Sections: Geography

Duration: 45 minutes (1 lesson).

Class: Lesson type 6: updating knowledge and skills; research lesson (according to the basic plan: geography 1 hour per week). Textbook "Geography" authors T.P. Gerasimova, N.P. Neklyukov. Moscow, 2015, Bustard.

Goals: students should know:

1. Elements of the mandatory minimum: to form students' ideas about the daily and annual course of air temperatures, about the daily and annual amplitude of air temperature.

2. Creation of conditions for the development of skills in working with digital data in different form(table, graphic), the ability to compile and analyze graphs of daily and annual temperatures using a cool weather calendar.

Lesson objectives:

Tutorial:

1) Introduce students to the features of heating earth's surface and atmosphere. Belts of illumination and what is shown on climate maps lines are isotherms.

2) Find out how and by what amount the air temperature changes with height and how sunlight and heat depending on geographical latitude.

3) Identify factors that affect differences in air heating during the day and year. To teach, using the indicator of average temperatures, to calculate the average daily and average annual amplitudes of temperature fluctuations.

Developing:

1) To form the ability to analyze data graphs in the textbook and independently draw up temperature graphs.

2) Develop mathematical ability when determining average temperatures, daily and annual amplitudes; logical thinking and memory when learning new concepts, terms and definitions.

Educational:

1) Develop an interest in climate science native land, as one of the components natural complex. Professional orientation work "science meteorology" - profession "meteorologist".

Equipment: thermometer - demonstration, tables, graphs, drawings and text of the textbook, multimedia manual on geography grade 6.

During the classes

1. Organizational moment

2. Motivation for learning activities. Announcement of the topic of the lesson and setting tasks

Teacher. How did you dress this morning, going to leave the house for school?

Rail: Warm to keep you warm.

Teacher. Why could Rail freeze?

Gulnara. Because it's very cold outside.

Teacher. And now let's remember the summer. Where do you most often like to go on a clear sunny day?

Daniel. To our lake, to swim.

Teacher. What is the reason for this desire?

Ilnaz. Because it is hot in summer, and when you swim, it becomes so good and it is cool by the lake.

At the heart of knowledge about air temperature, we see your personal thermal sensations and representations of temperature changes over the seasons. From the lessons of natural history, we know about the heating of the air of the atmosphere from the earth's surface and the device for measuring temperature - a thermometer.

Teacher. I show a demo thermometer. Question for the class: How to measure air temperature with a thermometer? (We recall its device and principle of operation) What can be learned using a thermometer?

Students. You can find out the air temperature in the classroom, on the street, at home. Anywhere, any place and any time. High in the mountains and in the mountain valley. Any time of the year, be it spring, summer, autumn or winter. (I show different temperatures on a thermometer model - 10 * C; 25 * C -4 * C; -15 * C students answer).

3. Motivation for learning activities

Teacher. Who will now say what we will talk about today and what topic to study?

Students. temperature; air temperature.

Working with notebooks. We write down the topic of the lesson: “Heating air and its temperature. Dependence of air temperature on geographic latitude”.

Teacher. Ilnaz, come to the window and see how many degrees our thermometer outside the window shows today.

Ilnaz.-21*С degree and in the class +20*С. Gulnara checks and confirms the correctness of the answer.
Today in the lesson we have to learn what determines the temperature of the air. We work according to the plan:

The lesson plan is displayed on the screen:

Block 1. Heating of the earth's surface and air temperature in the troposphere.
Block 2. The heating of the earth's surface and daily course temperatures a) in July and b) in December in temperate latitudes.
Block 3. Illumination belts and annual course of air temperature in Moscow, Kazan and at different latitudes; determination of average daily and average annual air temperatures.
Block 4. Generalization of knowledge and consolidation.

4. Learning new material

Block 1. Teacher. What is the source of light and heat on Earth? (SUN).

We are all familiar with temperature readings. early childhood. It depends on them what you wear, whether your parents will allow you to swim in the lake.

