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The energy of the Sun is the source of life on our planet. The sun heats the atmosphere and surface of the Earth. Thanks to solar energy, winds blow, the water cycle occurs in nature, seas and oceans heat up, plants develop, and animals have food (see Fig. 1.1). It is thanks to solar radiation that fossil fuels exist on Earth.

Figure 1.1 – The influence of solar radiation on the Earth

Solar energy can be converted into heat or cold, motive power and electricity. The main source of energy for almost all natural processes occurring on the surface of the Earth and in the atmosphere is the energy coming to the Earth from the Sun in the form of solar radiation.

Figure 1.2 presents a classification scheme that reflects the processes that occur on the Earth's surface and in its atmosphere under the influence of solar radiation.

The results of direct solar activity are the thermal effect and the photoelectric effect, as a result of which the Earth receives thermal energy and light. The results of the indirect activity of the Sun are corresponding effects in the atmosphere, hydrosphere and geosphere, which cause the appearance of wind and waves, determine the flow of rivers, and create conditions for preserving the internal heat of the Earth.

Figure 1.2 - Classification of renewable energy sources

The Sun is a ball of gas with a radius of 695,300 km, 109 times the radius of the Earth, with a radiating surface temperature of about 6000°C. The temperature inside the Sun reaches 40 million °C.

Figure 1.3 shows a diagram of the structure of the Sun. The sun is a giant “thermonuclear reactor” that runs on hydrogen and processes 564 million tons of hydrogen into 560 million tons of helium every second by melting. The loss of four million tons of mass is equal to 9:1-10 9 GW h of energy (1 GW equals 1 million kW). In one second, more energy is produced than six billion nuclear power plants could produce in a year. Thanks to the protective shell of the atmosphere, only part of this energy reaches the Earth's surface.

The distance between the centers of the Earth and the Sun is on average 1.496 * 10 8 km.

Annually Sun sends about 1.6 to Earth 10 18 kW h of radiant energy or 1.3 * 10 24 cal heat. This is 20 thousand times more than current global energy consumption. Contribution Sun in the energy balance of the globe is 5000 times greater than the total contribution of all other sources.

This amount of heat would be enough to melt a 35 m thick layer of ice covering the earth's surface at 0°C.

Compared to solar radiation, all other sources of energy reaching the Earth are negligible. Thus, the energy of stars is one hundred millionth of the solar energy; cosmic radiation - two parts per billion. The internal heat coming from the depths of the Earth to its surface is one ten-thousandth of solar energy.

Figure 1.3 – Diagram of the structure of the Sun

Thus. The sun is virtually the only source of thermal energy on Earth.

At the center of the Sun is the solar core (see Fig. 1.4). The photosphere is the visible surface of the Sun, which is the main source of radiation. The sun is surrounded by a solar corona, which has a very high temperature, but it is extremely rarefied and therefore visible to the naked eye only during periods of total solar eclipse.

The visible surface of the Sun that emits radiation is called the photosphere (sphere of light). It consists of hot vapors of various chemical elements in an ionized state.

Above the photosphere is the luminous, almost transparent atmosphere of the Sun, consisting of rarefied gases, which is called the chromosphere.

Above the chromosphere is the outer shell of the Sun, called the corona.

The gases that form the Sun are in a state of continuous violent (intense) movement, which causes the appearance of so-called sunspots, torches and prominences.

Sunspots are large funnels formed as a result of vortex movements of gas masses, the speed of which reaches 1-2 km/s. The temperature of the spots is 1500°C lower than the temperature of the Sun and is about 4500°C. The number of sunspots varies from year to year with a period of about 11 years.

Figure 1.4 - Structure of the Sun

Solar torches are emissions of solar energy, and prominences are colossal explosions in the chromosphere of the Sun, reaching altitudes of up to 2 million km.

Observations have shown that with an increase in the number of sunspots, the number of faculae and prominences increases and, accordingly, solar activity increases.

With an increase in solar activity, magnetic storms occur on Earth, which have a negative impact on telephone, telegraph and radio communications, as well as on living conditions. An increase in auroras is associated with the same phenomenon.

It should be noted that during the period of increasing sunspots, the intensity of solar radiation first increases, which is associated with a general increase in solar activity in the initial period, and then solar radiation decreases, as the area of sunspots increases, having a temperature 1500 ° lower than the temperature of the photosphere.

The part of meteorology that studies the effects of solar radiation on Earth and in the atmosphere is called actinometry.

When performing actinometric work, it is necessary to know the position of the Sun in the firmament. This position is determined by the altitude or azimuth of the Sun.

Height of the Sun he is called the angular distance from the Sun to the horizon, that is, the angle between the direction to the Sun and the plane of the horizon.

The angular distance of the Sun from the zenith, that is, from its vertical direction is called azimuth or zenith distance.

There is a relationship between height and zenith distance

(1.1)

The azimuth of the Sun is rarely determined, only for special work.

The height of the Sun above the horizon is determined by the formula:

Where - latitude of the observation site;

- the declination of the Sun is the arc of the circle of declination from the equator to the Sun, which is calculated depending on the position of the Sun on both sides of the equator from 0 to ±90°;

t - hour angle of the Sun or true solar time in degrees.

The value of the declination of the Sun for each day is given in astronomical reference books over a long period.

Using formula (1.2) you can calculate for any time t height of the sun he or at a given height hc determine the time when the Sun is at a given height.

The maximum height of the Sun at noon for various days of the year is calculated by the formula:

(1.3)

Solar radiation called the flow of radiant energy from the sun going to the surface of the globe. Radiant energy from the sun is the primary source of other types of energy. Absorbed by the surface of the earth and water, it is converted into thermal energy, and in green plants - into the chemical energy of organic compounds. Solar radiation is the most important climate factor and the main cause of weather changes, since various phenomena occurring in the atmosphere are associated with thermal energy received from the sun.

