of all, it is, of course, determined by the latitude of the place. Depending on latitude, there are four main types of annual temperature variations.

1. Equatorial type. It has a very small amplitude. For the interior of the continents it is about 7°, for the coasts about 3°, on the oceans 1°. The warmest periods coincide with the zenithal position of the Sun at the equator (during the spring and autumn equinoxes), and the coldest seasons coincide with the periods of summer and winter solstice. Thus, during the year there are two warm and two cold periods, the difference between which is very small.

2. Tropical type. The highest position of the Sun is observed during the period summer solstice, lowest during the winter solstice. As a result, during the year - one period maximum temperatures and one period of minimum. The amplitude is also small: on the coast - about 5-6°, and inland - about 20°.

3. Temperate zone type. Here the highest temperatures are in July and the lowest in January (in the southern hemisphere the opposite). In addition to these two extreme periods of summer and winter, two more stand out transitional periods: spring and autumn. The annual amplitudes are very large: in coastal countries 8°, within continents up to 40°.

4. Polar type. It is characterized by very long winters and short summer. Within the continents winter time Great cold is setting in. The amplitude near the coast is about 20-25°, while inside the continent it is more than 60°. As an example of exceptionally large winter colds and annual amplitudes, one can cite Verkhoyansk, where the absolute minimum air temperature is recorded at -69°.8 and where the average temperature in January is -51°, and in July -+-.15°; the absolute maximum reaches +33°.7.

Looking closely at the temperature conditions of each of the types of annual temperature variations given here, we must first of all note the striking difference between the temperatures sea ​​coasts and the interiors of continents. This difference has long made it possible to distinguish two types of climates: nautical And continental. Within the same latitude, land is warmer in summer and colder in winter than the sea. For example, off the coast of Brittany the January temperature is 8°, in southern Germany at the same latitude it is 0°, and in the Lower Volga region it is -8°. The differences are even greater when we compare the temperatures of oceanic stations with those of continental stations. So, on the Faroe Islands (Grohavy station) the most cold month(March) has an average temperature of +3°, and the warmest (July) is +11°. In Yakutsk, located at the same latitudes, the average January temperature is 43°, and the average July temperature is +19°.

Isotherms. Various heating conditions due to the latitude of the place and the influence of the sea create a very complex picture of the distribution of temperatures over the earth's surface. To imagine this arrangement on geographical map, places with the same temperatures are connected by lines known as isotherm Due to the fact that the altitude of stations above sea level is different, and the altitude has a significant influence on temperatures, it is customary to reduce the temperature values ​​​​obtained at weather stations to sea level. Isotherms of average monthly and average annual temperatures are usually plotted on maps.

January and July isotherms. The brightest and most characteristic picture of temperature distribution is provided by maps of January and July isotherms (Fig. 43, 44).

Let's first look at the January isotherm map. What is most noticeable here is the warming influence Atlantic Ocean, and in particular the warm Gulf Stream on Europe, as well as the cooling influence of wide land areas in temperate and polar countries northern hemisphere. This influence is especially great in Asia, where closed isotherms of - 40, - 44 and - 48 ° surround the cold pole. The relatively small deviation of isotherms from the direction of parallels in the moderately cold zone is striking southern hemisphere, which is a consequence of the predominance of vast areas of water there. The map of July isotherms clearly reveals more high temperature continents compared to oceans at the same latitudes.

Annual isotherms and thermal belts Earth. To get an idea of ​​the distribution of heat over the earth's surface on average over a whole year, use maps of annual isotherms (Fig. 45). From these maps it is clear that the most warm places do not coincide with the equator.

The mathematical boundary between the hot and temperate zones is the tropics. The actual boundary, which is usually drawn along the annual isotherm of 20°, noticeably does not coincide with the tropics. On land, it most often moves towards the poles, and in the oceans, especially under the influence of cold currents, towards the equator.

It is much more difficult to draw the line between cold and temperate zones. For this, not the annual, but the July isotherm of 10° is best suited. Forest vegetation does not extend north of this border. On land, tundra dominates everywhere. This border does not coincide with the Arctic Circle. Apparently, the coldest points on the globe also do not coincide with the mathematical poles. The same maps of annual isotherms allow us to notice that the northern hemisphere at all latitudes is somewhat warmer than the southern one and that the western shores of the continents in the middle and high latitudes are much warmer than the eastern ones.

Izanomaly. Tracing the course of January and July isotherms on the map, you can easily notice that temperature conditions at the same latitudes of the globe are different. Moreover, some points have a lower temperature than the average temperature for a given parallel, while others, on the contrary, have a higher temperature. Deviation of air temperature at any point from average temperature the parallel on which this point is located is called temperature anomaly.

Anomalies can be positive or negative, depending on whether the temperature of a given point is greater or less than the average temperature of the parallel. If the temperature of a point is higher than the average temperature for a given parallel, then the anomaly is considered positive,

with the opposite temperature ratio, the anomaly is negative.

Lines on a map connecting places on the earth's surface with the same values temperature anomalies, are called temperature anomalies(Fig. 46 and 47). From the map of January anomalies it is clear that in this month the continents of Asia and North America have air temperatures below the average January temperature for these latitudes. Atlantic and

The Pacific Oceans, as well as Europe, on the contrary, have a positive temperature anomaly. This distribution of temperature anomalies is explained by the fact that in winter land cools faster than water areas.

In July, a positive anomaly is observed on the continents. There is a negative temperature anomaly over the oceans of the northern hemisphere at this time.

- Source-

Polovinkin, A.A. Fundamentals of general geoscience/ A.A. Polovinkin. - M.: State educational and pedagogical publishing house of the Ministry of Education of the RSFSR, 1958. - 482 p.

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