One of the properties of air is transparency. Prove that air is transparent. (We see through it). Air, like glass, is transparent, it passes the sun's rays through itself and does not heat up. The sun's rays first heat the surface of land or water, and then the heat from them is transferred to the air, and the higher the Sun is above the horizon, the more it heats up and heats the air. So how is air heated?

(The air is heated from the surface of land or water). / Working with figure 83. The consumption of solar energy entering the Earth. Page 91 of the textbook/.

Teacher. Where does it happen warmer in summer in the meadow or in the forest? By the lake or in the desert? In a city or a village? High in the mountains or on the plains? (In a clearing, in a desert, in a city, on a plain).

Conclusion/ Working with the text of the textbook p. 90 / The earth's surface of different composition heats up and cools down in different ways, so the air temperature depends on the nature of the underlying surface (table). When climbing up for each kilometer, the air temperature drops by 6 * C - degrees.

Block 2a./ In my work I use geographical problems from the textbook "Physical Geography" by O.V. Krylova Moscow, Enlightenment, 2001.

1. Geographic tasks:

1) On the day of the summer solstice on June 22 in the northern hemisphere, the Sun at noon is at its highest position above the horizon. Using Figure 81, describe the apparent path of the Sun and explain why June 22 is the longest day in the northern hemisphere. / Slide fig. 80-81/.

2. Analyze the graph of the daily course of air temperature in Moscow.

In July, in conditions of stable clear weather / slide fig. 82 / and Ozerny.

Teacher. I explain how to work with the schedule. On the horizontal line, we determine the hours of observation of the air temperature during the day, and on the vertical line, the positive temperature of the summer month is noted.

1) What air temperature is observed at 8 o'clock in the morning and how does it change by noon? (8 hours -19 * C to 12 hours -22 * C)

2) Tell us how the height of the Sun above the horizon changes from 8 am to 12 pm? (The height of the Sun above the horizon increases; the angle of incidence of the sun's rays increases; the Sun warms the Earth better and the air temperature rises; the Sun is higher above the horizon at noon, illuminating the smaller land surface; at this time, the most solar energy enters the Earth.)

3) At what time of the day is the temperature the highest? How high is the Sun at this time? (The highest temperature is observed at about 14:00 23*C. It takes about 2-3 hours to transfer heat from the Earth to the troposphere. The angle of incidence of the sun's rays above the horizon by this time decreases compared to 12:00.)

4) How does the air temperature and the height of the Sun above the horizon change from 15:00 to 21:00? (The angle of incidence of the sun's rays decreases, the area of illumination increases, the temperature drops from 22 * C to 16 * C.)

5) The lowest air temperature during the day is observed before sunrise. Explain why? (At night, in the Eastern Hemisphere, the Sun is absent. During the night, the surface of the Earth cools down and in the morning, before sunrise, you can observe the lowest temperature).

Teacher. Determining temperature changes, it is usually noted its highest and lowest values. Let's work with the graph in Fig. 82, determine the highest and lowest temperatures. (+12.9*C is the lowest and the highest is +22*C).

We work with the text of the textbook p.94 we read the definition - amplitude - A.

The difference between the highest and lowest readings is called the temperature range.

Algorithm for determining the daily amplitude of air temperature

1) Find the highest air temperature among the temperature indicators;

2) Find the lowest temperature among the temperature indicators;

3) Subtract the lowest air temperature from the highest air temperature. (Recording the solution by students in a notebook; + 4 * C - (-1 * C) \u003d 5 * C;

What is the daily range of air temperature? (Work with a blackboard. Solution: 22 * C - 12.9 \u003d 9.1 * C. A \u003d 9.1 * C

2. Geographic tasks

Block 2 b). In a day winter solstice On December 22, in the northern hemisphere, the Sun at noon is at its lowest position above the horizon:

1. a) According to (Fig. 83), describe the apparent path of the Sun and explain why December 22 in the northern hemisphere has the shortest daylight hours. (Our earth, with its axis, is constantly inclined to the plane of the orbit and forms an angle of various sizes with it. And when the sun's rays falling on the Earth are strongly inclined, the surface heats up slightly. The air temperature at this time drops, and winter sets in. The visible path that the Sun travels above ground in December is much shorter than in July.December 22 is the winter solstice and the shortest day in the latitudes of the northern hemisphere.)