Solar radiation, or radiant energy, by its nature is a stream of electromagnetic oscillations propagating in a straight line at a speed of 300,000 km/sec with a wavelength from 280 nm to 30,000 nm. Radiant energy is emitted in the form of individual particles called quanta, or photons. To measure the wavelength of light, nanometers (nm), or microns, millimicrons (0.001 microns) and anstromes (0.1 millimicrons) are used. There are infrared invisible heat rays with a wavelength from 760 to 2300 nm; visible light rays (red, orange, yellow, green, cyan, indigo and violet) with wavelengths from 400 (violet) to 759 nm (red); ultraviolet, or chemical invisible, rays with a wavelength from 280 to 390 nm. Rays with a wavelength less than 280 millimicrons do not reach the earth's surface due to their absorption by ozone in high layers of the atmosphere.

At the edge of the atmosphere, the spectral composition of solar rays in percentage is as follows: infrared rays 43%, light rays 52% and ultraviolet rays 5%. At the earth's surface, at a sun altitude of 40°, solar radiation has (according to N.P. Kalitin) the following composition: infrared rays 59%, light rays 40% and ultraviolet rays 1% of the total energy. The voltage of solar radiation increases with altitude above sea level, and also when the sun's rays fall vertically, since the rays have to pass through less atmosphere. In other cases, the surface will receive less sunlight the lower the sun, or depending on the angle of incidence of the rays. The voltage of solar radiation decreases due to cloudiness, atmospheric air pollution with dust, smoke, etc.

Moreover, first of all, the loss (absorption) of short-wave rays occurs, and then heat and light. The radiant energy of the sun is the source of life on earth for plant and animal organisms and the most important factor in the surrounding air environment. It has a variety of effects on the body, which, with optimal dosage, can be very positive, and with excessive (overdose) can be negative. All rays have both thermal and chemical effects. Moreover, for rays with a long wavelength, the thermal effect comes to the fore, and with a shorter wavelength, the chemical effect comes to the fore.

The biological effect of rays on an animal’s body depends on the wavelength and their amplitude: the shorter the waves, the more frequent their oscillations, the greater the quantum energy and the stronger the body’s reaction to such irradiation. Short-wave ultraviolet rays, when exposed to tissue, cause the phenomenon of photoelectric effect in them with the appearance of detached electrons and positive ions in atoms. The depth of penetration of different rays into the body is not the same: infrared and red rays penetrate several centimeters, visible (light) rays penetrate several millimeters, and ultraviolet rays penetrate only 0.7-0.9 mm; rays shorter than 300 millimicrons penetrate animal tissue to a depth of 2 millimicrons. With such an insignificant depth of penetration of the rays, the latter have a diverse and significant effect on the entire body.

Solar radiation- a very biologically active and constantly operating factor, which is of great importance in the formation of a number of body functions. For example, through the eye, visible light rays influence the entire organism of animals, causing unconditioned and conditioned reflex reactions. Infrared heat rays exert their influence on the body both directly and through objects surrounding the animal. Animals' bodies continuously absorb and emit infrared rays (radiative exchange), and this process can vary significantly depending on the temperature of the animal's skin and surrounding objects. Ultraviolet chemical rays, the quanta of which have significantly higher energy than the quanta of visible and infrared rays, are distinguished by the greatest biological activity and act on the animal body through humoral and neuroreflex pathways. UV rays primarily act on the exteroreceptors of the skin, and then reflexively affect the internal organs, in particular the endocrine glands.

Long-term exposure to optimal doses of radiant energy leads to skin adaptation and less reactivity. Under the influence of sunlight, hair growth, the function of sweat and sebaceous glands increase, the stratum corneum thickens and the epidermis thickens, which leads to an increase in the body's skin resistance. In the skin, biologically active substances (histamine and histamine-like substances) are formed, which enter the blood. These same rays accelerate cell regeneration during the healing of wounds and ulcers on the skin. Under the influence of radiant energy, especially ultraviolet rays, the pigment melanin is formed in the basal layer of the skin, which reduces the skin's sensitivity to ultraviolet rays. Pigment (tan) is like a biological screen that facilitates the reflection and dispersion of rays.

The positive effect of sunlight affects the blood. Systematic moderate exposure to them significantly enhances hematopoiesis with a simultaneous increase in the number of erythrocytes and hemoglobin content in the peripheral blood. In animals after blood loss or who have suffered from serious illnesses, especially infectious ones, moderate exposure to sunlight stimulates blood regeneration and increases its coagulability. Moderate exposure to sunlight increases gas exchange in animals. The depth of breathing increases and the frequency of breathing decreases, the amount of oxygen introduced increases, more carbon dioxide and water vapor are released, and therefore oxygen supply to tissues improves and oxidative processes increase.

An increase in protein metabolism is expressed by increased nitrogen deposition in tissues, resulting in faster growth in young animals. Excessive solar radiation can cause a negative protein balance, especially in animals suffering from acute infectious diseases, as well as other diseases accompanied by elevated body temperature. Irradiation leads to increased deposition of sugar in the liver and muscles in the form of glycogen. The amount of under-oxidized products (acetone bodies, lactic acid, etc.) in the blood sharply decreases, the formation of acetylcholine increases and metabolism is normalized, which is especially important for highly productive animals.

In emaciated animals, the intensity of fat metabolism slows down and fat deposition increases. Intense lighting in obese animals, on the contrary, increases fat metabolism and causes increased fat burning. Therefore, it is advisable to carry out semi-fat and fat fattening of animals under conditions of less solar radiation.

Under the influence of ultraviolet rays of solar radiation, ergosterol found in food plants and dehydrocholesterol in the skin of animals are converted into active vitamins D 2 and D 3, which enhance phosphorus-calcium metabolism; the negative balance of calcium and phosphorus becomes positive, which contributes to the deposition of these salts in the bones. Sunlight and artificial irradiation with ultraviolet rays are one of the effective modern methods for the prevention and treatment of rickets and other animal diseases associated with impaired calcium and phosphorus metabolism.

