Have you ever wondered why on some days you feel worse and lethargic, even though everything seems to be going on as usual? Perhaps you even associated this with the deterioration weather conditions, noticing that bad weather worsens diseases. However, it remains unclear exactly how bad weather displayed on health. The answer is simple - it’s all about the effect of atmospheric pressure on a person.
About atmospheric pressure
Atmospheric pressure is the force with which air presses on the surface of the Earth, as well as on all objects that are on it. It is constantly changing and depends on the height and mass of air, its density, temperature, direction of flow circulation, altitude above sea level, latitude.
Measured in the following units:
- torr or millimeter mercury(mmHg.);
- pascal (Pa, Ra);
- kilogram-force per 1 sq. cm;
- other units.
Which atmospheric pressure is low and which is high?
Exposure to the atmosphere decreases when the temperature rises (summer) and increases when it drops (winter). It also decreases after 12 hours and after 24 hours, and rises in the morning and evening.
On high points On the surface of the Earth there is a smaller layer of air pressing than on low ones, so the gravity of the atmosphere at such points is less. At points located closer to the poles, the atmosphere presses harder due to the cold. Therefore, there was a need to determine a starting point. The norm is considered to be at sea level and a latitude of 45°.
Important! Normal atmospheric pressure is 760 mm Hg. Art. or 101,325 Pa.
Video: atmospheric pressure Accordingly, if the pressure is more than 760 mm Hg. Art., it will be increased for meteorologists; if less, it will be decreased. However, this statement does not apply to specific people. Normal atmospheric pressure is a relative concept; it does not mean optimal for humans.
People live in different climatic zones, different latitudes, at different altitudes above sea level, so they feel different strength air gravity, so it is impossible to determine the optimal level for everyone.
We can only say that for a particular person, the optimal level will be that which is the norm (taking into account the altitude above sea level and other factors) for the area in which he lives.
In other words, the pressure, which would be considered normal for residents of Africa near the equator, may be lower for residents of the Arctic if they come to Africa on an excursion. 
Influence and relationship with the human body
About ¾ of the world's population are weather dependent and react to a decrease in atmospheric pressure by deteriorating their health. Weather-dependent people feel fluctuations in the mercury column when it is about 10 mm.
The deterioration of well-being at low atmospheric pressure is primarily due to the reduced oxygen content in it and the increase in air pressure inside us.
Important! Each person is pressed on average from 12 to 15 tons of air, which does not crush people due to the fact that there is also air inside us, pressing with equal force.
Video: the influence and relationship of atmospheric pressure with the human body The state of health deteriorates due to the fact that the air inside a person strives to enter into equilibrium with the air around him and leaves the body. Therefore, in space, where there is no atmosphere, without a spacesuit, all the air will come out of a person.The liquid boils in the presence of air resistance at +100 °C; when it weakens, the temperature decreases. If you rise to an altitude of 19,200 m above sea level, the blood in your body will boil.
Distinguish 3 types of addiction:
- Straight- when blood pressure rises following an increase in atmospheric pressure, and vice versa. This type is familiar to hypotensive patients, whose blood pressure is usually below normal.
- Reverse- when blood pressure drops when atmospheric pressure rises, and vice versa. This is mainly typical for hypertensive patients.
- Incomplete reverse- when only the upper or lower level of blood pressure changes. Yes, change meteorological conditions may affect people who are normal conditions I am not familiar with hypertension or hypotension.
The gravity of the atmosphere decreases before weather conditions worsen, this manifests itself in a person with the following symptoms:
- nervousness;
- migraine;
- lethargy;
- aching joints;
- numbness of fingers and toes;
- labored breathing;
- accelerated heartbeat;
- vasospasm, circulatory problems;
- blurred vision;
- nausea;
- suffocation;
- dizziness;
- rupture of the eardrum.
Why is low atmospheric pressure dangerous?
The mechanism of influence of reduced air gravity is manifested as follows:
- Air humidity rises, making it harder to breathe.
- The air becomes lighter because there is less of it, that is, the amount of oxygen contained in it also decreases. Oxygen starvation sets in.
- Brain cells, heart, blood vessels, and respiratory organs suffer from a lack of oxygen.
- Oxygen starvation of brain cells causes changes in the mental state - euphoria gives way to apathy and depression.
- As a result, the head begins to hurt, and conventional medications cannot relieve the pain. The person feels dizzy, nauseous, and weak.
- The body's reflex response to a decrease in oxygen supply is rapid breathing.
- On the other hand, intense work of the respiratory organs causes an increase in the need for oxygen. At the same time, due to the greater number of exhalations, the body leaves large quantity carbon dioxide. In response to this, the respiratory center weakens the load, and the number of breaths decreases.
