The daily variation of temperature is monotonous. Daily and annual changes in temperature over continents and seas. Learning new material

The daily and annual variation of air temperature in the surface layer of the atmosphere is determined by the temperature at a height of 2 m. This variation is mainly determined by the corresponding variation in the temperature of the active surface. Features of the course of air temperature are determined by its extremes, that is, the highest and lowest temperatures. The difference between these temperatures is called the amplitude of the air temperature. The pattern of daily and annual variations in air temperature is revealed by averaging the results of long-term observations. It is associated with periodic oscillations. Non-periodic disturbances in the daily and annual cycle, caused by the invasion of warm or cold air masses, distort the normal course of air temperature. The heat absorbed by the active surface is transferred to the adjacent layer of air. In this case, there is some delay in the increase and decrease in air temperature compared to changes in soil temperature. Under normal temperature conditions, the minimum temperature is observed before sunrise, the maximum is observed at 14-15 hours (Fig. 4.4).

Figure 4.4. Daily variation of air temperature in Barnaul(available when downloading the full version of the textbook)

Amplitude of daily variations in air temperature above land is always less than the amplitude of the daily variation of soil surface temperature and depends on the same factors, that is, on the time of year, latitude, cloudiness, terrain, as well as on the nature of the active surface and altitude above sea level. Amplitude of the annual cycle is calculated as the difference between the average monthly temperatures of the warmest and coldest months. Absolute annual temperature amplitude call the difference between the absolute maximum and absolute minimum air temperature for the year, that is, between the highest and lowest temperatures observed during the year. The amplitude of the annual variation of air temperature in a given place depends on the geographic latitude, distance from the sea, altitude of the place, the annual variation of cloudiness and a number of other factors. Small annual temperature amplitudes are observed over the sea and are characteristic of the marine climate. Over land there are large annual temperature amplitudes characteristic of a continental climate. However, the maritime climate also extends to the continental areas adjacent to the sea, where the frequency of marine air masses is high. Sea air brings a maritime climate to land. With distance from the ocean deeper into the continent, annual temperature amplitudes increase, that is, the continentality of the climate increases.

Based on the amplitude value and the time of onset of extreme temperatures, they are distinguished four types of annual variations in air temperature. Equatorial type characterized by two maxima - after the spring and autumn equinox, when the Sun is at its zenith at noon, and two minima - after the summer and earth solstice. This type is characterized by a small amplitude: over continents within 5-10°C, and over oceans only about 1°C. Tropical type characterized by one maximum - after the summer solstice and one minimum - after the winter solstice. The amplitude increases with distance from the equator and averages 10-20°C over continents and 5-10°C over oceans. Temperate zone type characterized by the fact that over the continents extremes are observed at the same times as in the tropical type, and over the ocean a month later. The amplitude increases with latitude, reaching 50-60°C over the continents, and 15-20°C over the oceans. Polar type similar to the previous type, but differs by a further increase in amplitude, reaching 25-40°C over the ocean and coasts, and exceeding 65°C over land

January and July isotherms in Russia??????

Lucas Rein Student (237) 1 year ago

THERMAL ZONES OF THE EARTH, temperature zones of the Earth, is a system of classifying climates by air temperature. Usually there are: a hot zone - between annual isotherms of 20° (reaches 30° latitude); 2 temperate zones (in each hemisphere) - between the annual isotherm of 20° and the isotherm of the warmest month. 10°; 2 cold zones - between the isotherms of the warmest month. 10° and 0°; 2 belts of eternal frost - from Wed. temperature of the warmest month. below 0°.

Juliette Student (237) 1 year ago

Thermal belts are wide bands encircling the Earth, with similar air temperatures inside the belt and differing from neighboring ones in the inhomogeneous latitudinal distribution of solar radiation. There are seven thermal zones: hot on both sides of the equator, limited by annual isotherms of +20°C; moderate 2 (northern and southern) with a boundary isotherm of +10°C of the warmest month; cold 2 within the boundaries of +10°C and 0°C of the warmest month of perpetual frost 2 with an average air temperature for the year below 0°C.

Optical phenomena. As already mentioned, when the sun's rays pass through the atmosphere, part of the direct solar radiation is absorbed by air molecules, scattered and reflected. As a result, various optical phenomena are observed in the atmosphere, which are perceived directly by our eyes. Such phenomena include: sky color, refraction, mirages, halo, rainbow, false sun, light pillars, light crosses, etc.

The color of the sky. Everyone knows that the color of the sky changes depending on the state of the atmosphere. A clear, cloudless sky during the day is blue. This color of the sky is due to the fact that there is a lot of scattered solar radiation in the atmosphere, which is dominated by short waves, which we perceive as blue or blue. If the air is dusty, the spectral composition of the scattered radiation changes and the blue of the sky weakens; the sky becomes whitish. The more cloudy the air, the weaker the blue of the sky.

The color of the sky changes with altitude. At an altitude of 15 to 20 km The color of the sky is black and purple. From the tops of high mountains the color of the sky appears deep blue, and from the surface of the Earth it appears blue. This color change from black-violet to light blue is caused by the ever-increasing scattering of first violet, then blue and cyan rays.

At sunrise and sunset, when the sun's rays pass through the greatest thickness of the atmosphere and lose almost all short-wave rays (violet and blue), and only long-wave rays reach the observer's eye, the color of the part of the sky near the horizon and the Sun itself has a red or orange color .

Refraction. As a result of reflection and refraction of solar rays when they pass through layers of air of varying density, their trajectory undergoes some changes. This leads to the fact that we see celestial bodies and distant objects on the earth's surface in a direction slightly different from the one in which they are actually located. For example, if we look at the top of a mountain from a valley, the mountain appears elevated to us; When looking from the mountain into the valley, an increase in the valley bottom is noticed.

The angle formed by a straight line extending from the observer's eye to any point and the direction in which the eye sees this point is called refraction.

The amount of refraction observed at the earth's surface depends on the density distribution of the lower layers of air and on the distance from the observer to the object. The density of air depends on temperature and pressure. On average, the value of terrestrial refraction depending on the distance to the observed objects under normal atmospheric conditions is equal to:

Mirages. The phenomena of mirages are associated with anomalous refraction of solar rays, which is caused by a sharp change in air density in the lower layers of the atmosphere. With a mirage, the observer sees, in addition to objects, their images below or above the actual position of the objects, and sometimes to the right or left of them. Often the observer can only see the image without seeing the objects themselves.

If the air density drops sharply with height, then the image of objects is observed above their actual location. So, for example, under similar conditions you can see the silhouette of a ship above sea level when the ship is hidden from the observer over the horizon.

Inferior mirages are often observed on open plains, especially in deserts, where air density increases sharply with altitude. In this case, a person often sees in the distance what appears to be a watery, slightly rippling surface. If there are any objects on the horizon, then they seem to rise above this water. And in this expanse of water their inverted outlines are visible, as if reflected in the water. The visibility of the water surface on a plain is created as a result of large refraction, which causes a reverse image below the earth's surface of the part of the sky located behind objects.

Halo. The halo phenomenon refers to light or rainbow-colored circles sometimes observed around the Sun or Moon. A halo occurs when these celestial bodies have to be seen through light cirrus clouds or through a veil of fog consisting of ice needles suspended in the air (Fig. 63).