1. b) What is the length of daylight on December 22 in the southern hemisphere? (In the southern hemisphere at this time the longest day; in the southern hemisphere summer).

2) Draw the apparent path of the Sun over the horizon at the spring and autumn equinoxes. What is the length of daylight hours these days and how can this be explained? (The sun, twice a year, passes through the equator - from the northern hemisphere to the southern. This phenomenon is observed in spring on March 21 and in autumn on September 23, when day is equal to night. These days are called equinox days. The apparent path of the Sun during the day is 12 hours. Night is - 12 noon

3) Analyze the graph (Fig. 84) of the daily course of air temperature in Moscow in January (all temperature indicators are negative; the lowest in the morning before sunrise - 6 hours 30 minutes -11 * C; the highest at 14 hours -9 * C ; in Kazan and Bugulma.

1.a) Determine what are the similarities and differences between the summer and winter course of air temperature. Compare the daily amplitude of air temperature in winter and summer (Fig. 82, 84). Explain the differences: (in summer the Sun is higher above the horizon, the earth warms up better and the air temperature is much higher than in winter, there are no negative temperatures; the amplitude of daily air temperatures in summer is much higher than in winter; on the contrary, the height of the Sun above the horizon in winter is much less, earth / snow - reflects / does not warm up at all, the air is cold, especially early in the morning before sunrise We decide at the blackboard and write in notebooks: Winter -11 * C and summer - + 22 * C; + 22 * C - (-11 * C) \u003d 33*C)

2.b) Once again, we will repeat and consolidate the knowledge gained during our conversation and draw a conclusion about the relationship between the daily variation in air temperature and the change in the height of the Sun above the horizon.

Block 3

1. We work with the drawing in the textbook on p.96 fig.88. Question: Name the five zones of illumination. At what latitudes are their borders? (1 hot, 2 - temperate belts, 2 - cold. The first zone is hot - from the equator to the north and to the south - up to 23.5 * north latitude. and 23.5*S. Two temperate - northern and southern temperate from the southern tropic to the south and from the northern tropic to the north. Two cold ones - north polar and south arctic circle. Work with the textbook - read aloud characteristics each of them, accompanying the reading with questions and working with a wall map at the blackboard - "average annual air temperatures of the Earth." We get acquainted with the concept of isotherm by reading the definition from the textbook. Answer the question: how are isotherms distributed and how do average temperatures change across latitudes - from the equator to the north and south?

Algorithm for determining the average daily and average annual temperature air:

1. Add up all negative indicators of daily / annual / air temperature;
2. Add up all positive indicators of daily / annual / air temperature;
3. Add up the sum of the positive and negative air temperature readings;
4. Divide the value of the amount received by the number of air temperature measurements per day.

3. Geographic tasks

1. Analyze the graph of the annual course of air temperature in Moscow and confirm its relationship with the height of the Sun above the horizon.

Determine the annual amplitude of air temperature: (In the rhythm of the Sun - when the Earth moves in orbit, the height of the Sun above the horizon and the angle of incidence of the sun's rays change. As a result, the air temperature changes from a higher to a lower indicator and vice versa. Therefore, there is a change of seasons - winter - spring - summer autumn.)

2. Working with the graph Fig. 85 p. 114: The annual course of air temperature in Moscow, we determine the highest temperature in the year - (July - + 17.5 * C and the lowest - January - 10 * C). A student at the blackboard solves the problem of determining the annual temperature amplitude in the capital of the Russian Federation and the Republic of Tatarstan. Pupils work with notebooks.)

3. Determine:
(The average daily temperature according to four measurements per day: -8 * C, -4 * C, + 3 * C, + 1 * C; (work in notebooks and at the blackboard: -8 * + (-4 *) \u003d - 12*; +3*+ (+1*) = 4*C; -12*+4* = -8*; -8*: 4 = -2*.)