Solar radiation, especially light and ultraviolet rays, is the main factor causing seasonal sexual periodicity in animals, since light stimulates the gonadotropic function of the pituitary gland and other organs. In spring, during the period of increasing intensity of solar radiation and light exposure, the secretion of the gonads, as a rule, increases in most animal species. An increase in sexual activity in camels, sheep and goats is observed with a shortening of daylight hours. If sheep are kept in darkened rooms in April-June, then they will come into estrus not in the fall (as usual), but in May. Lack of light in growing animals (during the period of growth and puberty), according to K.V. Svechin, leads to profound, often irreversible qualitative changes in the gonads, and in adult animals it reduces sexual activity and fertility or causes temporary infertility.

Visible light or the degree of illumination has a significant impact on egg development, estrus, duration of the breeding season and pregnancy. In the northern hemisphere, the breeding season is usually short, and in the southern hemisphere it is the longest. Under the influence of artificial lighting in animals, their pregnancy duration is reduced from several days to two weeks. The effect of visible light rays on the gonads can be widely used in practice. Experiments carried out in the laboratory of zoohygiene VIEV have proven that the illumination of premises at a geometric coefficient of 1: 10 (according to KEO, 1.2-2%) compared to the illumination of 1: 15-1: 20 and lower (according to KEO, 0.2 -0.5%) has a positive effect on the clinical and physiological state of pregnant sows and piglets up to 4 months of age, ensuring the production of strong and viable offspring. The weight gain of piglets increases by 6% and their safety by 10-23.9%.

Sun rays, especially ultraviolet, violet and blue, kill or weaken the viability of many pathogenic microorganisms and delay their reproduction. Thus, solar radiation is a powerful natural disinfectant of the external environment. Under the influence of sunlight, the general tone of the body and its resistance to infectious diseases increase, and specific immune reactions also increase (P. D. Komarov, A. P. Onegov, etc.). It has been proven that moderate irradiation of animals during vaccination helps to increase the titer and other immune bodies, the growth of the phagocytic index, and, conversely, intense irradiation reduces the immune properties of the blood.

From all that has been said, it follows that the lack of solar radiation must be considered as a very unfavorable external condition for animals, under which they are deprived of the most important activator of physiological processes. Taking this into account, animals should be placed in sufficiently bright rooms, exercised regularly, and kept on pasture in the summer.

Normalization of natural lighting in rooms is carried out using geometric or lighting methods. In the practice of constructing livestock and poultry buildings, the geometric method is mainly used, according to which the norms of natural lighting are determined by the ratio of the area of windows (glass without frames) to the floor area. However, despite the simplicity of the geometric method, illumination standards are not established accurately using it, since in this case the light-climatic features of different geographical zones are not taken into account. To more accurately determine the illumination in rooms, use the lighting method, or determination daylight factor(KEO). The natural light factor is the ratio of room illumination (measured point) to external illumination in the horizontal plane. KEO is derived by the formula:

K = E:E n ⋅100%

Where K is the coefficient of natural light; E - indoor illumination (in lux); E n - outdoor illumination (in lux).

It must be borne in mind that excessive use of solar radiation, especially on days with high insolation, can cause significant harm to animals, in particular cause burns, eye disease, sunstroke, etc. Sensitivity to the effects of sunlight increases significantly from the introduction of so-called sensitizers (hematoporphyrin, bile pigments, chlorophyll, eosin, methylene blue, etc.). It is believed that these substances accumulate short-wave rays and convert them into long-wave rays with the absorption of part of the energy released by the tissues, as a result of which the reactivity of the tissues increases.

Sunburn in animals is most often observed on areas of the body with delicate, sparsely covered with hair, non-pigmented skin as a result of exposure to heat (solar erythema) and ultraviolet rays (photochemical inflammation of the skin). In horses, sunburn is noted on non-pigmented areas of the scalp, lips, nostrils, neck, groin and limbs, and in cattle on the skin of the udder teats and perineum. In the southern regions, sunburn is possible in white pigs.

Strong sunlight can irritate the retina, cornea and choroids of the eye and damage the lens. With prolonged and intense radiation, keratitis, clouding of the lens and impaired visual accommodation occur. Accommodation disturbances are more often observed in horses if they are kept in stables with low windows facing south, against which the horses are tied.

Sunstroke occurs as a result of severe and prolonged overheating of the brain, predominantly by thermal infrared rays. The latter penetrate through the scalp and skull, reach the brain and cause hyperemia and an increase in its temperature. As a result, the animal first appears depressed, and then excited, the respiratory and vasomotor centers are disturbed. Weakness, uncoordinated movements, shortness of breath, rapid pulse, hyperemia and cyanosis of the mucous membranes, trembling and convulsions are noted. The animal cannot stand on its feet and falls to the ground; severe cases often end in the death of the animal due to symptoms of paralysis of the heart or respiratory center. Sunstroke is especially severe if it is combined with heatstroke.

To protect animals from direct sunlight, it is necessary to keep them in the shade during the hottest hours of the day. To prevent sunstroke, particularly in working horses, they are given white canvas forehead protectors.