The halo phenomenon occurs due to refraction in ice crystals and reflection of sunlight from their faces.

Rainbow. A rainbow is a large multi-colored arc, usually observed after rain against the background of rain clouds located opposite the part of the sky where the Sun shines. The size of the arc varies, sometimes a full rainbow semicircle is observed. We often see two rainbows at the same time. The intensity of development of individual colors in the rainbow and the width of their stripes are different. A clearly visible rainbow has red on one edge and violet on the other; the other colors in the rainbow are in the order of the colors of the spectrum.

Rainbow phenomena are caused by the refraction and reflection of sunlight in water droplets in the atmosphere.

Sound phenomena in the atmosphere. Longitudinal vibrations of particles of matter, propagating through the material medium (through air, water and solids) and reaching the human ear, cause sensations called “sound”.

Atmospheric air always contains sound waves of varying frequencies and strengths. Some of these waves are created artificially by humans, and some of the sounds are of meteorological origin.

Sounds of meteorological origin include thunder, the howling of the wind, the hum of wires, the noise and rustling of trees, the “voice of the sea”, sounds and noises that arise when sand masses move in deserts and over dunes, as well as snowflakes over a smooth snow surface, sounds when falling on the earth's surface of solid and liquid sediments, the sounds of the surf off the coast of seas and lakes, etc. Let's dwell on some of them.

Thunder is observed during lightning discharge phenomena. It arises in connection with special thermodynamic conditions that are created along the path of lightning. Usually we perceive thunder in the form of a series of blows - the so-called peals. Thunderclaps are explained by the fact that sounds generated at one time along the long and usually winding path of lightning reach the observer sequentially and with varying intensities. Thunder, despite the great power of sound, is heard at a distance of no more than 20-25 km(on average about 15 km).

The howling of the wind occurs when the air moves quickly and swirls around some objects. In this case, there is an alternation of accumulation and outflow of air from objects, which gives rise to sounds. The hum of wires, the noise and rustling of trees, the “voice of the sea” are also connected by air movement.

Speed ​​of sound in the atmosphere. The speed of sound propagation in the atmosphere is affected by air temperature and humidity, as well as wind (direction and its strength). On average, the speed of sound in the atmosphere is 333 m per second. As air temperature increases, the speed of sound increases slightly. Changes in absolute air humidity have less effect on the speed of sound. The wind has a strong influence: the speed of sound in the direction of the wind increases, against the wind it decreases.

Knowing the speed of sound propagation in the atmosphere is of great importance when solving a number of problems in studying the upper layers of the atmosphere using the acoustic method. Using the average speed of sound in the atmosphere, you can find out the distance from your location to the point where thunder occurs. To do this, you need to determine the number of seconds between the visible flash of lightning and the moment the sound of thunder arrives. Then you need to multiply the average speed of sound in the atmosphere - 333 m/sec. for the resulting number of seconds.

Echo. Sound waves, like light rays, experience refraction and reflection when passing from one medium to another. Sound waves can be reflected from the earth's surface, from water, from surrounding mountains, clouds, from the interface of air layers having different temperatures and humidity. The sound may be reflected and repeated. The phenomenon of repetition of sounds due to the reflection of sound waves from various surfaces is called “echo”.

The echo is especially often observed in the mountains, near rocks, where a loudly spoken word is repeated one or several times after a certain period of time. For example, in the Rhine Valley there is the Lorelei rock, whose echo is repeated up to 17-20 times. An example of an echo is the sound of thunder, which occurs due to the reflection of the sounds of electrical discharges from various objects on the earth's surface.

Electrical phenomena in the atmosphere. Electrical phenomena observed in the atmosphere are associated with the presence in the air of electrically charged atoms and gas molecules called ions. Ions come with both negative and positive charges, and according to their mass they are divided into light and heavy. Ionization of the atmosphere occurs under the influence of short-wave solar radiation, cosmic rays and radiation from radioactive substances contained in the earth's crust and in the atmosphere itself. The essence of ionization is that these ionizers transfer energy to a neutral molecule or atom of air gas, under the influence of which one of the outer electrons is removed from the sphere of action of the nucleus. As a result, an atom deprived of one electron becomes a positive light ion. An electron removed from a given atom quickly attaches to a neutral atom and in this way a negative light ion is created. Light ions, meeting suspended air particles, give them their charge and thus form heavy ions.

The amount of ions in the atmosphere increases with altitude. On average every 2 km height, their number increases by a thousand ions in one cubic meter. centimeter In high layers of the atmosphere, the maximum concentration of ions is observed at altitudes of about 100 and 250 km.

The presence of ions in the atmosphere creates electrical conductivity in the air and an electric field in the atmosphere.

The conductivity of the atmosphere is created due to the high mobility of mainly light ions. Heavy ions play a small role in this regard. The higher the concentration of light ions in the air, the greater its conductivity. And since the number of light ions increases with height, the conductivity of the atmosphere also increases with height. So, for example, at a height of 7-8 km conductivity is approximately 15-20 times greater than that of the earth's surface. At an altitude of about 100 km conductivity is very high.

Clean air has few suspended particles, so it contains more light ions and fewer heavy ones. In this regard, the conductivity of clean air is higher than the conductivity of dusty air. Therefore, during haze and fog, conductivity is low. The electric field in the atmosphere was first established by M. V. Lomonosov. In clear, cloudless weather, the field strength is considered normal. Towards

The atmosphere on the earth's surface is positively charged. Under the influence of the electric field of the atmosphere and the negative field of the earth's surface, a vertical current of positive ions from the earth's surface upwards, and negative ions from the atmosphere downwards, is established. The electric field of the atmosphere near the earth's surface is extremely variable and depends on the conductivity of the air. The lower the conductivity of the atmosphere, the greater the intensity of the electric field of the atmosphere. The conductivity of the atmosphere mainly depends on the amount of solid and liquid particles suspended in it. Therefore, during haze, precipitation and fog, the intensity of the electric field of the atmosphere increases and this often leads to electrical discharges.

Elmo's Lights. During thunderstorms and squalls in the summer or snowstorms in the winter, one can sometimes observe quiet electrical discharges on the tips of objects protruding above the earth's surface. These visible discharges are called “Elmo lights” (Fig. 64). Most often, Elmo's lights are observed on masts and on mountain tops; sometimes they are accompanied by a slight crackling sound.

Elmo lights are formed at high electric field strengths. The tension can be so great that ions and electrons, moving at high speed, split air molecules on their way, which increases the number of ions and electrons in the air. In this regard, the conductivity of the air increases and the flow of electricity and discharge begins from sharp objects where electricity accumulates.

Lightning. As a result of complex thermal and dynamic processes in thunderclouds, electrical charges are separated: usually negative charges are located at the bottom of the cloud, positive charges at the top. Due to this separation of space charges inside the clouds, strong electric fields are created both within the clouds and between them. The field strength at the earth's surface can reach several hundred kilovolts per 1 m. High electric field strength leads to electrical discharges occurring in the atmosphere. Strong electrical spark discharges that occur between thunderclouds or between clouds and the earth's surface are called lightning.