Homework: paragraph No. 24-25, work with questions and pictures in the textbook. Handed out tasks different levels on cards, taking into account the students' knowledge of determining average temperatures and building one graph.

Block 4. Generalization and consolidation of knowledge gained in the lesson

1. Let's go back to the beginning of the lesson - to the work plan for this lesson. What goals and objectives were before us?

What new did you learn at the lesson today? What have you learned?

Will this knowledge be useful to you in life?

Why do people need knowledge about air temperature?

2. Look at the screen (I demonstrate a problematic one - a logical abstract) and draw a conclusion, what does the air temperature depend on?

1. The height of the Sun above the horizon.

2. The angle of incidence of the sun's rays.

3. Latitude of the area.

4. The nature of the underlying surface.

5. Another reason that can change the air temperature is air masses but we'll talk about that in the next lesson.

5. Reflection

Teacher.

What did the lesson give you?
What new did you learn?
How far you have progressed in learning the material.
Have you received new knowledge and will you need it in your life?
What difficulties did you encounter when learning a new topic?

When leaving the class, put your emoticons on the table with a review of the last lesson. According to them, I will find out how you learned the material, whether there are any unclear questions. What are your impressions of the lesson?

Green - everything is clear, I am satisfied with the lesson. Blue smiley - a lot happened, not everything was clear.
Red - the material is very difficult to digest, the mood is not very good, but I will try to prepare for the next lesson.

A). Commenting on the activity in the lesson, I give grades. I note only positive sides in the work of students in the classroom.

b). Thank you for the lesson. The topic "Atmosphere" is very difficult to understand, but also the most interesting. We all feel that we are very much dependent on the state of this (sphere) of the Earth, and sometimes it is very harsh on us. Therefore, in order not to be helpless before the elements of nature, one must know everything about it. Atmosphere - scientists - meteorologists - are engaged in - maybe one of you in the future will take up this science.

List of additional literature

1. Krylova O.V. Implementation of the requirements of the Federal Educational Standards for Basic General Education in the Teaching of Geography (1-8 lectures). Moscow. Pedagogical University September 1st 2013

2. V.P. Dronov, L.E. Savelyeva, Geography. Earth science grade 6. Moscow. Bustard. 2009

3. O.V. Krylova. Physical geography. Grade 6. Moscow. Education. 2001

4. T.P. Gerasimova, O.V. Krylov. Toolkit in physical geography grade 6. Moscow. Education. 1991

5. N.A. Nikitin. Lesson developments in geography Grade 6 (to the training kits of O.V. Krylova, T.P. Gerasimova, N.P. Neklyukova. M: Bustard).

6. Sample Programs By academic subjects, geography grades 5-9. Moscow. Education.

Daily variation of air temperature

Soil surface temperature affects air temperature. Heat exchange occurs when a thin film of air comes into direct contact with the earth's surface due to molecular heat conduction. Further, the exchange occurs inside the atmosphere due to turbulent heat conduction, which is a more efficient mechanism for heat transfer, since air mixing during turbulence contributes to a very rapid heat transfer from one atmospheric layer to another.

Fig No. 2 Graph of the daily course of air temperature.

As can be seen in Fig. 2, during the day, the air heats up and cools from the earth's surface, approximately repeating changes in air temperature (see Fig. 1) with a smaller amplitude. It can even be seen that the amplitude of the daily variation of air temperature is less than the amplitude of the change in soil temperature by about 1/3. The air temperature begins to rise at the same time as the temperature of the soil surface: after sunrise, and its maximum is already observed at later hours, and in our case at 15:00, and then begins to decrease.

As noted earlier, the maximum soil surface temperature is higher than the maximum air temperature (32.8°C). This is explained by the fact that solar radiation first of all heats the soil, from which the air is then heated. And nighttime lows on the soil surface are lower than in the air, as the soil radiates heat into the atmosphere.

Daily variation of water vapor pressure

Water vapor continuously enters the atmosphere through evaporation from water surfaces and moist soil, as well as as a result of transpiration by plants. At the same time, in different places and in different time it enters the atmosphere in various quantities. It spreads upward from the earth's surface, and is carried by air currents from one place on the Earth to another.