- An accelerated heart rate leads to an increase in heart attacks. Blood begins to flow through the vessels with greater force, and blood pressure rises.
- On the other hand, in response to a decrease in oxygen in the blood, red blood cells begin to be produced in increased quantities in order to carry more oxygen. The blood thickens, the internal organs enlarge, it becomes more difficult for the heart to pump blood, it flows more slowly through the vessels, and blood pressure drops.
- A drop in blood pressure worsens the well-being of not only hypotensive patients, but also hypertensive patients taking medications to lower it.
- Blood thickening impairs its flow through small vessels, blood supply to joints and limbs deteriorates, aching joints and numbness of the limbs appear.
- Deterioration of blood supply and brain function reduces visual acuity.
- The air pressure inside the body increases - in gastrointestinal tract, this causes the diaphragm to rise and the lungs to compress, meaning breathing becomes difficult. The same reason can cause a ruptured eardrum.
- The skin's resistance increases, the body senses stress, produces more stress hormones, and the number of leukocytes in the blood increases.
Did you know? Blaise Pascal calculated that the mass of the entire atmosphere of the Earth is 5 quadrillion tons.
What to do when there is low atmospheric pressure
Most often, problems with weather sensitivity occur in people with overweight, leading sedentary image life and malnutrition.
Did you know? If the Earth's atmosphere disappears, the air temperature will become -170° There will be no sounds, the sky will turn black.
Thus, the indicator of low atmospheric pressure will be different for residents of different areas, so there is no optimal indicator for everyone. 
A decrease in air gravity has a negative impact on the well-being of most people, so such indicators should be closely monitored. To reduce the negative impact, you should lead a calmer and healthier lifestyle on such days.
There is an atmosphere around our planet that puts pressure on everything inside it: rocks, plants, people. Normal atmospheric pressure is safe for humans, but changes in it can seriously affect health and well-being. To avoid possible troubles, scientists from various specialties are studying the effects of blood pressure on humans.
Atmospheric pressure - what is it?
The planet is surrounded by an air mass, which, under the influence of gravity, exerts pressure on all objects located on Earth. The human body is no exception. This is what atmospheric pressure is, and in more simple and understandable terms: blood pressure is the force with which air pressure is exerted on the earth’s surface. It can be measured in pascals, millimeters of mercury, atmospheres, millibars.
Atmospheric pressure under normal conditions
A column of air weighing 15 tons presses on the planet. Logically, such a mass should crush all living things on Earth. Why doesn't this happen? It's simple: the fact is that the pressure inside the body and normal atmospheric pressure for a person are equal. That is, the forces outside and inside are balanced, and the person feels quite comfortable. This effect is achieved due to gases dissolving in tissue fluids.
What is normal atmospheric pressure? Ideal blood pressure is considered to be 750-765 mmHg. Art. These values are considered correct for living conditions, but they are not true for all areas. There are low zones on the planet - up to 740 mm Hg. Art. – and elevated – up to 780 mm Hg. Art. – pressure. People living in them adapt and do not feel any discomfort. At the same time, visitors will immediately feel the difference and will complain of feeling unwell for some time.
Atmospheric pressure standards by region
For different points of the globe, normal atmospheric pressure in mmHg is excellent. This is explained by the fact that the atmosphere affects regions differently. The entire planet is divided into atmospheric belts, and even within small areas, readings can differ by several units. True, sudden changes are rarely felt and are perceived by the body normally.
Normal atmospheric pressure for a person changes under the influence of various factors. It depends on the elevation of the area above sea level, average humidity and temperature. Over warm zones, for example, the compression of the atmosphere is not as strong as over cold ones. Altitude has a strong influence on blood pressure:
- at 2000 m above sea level, a pressure of 596 mmHg is considered normal. Art.,
- at 3000 m – 525 mm Hg. Art.;
- at 4000 m – 462 mm Hg. Art.
What atmospheric pressure is considered normal for humans?
Blood pressure must be determined under ideal conditions: clearly above sea level at a temperature of 15 degrees. What is normal atmospheric pressure? There is no single indicator that is fair for everyone. What normal atmospheric pressure will be for one or another person depends on the state of health, living conditions, hereditary factors. The only thing that can be said with certainty is that optimal blood pressure is one that does not cause harm and is not felt.
How does atmospheric pressure affect people?
Not everyone feels its effects, but this does not mean that the influence of atmospheric pressure on people is absent. Sudden changes, as a rule, make themselves felt. Blood pressure in the human body depends on the force of pushing blood out of the heart and vascular resistance. Both indicators can fluctuate when cyclones and anticyclones change. The body's reaction to pressure surges depends on what normal atmospheric pressure is for that person. Hypotonic patients, for example, react poorly to low blood pressure, and hypertensive patients suffer from an even greater increase in blood pressure.