The average duration of a lightning flash is about 0.2 seconds. The amount of electricity carried by lightning is 10-50 coulombs. The current strength can be very high; sometimes it reaches 100-150 thousand amperes, but in most cases it does not exceed 20 thousand amperes. Most lightning has a negative charge.

Based on the appearance of the spark flash, lightning is divided into linear, flat, spherical, and beaded.

Linear lightning is most often observed, among which there are a number of varieties: zigzag, branched, ribbon, rocket-shaped, etc. If linear lightning is formed between a cloud and the earth's surface, then its average length is 2-3 km; lightning between clouds can reach 15-20 km length. The lightning discharge channel, which is created under the influence of air ionization and through which there is an intense counter flow of negative charges accumulated in the clouds and positive charges accumulated on the earth's surface, has a diameter of 3 to 60 cm.

Flat lightning is a short-term electrical discharge that covers a significant part of the cloud. Flat lightning is not always accompanied by thunder.

Ball lightning is a rare phenomenon. It is formed in some cases after a strong discharge of linear lightning. Ball lightning is a fireball with a diameter usually 10-20 cm(and sometimes up to several meters). On the earth's surface, this lightning moves at a moderate speed and has a tendency to penetrate into buildings through chimneys and other small openings. Without causing harm and having performed complex movements, ball lightning can safely leave the building. Sometimes it causes fires and destruction.

An even rarer phenomenon is beaded lightning. They occur when an electric discharge consists of a number of luminous spherical or oblong bodies.

Lightning often causes great damage; They destroy buildings, cause fires, melt electrical wires, split trees and infect people. To protect buildings, industrial structures, bridges, power plants, power lines and other structures from direct lightning strikes, lightning rods (usually called lightning rods) are used.

The greatest number of days with thunderstorms is observed in tropical and equatorial countries. So, for example, on about. Java has 220 days a year with thunderstorms, in Central Africa 150 days, in Central America about 140. In the USSR, the most days with thunderstorms occur in the Caucasus (up to 40 days a year), in Ukraine and in the southeast of the European part of the USSR. Thunderstorms are usually observed in the afternoon, especially between 15:00 and 18:00.

Polar lights. Auroras are a peculiar form of glow in the high layers of the atmosphere, observed from time to time at night, mainly in the polar and subpolar countries of the northern and southern hemispheres (Fig. 65). These glows are a manifestation of the electrical forces of the atmosphere and occur at an altitude of 80 up to 1000 km in highly rarefied air when electric charges pass through it. The nature of the auroras has not yet been fully understood, but it has been precisely established that the cause of their occurrence is

the impact of the upper, highly rarefied layers of the earth's atmosphere of charged particles (corpuscles) entering the atmosphere from active regions of the Sun (spots, prominences and other areas) during flares of solar radiation.

The maximum number of auroras is observed near the Earth's magnetic poles. For example, at the magnetic pole of the northern hemisphere there are up to 100 auroras per year.

According to the form of glow, auroras are very diverse, but they are usually divided into two main groups: auroras of a non-ray form (uniform stripes, arcs, calm and pulsating luminous surfaces, diffuse glows, etc.) and auroras of a radiant structure (stripes, drapes, rays, corona and etc.). Auroras with a beamless structure are distinguished by a calm glow. The radiances of the ray structure, on the contrary, are mobile; their shape, brightness and color of the glow change. In addition, radiant auroras are accompanied by magnetic excitations.

The following types of precipitation are distinguished by shape. Rain- liquid precipitation consisting of droplets with a diameter of 0.5-6 mm. Drops of larger sizes break into pieces when falling. In torrential rains, the drop size is larger than in regular rains, especially at the beginning of the rain. At subzero temperatures, supercooled drops can sometimes fall out. When they come into contact with the earth's surface, they freeze and cover it with an ice crust. Drizzle is liquid precipitation consisting of droplets with a diameter of about 0.5-0.05 mm with a very low falling speed. They are easily transported by the wind in a horizontal direction. Snow- solid precipitation consisting of complex ice crystals (snowflakes). Their forms are very diverse and depend on the conditions of education. The basic shape of snow crystals is a six-pointed star. Stars are made from hexagonal plates because sublimation of water vapor occurs most quickly at the corners of the plates, where the rays grow. On these rays, in turn, branches are created. The diameters of falling snowflakes can be very different (Nimbostratus and cumulonimbus clouds at subzero temperatures also produce cereals, snow and ice, - sediments consisting of icy and heavily grained snowflakes with a diameter of more than 1 mm. Most often, groats are observed at temperatures close to zero, especially in autumn and spring. Snow pellets have a snow-like structure: the grains are easily compressed with your fingers. The kernels of ice grains have a frozen surface. It is difficult to crush them; when they fall to the ground, they jump. Instead of drizzle, fall from stratus clouds in winter snow grains- small grains with a diameter of less than 1 mm, reminiscent of semolina. In winter, at low temperatures, clouds sometimes fall out of the lower or middle tier clouds. snow needles- sediments consisting of ice crystals in the form of hexagonal prisms and plates without branches. During significant frosts, such crystals can appear in the air near the earth's surface. They are especially visible on a sunny day, when their edges sparkle, reflecting the sun's rays. The upper tier clouds consist of such ice needles. Has a special character freezing rain- precipitation consisting of transparent ice balls (rain drops frozen in the air) with a diameter of 1-3 mm. Their loss clearly indicates the presence of a temperature inversion. Somewhere in the atmosphere there is a layer of air with a positive temperature

In recent years, several methods have been proposed and successfully tested to artificially sediment clouds and form precipitation from them. To do this, small particles (“grains”) of solid carbon dioxide at a temperature of about -70 °C are scattered from an airplane into a supercooled droplet cloud. Due to such a low temperature, a huge number of very small ice crystals are formed around these grains in the air. These crystals are then dispersed into the cloud due to air movement. They serve as the embryos on which large snowflakes later grow - exactly as described above (§ 310). In this case, a wide (1-2 km) gap is formed in the layer of clouds along the entire path that the plane has traversed (Fig. 510). The resulting snowflakes can create quite heavy snowfall. It goes without saying that in this way only as much water can be deposited as was previously contained in the cloud. It is not yet possible for humans to enhance the process of condensation and formation of the primary, smallest cloud drops.

Clouds- products of condensation of water vapor suspended in the atmosphere, visible in the sky from the surface of the earth.

Clouds are made up of tiny droplets of water and/or ice crystals (called cloud elements). Drip cloud elements are observed when the air temperature in the cloud is above −10 °C; from −10 to −15 °C clouds have a mixed composition (droplets and crystals), and at temperatures in the cloud below −15 °C they are crystalline.

Clouds are classified into a system that uses Latin words for the appearance of clouds as seen from the ground. The table summarizes the four main components of this classification system (Ahrens, 1994).

Further classification describes clouds according to the height of their location. For example, clouds containing the prefix "cirr-" in their name, like cirrus clouds, are located in the upper tier, while clouds with the prefix " alto-" in the name, such as high-stratus (altostratus), are located in the middle tier. Several groups of clouds are distinguished here. The first three groups are determined by the height of their location above the ground. The fourth group consists of clouds of vertical development. The last group includes a collection of mixed types clouds

Low clouds Low-level clouds are mainly composed of water droplets because they are located at altitudes below 2 km. However, when the temperature is low enough, these clouds may also contain ice particles and snow.