The pressure of water vapor is called water vapor pressure. Water vapor, like any gas, creates a certain pressure. The pressure of water vapor is proportional to its density (mass per unit volume) and its absolute temperature.

Rice. No. 3 Graph of the daily course of water vapor elasticity.

Observations were carried out in the depths of the mainland in warm time year, so the graph shows a double daily course (Fig. 3). The first minimum in such cases occurs after sunrise, as does the temperature minimum.

The soil begins to heat up after sunrise, its temperature rises, and, as a result, evaporation increases, which means that the vapor pressure increases. This trend continues until 09:00, when evaporation predominates over the transfer of vapor from below to higher layers. By this time, unstable stratification is already established in the surface layer, and convection is sufficiently developed. In the process of convection, the intensity of turbulent mixing increases, and the transfer of water vapor in the direction of its gradient, from bottom to top, is established. The outflow of water vapor from below does not have time to be compensated by evaporation, which leads to a decrease in the vapor content (and, consequently, pressure) near the earth's surface by 12-15 hours. And only then, the pressure begins to increase, as the convection weakens, and evaporation from the heated soil is still large, and the vapor content increases. After 18h evaporation decreases, so the pressure drops.

The daily course of air temperature is called the change in air temperature during the day - in general, it reflects the course of the temperature of the earth's surface, but the moments of the onset of maxima and minima are somewhat late, the maximum occurs at 14 o'clock, the minimum after sunrise.

Daily amplitude of air temperature(difference between maximum and minimum temperatures air during the day) is higher on land than over the ocean; decreases when moving to high latitudes (greatest in tropical deserts- up to 40 0 C) and increases in places with bare soil. The magnitude of the daily amplitude of air temperature is one of the indicators of the continentality of the climate. In deserts, it is much greater than in areas with a maritime climate.

Annual variation of air temperature(change in the average monthly temperature during the year) is determined primarily by the latitude of the place. Annual amplitude of air temperature- the difference between the maximum and minimum average monthly temperatures.

The geographical distribution of air temperature is shown using isotherms- lines connecting points on the map with the same temperature. The distribution of air temperature is zonal; annual isotherms generally have a sublatitudinal strike and correspond to the annual distribution of the radiation balance.

On average for the year, the warmest parallel is 10 0 N.L. with a temperature of 27 0 C is thermal equator. In summer, the thermal equator shifts to 20 0 N, in winter it approaches the equator by 5 0 N. The shift of the thermal equator in SP is explained by the fact that in SP the land area located in low latitudes ah, more compared to UP, and she has more than a year high temperatures.

Heat on the earth's surface is distributed zonal-regional. In addition to geographic latitude, the distribution of temperatures on Earth is influenced by: the nature of the distribution of land and sea, relief, altitude above sea level, sea and air currents.

The latitudinal distribution of annual isotherms is disturbed by warm and cold currents. In the temperate latitudes of the SP, the western shores washed by warm currents, warmer than the eastern shores, along which cold currents pass. Consequently, the isotherms at the western coasts are bent towards the pole, at the eastern coasts - towards the equator.

Medium annual temperature SP +15.2 0 С, and SP +13.2 0 С. The minimum temperature in SP reached –77 0 С (Oymyakon) (the absolute minimum of SP) and –68 0 С (Verkhoyansk). In SP, minimum temperatures are much lower; at the stations "Sovetskaya" and "Vostok" the temperature was -89.2 0 С (absolute minimum of SP). The minimum temperature in cloudless weather in Antarctica can drop to -93 0 C. The highest temperatures are observed in deserts tropical zone, in Tripoli +58 0 С, in California, in Death Valley, the temperature is +56.7 0 С.