High atmospheric pressure - impact on humans
An anticyclone is characterized by dry, clear and windless weather. High blood pressure is accompanied by clear skies. Under such conditions, no temperature surges are observed. Hypertensive patients, especially the elderly, people suffering from diseases of the cardiovascular system, and allergy sufferers react most severely to high blood pressure. During anticyclones, hospitals often record cases of heart attacks, strokes, and hypertensive crises.
You can understand that your blood pressure is high by knowing what normal atmospheric pressure is for a person. If the tonometer shows a value 10-15-20 units higher than it, such blood pressure is already considered high. In addition, increased pressure is determined by symptoms such as:
- headache;
- pulsation in the head;
- facial hyperemia;
- noise and whistling in the ears;
- tachycardia;
- ripples before the eyes;
- weakness;
- fast fatiguability.
How does low atmospheric pressure affect people?
The first to feel low blood pressure are heart patients and people suffering from intracranial pressure. They feel general weakness, malaise, complain of migraines, shortness of breath, lack of oxygen and sometimes pain in the intestinal area. The cyclone is accompanied by an increase in temperature and humidity. Hypotensive organisms react to this by dilating blood vessels with a decrease in their tone. Cells and tissues do not get enough oxygen.
The following signs are also considered characteristic of low atmospheric pressure:
- rapid and difficult breathing;
- paroxysmal spasmodic headache;
- nausea;
- prostration.
Weather dependence - how to deal with it?
This problem is complex and unpleasant, but it can be overcome.
How to deal with weather dependence for hypotensive patients:
- Healthy and long sleep – at least 8 hours – strengthens the immune system and makes it more resistant to changes in blood pressure.
- Douses or regular contrast showers are suitable for vascular training.
- Immunomodulators and tonics help improve well-being.
- You should not subject your body to too much physical stress.
- Your diet must include foods containing beta-carotene and ascorbic acid.
Advice for hypertensive patients is slightly different:
- It is recommended to eat more vegetables and fruits, which contain potassium. It is better to exclude salts and liquids from the diet.
- You should take a light, contrasting shower several times throughout the day.
- Measure your blood pressure regularly and, if necessary, take
- During periods of high blood pressure, do not take on complex tasks that require high concentration attention.
- Do not rise to high altitudes during a stable anticyclone.
Man is far from being the king of nature, but rather its child, an integral part of the universe. We live in a world where everything is strictly interconnected and subordinated to a single system.
Everyone knows that the Earth is surrounded by a dense air mass, which is commonly called the atmosphere. And any object, including the human body, is “pressed” by an air column having a certain weight. Scientists have experimentally established that for every square centimeter human body exposed to atmospheric pressure weighing 1.033 kilograms. And if you carry out simple mathematical calculations, it turns out that the average person is under pressure of 15,550 kg.
The weight is colossal, but, fortunately, completely imperceptible. This may be due to the presence of dissolved oxygen in human blood.
What is the effect of atmospheric pressure on humans? Let's talk a little more about this.
Atmospheric pressure standard
Doctors, when talking about what atmospheric pressure is considered normal, indicate a range of 750....760 mmHg. Such a scatter is quite acceptable, since the planet’s topography is not perfectly flat.
Meteor dependence
Doctors say that some people's bodies are able to adapt to any conditions. They don’t even care about such serious tests as long-distance flights on an airplane from one climate zone to another.
At the same time, others, without leaving their apartment, feel the approach of changes in the weather. This can manifest itself in the form of severe headaches, unexplained weakness, or constantly wet palms, for example. Such people are more often diagnosed with diseases of the blood vessels and endocrine system.
It is especially difficult when atmospheric pressure makes a sharp jump over a short time. According to statistics most of people whose bodies react so violently to changes in atmospheric pressure are women living in major cities. Unfortunately, the harsh rhythm of life, overcrowding, and the environment are not the best companions for health.
If desired, you can get rid of addiction. You just need to show persistence and consistency. Everyone knows the methods. These are the basics healthy image life: hardening, swimming, walking-running, healthy eating, adequate sleep, elimination bad habits, weight loss.
How does our body react to increased atmospheric pressure?
Atmospheric pressure (normal for humans) is ideally 760 mmHg. But this figure is very rarely maintained.
As a result of the increase in pressure in the atmosphere, clear weather, there are no sudden changes in humidity and air temperature. The body of hypertensive and allergy sufferers actively reacts to such changes.