Clouds of vertical development These are cumulus clouds, which have the appearance of isolated cloud masses, the vertical dimensions of which are of the same order as the horizontal ones. They are usually called or temperature convection or front lift, and can grow to heights of 12 km, realizing growing energy through condensation water vapor within the cloud itself.

Other types of clouds Finally, we present collections of mixed cloud types that do not fit into any of the four previous groups.

Most of Russia has moderate rainfall. In the Aral-Caspian and Turkestan steppes, as well as in the far North, very little of it falls. Very rainy areas include only some of the southern outskirts of Russia, especially Transcaucasia.

Pressure

Atmosphere pressure- atmospheric pressure on all objects in it and the earth's surface. Atmospheric pressure is created by the gravitational attraction of air towards the Earth. Atmospheric pressure is measured by a barometer. Atmospheric pressure equal to the pressure of a column of mercury 760 mm high at a temperature of 0 °C is called normal atmospheric pressure. (International Standard Atmosphere - ISA, 101,325 Pa

The presence of atmospheric pressure led people to confusion in 1638, when the Duke of Tuscany's idea to decorate the gardens of Florence with fountains failed - the water did not rise above 10.3 meters. The search for the reasons for this and experiments with a heavier substance - mercury, undertaken by Evangelista Torricelli, led to the fact that in 1643 he proved that air has weight. Together with V. Viviani, Torricelli conducted the first experiment in measuring atmospheric pressure, inventing Torricelli pipe(the first mercury barometer) - a glass tube in which there is no air. In such a tube, mercury rises to a height of about 760 mm. Measurementpressure necessary to control technological processes and ensure production safety. In addition, this parameter is used for indirect measurements of other process parameters: level, flow, temperature, density etc. In the SI system, the unit of pressure is taken pascal (Pa) .

In most cases, pressure transducers have a non-electrical output signal in the form of force or displacement and are combined into a single unit with the measuring instrument. If the measurement results need to be transmitted over a distance, then an intermediate conversion of this non-electric signal into a unified electrical or pneumatic signal is used. In this case, the primary and intermediate converters are combined into one measuring transducer.

To measure pressure use pressure gauges, vacuum gauges, pressure and vacuum gauges, pressure gauges, draft gauges, thrust gauges, Pressure Sensors, differential pressure gauges.

In most devices, the measured pressure is converted into the deformation of elastic elements, which is why they are called deformation devices.

Deformation devices widely used for measuring pressure during technological processes due to the simplicity of the device, convenience and safety in operation. All deformation devices have some kind of elastic element in the circuit, which is deformed under the influence of the measured pressure: tubular spring, membrane or bellows.

Distribution

On the earth's surface Atmosphere pressure varies from place to place and over time. Non-periodic changes are especially important Atmosphere pressure associated with the emergence, development and destruction of slowly moving areas of high pressure - anticyclones and relatively fast moving huge vortices - cyclones, in which low pressure prevails. The extremes noted so far Atmosphere pressure(at sea level): 808.7 and 684.0 mmHg cm. However, despite the large variability, the distribution of monthly averages Atmosphere pressure on the surface of the globe every year is approximately the same. Average annual Atmosphere pressure is lowered near the equator and has a minimum at 10° N. w. Further Atmosphere pressure rises and reaches a maximum at 30-35° northern and southern latitudes; then Atmosphere pressure decreases again, reaching a minimum at 60-65°, and increases again towards the poles. For this latitudinal distribution Atmosphere pressure The time of year and the nature of the distribution of continents and oceans have a significant influence. Over cold continents in winter, areas of high Atmosphere pressure Thus, the latitudinal distribution Atmosphere pressure is disrupted and the pressure field breaks up into a series of high and low pressure areas called centers of atmospheric action. With height, the horizontal pressure distribution becomes simpler, approaching the latitudinal one. Starting from a height of about 5 km Atmosphere pressure throughout the globe decreases from the equator to the poles. On a daily basis Atmosphere pressure 2 maxima are detected: at 9-10 h and 21-22 h, and 2 minimums: at 3-4 h and 15-16 h. It has a particularly regular diurnal variation in tropical countries, where the daily variation reaches 2.4 mmHg Art., and night - 1.6 mmHg cm. With increasing latitude, the amplitude of change Atmosphere pressure decreases, but at the same time non-periodic changes become stronger Atmosphere pressure

The air is constantly moving: it rises - upward movement, falls - downward movement. The movement of air in a horizontal direction is called wind. The cause of wind is the uneven distribution of air pressure on the Earth's surface, which is caused by the uneven distribution of temperature. In this case, the air flow moves from places with high pressure to the side where the pressure is less. When there is wind, the air does not move evenly, but in shocks and gusts, especially near the surface of the Earth. There are many reasons that influence the movement of air: friction of the air flow on the surface of the Earth, encountering obstacles, etc. In addition, air flows, under the influence of the rotation of the Earth, are deflected to the right in the northern hemisphere, and to the left in the southern hemisphere. Wind is characterized by speed, direction and strength. Wind speed is measured in meters per second (m/s), kilometers per hour (km/h), points (on the Beaufort scale from 0 to 12, currently up to 13 points). The wind speed depends on the pressure difference and is directly proportional to it: the greater the pressure difference (horizontal baric gradient), the greater the wind speed. The average long-term wind speed at the earth's surface is 4-9 m/s, rarely more than 15 m/s. In storms and hurricanes (moderate latitudes) - up to 30 m/s, in gusts up to 60 m/s. In tropical hurricanes, wind speeds reach up to 65 m/s, and gusts can reach 120 m/s. The direction of the wind is determined by the side of the horizon from which the wind blows. To designate it, eight main directions (points of reference) are used: N, NW, W, SW, S, SE, E, NE. The direction depends on the pressure distribution and on the deflecting effect of the Earth's rotation. The strength of the wind depends on its speed and shows what dynamic pressure the air flow exerts on any surface. Wind force is measured in kilograms per square meter (kg/m2). Winds are extremely diverse in origin, character and meaning. Thus, in temperate latitudes, where westerly transport dominates, westerly winds (NW, W, SW) predominate. These areas occupy vast spaces - approximately from 30 to 60 in each hemisphere. In the polar regions, winds blow from the poles to low pressure zones at temperate latitudes. In these areas, northeast winds predominate in the Arctic and southeast winds in the Antarctic. At the same time, the southeastern winds of the Antarctic, in contrast to the Arctic, are more stable and have higher speeds. The most extensive wind zone on the globe is located in tropical latitudes, where the trade winds blow. Trade winds are constant winds of tropical latitudes. They are common in the zone from 30°C. w. up to 30° w. , that is, the width of each zone is 2-2.5 thousand km. These are sustained winds of moderate speed (5-8 m/s). At the earth's surface, due to friction and the deflecting effect of the Earth's daily rotation, they have a predominant northeast direction in the northern hemisphere and southeast in the southern hemisphere (Fig. IV.2). They are formed because heated air rises in the equatorial belt, and tropical air comes in its place from the north and south. Trade winds were and are of great practical importance in navigation, especially earlier for the sailing fleet, when they were called “trade winds.” These winds form stable surface currents in the ocean along the equator, directed from east to west. It was they who brought Columbus's caravels to America. Breezes are local winds that blow from sea to land during the day, and from land to sea at night. In this regard, day and night breezes are distinguished. The daytime (sea) breeze is formed as a result of the fact that during the day the land heats up faster than the sea, and a lower pressure is established above it. At this time, the pressure is higher over the sea (cooler) and air begins to move from sea to land. The night (shore) breeze blows from land to sea, since at this time the land cools faster than the sea, and low pressure appears over the water surface - air moves from the shore to the sea.