Maps give an idea of how much continents and oceans affect the distribution of temperatures. isonomal(isonomals are lines connecting points with the same temperature anomalies). Anomalies are deviations of actual temperatures from mid-latitude ones. Anomalies are positive and negative. Positive anomalies are observed in summer over heated continents. Over Asia, temperatures are 4 0 C higher than the mid-latitude ones. In winter, positive anomalies are located above warm currents (above the warm North Atlantic Current off the coast of Scandinavia, the temperature is 28 0 C above the norm). Negative anomalies are pronounced in winter over chilled continents and in summer over cold currents. For example, in Oymyakon in winter the temperature is 22 0 C below the norm.

On Earth, there are the following thermal belts(isotherms are taken beyond the boundaries of thermal zones):

1. Hot, is limited in each hemisphere by an annual isotherm of +20 0 С, passing near 30 0 s. sh. and y.sh.

2. Two temperate belts, which in each hemisphere lie between the annual isotherm +20 0 С and +10 0 С warm month(accordingly July or January).

3. two cold belts, the boundary passes along the 0 0 isotherm from the warmest month. Sometimes there are regions eternal frost, which are located around the poles (Shubaev, 1977)

Thus:

1. The only source of heat that is of practical importance for the course of exogenous processes in GO is the Sun. Heat from the Sun enters the world space in the form of radiant energy, which then, absorbed by the Earth, turns into thermal energy.

2. The sunbeam on its way is subjected to numerous influences (scattering, absorption, reflection) from the various elements of the medium it penetrates and the surfaces on which it falls.

3. For distribution solar radiation affect: the distance between the earth and the sun; the angle of incidence of the sun's rays; the shape of the Earth (predetermines the decrease in the intensity of radiation from the equator to the poles). This is the main reason for the allocation of thermal zones and, consequently, the reason for the existence of climatic zones.

4. The influence of the latitude of the area on the distribution of heat is corrected by a number of factors: relief; distribution of land and sea; influence of cold and warm sea currents; atmospheric circulation.

5. The distribution of solar heat is further complicated by the fact that the regularities and features of the vertical distribution are superimposed on the regularities of the horizontal (along the earth's surface) distribution of radiation and heat.

General information about air temperature

Definition 1

The indicator of the thermal state of the air, recorded measuring instruments, is called temperature.

The sun's rays, falling on the spherical shape of the planet, heat it in different ways, because they come from different angles. The sun's rays do not heat the atmospheric air, while the earth's surface heats up very strongly and transmits thermal energy adjacent layers of air. Warm air becomes light and rises, where it mixes with cold air, giving off part of its thermal energy. Warm air cools with height and at a height of $10$ km its temperature becomes constant $-40$ degrees.

Definition 2

In the stratosphere, temperatures are shifting, and its indicators begin to rise. This phenomenon has been named temperature inversion.

Most of all, the surface of the earth heats up where the sun's rays fall at right angles - this is the area equator. Minimal amount receive heat polar And polar regions, because the angle of incidence of the sun's rays is sharp and the rays glide over the surface, and besides, they are also scattered by the atmosphere. As a result of this, we can say that the air temperature decreases from the equator to the poles of the planet.

An important role is played by the inclination of the earth's axis to the plane of the orbit and the time of year, which leads to uneven heating of the Northern and Southern hemispheres. Air temperature is not a constant indicator, at any point the globe it changes throughout the day. On thematic climate maps, air temperature is shown by a special symbol, which was named isotherm.

Definition 3

Isotherms- these are lines connecting points on the earth's surface with the same temperature.

On the basis of isotherms, thermal belts are distinguished on the planet, going from the equator to the poles:

Equatorial or hot belt;
Two temperate belts;
two cold zones.

Thus, the air temperature big influence provide:

Geographic latitude of the place;
Heat transfer from low latitudes to high latitudes;
Distribution of continents and oceans;
Location of mountain ranges;
Currents in the ocean.

Temperature change

The air temperature changes continuously throughout the day. The land heats up quickly during the day, and the air heats up from it, but with the onset of the night, the land also cools quickly, and after it the air cools. Therefore, it will be coolest in the predawn hours, and warmest in the afternoon.