In city conditions, in calm weather, gas pollution naturally makes itself felt. The first to feel this are patients who have problems with the respiratory organs.
An increase in atmospheric pressure also affects the immune system. Specifically, this is expressed in a decrease in leukocytes in the blood. A weakened body will not easily cope with infections.
Doctors advise:
Start your day easy morning exercises. Take a contrast shower. For breakfast, give preference to foods high in potassium (cottage cheese, raisins, dried apricots, bananas). Don't indulge in large meals. Don't overeat. This day is not the best for great physical effort and expression of emotions. When you come home, rest for an hour, do routine household chores, and go to bed earlier than usual.
Low atmospheric pressure and well-being
Low atmospheric pressure, how much is it? To answer the question, we can conditionally say if the barometer readings are lower than 750 mmHg. But it all depends on the region of residence. In particular, for Moscow the figures are 748-749 mmHg. are the norm.
Among the first to feel this deviation from the norm are “heart patients” and those who have intracranial pressure. They complain of general weakness, frequent migraines, lack of oxygen, shortness of breath, and pain in the intestines.
Doctors advise:
Normalize your blood pressure. Reduce physical activity. Add ten minutes of rest to every working hour. Drink fluids more often, preferring green tea with honey. Drink morning coffee. Take herbal tinctures indicated for heart patients. Relax in the evenings under a contrast shower. Go to bed earlier than usual.
How changes in humidity affect the body
Low air humidity of 30–40 percent is not beneficial. It irritates the nasal mucosa. Asthmatics and allergy sufferers are the first to feel this deviation. In this case, moisturizing the mucous membrane of the nasopharynx with a slightly salted aqueous solution can help.
Frequent precipitation naturally increases air humidity to 70 - 90 percent. This also has a negative impact on health.
High humidity air can cause exacerbation of chronic kidney and joint diseases.
Doctors advise:
Change the climate to a dry one if possible. Reduce the time you spend outside in wet weather. Go out for a walk in warm clothes. Remember the vitamins
Atmospheric pressure and temperature
The optimal temperature for a person in a room is no higher than +18. This is especially true in the bedroom.
How does it work out? mutual influence atmospheric pressure and oxygen?
In the event of an increase in air temperature and a simultaneous decrease in atmospheric pressure, people with cardiovascular and respiratory diseases suffer.
If the temperature decreases and the atmospheric pressure increases, it becomes worse for hypertensive patients, asthmatics and those who have problems with the stomach and genitourinary system.
In the event of a sharp and repeated temperature fluctuation in the body, unacceptable a large number of histamine, the main trigger of allergies.
Good to know
Now you know what normal atmospheric pressure is for a person. This is 760 mmHg, but the barometer records such indicators very rarely.
It is also important to remember that the change in atmospheric pressure with altitude (at the same time it rapidly decreases) occurs quite sharply. It is precisely because of this difference that a person climbing a mountain very quickly can lose consciousness.
In Russia, atmospheric pressure is measured in mmHg. But the international system accepts pascals as a unit of measurement. In this case, normal atmospheric pressure in pascals will be equal to 100 kPa. If we convert our 760 mmHg. in pascals, then the normal atmospheric pressure in pascals for our country will be 101.3 kPa.
Weather-dependent people are more often than others interested in what atmospheric pressure is considered normal for a person. The weight of the air mass is so great that the human body can withstand a load of over 15 tons. Compensation through pressure helps you not to feel such a load. internal organs. When, due to problems in the body, the adaptation system cannot cope, a weather-dependent person becomes a slave to the weather disaster. The intensity of symptoms depends on how low or high your blood pressure is.
What does the barometer say?
It is known that the pressure force of the Earth's air shell on 1 cm² of surface is balanced by a column of mercury 760 mm high. This indicator is accepted as the norm. When the barometer gives a result higher than 760 mmHg, they speak of increased atmospheric pressure when it is less than 760 mmHg. Art. - about the reduced one. Considering the fact that the Earth's surface heats up unevenly and the terrain is heterogeneous (mountains, lowlands), the barometer readings will differ.
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Favorable weather
Every person is unique. The norm of atmospheric pressure for it will also be unique. Someone will not notice the flight to another climate zone, and someone will feel the approach of a cyclone, which will manifest itself as a headache and “twisting” of the knees. Others have climbed higher into the mountains and feel great, not paying attention to the thin air. A set of natural and weather conditions under which one can feel comfortable and have normal atmospheric pressure for a person. The older a person gets, the more strongly he feels climate change.