Wind speed at weather stations is measured with anemometers; if the device is self-recording, then it is called an anemograph. The anemormbograph determines not only the speed, but also the direction of the wind in continuous recording mode. Instruments for measuring wind speed are installed at a height of 10-15 m above the surface, and the wind measured by them is called wind at the earth's surface.

The direction of the wind is determined by naming the point on the horizon from where the wind is blowing or the angle formed by the direction of the wind with the meridian of the place from where the wind is blowing, i.e. its azimuth. In the first case, there are 8 main directions of the horizon: north, northeast, east, southeast, south, southwest, west, northwest and 8 intermediate ones. The 8 main directions have the following abbreviations (Russian and international): S-N, Yu-S, W-W, E-E, NW-NW, NE-NE, SW-SW, SE- S.E..

Air masses and fronts

Air masses are air masses that are relatively uniform in temperature and humidity and spread over an area of ​​several thousand kilometers and several kilometers in height.

They are formed under conditions of a long stay on more or less homogeneous surfaces of land or ocean. Moving in the process of general circulation of the atmosphere to other areas of the Earth, air masses are transferred to these areas and their own weather regime. The dominance in a given region in a particular season creates certain air masses. characteristic climate regime of the area.

There are four main geographical types of air masses that cover the entire troposphere of the Earth. These are the masses of Arctic (Antarctic), temperate, tropical and equatorial air. With the exception of the mainland, in each of them there are also marine and continental varieties that are formed according to land and ocean .

Polar (Arctic and Antarctic) air forms over the icy surfaces of the polar regions and is characterized by low temperatures, low moisture content and good transparency

Temperate air is much better warmed up; it is marked in summer by a high moisture content, especially over the ocean. The prevailing westerly winds and sea cyclones here transport temperate air into the depths of the continents, often accompanying its path with precipitation

Tropical air is generally characterized by high temperatures. But if above the sea it is also very humid, then above the land, on the contrary, it is extremely dry and dusty.

Equatorial air is characterized by constant high temperatures and increased moisture content both over the ocean and over land. In the afternoon there are frequent rain showers

Air masses with different temperatures and humidity constantly move and meet each other in a narrow space. The conditional surface separating the air masses is called the atmospheric front. When this imaginary surface intersects with the earth's surface, the so-called atmospheric front line is formed.

The surface separating Arctic (Antarctic) and temperate air is called the Arctic and Antarctic fronts, respectively. The air of temperate latitudes and tropics is separated by the polar front. Since the density of warm air is less than the density of cold air, the front is an inclined plane, which always has an inclination towards cold air at a very small angle (less than 1 °) to the surface of the earth. Cold air, like thicker air, when meeting warm air, seems to float under it and lift it up, causing the formation of HMAmar.

Having met, various air masses continue to move towards the mass that moved at a higher speed. At the same time, the position of the frontal surface separating these air masses changes, depending on the direction of movement of the frontal surface, cold and warm fronts are distinguished. When advancing cold air moves faster than retreating warm air, an atmospheric front is called cold After the passage of a cold front, atmospheric pressure rises and air humidity decreases. When warm air advances and the front moves towards low temperatures, the front is called a warm front. When a warm front passes, warming occurs, the pressure decreases, and the temperature rises.

Fronts are of great importance for the weather, since clouds form near them and precipitation often falls. Where warm and cold air meet, cyclones arise and develop, the weather becomes unnatural. Knowing the location of atmospheric fronts, the directions and speed of their movement, and also having meteorological data, characterizing air masses, weather forecasts are made.

Anticyclone- an area of ​​high atmospheric pressure with closed concentric isobars at sea level and with a corresponding wind distribution. In a low anticyclone - cold, the isobars remain closed only in the lowest layers of the troposphere (up to 1.5 km), and in the middle troposphere increased pressure is not detected at all; It is also possible that there is a high-altitude cyclone above such an anticyclone.

A high anticyclone is warm and maintains closed isobars with anticyclonic circulation even in the upper troposphere. Sometimes an anticyclone is multicenter. The air in an anticyclone in the northern hemisphere moves around the center clockwise (that is, deviating from the pressure gradient to the right), in the southern hemisphere it moves counterclockwise. An anticyclone is characterized by a predominance of clear or partly cloudy weather. Due to the cooling of air from the earth's surface in the cold season and at night in an anticyclone, the formation of surface inversions and low stratus clouds (St) and fogs is possible. In summer, moderate daytime convection with the formation of cumulus clouds is possible over land. Convection with the formation of cumulus clouds is also observed in the trade winds on the equatorward periphery of subtropical anticyclones. When an anticyclone stabilizes in low latitudes, powerful, high and warm subtropical anticyclones arise. Stabilization of anticyclones also occurs in middle and polar latitudes. High, slow-moving anticyclones that disrupt the general westerly transport of mid-latitudes are called blocking ones.

Synonyms: high pressure area, high pressure area, baric maximum.

Anticyclones reach a size of several thousand kilometers across. At the center of the anticyclone, the pressure is usually 1020-1030 mbar, but can reach 1070-1080 mbar. Like cyclones, anticyclones move in the direction of the general air transport in the troposphere, that is, from west to east, while deviating towards low latitudes. The average speed of movement of the anticyclone is about 30 km/h in the Northern Hemisphere and about 40 km/h in the Southern Hemisphere, but often the anticyclone assumes a sedentary state for a long time.

Signs of an anticyclone:

Clear or partly cloudy weather

No wind

No precipitation

Stable weather pattern (does not change noticeably over time as long as the anticyclone exists)

In summer, the anticyclone brings hot, partly cloudy weather. In winter, the anticyclone brings severe frosts, and sometimes frosty fog is also possible.

An important feature of anticyclones is their formation in certain areas. In particular, anticyclones form over ice fields. And the thicker the ice cover, the more pronounced the anticyclone; That is why the anticyclone over Antarctica is very powerful, but over Greenland it is low-power, and over the Arctic it is average in severity. Powerful anticyclones also develop in the tropical zone.

Cyclone(from ancient Greek κυκλῶν - “rotating”) - an atmospheric vortex of huge (from hundreds to several thousand kilometers) diameter with reduced air pressure in the center.

Air movement (dashed arrows) and isobars (continuous lines) in a cyclone in the northern hemisphere.

Vertical section of a tropical cyclone

The air in cyclones circulates counterclockwise in the northern hemisphere and clockwise in the southern hemisphere. In addition, in air layers at a height from the earth's surface to several hundred meters, the wind has a component directed towards the center of the cyclone, along the baric gradient (in the direction of decreasing pressure). The magnitude of the term decreases with height.

Schematic representation of the process of cyclone formation (black arrows) due to the rotation of the Earth (blue arrows).

