Everything we see around us, matter, earth, water, air, appeared billions of years ago in the depths of stars. The world around us exists thanks to the heavenly bodies and their gifts. Life on Earth originated and exists thanks to the energy of our star - the Sun. All energy emitted by the Sun is called solar radiation.
Radiation is generally considered to be ionizing radiation accompanying nuclear and thermonuclear reactions, which has an extremely harmful and dangerous effect on living organisms. Solar radiation is a broader concept that includes the totality of matter, wave and thermal radiation coming to us from the star. With its deficiency, normal development and functioning of the human body is impossible; excess has a negative effect and can be destructive.
Answer
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Types of solar radiation.
1 Direct is radiation that reaches the Earth in the form of a beam of parallel rays directly from the Sun.
2 Scattered is radiation that falls on the ground in the form of rays that are directed in different directions.
3 Total is direct and scattered radiation combined.
4 Reflected is the part of the total solar radiation that is reflected from the earth's surface.
5 Absorbed is the part of the total solar radiation that is absorbed by the earth's surface.
The answer to the question, what is solar radiation, is the entire spectrum of light emitted by the sun. It includes visible light and all other frequencies of radiation in the electromagnetic spectrum. Compared to familiar energy sources on Earth, the Sun emits enormous amounts of energy. The type of radiation emitted by the sun is a product of its heat, which is caused by nuclear fusion within the sun's core. Solar radiation is studied by scientists because the influence of the Sun on the human body and the planet as a whole is very enormous.
Only a small fraction of solar radiation ever reaches Earth: most of it is radiated into empty space. However, the fraction that actually reaches the Earth is much larger than the amount of energy consumed on Earth by sources such as fossil fuels. The enormous amount of energy emitted by the sun can be explained by its large mass and high temperature.
Types of solar radiation
Total solar radiation, often called global radiation, is the sum of direct, diffuse, and reflected radiation. The solar radiation available to us is always a mixture of the above three components.
Types of solar radiation
Direct radiation
Direct radiation is obtained from the sun's rays moving directly from the sun to the earth. The direction of radiation is also called beam radiation or direct beam radiation. Since direct radiation is the sun's rays moving in a straight line, shadows of objects that appear in the path of the sun's rays are formed. Shadows indicate the presence of direct radiation. In sunny areas and during the summer, direct radiation accounts for almost 70-80% of the total radiation. Solar installations use solar tracking to absorb most of the direct radiation. If a solar tracking system is not installed, valuable direct radiation will not be captured.
Diffuse radiation
Direct radiation has a fixed direction. Diffuse radiation does not have a fixed direction. When the sun's rays are scattered by particles present in the atmosphere, these scattered sun rays account for diffuse radiation.
The influence of solar radiation on the human body
Speaking about the effect of the sun on the human body, it is impossible to determine exactly. What impact does it have on human health, harm or benefit? The sun's rays emit ultraviolet and infrared radiation. The rays of the sun are like kilocalories obtained from food. Their deficiency leads to emaciation, and in excess they cause obesity. So it is in this situation. A moderate amount of solar radiation has a positive effect on the body, while excess ultraviolet radiation provokes burns and the development of numerous diseases. Influence
Positive effects of infrared radiation
The main feature of infrared rays is that they create a thermal effect, which has a positive effect on the human body. The heating element helps to dilate blood vessels and normalize blood circulation. Heat has a relaxing effect on the muscles, providing a slight anti-inflammatory and analgesic effect. Under the influence of heat, metabolism increases and the processes of assimilation of biologically active components are normalized. Infrared radiation from the sun stimulates the brain and visual apparatus.
Interesting! Thanks to solar radiation, it synchronizes the biological rhythms of the body, starting with sleep and wakefulness. Treatment with infrared rays of the sun improves skin condition and eliminates acne. Warm light lifts the mood and improves a person’s emotional background. They also improve sperm quality in men and potency.
Positive effects of ultraviolet radiation
Despite all the controversy about the negative effects of ultraviolet radiation on the body, its absence can lead to serious health problems. This is one of the most important factors of existence. And the lack of ultraviolet light in the body brings the following changes: Firstly, it weakens the immune system (primarily the effect is on the cell in the body). This is due to impaired absorption of vitamins and minerals, metabolic disorders at the cellular level.
General hygiene. Solar radiation and its hygienic significance.By solar radiation we mean the entire flux of radiation emitted by the Sun, which is electromagnetic oscillations of various wavelengths. From a hygienic point of view, the optical part of sunlight, which occupies the range from 280-2800 nm, is of particular interest. Longer waves are radio waves, shorter ones are gamma rays, ionizing radiation does not reach the Earth's surface because it is retained in the upper layers of the atmosphere, in the ozone layer in particular. Ozone is distributed throughout the atmosphere, but at an altitude of about 35 km it forms the ozone layer.
