From what pressure in the atmosphere at this moment, sometimes a person’s well-being depends very much, because the atmosphere of our planet puts pressure on everything that is inside it. Atmospheric pressure affects human health and well-being, so scientists from various specialties identify these changes and monitor atmospheric pressure, which is subject to constant fluctuations. In our material we will tell you what normal Atmosphere pressure for person in mm mercury and pascals.
What does atmospheric pressure depend on?
First, let's look at what atmospheric pressure is. This is the force of pressure of an air column on a certain unit of surface area.
The ideal conditions for measuring atmospheric pressure are a latitude of 45 degrees and an air temperature of 0°C. The measurement must also be taken at sea level.
But it is worth noting that due to changes in the altitude of the area above sea level, the atmospheric pressure will also change. But at the same time, it will also be considered the norm, so normal atmospheric pressure is different for each area.
Atmospheric pressure also depends on the time of day: at night the atmospheric pressure is always higher because the air temperature is lower. But a person does not notice this, since the difference is 1-2 mmHg. In addition, in areas that are close to the poles of the earth, fluctuations in atmospheric pressure become more noticeable. But at the equator there are no fluctuations.
What is normal atmospheric pressure for a person?
It is generally accepted that normal atmospheric pressure in mmHg is 760 mmHg. That is, on 1 square centimeter of area, a column of air presses with the same force as a column of mercury 760 mm high. This is the normal atmospheric pressure of the Earth, which does not exert negative influence on the human body.
A person does not feel normal atmospheric pressure due to dissolved air gases in tissue fluids, which balance everything. But at the same time, it still exerts a pressure on us equal to 1.033 kg per 1 square centimeter of the body.
But each person must individually understand what atmospheric pressure is considered normal for health, since this largely depends on the person’s adaptation. For example, many people can calmly climb to the top of a mountain without feeling a change in atmospheric pressure, while others faint from rapid changes in atmospheric pressure.
Only a sharp fluctuation in blood pressure can significantly affect a person’s well-being if the atmospheric pressure rises or falls faster than 1 mm Hg. column in 3 hours.
Note also that millimeters of mercury are not a standard unit of change in blood pressure. In the world it is customary to find out the norm of atmospheric pressure in pascals. 100 kPa is normal atmospheric pressure for humans in pascals. A 760 mm Hg. column is 101.3 kPa.
Normal atmospheric pressure for Moscow
Capital Russian Federation located on the Central Russian Upland. There is always low pressure in Moscow, because the city is located above sea level ( maximum point above sea level - 255 meters in Teply Stan, and the average is 130-150 meters above the sea surface).
The normal atmospheric pressure in Moscow is 746-749 mmHg. Accurate result It is very difficult to give, since the capital of Russia has uneven terrain. Also, the normal atmospheric pressure for a person in Moscow is affected by the time of year. The norm of atmospheric pressure always increases slightly in spring and summer, and decreases in winter and autumn. If you permanently live in Moscow, then you will feel comfortable with blood pressure in Moscow from 745 to 755 mm Hg. pillar
Normal blood pressure in St. Petersburg
The height of the Northern capital above sea level is less than the height of Moscow. That's why Therefore, the blood pressure norm here is slightly higher. Normal atmospheric pressure in St. Petersburg ranges from 753 to 755 mmHg.
The lowest-lying areas of St. Petersburg are characterized by a “classical” blood pressure norm. The maximum pressure in St. Petersburg can approach 780 mmHg - such an increase can be caused by a powerful anticyclone.
Standard atmospheric pressure by region
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It is known that each specific area corresponds to certain normal indicators atmospheric pressure. The indicator changes according to the height of the object above sea level. Changes in indicators occur due to the movement of air masses between areas with different pressure. Atmospheric pressure changes due to uneven heating of the air above the surface of our planet. Influenced whole line factors:
- Landscape features
- Planet rotation
- The difference in the heat capacity of water and earth's surface
- Differences in reflectivity between water and land
As a result, cyclones and anticyclones form, forming weather terrain. A cyclone implies fast-moving vortices with a low blood pressure level. A summer cyclone means rainy and cool weather, while winter means warmer weather and snow. Anticyclones are characterized by high atmospheric pressure; in summer they bring dry and hot weather, in winter - frosty and clear.
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The lowest atmospheric pressure is at the equator, and the lowest at the North and South Poles. The amount of atmospheric pressure varies depending on the time of day - the highest at 9-10 and 21-22 hours.