A cyclone is not just the opposite of an anticyclone; they have a different mechanism of occurrence. Cyclones are constantly and naturally produced by the rotation of the Earth, thanks to the Coriolis force. A consequence of Brouwer's fixed point theorem is the presence of at least one cyclone or anticyclone in the atmosphere.

There are two main types of cyclones - extratropical and tropical. The first are formed at temperate or polar latitudes and have a diameter of from a thousand kilometers at the beginning of development, and up to several thousand in the case of the so-called central cyclone. Among extratropical cyclones, southern cyclones are distinguished, forming on the southern border of temperate latitudes (Mediterranean, Balkan, Black Sea, South Caspian, etc.) and moving to the north and northeast. Southern cyclones have enormous reserves of energy; It is with southern cyclones in central Russia and the CIS that the heaviest precipitation, winds, thunderstorms, squalls and other weather phenomena are associated.

Tropical cyclones form in tropical latitudes and have smaller sizes (hundreds, rarely more than a thousand kilometers), but larger pressure gradients and wind speeds reaching pre-storm levels. Such cyclones are also characterized by the so-called “eye of the storm” - a central area with a diameter of 20-30 km with relatively clear and calm weather. Tropical cyclones can become extratropical during their development. Below 8-10° northern and southern latitudes, cyclones occur very rarely, and in the immediate vicinity of the equator they do not occur at all.

Cyclones arise not only in the atmosphere of the Earth, but also in the atmospheres of other planets. For example, in the atmosphere of Jupiter, the so-called Great Red Spot has been observed for many years, which is, apparently, a long-lived anticyclone.

Daily variation of air temperature at the earth's surface

1. Air temperature changes daily following the temperature of the earth's surface. Since the air is heated and cooled from the earth's surface, the amplitude of the daily temperature variation in the meteorological booth is less than on the soil surface, on average by about one third. Above the sea surface, conditions are more complex, as will be discussed later.

An increase in air temperature begins along with an increase in soil temperature (15 minutes later) in the morning, after sunrise. At 13-14 hours the soil temperature, as we know, begins to decrease. At 14-15 hours the air temperature begins to drop. Thus, the minimum in the daily variation of air temperature at the earth's surface occurs shortly after sunrise, and the maximum - at 14-15 hours.

The diurnal variation of air temperature appears quite correctly only in conditions of stable clear weather. It seems even more natural on average from a large number of observations: long-term curves of the daily variation of temperature are smooth curves similar to sinusoids.

But on some days the daily variation of air temperature can be very incorrect. This depends on changes in cloudiness, changing radiation conditions on the earth's surface, as well as on advection, i.e., on the influx of air masses with a different temperature. As a result of these reasons, the minimum temperature may shift even to daytime hours, and the maximum to night. The diurnal variation in temperature may disappear altogether, or the diurnal change curve may take on a complex shape. In other words, the regular daily cycle is blocked or masked by non-periodic temperature changes. For example, in Helsinki in January, with a 24% probability, the daily maximum temperature occurs between midnight and one in the morning, and only in 13% does it occur between 12 and 14 hours.

Even in the tropics, where non-periodic temperature changes are weaker than in temperate latitudes, maximum temperatures occur in the afternoon hours in only 50% of all cases.

In climatology, the daily variation of air temperature averaged over a long-term period is usually considered. In such an averaged daily cycle, non-periodic temperature changes, occurring more or less uniformly at all hours of the day, cancel each other out. As a result, the long-term diurnal curve has a simple character, close to sinusoidal.
For example, we show in Fig. 22 daily variation of air temperature in Moscow in January and July, calculated from long-term data. The long-term average temperature was calculated for each hour of a January or July day, and then, using the obtained average hourly values, long-term diurnal curves were constructed for January and July.

Rice. 22. Daily variation of air temperature in January (1) and July (2). Moscow. The average monthly temperature is 18.5 °C for July, -10 °C for January.

2. The daily amplitude of air temperature depends on many influences. First of all, it is determined by the daily amplitude of temperature on the soil surface: the greater the amplitude on the soil surface, the greater it is in the air. But the daily amplitude of temperature on the soil surface depends mainly on cloudiness. Consequently, the daily amplitude of air temperature is closely related to cloudiness: in clear weather it is much greater than in cloudy weather. This is clearly seen from Fig. 23, which shows the daily variation of air temperature in Pavlovsk (near Leningrad), average for all days of the summer season and separately for clear and cloudy days.

The daily amplitude of air temperature also varies by season, by latitude, and also depending on the nature of the soil and terrain. In winter it is less than in summer, as well as the amplitude of the temperature of the underlying surface.

With increasing latitude, the daily amplitude of air temperature decreases, as the midday height of the sun above the horizon decreases. At latitudes of 20-30° on land, the average annual daily temperature amplitude is about 12 °C, at latitude 60° about 6 °C, at latitude 70° only 3 °C. In the highest latitudes, where the sun does not rise or set for many days in a row, there is no regular daily temperature variation at all.

The nature of the soil and soil cover also matters. The greater the daily amplitude of the temperature of the soil surface itself, the greater the daily amplitude of the air temperature above it. In steppes and deserts, the average daily amplitude

There it reaches 15-20 °C, sometimes 30 °C. Above dense vegetation cover it is smaller. The daily amplitude is also affected by the proximity of water basins: in coastal areas it is smaller.

Rice. 23. Daily variation of air temperature in Pavlovsk depending on cloudiness. 1 - clear days, 2 - cloudy days, 3 - all days.

On convex landforms (on the tops and slopes of mountains and hills), the daily amplitude of air temperature is reduced in comparison with flat terrain, and on concave landforms (in valleys, ravines and hollows) it is increased (Voeikov’s law). The reason is that on convex forms of relief, the air has a reduced area of ​​​​contact with the underlying surface and is quickly carried away from it, being replaced by new masses of air. In concave relief forms, the air heats up more strongly from the surface and stagnates more during the daytime, and at night it cools more and flows down the slopes. But in narrow gorges, where both the influx of radiation and effective radiation are reduced, the daily amplitudes are smaller than in wide valleys.

3. It is clear that small daily amplitudes of temperature on the sea surface also result in small daily amplitudes of air temperature above the sea. However, these latter are still higher than the daily amplitudes on the sea surface itself. Daily amplitudes on the surface of the open ocean are measured only in tenths of a degree, but in the lower layer of air above the ocean they reach 1 - 1.5 °C (see Fig. 21), and even more over inland seas. Air temperature amplitudes are increased because they are influenced by the advection of air masses. The direct absorption of solar radiation by the lower layers of air during the day and its emission at night also plays a role.

Number: 15.02.2016

Class: 6"B"

Lesson No.42

Lesson topic:§39. Air temperature and daily temperature variation

The purpose of the lesson:

Educational: To develop knowledge about the patterns of air temperature distribution.

Developmental I : Develop skills, the ability to determine temperature, calculate the daily temperature, draw up graphs, solve problems on temperature changes, find the amplitude of temperatures.

Educating: Cultivate a desire to study the subject.

Lesson type: combined

Lesson type: problem-based learning

Equipmentlesson: ICT, thermometers, weather calendars,

I. Organizational moment: Greetings. Identification of missing persons.

II.Checking homework:

Test.

1.What reasons determine the heating of the Earth?