The intensity of solar radiation depends primarily on the height of the sun above the horizon. If the sun is at its zenith, then the path taken by the sun's rays will be much shorter than their path if the sun is at the horizon. By increasing the path, the intensity of solar radiation changes. The intensity of solar radiation also depends on the angle at which the sun's rays fall, and the illuminated area also depends on this (as the angle of incidence increases, the area of illumination increases). Thus, the same solar radiation falls on a larger surface, so the intensity decreases. The intensity of solar radiation depends on the mass of air through which the sun's rays pass. The intensity of solar radiation in the mountains will be higher than above sea level, because the layer of air through which the sun's rays pass will be less than above sea level. Of particular importance is the influence on the intensity of solar radiation by the state of the atmosphere and its pollution. If the atmosphere is polluted, then the intensity of solar radiation decreases (in the city, the intensity of solar radiation is on average 12% less than in rural areas). The voltage of solar radiation has a daily and annual background, that is, the voltage of solar radiation changes throughout the day, and also depends on the time of year. The highest intensity of solar radiation is observed in summer, the lowest in winter. In terms of its biological effect, solar radiation is heterogeneous: it turns out that each wavelength has a different effect on the human body. In this regard, the solar spectrum is conventionally divided into 3 sections:
1. ultraviolet rays, from 280 to 400 nm
2. visible spectrum from 400 to 760 nm
3. infrared rays from 760 to 2800 nm.
With daily and annual solar radiation, the composition and intensity of individual spectra undergo changes. The rays of the UV spectrum undergo the greatest changes.
We estimate the intensity of solar radiation based on the so-called solar constant. The solar constant is the amount of solar energy received per unit time per unit area located at the upper boundary of the atmosphere at right angles to the sun's rays at the average distance of the Earth from the Sun. This solar constant was measured by satellite and is equal to 1.94 calories/cm2 per minute. Passing through the atmosphere, the sun's rays are significantly weakened - scattered, reflected, absorbed. On average, with a clear atmosphere on the Earth's surface, the intensity of solar radiation is 1.43 - 1.53 calories/cm2 per minute.
The intensity of solar rays at noon in May in Yalta is 1.33, in Moscow 1.28, in Irkutsk 1.30, in Tashkent 1.34.
Biological significance of the visible part of the spectrum.
The visible part of the spectrum is a specific irritant of the organ of vision. Light is a necessary condition for the functioning of the eye, the most subtle and sensitive sense organ. Light provides approximately 80% of information about the outside world. This is the specific effect of visible light, but also the general biological effect of visible light: it stimulates the body’s vital activity, enhances metabolism, improves overall well-being, affects the psycho-emotional sphere, and increases performance. Light makes the environment healthier. With a lack of natural light, changes occur in the organ of vision. Fatigue quickly sets in, performance decreases, and work-related injuries increase. The body is affected not only by illumination, but also different colors have different effects on the psycho-emotional state. The best performance indicators were obtained with the preparation under yellow and white lighting. Psychophysiologically, colors act opposite to each other. In this regard, 2 groups of colors were formed: 1) warm colors - yellow, orange, red. 2) cold colors - blue, blue, violet. Cold and warm tones have different physiological effects on the body. Warm tones increase muscle tension, increase blood pressure, and increase the breathing rate. Cold tones, on the contrary, lower blood pressure and slow down the rhythm of the heart and breathing. This is often used in practice: for patients with high temperatures, wards painted purple are most suitable; dark ocher improves the well-being of patients with low blood pressure. Red color increases appetite. Moreover, the effectiveness of the drug can be increased by changing the color of the tablet. Patients suffering from depressive disorders were given the same medicine in tablets of different colors: red, yellow, green. Treatment with yellow tablets brought the best results.
Color is used as a carrier of coded information, for example in production to indicate danger. There is a generally accepted standard for signal identification colors: green - water, red - steam, yellow - gas, orange - acids, purple - alkalis, brown - flammable liquids and oils, blue - air, gray - other.
From a hygienic point of view, the assessment of the visible part of the spectrum is carried out according to the following indicators: natural and artificial lighting are assessed separately. Natural lighting is assessed according to 2 groups of indicators: physical and lighting. The first group includes:
1. light coefficient - characterizes the ratio of the area of the glazed surface of windows to the floor area.
2. Angle of incidence - characterizes the angle at which the rays fall. According to the norm, the minimum angle of incidence should be at least 270.
3. Hole angle—characterizes the illumination by heavenly light (must be at least 50). On the first floors of Leningrad houses - wells, this angle is virtually absent.
4. The depth of the room is the ratio of the distance from the top edge of the window to the floor to the depth of the room (the distance from the outer to the inner wall).