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Table of optimal weather conditions
Everyone is influenced not only by atmospheric pressure, but also by air temperature and humidity both outside and in the house. Optimal performance and possible consequences deviations from the norm are shown in the table:
| Atmosphere pressure | 750-760 mm Hg. Art. | above 760 mm Hg. Art. | less than 750 mm Hg. Art. |
| Influence | Comfortable for a person’s well-being. |
|
|
| Air temperature | 18-20° C | Above 25 °C | Less than 16°C |
| Impact | Suitable for work, relaxation, sleep. | Exceeding the air temperature by even 5 ° C from the norm leads to a significant decrease in performance and fatigue. |
|
| Humidity | 50-55% | Less than 45% | More than 60% |
| Effect | Comfortable for your well-being. | The mucous surface of the nasopharynx dries out, its ability to resist viruses and bacteria decreases. | The body's resistance to cold decreases. |
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What is weather dependence?
Weather dependence is the inability of the human body to adapt to changing weather conditions.
People suffering from vegetative-vascular dystonia, hypertension, atherosclerosis, and endocrine diseases are more prone to weather dependence. The baroreceptors of our organs react to the approach of a cyclone or anticyclone, reducing or increasing blood pressure, making them dependent on weather conditions.
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The effect of high atmospheric pressure on blood pressure
The body has the ability to equalize atmospheric pressure with arterial pressure.
An increase in atmospheric pressure forces blood pressure to equalize the imbalance. Arterial pressure decreases, the walls of blood vessels expand. Consequences of hypotension:
- worries bad feeling and general weakness;
- suffer from headaches;
- there is an unpleasant “fullness” in the ears;
- Chronic diseases are getting worse.
Blood chemistry under these conditions will show a decrease in white blood cell levels, which means that immune system it will be more difficult to cope with the infection or virus. The best solution in this situation:
- do not overexert yourself and have a good rest;
- limit alcohol intake during this time;
- enrich the diet with foods containing potassium (dried fruits) and magnesium (cereals, rye bread).
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The effect of low atmospheric pressure on humans
A drop in atmospheric pressure when the weather changes leads to symptoms that are similar to mountain climbing. An insufficient amount of oxygen is unable to saturate the organs of the human body. Shortness of breath appears, the heart beats faster, pain presses in the temples and squeezes the head like a hoop. People with increased intracranial pressure, head injuries, and cardiovascular diseases react sharply to this.
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How to deal with weather dependence?
- nutrition - limit the consumption of fatty, salty foods, focus on dairy products, fruits and vegetables;
- work - balance periods of rest and intensive work, take breaks more often;
- sleep - it should be sufficient, not exceed 7-8 hours, a good solution is not to go to bed later than 11 pm;
- physical activity - regular, moderately intense (daily morning work-out, jogging in summer, skiing in winter);
- water procedures - rubbing with cool water is recommended; too hot baths are not recommended.
Find something favorable ideal condition for life, considering weather influence per person, very difficult. Optimal treatment of weather dependence should be aimed at increasing the elasticity of the walls of blood vessels. Strengthens the cardiovascular system, aligns the mental and emotional background. To feel more comfortable, weather dependent person Doctors recommend taking natural adaptogens, such as tinctures of ginseng, eleutherococcus, and hawthorn.
Our Earth has an atmosphere that puts pressure on everything inside it. In 1634, the Italian scientist Torricelli was the first to determine the value that equals atmospheric pressure. The impact of changes on a person is studied by scientists from various specialties. As it turned out, atmospheric pressure depends on temperature, air density, altitude, gravity, and latitude. It is subject to constant fluctuations.
What atmospheric pressure is considered normal? What is it equal to? Physicists answer: 760 millimeters of mercury. The measurement must be taken exactly at sea level and the temperature must be within 15 degrees.
Per square centimeter of body normal pressure acts as a weight equal to 1.033 kg, but we do not notice it. This is because air gases are dissolved in tissue fluids. They completely balance the atmospheric pressure. An imbalance during weather changes is perceived as a deterioration in well-being. What atmospheric pressure is considered normal? Obviously, one that does not have a negative effect on the body. According to doctors, it is equal to 750 mm. rt. Art.
However, people living in places below or above sea level in conditions of constantly elevated or low blood pressure, adapting, they tolerate it well. Therefore, what atmospheric pressure is considered normal for health also depends on our adaptation.
It is not so much the atmospheric pressure itself that has a negative effect, but rather its rapid changes. Drops or rises in blood pressure cause deterioration in health and heart problems. Normal atmospheric pressure is imperceptible to humans. But with a rapid change, the air in various body cavities acts on the baroreceptors of the internal organs. Some people feel unwell, have joint pain, experience pressure surges and other unpleasant phenomena.