Solar radiation

electromagnetic radiation emanating from the Sun and entering the earth's atmosphere. Solar radiation wavelengths are concentrated in the range from 0.17 to 4 µm with a max. at a wavelength of 0.475 µm. OK. 48% of the energy of solar radiation falls on the visible part of the spectrum (wavelength from 0.4 to 0.76 microns), 45% on the infrared (more than 0.76 microns), and 7% on the ultraviolet (less than 0.4 µm). Solar radiation is the main source of energy for processes in the atmosphere, ocean, biosphere, etc. It is measured in units of energy per unit area per unit time, for example. W/m². Solar radiation at the upper boundary of the atmosphere on Wednesday. the distance of the Earth from the Sun is called solar constant and amounts to approx. 1382 W/m². Passing through the earth's atmosphere, solar radiation changes in intensity and spectral composition due to absorption and scattering on air particles, gaseous impurities and aerosol. At the Earth's surface, the spectrum of solar radiation is limited to 0.29–2.0 μm, and the intensity is significantly reduced depending on the content of impurities, altitude and cloud cover. Direct radiation, weakened when passing through the atmosphere, as well as scattered radiation, formed when the direct line is scattered in the atmosphere, reaches the earth's surface. Part of the direct solar radiation is reflected from the earth's surface and clouds and goes into space; scattered radiation also partially escapes into space. The rest of the solar radiation is mainly turns into heat, heating the earth's surface and partly the air. Solar radiation, i.e., is one of the main. components of the radiation balance.

Geography. Modern illustrated encyclopedia. - M.: Rosman. Edited by prof. A. P. Gorkina. 2006 .

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Solar radiation, which includes electromagnetic wavelengths less than 4 μm1, is commonly called short-wave radiation in meteorology. In the solar spectrum there is ultraviolet (< 400 нм), видимую (= 400…760 нм) и инфракрасную (>760 nm) parts.

Solar radiation coming directly from the solar disk is called direct solar radiation S. It is usually characterized by intensity, i.e., the amount of radiant energy in calories passing in 1 minute through 1 cm2 of area located perpendicular to the sun's rays.

The intensity of direct solar radiation arriving at the upper boundary of the earth's atmosphere is called the solar constant S 0 . It is approximately 2 cal/cm2 min. At the earth's surface, direct solar radiation is always significantly less than this value, since, passing through the atmosphere, its solar energy is weakened due to absorption and scattering by air molecules and suspended particles (dust particles, droplets, crystals). The attenuation of direct solar radiation by the atmosphere is characterized either by the attenuation coefficient a or the transparency coefficient t.

To calculate direct solar radiation falling on a perpendicular surface, the Bouguer formula is usually used:

					Sm S0 pm m ,

where S m is direct solar radiation, cal cm-2 min-1, for a given mass of the atmosphere; S 0 is the solar constant; p t is the transparency coefficient for a given mass of the atmosphere; t is the mass of the atmosphere in the path of the sun

sa is found not according to the formula, but according to the Bemporad table. From formula (3.1) it follows that

		Or p = e
		Or p = e


Direct solar radiation falling on the horizontal plane
surface S" is calculated by the formula
	S = S sinh .,

1 1 µm = 10-3 nm = 10-6 m. Micrometers are also called microns, and nanometers are called millimicrons. 1 nm = 10-9 m.

where h is the height of the sun above the horizon.

Radiation arriving on the earth's surface from all points of the sky is called diffuse D. The sum of direct and diffuse solar radiation arriving on the horizontal earth's surface is the total solar radiation Q:

Q = S" + D.(3.4)

The total radiation that reaches the earth's surface, partially reflected from it, creates reflected radiation R, directed from the earth's surface into the atmosphere. The rest of the total solar radiation is absorbed by the earth's surface. The ratio of radiation reflected from the earth's surface to the total incoming radiation is called albedoA.

The value A R characterizes the reflectivity of the earth

new surface. It is expressed in fractions of a unit or percentage. The difference between the total and reflected radiation is called absorbed radiation, or the balance of short-wave radiation of the earth's surface B k:

The surface of the earth and the earth's atmosphere, like all bodies with a temperature above absolute zero, also emit radiation, which is conventionally called long-wave radiation. Its wavelengths are approximately from

4 to 100 µm.

The natural radiation of the earth's surface, according to the Stefan-Boltzmann law, is proportional to the fourth power of its absolute temperature.

T angles:
Ez = T4,

where = 0.814 10-10 cal/cm2 min deg4 Stefan-Boltzmann constant; relative emissivity of the active surface: for most natural surfaces 0.95.

Atmospheric radiation is directed both towards the Earth and into outer space. The portion of long-wave atmospheric radiation directed downward and arriving at the earth's surface is called counter-radiation of the atmosphere and is designated E a.

The difference between the natural radiation of the earth's surface E z and the counter radiation of the atmosphere E a is called effective radiation.

reduction of the earth's surface E eff:
E ef = E zE a.

The value E eff, taken with the opposite sign, is the balance of long-wave radiation on the earth's surface.

The difference between all incoming and all outgoing radiation is called

3.1. Instruments for measuring radiation balance

And its components

To measure the intensity of radiant energy, actinometric instruments of various designs are used. Devices can be absolute and relative. For absolute instruments, readings are obtained immediately in thermal units, and for relative ones - in relative ones, therefore for such instruments it is necessary to know the conversion factors for the transition to thermal units.

Absolute devices are quite complex in design and handling and are not widely used. They are used primarily for checking relative instruments. In the design of relative devices, the thermoelectric method is most often used, which is based on the dependence of the strength of the thermocurrent on the temperature difference between the junctions.

The receiver of thermoelectric devices are thermopiles made from junctions of two metals (Fig. 3.1). The temperature difference between the junctions is created as a result of different absorptivity of the junctions or

vanometer 3. In the second case, the temperature difference between the junctions is achieved by shading some (junction 3) and irradiating others (junction 2) with solar radiation. Since the temperature difference between the junctions is determined by incoming solar radiation, its intensity will be proportional to the strength of the thermoelectric current:

where N is the deviation of the galvanometer needle; a is the conversion factor, cal/cm2 min.

Thus, to express the radiation intensity in thermal units, it is necessary to multiply the galvanometer readings by a conversion factor.