Lighting indicators are indicators determined using a device - a lux meter. Absolute and relative illumination is measured. Absolute illumination is the illumination on the street. Illuminance coefficient (KEO) is defined as the ratio of relative illuminance (measured as the ratio of relative illuminance (measured in a room) to absolute, expressed in %. Illumination in a room is measured at the workplace. The principle of operation of a lux meter is that the device has a sensitive photocell (selenium - since selenium is close in sensitivity to the human eye).The approximate illumination on the street can be determined using the light climate graph.
To evaluate artificial lighting of premises, brightness, lack of pulsation, color, etc. are important.
Infrared rays. The main biological effect of these rays is thermal, and this effect also depends on the wavelength. Short rays carry more energy, so they penetrate deeper and have a strong thermal effect. The long-length section exerts its thermal effect on the surface. This is used in physiotherapy to warm up areas at different depths.
In order to measure infrared rays, there is a device - an actinometer. Infrared radiation is measured in calories per cm2\min. The adverse effects of infrared rays are observed in hot shops, where they can lead to occupational diseases - cataracts (clouding of the lens). Cataracts are caused by short infrared rays. A preventative measure is the use of protective glasses and protective clothing.
Features of the effect of infrared rays on the skin: burns occur - erythema. It occurs due to thermal expansion of blood vessels. Its peculiarity is that it has different boundaries and appears immediately.
Due to the action of infrared rays, 2 conditions of the body can occur: heatstroke and sunstroke. Sunstroke is the result of direct exposure to sunlight on the human body, mainly affecting the central nervous system. Sunstroke affects those who spend many hours in a row under the scorching rays of the sun with their heads uncovered. The meninges are warmed up.
Heat stroke occurs due to overheating of the body. It can happen to those who do heavy physical work in a hot room or in hot weather. Heat strokes were especially common among our military personnel in Afghanistan.
In addition to actinometers for measuring infrared radiation, there are various types of pyramidometers. The basis of this action is the absorption of radiant energy by the black body. The receptive layer consists of blackened and white plates, which, depending on infrared radiation, heat up differently. A current is generated on the thermopile and the intensity of infrared radiation is recorded. Since the intensity of infrared radiation is important in production conditions, there are standards for infrared radiation for hot shops in order to avoid adverse effects on the human body, for example, in a pipe rolling shop the bench is 1.26 - 7.56, iron smelting 12.25. Radiation levels exceeding 3.7 are considered significant and require preventive measures - the use of protective screens, water curtains, and special clothing.
Ultraviolet rays (UV).
This is the most biologically active part of the solar spectrum. It is also heterogeneous. In this regard, a distinction is made between long-wave and short-wave UV. UV promotes tanning. When UV enters the skin, 2 groups of substances are formed in it: 1) specific substances, these include vitamin D, 2) non-specific substances - histamine, acetylcholine, adenosine, that is, these are products of protein breakdown. The tanning or erythema effect is reduced to a photochemical effect - histamine and other biologically active substances contribute to vasodilation. The peculiarity of this erythema is that it does not appear immediately. Erythema has clearly defined boundaries. Ultraviolet erythema always leads to a more or less pronounced tan, depending on the amount of pigment in the skin. The mechanism of tanning action has not yet been sufficiently studied. It is believed that first erythema occurs, nonspecific substances such as histamine are released, the body converts the products of tissue breakdown into melanin, as a result of which the skin acquires a peculiar shade. Tanning, therefore, is a test of the body's protective properties (a sick person does not tan, tans slowly).
The most favorable tanning occurs under the influence of UV rays with a wavelength of approximately 320 nm, that is, when exposed to the long-wavelength part of the UV spectrum. In the south, short-wave UV rays predominate, and in the north, long-wave UV rays predominate. Short-wavelength rays are most susceptible to scattering. And dispersion occurs best in a clean atmosphere and in the northern region. Thus, the most useful tan in the north is longer, darker. UFL are a very powerful factor in the prevention of rickets. With a lack of UVB, rickets develops in children, and osteoporosis or osteomalacia in adults. This is usually encountered in the Far North or among groups of workers working underground. In the Leningrad region, from mid-November to mid-February, there is practically no UV part of the spectrum, which contributes to the development of solar starvation. To prevent sunburn, artificial tanning is used. Light starvation is a long-term absence of the UV spectrum. When exposed to UV in the air, ozone is formed, the concentration of which must be controlled.
UFLs have a bactericidal effect. It is used to disinfect large wards, food products, and water.
The intensity of UV radiation is determined by the photochemical method by the amount of oxalic acid decomposed under the influence of UV in quartz test tubes (ordinary glass does not transmit UV light). The intensity of UV radiation is also determined by an ultraviolet meter. For medical purposes, ultraviolet radiation is measured in biodoses.