For example, eardrums hurt, abdominal pain bothers you. This is caused by the fact that the air in the body cavities presses on their walls. This is especially felt during cyclones. Anticyclones have less negative influence on the body.
Heart pain, palpitations, and heart rhythm disturbances may occur. Dizziness, heart pain, difficulty breathing are the most typical complaints. Nervous system reacts with increased anxiety and irritability. Some people become more aggressive and conflict prone. This is due to impulses coming from baroreceptors to the brain during changes in atmospheric pressure.
The dependence of well-being on the weather is what weather dependence is. It is most pronounced in people with chronic diseases of blood vessels, heart, lungs and joints.
What atmospheric pressure is considered normal in your area can be found at a weather station. Usually, when making forecasts, meteorologists reduce the pressure at each specific point to the pressure at sea level using a special formula.
Changes in atmospheric pressure are especially important when ascending to high altitudes. High in the mountains decreases partial pressure oxygen. This leads to a decrease in the saturation of the blood with it and the development of hypoxia - high-altitude, or mountain, illness. On high altitude Pulmonary edema may develop, leading to death if untreated.
When an aircraft cabin depressurizes at high altitude, a sharp drop in pressure leads to the fact that all liquids human body boil. Air vascular embolism, paralysis, paresis and infarction of various organs develop.
Atmospheric pressure must be taken into account not only when lifting to high altitudes, but also when working in an environment with low or high pressure. For this purpose, special caisson chambers are used. Violation of safety precautions while working in them can lead to decompression sickness.
If you suffer from weather sensitivity, keep an eye on the weather forecasts. Taking medications in a timely manner will make it easier for you to withstand surges in atmospheric pressure.
Atmosphere pressure
Air, surrounding the Earth, has mass, and despite the fact that the mass of the atmosphere is approximately a million times less than the mass of the Earth (the total mass of the atmosphere is 5.2 * 1021 g, and 1 m3 of air has earth's surface weighs 1.033 kg), this mass of air exerts pressure on all objects located on the earth's surface. The force with which air presses on the earth's surface is called atmospheric pressure.
A column of air weighing 15 tons presses on each of us. Such pressure can crush all living things. Why don't we feel it? This is explained by the fact that the pressure inside our body is equal to atmospheric pressure.
In this way, internal and external pressures are balanced.
Barometer
Atmospheric pressure is measured in millimeters of mercury (mmHg). To determine it, they use a special device - a barometer (from the Greek baros - heaviness, weight and metreo - I measure). There are mercury and liquid-free barometers.
Liquidless barometers are called aneroid barometers(from the Greek a - negative particle, nerys - water, i.e. acting without the help of liquid) (Fig. 1).
Rice. 1. Aneroid barometer: 1 - metal box; 2 - spring; 3 - transmission mechanism; 4 - pointer arrow; 5 - scale
Normal atmospheric pressure
Normal atmospheric pressure is conventionally taken to be air pressure at sea level at a latitude of 45° and at a temperature of 0 °C. In this case, the atmosphere presses on every 1 cm2 of the earth's surface with a force of 1.033 kg, and the mass of this air is balanced by a mercury column 760 mm high.
Torricelli experience
The value of 760 mm was first obtained in 1644. Evangelista Torricelli(1608-1647) and Vincenzo Viviani(1622-1703) - students of the brilliant Italian scientist Galileo Galilei.
E. Torricelli sealed a long glass tube with divisions at one end, filled it with mercury and lowered it into a cup of mercury (this is how the first mercury barometer was invented, which was called the Torricelli tube). The mercury level in the tube dropped as some of the mercury spilled into the cup and settled at 760 millimeters. A void formed above the column of mercury, which was called Torricelli's void(Fig. 2).
E. Torricelli believed that the atmospheric pressure on the surface of the mercury in the cup is balanced by the weight of the mercury column in the tube. The height of this column above sea level is 760 mm Hg. Art.
Rice. 2. Torricelli experience
1 Pa = 10-5 bar; 1 bar = 0.98 atm.
High and low atmospheric pressure
Air pressure on our planet can vary widely. If the air pressure is more than 760 mm Hg. Art., then it is considered elevated, less - reduced.
Since the air becomes more and more rarefied as it rises upward, the atmospheric pressure decreases (in the troposphere on average 1 mm for every 10.5 m of rise). Therefore, for territories located at different altitudes above sea level, the average value of atmospheric pressure will be different. For example, Moscow lies at an altitude of 120 m above sea level, so the average atmospheric pressure for it is 748 mm Hg. Art.