The conversion factor for a thermoelectric device-galvanometer pair is determined by comparison with a control device or calculated from the electrical characteristics contained in the certificates of the galvanometer and actinometric device, with an accuracy of 0.0001 cal/cm2 min using the formula

				(R bR rR ext),

where a is the conversion factor; galvanometer scale division price, mA; k sensitivity of the thermoelectric device, millivolt per 1 cal/cm2 min; R b resistance of the thermopile, Ohm; R r internal resistance of the galvanometer, Ohm; R additional additional resistance of the galvanometer, Ohm.

Thermoelectric actinometer AT-50 serves to measure direct solar radiation.

Actinometer device. The actinometer receiver is a disk 1 made of silver foil (Fig. 3.2). On the side facing the sun, the disk is blackened, and on the other side, internal junctions of thermal stars made of manganin and constantan, consisting of 36 thermoelements, are glued to it through an insulating paper gasket (only seven thermoelements are shown in the diagram). External junctions 3 thermal stars through insulating paper pro-

Rice. 3.2. Thermal star circuit

masonry 5 is glued to a copper disk4. By-

daughters of actinometer the latter is placed in a massive copper case with brackets to which are attached

thermopile leads and soft wires 6 (Fig. 3.3).

The body with brackets is closed by a casing 7, secured with a nut8, and connected by a screw10 to a measuring tube9. Inside the tube there are five diaphragms, arranged in decreasing order of their diameter from 20 to 10 mm towards the body. The diaphragms are held in place by flat and spring washers installed between the body and the smallest diaphragm. The inside of the diaphragm is blackened.

At the ends of the tube there are rings 12 and 13 for aiming the actinometer at the sun. There is a hole on ring 13, and a dot on ring 12. When installed correctly, the beam of light passing through the hole should precisely hit the ring point12. The tube is closed with a removable cap 11, which serves to determine the zero position of the galvanometer and protects the receiver from contamination.

Tube 9 is connected to a stand14, mounted on a plateau16 with a parallax tripod17. To set the tripod axis according to the latitude of the place, use a scale 18 with divisions, a mark 19 and a screw 20.

Installation. First, the tripod axis is set according to the latitude of the observation site. To do this, loosen the screw 20 and turn the tripod axis until the scale division 18, corresponding to

given latitude, with a risk of 19 and Rice. 3.3.Thermoelectricfix the axis in this position

actinometer AT-50

NI. Then the actinometer is installed on a horizontal stand so that the arrow on the plateau is oriented to the north, and, after removing the cover, it is oriented towards the sun by loosening the screw 23 and rotating the handle 22; the tube9 is turned until the beam of light through the hole on the ring13 hits a point on the ring12. After this, the actinometer wires, with the cover 11 open, are connected to the galvanometer terminals (+) and (C), observing the polarity. If the galvanometer needle deviates beyond zero, the wires are swapped.

Observations. 1 minute before the start of observation, check the installation of the actinometer receiver in the sun. After this, the lid is closed and the zero position N 0 is measured using the galvanometer. Then remove the cover, check the accuracy of aiming at the sun and read the galvanometer readings 3 times with an interval of 10-15 s (N 1, N 2, N 3) and the temperature on the galvanometer. After observations, the device is closed with the lid of the case.

Processing observations. From three readings using a galvanometer, the average value N c is found with an accuracy of 0.1:

N with N 1N 2N 3. 3

To obtain a corrected reading N to the average value N, enter a scale correction N, a temperature correction N t from the galvanometer calibration certificate and subtract the position of the zero point N 0:

N N Nt N0 .

To express the intensity of solar radiation S in cal/cm2 min, the readings of the galvanometer N are multiplied by the conversion factor:

The intensity of direct solar radiation on a horizontal surface is calculated using formula (3.3).

The height of the sun above the horizon h and sinh can be determined by the equation

sin h = sin sin+ cos cos cos,

where is the latitude of the observation site; sun declination for a given day (Appendix 9); the hour angle of the sun, measured from true noon. It is determined by the true time of the middle of observations: t source = 15 (t source 12 hours).

Thermoelectric pyranometer P-3x3 used to measure diffuse and total solar radiation.

Pyranometer structure (Fig. 3.4).

The receiving part of the pyranometer is a thermoelectric battery 1, consisting of 87 thermoelements made of manganin and constantan. Strips of manganin and constantan 10 mm long are sequentially soldered together and laid in a 3x3 cm square so that the solders are located in the middle and at the corners. On the outside, the surface of the thermopile is covered with soot and magnesium. The even junctions of the thermopile are painted white, and the odd junctions

- in black. The junctions are located so that

black and white areas alternate in

Rice. 3.4. Thermoelectric pyranometer P-3x3

checkerboard pattern. Through an insulating paper gasket, the thermopile is attached to the ribs of the tile 2, screwed to the body3.

Due to the different absorption of solar radiation, a temperature difference between the black and white junctions is created, therefore a thermal current occurs in the circuit. The leads from the thermopile are connected to terminals 4, to which the wires connecting the pyranometer to the galvanometer are connected.

The top of the housing is closed with a glass hemispherical cap 5 to protect the thermopile from wind and precipitation. To protect the thermopile and glass cap from possible condensation of water vapor, there is a glass dryer6 with a chemical moisture absorber (sodium metal, silica gel, etc.) on the bottom of the body.

A housing with a thermopile and a glass cap makes up the pyranometer head, which is screwed to a stand 7, clamped in a tripod 8 with a screw 9. The tripod is mounted on the base of the case and has two set screws10. When measuring scattered or total radiation, the pyranometer is installed horizontally at a level by rotating the screws10.

To shade the pyranometer head from direct sunlight, a shadow screen is used, the diameter of which is equal to the diameter of the glass cap. The shadow screen is mounted on a tube 14, which is connected with a screw 13 to a horizontal rod 12.

When the pyranometer receiver is shaded by a shadow screen, the scattered radiation is measured, and without shade, the total radiation is measured.

To determine the zero position of the galvanometer needle, as well as to protect the glass cap from damage, the pyranometer head is covered with a metal cover 16.