The exchange of heat, mass and momentum between the individual layers of the atmosphere occurs constantly. The interaction of the atmosphere with the earth's surface is characterized by the same processes and is carried out in the following ways:

Radiation path (air absorption of solar radiation);
Thermal conduction path;
Heat transfer by evaporation, condensation or crystallization of water vapor.

The air temperature even at the same latitude cannot be constant. On Earth, only in one climatic zone there is no daily temperature fluctuation - it is hot or cold. equatorial belt. Here same value will be at both night and day air temperatures. On the coasts of large reservoirs and above their surface, the daily amplitude is also insignificant, but in the desert climate zone, the difference between day and night temperatures sometimes reaches $50-60$ degrees.

In temperate climatic zones The maximum solar radiation occurs on the days of the summer solstices - in the Northern Hemisphere it is July month, and in the southern hemisphere - January. The reason for this lies not only in intense solar radiation, but also in the fact that the strongly heated surface of the planet gives off great amount thermal energy.

Middle latitudes are characterized by higher annual amplitudes. Any area of the planet is characterized by its average and absolute temperatures air. The hottest place on earth is Libyan desert, where the absolute maximum is fixed - ($ +58 $ degrees), and the coldest place is Russian station"East" in Antarctica - ($ -89.2 $ degrees). All average temperatures - average daily, average monthly, average annual - are arithmetic mean values of several indicators of the thermometer. We already know that air temperature in the troposphere decreases with height, but in the surface layer its distribution can be different - it can increase, decrease or remain constant. The idea of how air temperature is distributed with height gives vertical gradient temperature (VGT). time of year, time of day, weather have an impact on the value of VGT. For example, the wind contributes to the mixing of air and at different heights its temperature levels off, which means that the WGT wind decreases. The VGT sharply decreases if the soil is wet, the fallow field has a VGT greater than that of a densely sown field, because these surfaces have different temperature regimes.

The sign of the VGT indicates how the temperature changes with height, if it is less than zero, then the temperature increases with height. And, conversely, if the sign is greater than zero, the temperature will decrease with distance from the surface and will remain unchanged at VGT = 0. Such a distribution of temperature with height is called inversions.

Inversions can be:

Radiation (radiation cooling of the surface);
Advective (formed when warm air moves onto a cold surface).

There are four types of annual temperature variation based on the average long-term amplitude and time of onset of extreme temperatures:
Equatorial type - there are two maxima and two minima;

Tropical type (maximum and minimum observed after the solstices);

Moderate type (maximum and minimum are observed after the solstices);

Polar type (minimum temperature during the polar night);

The height of a place above sea level also affects the annual course of air temperature. The annual amplitude decreases with height. Air temperature is measured by specialists at meteorological stations.

The daily course of air temperature is the change in air temperature during the day - in general, it reflects the course of the temperature of the earth's surface, but the moments of the onset of maxima and minima are somewhat late, the maximum occurs at 2 pm, the minimum after sunrise.

The daily amplitude of air temperature (the difference between the maximum and minimum air temperatures during the day) is higher on land than over the ocean; decreases when moving to high latitudes (the greatest in tropical deserts - up to 400 C) and increases in places with bare soil. The magnitude of the daily amplitude of air temperature is one of the indicators of the continentality of the climate. In deserts, it is much greater than in areas with a maritime climate.

The annual course of air temperature (change in the average monthly temperature during the year) is determined, first of all, by the latitude of the place. The annual amplitude of air temperature is the difference between the maximum and minimum average monthly temperatures.

Theoretically, one would expect that the diurnal amplitude, i.e., the difference between the highest and lowest temperature, will be greatest near the equator, because there the sun is much higher during the day than at higher latitudes, and at noon on the days of the equinox even reaches the zenith, i.e. sends vertical rays and, therefore, gives the largest number heat. But this is not actually observed, since, in addition to latitude, many other factors also influence the daily amplitude, the totality of which determines the magnitude of the latter. In this regard, it has great value position of the area relative to the sea: whether the given area represents land, remote from the sea, or an area close to the sea, such as an island. On the islands, due to the softening influence of the sea, the amplitude is insignificant, it is even less in the seas and oceans, but in the depths of the continents it is much greater, and the magnitude of the amplitude increases from the coast into the interior of the continent. At the same time, the amplitude also depends on the time of year: in summer it is larger, in winter it is smaller; the difference is explained by the fact that in summer the sun is higher than in winter, and the duration summer day much more wintery. Further, cloud cover influences the diurnal amplitude: it moderates the temperature difference between day and night, retaining the heat emitted by the earth at night, and at the same time moderating the action of the sun's rays.