And the polar night and the polar day

B angle of incidence of sunlight

In the change of day and night

G pressure, temperature, wind.

2.What is the difference in surface heating at the equator and temperate latitudes:

And equatorial latitudes are heated more throughout the year

B equatorial latitudes are heated more in summer

At equatorial latitudes they are heated equally throughout the year.

3.How many zones of illumination?

A 3 B 5 C 6 D 4

4. What are the features of the polar belt?

A Twice a year the sun is in the tropics

B There is a polar day and a polar night throughout the year.

In the summer the sun is at its zenith.

5.Does the weather change often in the tropical zone?

A Yes B No C 4 times a year

III.Preparing to explain a new topic: Write the topic of the lesson on the board and explain

IV.Explanation of new topicss:

Air temperature- degree of air heating, determined using a thermometer.

Air temperature- one of the most important characteristics of weather and climate.

Thermometer is a device for determining air temperature. The thermometer is a capillary tube soldered to a reservoir, filled with liquid (mercury, alcohol). The tube is attached to a bar on which the thermometer scale is printed. As it gets warmer, the liquid in the tube begins to rise, and as it gets colder, it starts to fall. Thermometers are available for outdoor and indoor use.

Daily change in air temperature – amplitude.

Research has shown that temperature changes over time, i.e. over the course of a day, a month, a year. The daily temperature change depends on the rotation of the Earth around its axis.

At night, when there is no heat from the sun, the Earth's surface cools. During the day, on the contrary, it heats up.

Due to this, the air temperature changes.

Lowest temperature of the day -before sunrise.

The highest temperature is 2-3 hours after noon

During the day, temperature readings at weather stations are taken 4 times: at 1 o'clock, 7 o'clock, 13 o'clock, 19 o'clock, then summed up and divided by 4 - the average daily temperature

For example:

1h +5 0 С, 7 h +7 0 С, 13 h +15 0 С, 19 h +11 0 С,

5 0 С+7 0 С+15 0 С+11 0 С=38 0 С:4=9.5 0 С

V.Mastering a new topic:

Test

1. Air temperature with altitude:

a) decreases

b) increases

c) does not change

2. Land, unlike water, heats up:

a) slower

b) faster

3. Air temperature is measured:

a) barometer

b) thermometer

c) hygrometer

a) at 7 o'clock

b) at 12 o'clock

c) at 14 o'clock

5. Temperature fluctuations during the day depend on:

a) cloudiness

b) angle of incidence of sunlight

6. Amplitude is:

a) the sum of all temperatures during the day

b) the difference between the highest temperature and the lowest

7. The average temperature (+2 o; +4 o; +3 o; -1 o) is equal to:

VI. Lesson summary:

1. determine the amplitude of temperatures, the average daily temperature,

VII.Homework:

1.§39. Air temperature and daily temperature variation

VII. Grading:

Evaluation teacher student

Sections: Geography

Duration: 45 minutes (1 lesson).

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

Goals: students should know:

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

2.Creating conditions for developing skills in working with digital data in various forms (tabular, graphical), the ability to draw up and analyze graphs of daily and annual temperatures using a cool weather calendar.

Lesson Objectives:

Educational:

1) Introduce students to the features of heating the earth's surface and atmosphere. Illumination zones and what lines - isotherms - show on climate maps.

2) Find out how and by what amount air temperature changes with altitude and how sunlight and heat are distributed depending on latitude.

3) Identify factors influencing differences in air heating during the day and year. Teach, using the average temperature indicator, to calculate the average daily and average annual amplitudes of temperature fluctuations.

Developmental:

1) Develop the ability to analyze graphs of data in a textbook and independently draw graphs of temperature progression.

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

Educational:

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

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

During the classes

1. Organizational moment

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

Teacher. How did you dress this morning when you were getting ready to leave home for school?

Rail: Warm so as not to freeze.

Teacher. Why might Rail freeze?

Gulnara. Because it's very cold outside.

Teacher. Now let's remember 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 in the summer it can be hot, but when you take a swim, it becomes so nice and cool by the lake.

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

Teacher. Showing a demo thermometer. Question for the class: How to measure air temperature using a thermometer? (We recall its structure and principle of operation) What can you find out using a thermometer?

Students. You can find out the air temperature in the classroom, outside, at home. Anywhere, anywhere, anytime. High in the mountains and in the mountain valley. At 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 we will study?

Students. Temperature; air temperature.

Working with notebooks. We write down the topic of the lesson: “Heating of 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*C degrees and in the classroom +20*C. Gulnara checks and confirms the correctness of the answer.
Today in class we must learn what air temperature depends on. We are working according to plan:

The lesson plan is shown on the screen:

• Block 1. Heating of the earth's surface and air temperature in the troposphere.
• Block 2. Warming of the earth's surface and the daily variation of temperatures a) in July and b) in December in temperate latitudes.
• Block 3. Illumination zones and annual variation 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 indicators from early childhood. It depends on them what you wear and whether your parents will allow you to swim in the lake.

One of the properties of air is transparency. Prove that the air is transparent. (We see through it). The air is transparent like glass; it allows the sun's rays to pass through it 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 does air heat up?

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

Teacher. Where is it warmer in the summer in a clearing or in a forest? By the lake or in the desert? In a city or a village? High in the mountains or on the plain? (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, different in composition, heats up differently and cools down differently, so the air temperature depends on the nature of the underlying surface (table). As you rise upward for every 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, Education, 2001.

1. Geographical tasks:

1) On the summer solstice, June 22, in the northern hemisphere, the Sun at noon occupies 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 variation 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 a schedule. Along the horizontal line we determine the hours of observation of air temperature during the day, and along the vertical line we mark the positive temperature of the summer month

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

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

3) At what time of day is the highest air temperature observed? At what altitude is the Sun at this time? (The highest temperature is observed at approximately 14:00 23*C. The transfer of heat from the Earth to the troposphere takes approximately 2-3 hours. 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 to 21 hours? (The angle of incidence of sunlight 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 Earth's surface cools down and in the morning, before sunrise, the lowest temperature can be observed).

Teacher. When determining temperature changes, the highest and lowest values ​​are usually noted. Let's work with the graph in Fig. 82 and determine the highest and lowest temperatures. (+12.9*C is the lowest indicator and the highest indicator is +22*C).

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

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

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. (Students write down the solution in a notebook; +4*С- (-1*С)=5*С;

What is the daily range of air temperature? (Work with a chalkboard. Solution: 22*C – 12.9= 9.1*C. A= 9.1*C

2. Geographical tasks

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

1. a) According to (Fig. 83), describe the apparent path of the Sun and explain why December 22 is the shortest daylight in the northern hemisphere. (Our earth, with its axis, is constantly inclined to the orbital plane and forms an angle of varying sizes with it. And when the sun's rays falling on the Earth are strongly inclined, the surface heats up weakly. The air temperature at this time drops, and winter sets in. The apparent path that the Sun travels above the earth 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, the day is longest at this time; in the southern hemisphere, it is summer).