Even within a small area, atmospheric pressure measurements can vary. For example, for Central Asia normal blood pressure is 715-730 mmHg. And for Middle zone In Russia, blood pressure fluctuations are at the level of 730-770 millimeters of mercury. In Mexico City, the capital of Mexico, the atmospheric pressure can drop to 580 mmHg, since the city is located over 2000 meters above sea level. And the atmospheric pressure in China is even lower: for example, in the Tibetan city of Lhasa, the average annual blood pressure is approximately 487 mmHg. pillar The city is located 3500 meters above sea level.
Normal atmospheric pressure for regions of Russia in mm of mercury
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IN winter months above for the most part territory of the Russian Federation is observed increased level atmospheric pressure. The highest blood pressure during this period is observed over the Mongolian Altai and Yakutia - about 772 mmHg. The lowest pressure in the areas above the Barents, Berengov and Okhotsk seas is 753 mmHg. For Vladivostok, normal blood pressure is 761 mmHg
As we have already said, within one region, atmospheric pressure can vary significantly. Even the indicators for Moscow and the Moscow region may differ, since they have slightly different altitudes above sea level. Therefore, we provide data on normal atmospheric pressure for Russian cities. But you should remember: even within the same city, the data may vary slightly, depending on the elevation of the area.
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Standard atmospheric pressure for Russian cities: table |
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Normal atmospheric pressure (mmHg) |
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Rostov on Don |
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Saint Petersburg |
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Ekaterinburg |
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Chelyabinsk |
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Yaroslavl |
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Vladivostok |
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How to measure atmospheric pressure
The atmospheric pressure in a specific area is measured either using special instruments: a mercury barometer, aneroid barometer, liquid and electronic barograph, or using a special formula if the altitude of the area and the pressure at sea level are known.
The formula for determining pressure is as follows: P=P0 * e^(-Mgh/RT)
- PO - pressure at sea level in Pascals
- M - molar mass of air -0.029 kg/mol
- g - Earth's acceleration due to gravity, approximately 9.81 m/s²
- R - universal gas constant - 8.31 J/mol K
- T - air temperature in Kelvin. Measured by the formula: t Celsius + 273
- h - height above sea level in meters
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A mercury barometer is a glass tube approximately 80 cm long containing mercury inside. This tube is sealed on one side and open on the other, the open end is immersed in a bowl of mercury. The height of the liquid column, starting from the level of the cup, will indicate the atmospheric pressure at the moment. It is not safe to use such devices, so they are used mainly in laboratory conditions, at meteorological stations and at industrial facilities, where the accuracy of measurements is very important. Electronic barometers, digital weather stations They can be used even on camping trips and at home, and they are inexpensive.
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 * 10 21 g, and 1 m 3 of air at the earth’s surface weighs 1.033 kg), this mass of air exerts pressure to 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 cm 2 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 its average atmospheric pressure 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 the change and movement of air. During the year on the continents, the maximum pressure is observed in winter, when the air is supercooled and compacted, and the minimum pressure is observed 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 of 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 oceans as closed areas low blood pressure— Icelandic and Aleutian minimums. 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 — formed 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.
Atmospheric air has physical density, as a result of which it is attracted to the Earth and creates pressure. During the development of the planet, both the composition of the atmosphere and its atmospheric pressure changed. Living organisms were forced to adapt to the existing air pressure, changing their physiological characteristics. Deviations from average atmospheric pressure cause changes in a person’s well-being, and the degree of sensitivity of people to such changes varies.
Normal atmospheric pressure
The air extends from the Earth's surface to heights of the order of hundreds of kilometers, beyond which interplanetary space begins, while the closer to the Earth, the more compressed the air is under the influence of own weight, accordingly, atmospheric pressure is highest at the earth's surface, decreasing with increasing altitude.
At sea level (from which all altitudes are usually measured), at a temperature of +15 degrees Celsius, the atmospheric pressure averages 760 millimeters of mercury (mmHg). This pressure is considered normal (from a physical point of view), which does not mean that this pressure is comfortable for a person under any conditions.
Atmospheric pressure is measured by a barometer, graduated in millimeters of mercury (mmHg), or in other physical units, such as pascals (Pa). 760 millimeters of mercury corresponds to 101,325 pascals, but in everyday life the measurement of atmospheric pressure in pascals or derived units (hectopascals) has not taken root.
Previously, atmospheric pressure was also measured in millibars, which fell out of use and were replaced by hectopascals. Normal atmospheric pressure is 760 mm Hg. Art. corresponds to the standard atmospheric pressure of 1013 mbar.
Pressure 760 mm Hg. Art. corresponds to the action of a force of 1.033 kilograms on each square centimeter of the human body. In total, air presses on the entire surface of the human body with a force of about 15-20 tons.