The most significant daily amplitude is observed in deserts and high plateaus. Rocks deserts, completely devoid of vegetation, become very hot during the day and quickly radiate during the night all the heat received during the day. In the Sahara, the daily air amplitude was observed at 20-25° and more. There were cases when, after a high daytime temperature, the water even froze at night, and the temperature on the surface of the earth fell below 0 °, and in the northern parts of the Sahara even to -6, -8 °, rising much higher than 30 ° during the day.

The daily amplitude is much less in areas covered with rich vegetation. Here, part of the heat received during the day is spent on the evaporation of moisture by plants, and, in addition, the vegetation cover protects the earth from direct heating, while at the same time delaying radiation at night. On high plateaus, where the air is considerably rarefied, the balance of heat inflow and outflow at night is sharply negative, and during the day it is sharply positive, so the daily amplitude here is sometimes greater than in deserts. For example, Przhevalsky during his trip to Central Asia observed in Tibet a daily fluctuation in air temperature, even up to 30 °, and on the high plateaus of the southern part North America(in Colorado and Arizona) daily fluctuations, as shown by observations, reached 40 °. Insignificant fluctuations in daily temperature are observed: in polar countries; for example, on Novaya Zemlya the amplitude does not exceed 1–2 on average even in summer. At the poles and in general in high latitudes, where the sun does not appear at all during the day or months, at this time there are absolutely no daily temperature fluctuations. It can be said that the daily course of temperature merges with the annual one at the poles, and winter represents night, and summer represents day. Of exceptional interest in this respect are the observations of the Soviet drifting station "North Pole".

Thus, we observe the highest daily amplitude: not at the equator, where it is about 5 ° on land, but closer to the tropic of the northern hemisphere, since it is here that the continents have the greatest extent, and here the greatest deserts, and plateaus. The annual temperature amplitude depends mainly on the latitude of the place, but, in contrast to the daily temperature, the annual amplitude increases with distance from the equator to the pole. At the same time, the annual amplitude is influenced by all the factors that we have already dealt with when considering daily amplitudes. In the same way, fluctuations increase with distance from the sea deep into the mainland, and the most significant amplitudes are observed, for example, in the Sahara and in Eastern Siberia, where the amplitudes are even greater, because both factors play a role here: continental climate and high latitude, while in Sahara amplitude depends mainly on the continentality of the country. In addition, fluctuations also depend on the topographic nature of the area. To see how this last factor plays a significant role in changing the amplitude, it suffices to consider temperature fluctuations in the Jurassic and in the valleys. In summer, as you know, the temperature decreases quite quickly with height, therefore, on lonely peaks, surrounded on all sides by cold air, the temperature is much lower than in valleys, which are very hot in summer. In winter, on the contrary, cold and dense layers of air are located in the valleys, and the temperature of the air rises with height to a certain limit, so that individual small peaks are sometimes like heat islands in winter, while in summer they are colder points. Consequently, the annual amplitude, or the difference between winter and summer temperatures, is greater in the valleys than in the mountains. The outskirts of the plateaus are in the same conditions as individual mountains: surrounded by cold air, they at the same time receive less heat compared to flat, flat areas, so that their amplitude cannot be significant. The conditions for heating the central parts of the plateaus are already different. Strongly heated in summer due to rarefied air, they are compared with separately standing mountains they radiate much less heat, because they are surrounded by the heated parts of the plateau, and not by cold air. Therefore, in summer the temperature on the plateaus can be very high, while in winter the plateaus lose a lot of heat by radiation due to the rarefaction of the air above them, and it is natural that very strong temperature fluctuations are observed here.