Installation. The device is installed in an open area. Before observation, check the presence of desiccant in the glass dryer (1/3 of the dryer should be filled with desiccant). Then the tube 14 with the shadow screen 15 is attached to the rod 12 using a screw 13.

The pyranometer is always turned towards the sun with the same side, marked with a number on the head. To turn the pyranometer head numbered towards the sun, screw 9 is slightly loosened and secured in this position.

The horizontality of the thermopile is checked at level 11 and, if not correct, it is adjusted using set screws 10.

The galvanometer for measuring the strength of the thermocurrent is installed on the north side of the pyranometer at such a distance that the observer, when making readings, does not shade the pyranometer not only from direct sunlight.

rays, but also from parts of the sky. The correct connection of the pyranometer to the galvanometer is checked with the pyranometer cover removed and the galvanometer lock released. When the needle deviates beyond zero on the scale, the wires are swapped.

Observations. Immediately before observation, check that the device is installed correctly in level and relative to the sun. To measure the zero position of the galvanometer, the pyranometer head is closed with a lid 16 and the readings of the galvanometer N 0 are recorded. After this, the pyranometer cover is removed and a series of readings are made at intervals of 10-15 s.

First, the galvanometer readings are taken with the pyranometer shaded to determine the scattered radiation N 1, N 2, N 3, then in the unshaded position (the shadow screen is lowered by loosening the screw 13) to determine the total radiation N 4, N 5, N 6. After observations, the tube with the shadow screen is unscrewed and the pyranometer is closed with the lid of the case.

Processing observations. From a series of readings on a galvanometer for each type of radiation, the average values N D and N Q are determined:

			N 1N 2N 3					N 4N 5N 6

The corrected values of N D and N Q are then obtained. For this purpose, the scale corrections N D and N Q are determined from the average values from the calibration certificate of the galvanometer and the bullet reading of the galvanometer is subtracted:

ND ND N N0 , NQ NQ N N0 .

To determine the intensity of scattered radiation D in cal/cm2 min, it is necessary to multiply the galvanometer readings N D by the conversion factor:

D = ND.

To determine the total radiation Q in cal/cm2 min, a correction factor for the height of the sun F h is also introduced. This correction factor is given in the verification certificate in the form of a graph: the height of the sun above the horizon is plotted on the abscissa axis, and the correction factor is plotted on the ordinate axis.

Taking into account the correction factor for the height of the sun, the total radiation is determined by the formula

Q = a (NQ ND )Fh + ND .

When observing with a pyranometer, the intensity of direct radiation on a horizontal surface can be calculated as the difference between the total and scattered radiation:

Traveling thermoelectric albedometer AP-3x3 is intended for

ideal for measuring total, scattered and reflected radiation in field conditions. In practice, it is used mainly to measure the albedo of the active surface.

Albedometer device. The albedometer receiver (Fig. 3.5) is the pyranometer head1, screwed on a sleeve2 to a tube3 with a gimbal4 and a handle5. By rotating the handle 180°, the receiver can be facing upward to measure incoming shortwave radiation and downward to measure reflected shortwave radiation. To ensure that the tube is in a vertical position, a special weight slides inside it on a rod, which always moves down when the device is turned. To soften shocks when turning the device, rubber gaskets are placed at the ends of the tube6.

When disassembled, the device is mounted on the base of a metal case.

	Installation. Before observation with basic
	When removing the case, remove the head, tube,
	handle and screw together: head-
	the tube is screwed to the tube, and the handle is screwed to
	gimbal suspension. To exclude radio-
	ation, which can be reflected by the observation itself
	giver, the handle is mounted on a wooden
	pole about 2 m long.	Rice. 3.5. Travel albedometer
	The albedometer is connected with soft	Rice. 3.5. Travel albedometer
	The albedometer is connected with soft
	wires to the galvanometer terminals (+) and
	wires to the galvanometer terminals (+) and

(C) with the receiver open and the galvanometer arrester released. If the galvanometer needle goes beyond zero, the wires are swapped.

During observations in a permanent area, the albedometer receiver is installed at a height of 1-1.5 m above the active surface, and in agricultural fields - at a distance of 0.5 m from the top level of the vegetation cover. When measuring total and scattered radiation, the albedometer head is turned with its number towards the sun.

Observations. 3 minutes before the start of observations, mark the zero point. To do this, the albedometer head is closed with a lid and the readings of the galvanometer N 0 are taken. Then open the lid and make three readings on the galvanometer with the albedometer receiver positioned upward to measure the incoming total radiation: N 1, N 2, N 3. After the third reading, the receiver is turned down and after 1 minute, three readings are made to measure the reflected radiation: N 4, N 5, N 6. Then the receiver is turned up again and after 1 minute three more readings are made to measure the incoming total radiation: N 7, N 8, N 9. After completing a series of readings, the receiver is closed with a lid.

Processing observations. First, calculate the average readings from the galvanometer for each type of radiation N Q and N Rk:

N Q N 1N 2N 3N 7N 8N 9, 6

N Rk N 4N 5N 6. 3

Then a scale correction from the calibration certificate N Q and N Rk is introduced to the average values, the zero point N 0 is subtracted and the corrected values N Q and N Rk are determined:

N QN QN N 0 , N RkN RkN N 0 .

Since albedo is expressed as the ratio of reflected radiation to total radiation, the conversion factor is reduced and albedo is calculated as the ratio of the corrected galvanometer readings when measuring reflected and total radiation (in percent):

The albedometer is the most versatile device. If there is a conversion factor, it can be used to determine the total radiation, scattered, reflected, and calculate the direct radiation on a horizontal surface. When observing scattered radiation, it is necessary to use a shadow screen to protect the receiver from direct sunlight.

