Solar radiation and its effect on the human body and the climate
Blinding solar disk at all times, excited people's minds, served as a fertile topic for legends and myths. Since ancient times people have guessed about its impact on the Earth. How close our ancestors were to the truth. It is the radiant energy of the Sun that we owe the existence of life on Earth.
What is the radioactive radiation of our luminaries and how does it affect the terrestrial processes?
What is solar radiation?
Solar radiation is a collection of solar matter and energy coming to Earth. Energy is distributed in the form of electromagnetic waves at a speed of 300 thousand kilometers per second, passes through the atmosphere and reaches the Earth in 8 minutes. The range of waves participating in this "marathon" is very wide - from radio waves to X-rays, including the visible part of the spectrum. The Earth's surface is under the influence of both direct and scattered by the earth's atmosphere, the sun's rays. It is the scattering in the atmosphere of blue-blue rays that explains the blueness of the sky on a clear day. The yellow-orange color of the solar disk is due to the fact that the waves corresponding to it pass almost without scattering.
With a delay of 2-3 days the earth reaches the "solar wind", which is a continuation of the solar corona and consisting of the nuclei of atoms of light elements (hydrogen and helium), as well as electrons. It is quite natural that solar radiation has a strong influence on the human body.
The effect of solar radiation on the human body
The electromagnetic spectrum of solar radiation consists of the infrared, visible and ultraviolet parts. Since their quanta have different energies, they have a variety of effects on humans.
The result of exposure to infrared radiation is the thermal effect, which is accompanied by the expansion of blood vessels, increased blood flow and skin respiration. There is a relaxation of blood vessels and muscles, which has analgesic and anti-inflammatory effect. Soft heat stimulates the formation and assimilation of biologically active substances.
- Visible radiation has a significant photochemical effect, due to which in the surrounding tissues are very important for the body processes. It is the quanta of visible light that activate the work of the visual analyzer, and the person sees the world in all the variety of colors. Sunlight activates metabolic processes in the body, stimulates the work of the cerebral cortex, improves the emotional state of a person. It is the light that synchronizes the diurnal and seasonal rhythms in a person, determining the time of sleep and wakefulness. Their violation leads to insomnia, impaired ability to work and depression.
- The ultraviolet part is a vital factor. Its deficiency leads to a weakening of immunity, exacerbation of chronic diseases and functional disorders of the nervous system, inhibits the production of vital substances.
The hygienic value of solar radiation is also extremely great. Since visible light is the decisive factor in obtaining information about the outside world, it is necessary to provide a sufficient level of illumination in the room. Its regulation is carried out in accordance with SNiP, which for solar radiation are compiled taking into account the light-climatic features of different geographic zones and are taken into account in the design and construction of various facilities.
Even a superficial analysis of the electromagnetic spectrum of solar radiation proves how great the effect of this type of radiation on the human body.
Distribution of solar radiation across the Earth
Far from all the radiation coming from the Sun reaches the surface of the earth. And there are many reasons for this. The earth steadfastly reflects the attack of those rays that are fatal to its biosphere. This function is performed by the ozone shield of our planet, not missing the most aggressive part of the ultraviolet radiation. The atmospheric filter in the form of water vapor, carbon dioxide, suspended in air dust particles - largely reflects, dissipates and absorbs solar radiation.
That part of it, which overcame all these obstacles, falls to the surface of the earth at different angles, depending on the latitude of the terrain. The life-giving solar heat is distributed unevenly throughout our planet. As the height of the sun's position changes over the course of the year, the mass of air through which the path of the sun's rays passes over the horizon changes. All this has an effect on the distribution of the intensity of solar radiation throughout the planet. The general trend is this: this parameter increases from the pole to the equator, since the greater the angle of incidence of the rays, the more heat it gets per unit area.
Maps of solar radiation allow us to have a picture of the distribution of the intensity of solar radiation across the Earth.
The influence of solar radiation on the Earth's climate
Infrared component of solar radiation has a decisive influence on the Earth's climate.
It is clear that this happens only at a time when the sun is above the horizon. This influence depends on the remoteness of our planet from the Sun, which changes throughout the year. The Earth's orbit is an ellipse, inside which the Sun is located. Making its annual path around the Sun, the Earth then moves away from its star, then approaches it.
In addition to changing the distance, the amount of radiation delivered to the earth is determined by the inclination of the earth's axis to the plane of the orbit (66.5 °) and the change in the seasons caused by it. In summer it is more than in winter. This factor does not exist at the equator, but as the latitude of the observation site increases, the gap between summer and winter becomes significant.
In the processes occurring on the Sun, there are all sorts of cataclysms. Their impact is partly offset by the enormous distances, the protective properties of the earth's atmosphere and the magnetic field of the Earth.
How to protect yourself from solar radiation
The infrared component of solar radiation is the desired heat, which residents of the middle and northern latitudes are eagerly waiting for all the other seasons of the year. Solar radiation as a health factor is enjoyed by both healthy and sick people.
However, we must not forget that heat, like ultraviolet radiation, refers to very strong stimuli. Abuse of their action can lead to a burn, a general overheating of the body, and even to exacerbation of chronic diseases. Taking sunbathing, you should adhere to life-tested rules. It is especially cautious to sunbathe on clear sunny days. Breast children and the elderly, patients with a chronic form of tuberculosis and problems with the cardiovascular system should be content with scattered sunlight in the shade. This ultraviolet, it is enough to meet the needs of the body.
Even young people who do not have special health problems should be protected from solar radiation.
Now there was a movement, whose activists are against sunburn. And not in vain. Tanned skin is undoubtedly beautiful. But the melanin produced by the body (what we call tan) is his defensive reaction to the effects of solar radiation. Benefits of sunburn there! There is even information that tanning shortens life, since radiation has a cumulative property - it accumulates throughout life.
If this is so serious, you should scrupulously observe the rules that prescribe how to protect yourself from solar radiation:
- strictly limit the time for tanning and do it only in safe hours;
- while in the active sun, you should wear a wide-brimmed hat, closed clothing, sunglasses and umbrella;
- use only a quality sunscreen.
In all the seasons of the year, solar radiation is dangerous for humans? The amount of solar radiation entering the earth is associated with a change in the seasons. At mid-latitudes in summer it is 25% more than in winter. At the equator, there is no such difference, but as the latitude of the observation point increases, this difference increases. This is due to the fact that our planet in relation to the sun is inclined at an angle of 23.3 degrees. In winter it is low above the horizon and illuminates the earth only by sliding rays, which warm the illuminated surface less. This position of the rays causes their distribution over a larger surface, which reduces their intensity compared to the summer steep fall. In addition, the presence of an acute angle during the passage of rays through the atmosphere, "lengthens" their path, causing more heat to lose. This circumstance reduces the effect of solar radiation in winter.
The sun is a star, which is a source of heat and light for our planet. It "controls" the climate, the change of the seasons and the state of the entire biosphere of the Earth. And only knowledge of the laws of this powerful influence will allow using this vivifying gift for the benefit of people's health.