Atmospheric pressure rises twice during the day (morning and evening) and decreases twice (after noon and after midnight). These changes are due to temperature changes and air movement. During the year on the continents, the maximum pressure is observed in winter, when the air is supercooled and compacted, and the minimum in summer.
The distribution of atmospheric pressure over the earth's surface has a pronounced zonal character. This is due to uneven heating of the earth's surface, and consequently, changes in pressure.
On globe Three belts with a predominance of low atmospheric pressure (minima) and four zones with a predominance of high atmospheric pressure (maxima) are distinguished.
IN equatorial latitudes The Earth's surface is warming up greatly. Heated air expands, becomes lighter and therefore rises. As a result, low atmospheric pressure is established near the earth's surface near the equator.
At the poles, under the influence of low temperatures, the air becomes heavier and sinks. Therefore, at the poles the atmospheric pressure is increased by 60-65° compared to the latitudes.
In the high layers of the atmosphere, on the contrary, over hot areas the pressure is high (although lower than at the Earth's surface), and over cold areas it is low.
General scheme The distribution of atmospheric pressure is as follows (Fig. 3): along the equator there is a belt low pressure; at 30-40° latitude of both hemispheres - belt high pressure; 60-70° latitude - low pressure zones; in the polar regions there are areas of high pressure.
As a result of the fact that in temperate latitudes Northern Hemisphere In winter, atmospheric pressure over the continents increases greatly, and the low pressure belt is interrupted. It persists only over the oceans in the form of closed areas of low pressure - the Icelandic and Aleutian lows. On the contrary, winter maximums form over the continents: Asian and North American.
Rice. 3. General diagram of atmospheric pressure distribution
In summer, in the temperate latitudes of the Northern Hemisphere, the belt of low atmospheric pressure is restored. A huge area of low atmospheric pressure centered at tropical latitudes- Asian low - forms over Asia.
In tropical latitudes, the continents are always warmer than the oceans, and the pressure above them is lower. Thus, there are maxima over the oceans throughout the year: North Atlantic (Azores), North Pacific, South Atlantic, South Pacific and South Indian.
Lines that are on climate map connect points with the same atmospheric pressure are called isobars(from the Greek isos - equal and baros - heaviness, weight).
The closer the isobars are to each other, the faster the atmospheric pressure changes over a distance. The amount of change in atmospheric pressure per unit distance (100 km) is called pressure gradient.
The formation of atmospheric pressure belts near the earth's surface is influenced by uneven distribution solar heat and rotation of the Earth. Depending on the time of year, both hemispheres of the Earth are heated by the Sun differently. This causes some movement of the atmospheric pressure belts: in summer - to the north, in winter - to the south.
Man learned to use the force of air pressure a long time ago. This was manifested in all areas of his activity: people forced the wind to move boats under sails, with the help air flow The wings of windmills rotated. But the most surprising thing is that for centuries no one could prove that air has weight. Only in the seventeenth century was an experiment carried out, as a result of which it was established that air, after all, has weight.
Back in 1640, the Duke of Tuscany came up with a fountain that he wanted to install on the terrace of his own palace. For this construction it was supposed to take water from a lake located nearby. But no matter how hard the workers tried, the water did not want to rise above ten meters. Strange phenomenon worried the Duke, and he turned to wise old man Galileo. But even the great scientist could not immediately find the reason for this phenomenon. Then Torricelli, a student of Galileo, took up the matter, and after lengthy experiments he was able to prove that air has mass. A little later, thanks to this discovery, the barometer was invented.
Human well-being and atmospheric pressure
The influence of atmospheric pressure on our body is inevitable, but we can fight it: don’t be nervous, don’t overexert yourself physically, take herbs.
Needless to say, the influence of atmospheric pressure on humans could not but interest scientists. Researchers have long noticed that normal pressure does not affect the well-being of a person living in a certain area for a long time. great influence. Even being in conditions of high atmospheric pressure does not in any way affect your health and well-being. But, nevertheless, doctors have proven that with high blood pressure a person’s heart rate noticeably decreases, and there is also a decrease blood pressure. Breathing becomes deep, but less frequent. The sense of smell and hearing deteriorates slightly, and the voice sounds muffled. Skin seem a little numb, dry mucous membranes of the nose, eyes and oral cavity. It should be noted that all of the above phenomena are tolerated by the body quite easily. Adverse Events observed with changes in atmospheric pressure. It will be better for people if the pressure begins to change gradually. In this case, the body will have time to adapt to new conditions without consequences. At low atmospheric pressure, breathing increases, and the heart rate also increases, but the force of the heart beat becomes weaker. The number of red blood cells in the blood increases. With a decrease in atmospheric pressure, a phenomenon such as oxygen starvation is possible. This is due to the fact that during normal functioning of the circulatory and respiratory systems, less oxygen enters the body.