Thermoelectric balance meter M-10 used for measuring

tion of the radiation balance of the underlying surface, or residual radiation, which is the algebraic sum of all types of radiation received and lost by this surface. The incoming part of the radiation consists of direct radiation on the horizontal surface S", scattered radiation D and atmospheric radiation E a. The outgoing part of the radiation balance, or outgoing radiation, is reflected short-wave radiation R K and long-wave radiation from the earth E 3.

The operation of the balance meter is based on the conversion of radiation fluxes into thermoelectromotive force using a thermopile.

The electromotive force arising in the thermopile is proportional to the temperature difference between the upper and lower receivers of the balance meter. Since the temperature of the receivers depends on the incoming and outgoing radiation, the electromotive force will be proportional to the difference in the radiation fluxes arriving from above and below the receivers.

Radiation balance B when measured with a balance meter is expressed by the equation

N galvanometer reading; k correction factor taking into account the influence of wind speed (Table 3.1).

Table 3.1

Correction factor k (example)

Wind speed,

Corrective

factor k

The balance meter readings, multiplied by the correction factor corresponding to a given wind speed, are reduced to the balance meter readings in calm conditions.

Balance meter device(Fig. 3.6). The receiver of the balance meter is two blackened thin copper plates 1 and 2, shaped like a square with a side of 48 mm. On the inside, 3 and 4 thermopiles are glued to them through paper gaskets. The junctions are formed by turns of constantan tape wound on a copper block5. Each turn of the ribbon is half silver plated. The beginning and end of the silver layer serve as thermoseals. The even-numbered junctions are glued to the top, and the odd-numbered

to the bottom plate. The entire thermopile consists of ten bars, each of which has 32-33 turns wound on it. The balance meter receiver is placed in a housing6 shaped like a disk with a diameter of 96 mm and a thickness of 4 mm. The body is connected to a handle7 through which leads8 from the thermopile are passed. Balance meter using ball joints


	ov 9 is installed on pa-
	nelke 10. Attached to the panel
	flutters				hinges
	rod 11 with screen 12, which
		protects		receiver
	direct sunlight. At
	using a screen on a rod,
	visible from the center of the receiver
	at an angle of 10°, direct sunlight
		radiation is excluded
	balance meter readings,
	increases measurement accuracy,
	but in this case the intensity
			solar		radiation
	must be measured separately
Rice. 3.6. Thermoelectric	actinometer. Case 13 protective
balance meter M-10	protects the balance meter from precipitation and

Installation. The device is attached with a socket to the end of a wooden batten at a height of 1.5 m from the ground. The receiver is always installed horizontally with the same receiving side up, marked on the device with the number 1. The leads from the thermopile are connected to the galvanometer.

In most cases, the balance meter is shaded with a screen from direct solar radiation. Therefore, an actinometer is installed on the same rail with the balance meter to measure direct solar radiation. To take into account the influence of wind speed, an anemometer is installed at the level of the balance meter and at a short distance from it.

Observations. 3 minutes before the start of observation, the zero point of the balance meter N 0 is determined. This is done with an open circuit. After this, the balance meter is connected to the galvanometer so that the galvanometer needle deviates to the right, and three readings are made on the balance meter N 1, N 2, N 3 and simultaneously three readings on the anemometer 1, 2, 3. If the balance meter is installed with a shadow screen, then after the first and second readings on the balance meter, two readings are made on the actinometer

The sun is a source of warmth and light, giving strength and health. However, its impact is not always positive. A lack of energy or an excess of it can disrupt the natural processes of life and provoke various problems. Many are sure that tanned skin looks much more beautiful than pale skin, but if you spend a long time under direct rays, you can get a severe burn. Solar radiation is a stream of incoming energy distributed in the form of electromagnetic waves passing through the atmosphere. It is measured by the power of the energy it transfers per unit surface area (watt/m2). Knowing how the sun affects a person, you can prevent its negative effects.

Many books have been written about the Sun and its energy. The sun is the main source of energy for all physical and geographical phenomena on Earth. One two-billionth part of light penetrates into the upper layers of the planet’s atmosphere, while most of it settles in cosmic space.

Rays of light are the primary sources of other types of energy. When they fall on the surface of the earth and into water, they form into heat and affect climatic conditions and weather.

The degree to which a person is exposed to light rays depends on the level of radiation, as well as the period spent under the sun. People use many types of waves to their advantage, using x-rays, infrared rays, and ultraviolet. However, solar waves in their pure form in large quantities can negatively affect human health.

The amount of radiation depends on:

position of the Sun. The greatest amount of radiation occurs in plains and deserts, where the solstice is quite high and the weather is cloudless. The polar regions receive a minimal amount of light, since clouds absorb a significant part of the light flux;
length of the day. The closer to the equator, the longer the day. This is where people get the most heat;
atmospheric properties: cloudiness and humidity. At the equator there is increased cloudiness and humidity, which is an obstacle to the passage of light. That is why the amount of light flux there is less than in tropical zones.

The distribution of sunlight over the earth's surface is uneven and depends on:

density and humidity of the atmosphere. The larger they are, the lower the radiation exposure;
geographic latitude of the area. The amount of light received increases from the poles to the equator;
Earth movements. The amount of radiation varies depending on the time of year;
characteristics of the earth's surface. A large amount of light is reflected in light-colored surfaces, such as snow. Chernozem reflects light energy most poorly.

Due to the extent of its territory, Russia's radiation levels vary significantly. Solar irradiation in the northern regions is approximately the same - 810 kWh/m2 for 365 days, in the southern regions - more than 4100 kWh/m2.

The length of the hours during which the sun shines is also important.. These indicators vary in different regions, which is influenced not only by geographic latitude, but also by the presence of mountains. The map of solar radiation in Russia clearly shows that in some regions it is not advisable to install power supply lines, since natural light is quite capable of meeting the residents’ needs for electricity and heat.