Hygiene
Negative effects of the sun
Exposure time to infrared and ultraviolet waves must be strictly limited. Excessive solar radiation:
- may provoke a deterioration in the general condition of the body (so-called thermal shock due to overheating);
- negatively affect the skin, they can cause permanent changes;
- impairs vision;
- causes hormonal disturbances in the body;
- may provoke the development of allergic reactions;
- can provoke a negative impact on the human genome and the structure of human DNA;
- negatively affects the fetus;
- negatively affects the human psyche.
The effect of the sun on the skin
Excessive amounts of solar radiation lead to serious skin problems. In the short term, you risk burns or dermatitis. This is the smallest problem you may encounter when enchanted by the sun on a hot day. If this situation is repeated with enviable regularity, solar radiation will stimulate the formation of malignant tumors in skin melanoma.
In addition, ultraviolet irradiation dehydrates the skin, making it thin and sensitive. But permanent residence under direct rays accelerates the aging process, causing the appearance of early wrinkles.
Negative impact on vision
The effect of sunlight on the visual apparatus is enormous. Indeed, thanks to the rays of light, we receive information about the world around us. Artificial lighting can be an alternative to natural light in some ways, but in terms of reading and writing using lamp light, it increases eye strain. When talking about the negative effects on humans and visible sunlight, this means eye damage from prolonged exposure to the sun without sunglasses. Due to the discomfort you may experience, you may experience eye pain, redness, and photophobia. The most serious damage to the retina is burning. It is also possible to dry out the skin and form wrinkles.
What is solar radiation and what types does it exist?
We all know how important the Sun is for our planet. All the energy it emits is called solar radiation. Its path from the star itself to the Earth is very long, and therefore part of the solar energy is absorbed, and part is scattered. Solar radiation is divided into several types:
- straight;
- absent-minded;
- total;
- absorbed;
- reflected.
Direct solar radiation is that which reaches the Earth's surface in full, while scattered radiation does not penetrate the atmosphere. Together these two radiations are called total. A certain portion of the sun's heat escapes into the earth's surface. Such radiation is usually called absorbed. Some areas of the ground may reflect the sun's rays. This is where the name comes from - reflected solar radiation. Before sunrise, the total energy of the Sun. When the Sun is not very high, most of the radiation is scattered.
Energy of sun
To evaluate its quantitative characteristics, the radiant energy flux density and the amount of radiation are used. It is measured in W/m² or cal (J)/cm², that is, energy power per square meter of the Earth. It is divided into two types:
- Arriving in the form of direct sunlight is called direct radiation. It brings the greatest amount of light and warmth.
- In the atmosphere, some part tends to be dissipated by impurities and gas molecules. A small fraction reaches the earth's surface in the form of scattered radiation. It creates daylight and blue sky.
Solar radiation often refers to electromagnetic radiation. But it contains two components that have different properties:
- Electromagnetic. Penetrates the Earth's atmosphere, reaching it at the speed of light. The spectrum of this component extends from radio waves to x-rays.
- Corpuscular. This part consists of protons. Has a speed of 300 to 1500 km per second. During solar flares, high-energy particles are formed, which are a component of cosmic rays. The largest proportion of particles are retained by the Earth's magnetic field or the upper layers of the atmosphere. Therefore, the first component has the most significant intensity.
Impact of solar radiation on humans
The sun can both improve your health and have a detrimental effect on it. If you are exposed to sunlight too often, your risk of developing skin diseases, including cancer, increases. In addition, vision problems may appear.
Although being in the sun a lot is harmful, I would never want to live in the northern regions, where people are constantly waiting for sunny weather. Lack of sun exposure can disrupt the body's metabolism and cause excess weight. For children, lack of sunshine is also extremely undesirable.
Under normal living conditions, solar radiation maintains human health at the desired level. All organs and systems function without failures. In general, solar radiation is good in moderation, and this should always be remembered.
How to protect yourself from solar radiation
It should be understood that the main protection against the harmful effects of radiation is limiting the time spent in direct sunlight. Sunbathing is possible only in the morning and evening hours, when the height of the sun above the horizon is not high and the earth's atmosphere creates additional protection against aggressive radiation.
The use of sunscreens partially saves the skin from burns, but does not provide the desired effect against ultraviolet radiation in the shortest range.
Therefore, if it is not possible to wait out the midday heat indoors, the only reliable protection is to use light-colored clothing, a hat, and sunglasses. Despite the high air temperature, the fabric should cover most of the body and prevent prolonged contact of individual areas of the skin with solar radiation.
It must be remembered that active midday sun is dangerous not only due to burns, but also, first of all, metabolic disorders, disruption of the general hormonal levels, as a result of the risk of developing cancer of the skin and the hematopoietic system of the body.
At this point in time, it has been proven that sun tanning is a protective function of the skin and does not have any positive effect. Therefore, there is no need to risk your health for the sake of dubious beauty. For the human body to maintain the required level of ultraviolet exposure, one hour in the morning on the beach, the radiation received during the day and an evening walk is enough.