What atmospheric pressure is considered normal?
Atmospheric pressure is considered to be the air pressure on the earth's surface and all objects located on it. At any point in the atmosphere, the pressure will be equal to the weight of a higher column of air with a base equal to a unit surface area. According to international system units, the basic unit for measuring atmospheric pressure is the hectopascal. But it is also possible to use the old units of measurement - millibar and millimeter of mercury. As you know, normal atmospheric pressure is a pressure of 760 mmHg at a temperature of zero degrees Celsius. In addition, measuring atmospheric pressure helps predict weather changes. There is a direct relationship between weather changes and changes in atmospheric pressure.
Answering the question of what atmospheric pressure is considered normal, it should be noted that pressure can change with altitude. Gas is highly compressible, therefore, the more it is compressed, the higher its density, and accordingly, the pressure will be greater. The layers of air located below are compressed by all the layers above. The farther from the earth's surface, the thinner the air. Its density decreases, which means the atmospheric pressure will be low. All weather stations are located at different heights relative to sea level. Therefore, to create unified system measurements, it was customary to present the obtained indicators taking into account the altitude above sea level.
It is also worth knowing that blood pressure changes throughout the day. At night it increases, and during the day it decreases. This happens due to temperature changes. With increasing latitude, the amplitude of changes in atmospheric pressure decreases, but closer to the poles non-periodic changes in blood pressure become more noticeable to humans. Due to the different distribution of blood pressure over the Earth's surface, movement occurs atmospheric fronts And air masses, which determines the speed and direction of the wind.
Of course, we cannot change the effect of atmospheric pressure on a person, but helping our own body is not so difficult. To get through a difficult period, you need to calm down, reduce physical activity if possible and not panic. People who find adaptation particularly difficult should consult a doctor for advice. The doctor will prescribe medicines and will give individual recommendations.
Atmospheric pressure means the pressure of the mass atmospheric air on the surface of the Earth and objects located on it. The degree of pressure corresponds to the weight of atmospheric air with a base of a certain area and configuration.
The main unit of measurement of atmospheric pressure in the SI system is Pascal (Pa). In addition to Pascals, other units of measurement are also used:
- Bar (1 Ba=100000 Pa);
- millimeter of mercury (1 mm Hg = 133.3 Pa);
- kilogram of force per square centimeter (1 kgf/cm 2 =98066 Pa);
- technical atmosphere (1 at = 98066 Pa).
The above units are used for technical purposes, with the exception of millimeters of mercury, which is used for weather forecasts.
The main instrument for measuring atmospheric pressure is the barometer. Devices are divided into two types - liquid and mechanical. The design of the first is based on flasks filled with mercury and immersed with the open end in a vessel with water. The water in the vessel transmits the pressure of the atmospheric air column to mercury. Its height acts as an indicator of pressure.
Mechanical barometers are more compact. The principle of their operation lies in the deformation of a metal plate under the influence of atmospheric pressure. The deforming plate presses on the spring, which, in turn, sets the needle of the device in motion.
The influence of atmospheric pressure on the weather
Atmospheric pressure and its effect on weather conditions varies depending on place and time. It varies depending on the altitude above sea level. Moreover, there are dynamic changes associated with the movement of areas of high pressure (anticyclones) and low pressure (cyclones).
Changes in weather associated with atmospheric pressure occur due to the movement of air masses between areas with different pressure. The movement of air masses is formed by wind, the speed of which depends on the difference in pressure in local areas, their scale and distance from each other. In addition, movements of air masses lead to temperature changes.
Standard atmospheric pressure is 101325 Pa, 760 mm Hg. Art. or 1.01325 bar. However, a person can safely tolerate wide range pressure. For example, in the city of Mexico City, the capital of Mexico with a population of almost 9 million people, the average atmospheric pressure is 570 mm Hg. Art.
Thus, the value of the standard pressure is determined accurately. A comfortable pressure has a significant range. This value is quite individual and completely depends on the conditions in which you were born and lived. special person. Thus, a sudden movement from an area with relatively high pressure to an area of lower pressure can affect the work circulatory system. However, with prolonged acclimatization Negative influence fades away.
High and low atmospheric pressure
In high pressure areas the weather is calm, the sky is cloudless and the wind is moderate. High atmospheric pressure in summer leads to heat and drought. In low pressure areas the weather is predominantly cloudy with wind and precipitation. Thanks to such zones, it is cool in summer cloudy weather with rain, and in winter there are snowfalls. The high pressure difference in the two areas is one of the factors leading to the formation of hurricanes and storm winds.
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