Light streams reach the Earth in different ways. The types of solar radiation depend on this:

The rays emanating from the sun are called direct radiation. Their strength depends on the height of the sun above the horizon. The maximum level is observed at 12 noon, the minimum - in the morning and evening. In addition, the intensity of the impact is related to the time of year: the greatest occurs in summer, the least in winter. It is characteristic that in the mountains the level of radiation is higher than on flat surfaces. Dirty air also reduces direct light fluxes. The lower the sun is above the horizon, the less ultraviolet radiation there is.
Reflected radiation is radiation that is reflected by water or the surface of the earth.
Scattered solar radiation is formed when the light flux is scattered. The blue color of the sky in cloudless weather depends on it.

Absorbed solar radiation depends on the reflectivity of the earth's surface - albedo.

The spectral composition of the radiation is diverse:

colored or visible rays provide illumination and are of great importance in the life of plants;
ultraviolet radiation should penetrate the human body moderately, since its excess or deficiency can cause harm;
Infrared irradiation gives a feeling of warmth and affects the growth of vegetation.

Total solar radiation is direct and scattered rays penetrating the earth. In the absence of clouds, around 12 noon, as well as in the summer, it reaches its maximum.

Vladimir
61 years old

Electromagnetic waves are made up of different parts. There are invisible, infrared and visible, ultraviolet rays. It is characteristic that radiation flows have different energy structures and affect people differently.

Light flux can have a beneficial, healing effect on the condition of the human body. Passing through the visual organs, light regulates metabolism, sleep patterns, and affects a person’s overall well-being. In addition, light energy can cause a feeling of warmth. When the skin is irradiated, photochemical reactions occur in the body that promote proper metabolism.

Ultraviolet has a high biological ability, having a wavelength from 290 to 315 nm. These waves synthesize vitamin D in the body and are also capable of destroying the tuberculosis virus in a few minutes, staphylococcus - within a quarter of an hour, and typhoid bacilli - in 1 hour.

It is characteristic that cloudless weather reduces the duration of emerging epidemics of influenza and other diseases, for example, diphtheria, which can be transmitted by airborne droplets.

The natural forces of the body protect a person from sudden atmospheric fluctuations: air temperature, humidity, pressure. However, sometimes such protection weakens, which, under the influence of strong humidity together with elevated temperature, leads to heat stroke.

The impact of radiation depends on the degree of its penetration into the body. The longer the waves, the stronger the radiation force. Infrared waves can penetrate up to 23 cm under the skin, visible streams - up to 1 cm, ultraviolet - up to 0.5-1 mm.

People receive all types of rays during the activity of the sun, when they are in open spaces. Light waves allow a person to adapt to the world, which is why to ensure comfortable well-being in the premises it is necessary to create conditions for an optimal level of lighting.

The influence of solar radiation on human health is determined by various factors. The place of residence of a person, the climate, as well as the amount of time spent under direct rays matter.

With a lack of sun, residents of the Far North, as well as people whose activities involve working underground, such as miners, experience various dysfunctions, decreased bone strength, and nervous disorders.

Children who do not receive enough light suffer from rickets more often than others. In addition, they are more susceptible to dental diseases and also have a longer course of tuberculosis.

However, too much exposure to light waves without a periodic change of day and night can have detrimental effects on health. For example, residents of the Arctic often suffer from irritability, fatigue, insomnia, depression, and decreased ability to work.

Radiation in the Russian Federation is less active than, for example, in Australia.

Thus, people who are exposed to long-term radiation:

are at high risk of developing skin cancer;
have an increased tendency to dry skin, which, in turn, accelerates the aging process and the appearance of pigmentation and early wrinkles;
may suffer from deterioration of visual abilities, cataracts, conjunctivitis;
have weakened immunity.

Lack of vitamin D in humans is one of the causes of malignant neoplasms, metabolic disorders, which leads to excess body weight, endocrine disorders, sleep disorders, physical exhaustion, and bad mood.

A person who systematically receives the light of the sun and does not abuse sunbathing, as a rule, does not experience health problems:

has stable functioning of the heart and blood vessels;
does not suffer from nervous diseases;
has a good mood;
has a normal metabolism;
rarely gets sick.

Thus, only a dosed amount of radiation can have a positive effect on human health.

Excessive exposure to radiation can cause overheating of the body, burns, and exacerbation of some chronic diseases.. Fans of sunbathing need to take care of following simple rules:

Sunbathe in open spaces with caution;
During hot weather, hide in the shade under scattered rays. This is especially true for young children and elderly people suffering from tuberculosis and heart disease.

It should be remembered that it is necessary to sunbathe at a safe time of day, and also not to be under the scorching sun for a long time. In addition, you should protect your head from heatstroke by wearing a hat, sunglasses, closed clothing, and also use various sunscreens.

At low values of the sun's altitude (h

< 100 ) мас-

Light fluxes are actively used in medicine:

X-rays use the ability of waves to pass through soft tissue and the skeletal system;
the introduction of isotopes makes it possible to record their concentration in internal organs and detect many pathologies and foci of inflammation;
Radiation therapy can destroy the growth and development of malignant tumors.

The properties of waves are successfully used in many physiotherapeutic devices:

Devices with infrared radiation are used for heat treatment of internal inflammatory processes, bone diseases, osteochondrosis, rheumatism, due to the ability of the waves to restore cellular structures.
Ultraviolet rays can have a negative effect on living beings, inhibit plant growth, and suppress microorganisms and viruses.

The hygienic significance of solar radiation is great. Devices with ultraviolet radiation are used in therapy:

various skin injuries: wounds, burns;
infections;
diseases of the oral cavity;
oncological neoplasms.

In addition, radiation has a positive effect on the human body as a whole: it can give strength, strengthen the immune system, and replenish the lack of vitamins.

Sunlight is an important source of a full human life. A sufficient supply of it leads to the favorable existence of all living beings on the planet. A person cannot reduce the degree of radiation, but he can protect himself from its negative effects.