2) Draw the apparent path of the Sun above the horizon on the days of the spring and autumn equinoxes. What is the length of daylight 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 the spring of March 21 and in the fall of September 23, when day is equal to night. These days are called equinoxes. The apparent path of the Sun during the day is 12 hours. Night is - 12 o'clock

3) Analyze the graph (Fig. 84) of the daily variation 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 the similarities and differences between the summer and winter variations in 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 solve at the board and write in notebooks: Winter -11*C and summer - +22*C; + 22*C - (-11*C) = 33*C)

2.b) Let us once again repeat and consolidate the knowledge gained during our conversation and draw a conclusion about the relationship between the daily variation of 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 do their borders lie? (1 hot, 2 - temperate zones, 2 - cold. The first hot zone - from the equator to the north and south - to 23.5 * N 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 - the northern polar circle and the southern polar circle. Work with the textbook - read aloud the characteristic features of each of them, accompanying the reading with questions and working with a wall map at the board - “average annual air temperatures 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 air temperature:

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 positive and negative air temperature indicators;
4. Divide the value of the resulting amount by the number of air temperature measurements per day.

3. Geographical tasks

1. Analyze the graph of the annual variation 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 changes. As a result, the air temperature changes from a higher to a lower value and vice versa. Therefore, the seasons change - winter - spring - summer autumn.)

2. Working with the graph Fig. 85 p. 114: Annual variation of air temperature in Moscow, we will determine the highest temperature of 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. Students work with notebooks.)

3. Determine:
(Average daily temperature based on four measurements per day: -8*C, -4*C, +3*C, +1*C; (work in notebooks and at the board: -8*+(-4*) = - 12*; +3*+ (+1*) = 4*С; -12*+4* = -8*; -8*: 4 = -2*.)

Homework: paragraph No. 24-25, working with questions and pictures in the textbook. I distributed tasks of different levels on cards, taking into account the students’ knowledge of determining average temperatures and constructing one graph.

Block 4. Generalization and consolidation of knowledge acquired 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 set before us?

What new did you learn in class 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’m demonstrating a problematic one - a logical summary) and draw a conclusion: what does the air temperature depend on?

1. The height of the Sun above the horizon.

2. Angle of incidence of sunlight.

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 will talk about this in the next lesson.

5. Reflection

Teacher.

• What did the lesson teach you?
• What new have you learned?
• How far have you progressed in mastering the material?
• Have you gained new knowledge and will you need it in life?
• What difficulties did you encounter when studying a new topic?

When leaving class, put your emoticons on my desk with feedback about the last lesson. From them I will find out how you have mastered the material and whether there are any questions you do not understand. Your impressions of the lesson.

• Green - everything is clear, I’m happy with the lesson. Blue smiley - a lot happened, but not everything was clear.
• Red - the material is very difficult to comprehend, the mood is not very good, but I will try to prepare for the next lesson.

A). By commenting on the activity in the lesson, I give grades. I note only the positive aspects of the students’ work in the classroom.

b). Thank you for the lesson. The topic “Atmosphere” is very difficult to understand, but also the most interesting. You and I all feel that we depend a lot on the state of this (sphere) of the Earth and sometimes it can be very harsh towards us. Therefore, in order not to be helpless in front of the elements of nature, you need to know everything about it. The atmosphere is dealt with by scientists - meteorologists - maybe one of you will take up this science in the future.

List of additional literature

1. Krylova O.V. Implementation of the requirements of the Federal educational standards of basic general education in the teaching of geography (1-8 lectures). Moscow. Pedagogical University "First of September" 2013

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

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The daily variation of air temperature is the change in air temperature during the day - in general it reflects the variation of the temperature of the earth's surface, but the moments of the onset of maximums and minimums are somewhat delayed, the maximum occurs at 14:00, 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 highest in tropical deserts - up to 400 C) and increases in places with bare soil. The daily amplitude of air temperature is one of the indicators of climate continentality. In deserts it is much greater than in areas with a maritime climate.

The annual variation of air temperature (change in average monthly temperature throughout the year) is determined primarily 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 temperatures, would be greatest near the equator, because there the sun during the day is much higher than at higher latitudes, and even reaches the zenith at noon on the days of the equinox. that is, it sends out vertical rays and, therefore, produces the greatest amount of heat. But this is not actually observed, since, in addition to latitude, the daily amplitude is also influenced by many other factors, the totality of which determines the magnitude of the latter. In this regard, the position of the area relative to the sea is of great importance: whether the given area represents land distant from the sea, or an area close to the sea, for example an island. On the islands, due to the softening influence of the sea, the amplitude is insignificant, it is even less on the seas and oceans, but in the depths of the continents it is much greater, and the amplitude increases from the coast to the interior of the continent. At the same time, the amplitude also depends on the time of year: in summer it is greater, in winter it is less; the difference is explained by the fact that the sun is higher in summer than in winter, and the length of the summer day is much longer than the winter. Further, the daily amplitude is influenced by cloudiness: it moderates the temperature difference between day and night, retaining the heat radiated from the earth at night, and at the same time moderating the effect of the sun's rays.

The most significant daily amplitude is observed in deserts and high plateaus. Desert rocks, completely devoid of vegetation, become very hot during the day and quickly radiate during the night all the heat they received during the day. In the Sahara, the daily air amplitude was observed to be 20-25° or more. There have been cases when, after high daytime temperatures, water even froze at night, and the temperature on the surface of the earth dropped 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 significantly smaller in areas covered with rich vegetation. Here, part of the heat received during the day is spent on 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 significantly rarefied, the heat inflow-outflow balance is sharply negative at night, and sharply positive during the day, so the daily amplitude here is sometimes greater than in deserts. For example, Przhevalsky, during his travels in Central Asia, observed daily fluctuations in air temperature in Tibet, even up to 30°, and on the high plateaus of the southern part of North America (in Colorado and Arizona), daily fluctuations, as observations showed, reached 40°. Minor 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 generally in high latitudes, where the sun does not appear at all for days or months, at this time there are absolutely no daily temperature fluctuations. We can say that the daily variation of temperature merges at the poles with the annual one and winter represents night, and summer represents day. Of exceptional interest in this regard 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 tropics of the northern hemisphere, since it is here that the continents have the greatest extent, and the greatest deserts and plateaus are located here. The annual amplitude of temperature depends mainly on the latitude of the place, but, in contrast to the daily amplitude, the annual amplitude increases with distance from the equator to the pole. At the same time, the annual amplitude is influenced by all those factors that we have already dealt with when considering daily amplitudes. In the same way, fluctuations increase with distance from the sea inland, and the most significant amplitudes are observed, for example, in the Sahara and Eastern Siberia, where the amplitudes are even greater, because both factors play a role here: continental climate and high latitude, whereas in In the Sahara, the amplitude depends mainly on the continentality of the country. In addition, fluctuations also depend on the topographical nature of the area. To see how this last factor plays a significant role in the change in amplitude, it is enough to consider temperature fluctuations in the Jurassic and in the valleys. In summer, as is known, the temperature decreases quite quickly with height, so on lonely peaks, surrounded on all sides by cold air, the temperature is much lower than in the 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 air temperature 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 their amplitude cannot be significant. The heating conditions for the central parts of the plateaus are already different. Heating strongly in the summer due to the rarefied air, they emit much less heat compared to isolated mountains, because they are surrounded by heated parts of the plateau, and not by cold air. Therefore, in summer the temperature on the plateaus can be very high, but 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.