But a person does not feel this pressure, since it is balanced by air gases dissolved in tissue fluids. This balance is disrupted by changes in atmospheric pressure, which a person perceives as a deterioration in well-being.
For some areas, the average atmospheric pressure differs from 760 mm. rt. Art. So, if in Moscow the average pressure is 760 mm Hg. Art., then in St. Petersburg it is only 748 mm Hg. Art.
At night, the atmospheric pressure is slightly higher than during the day, and at the Earth's poles, fluctuations in atmospheric pressure are more pronounced than at equatorial zone, which only confirms the pattern that the polar regions (Arctic and Antarctic) as habitats are hostile to humans.
In physics, the so-called barometric formula is derived, according to which, with an increase in altitude for every kilometer, atmospheric pressure drops by 13%. The actual distribution of air pressure does not follow the barometric formula quite accurately, since temperature, atmospheric composition, water vapor concentration and other indicators change depending on the altitude.
Atmospheric pressure also depends on the weather when air masses move from one area to another. All living things on Earth also respond to atmospheric pressure. Thus, fishermen know that the standard atmospheric pressure for fishing is reduced, because when the pressure drops predatory fish prefers to go hunting.
Impact on human health
Weather-dependent people, and there are 4 billion of them on the planet, are sensitive to changes in atmospheric pressure, and some of them can quite accurately predict weather changes, guided by their well-being.
It is quite difficult to answer the question of what standard of atmospheric pressure is most optimal for a person’s place of stay and life, since people adapt to life in different climatic conditions. Typically the pressure is between 750 and 765 mmHg. Art. does not worsen a person’s well-being; these atmospheric pressure values can be considered within the normal range.
When atmospheric pressure changes, weather-dependent people may feel:
- headache;
- vascular spasms with circulatory disorders;
- weakness and drowsiness with increased fatigue;
- joint pain;
- dizziness;
- feeling of numbness in the limbs;
- decreased heart rate;
- nausea and intestinal disorders;
- shortness of breath;
- decreased visual acuity.
The first thing to react to changes in pressure are those located in the cavities of the body, joints and blood vessels baroreceptors.
When pressure changes, weather-sensitive people experience disturbances in the functioning of the heart, heaviness in the chest, pain in the joints, and in case of digestive problems, also flatulence and intestinal disorders. With a significant decrease in pressure, a lack of oxygen in brain cells leads to headaches.
Also, changes in pressure can lead to mental disorders - people feel anxious, irritated, sleep restlessly, or generally cannot sleep.
Statistics confirm that with sudden changes in atmospheric pressure, the number of crimes, accidents in transport and production increases. The influence of atmospheric pressure on arterial pressure is traced. In hypertensive patients, increased atmospheric pressure can cause a hypertensive crisis with headache and nausea, despite the fact that at this moment clear sunny weather sets in.
On the contrary, hypotensive patients react more sharply to a decrease in atmospheric pressure. The reduced concentration of oxygen in the atmosphere causes circulatory disorders, migraines, shortness of breath, tachycardia and weakness.
Weather sensitivity can be a consequence of an unhealthy lifestyle. The following factors can lead to weather sensitivity or aggravate its severity:
- low physical activity;
- poor nutrition with accompanying excess weight;
- stress and constant nervous tension;
- poor state of the external environment.
Elimination of these factors reduces the degree of meteosensitivity. For weather dependent people follows:
- include foods high in vitamin B6, magnesium and potassium in your diet (vegetables and fruits, honey, lactic acid products);
- limit the consumption of meat, salty and fried foods, sweets and spices;
- stop smoking and drinking alcohol;
- increase physical activity, take walks in the fresh air;
- organize your sleep, sleep at least 7-8 hours.
In our material we will tell you what normal atmospheric pressure is for a person in mm of mercury and pascals. Atmospheric pressure is the force of pressure of an air column per unit area. In summer, in the temperate latitudes of the Northern Hemisphere, the belt of low atmospheric pressure is restored. On the earth's surface, atmospheric pressure varies from place to place and over time.
The origin of this unit is related to the method of measuring atmospheric pressure using a barometer, in which the pressure is balanced by a column of liquid. Mercury is often used as a liquid because it has a very high density (≈13,600 kg/m³) and low pressure saturated steam at room temperature.
Accordingly, when a pressure of 25 microns is indicated on a vacuum pump, we are talking about the maximum vacuum created by this pump, measured in microns of mercury. Of course, no one uses a Torricelli pressure gauge to measure such low pressures. To measure low pressures, other instruments are used, for example, a McLeod pressure gauge (vacuum gauge).
Atmospheric pressure is the pressure of the atmosphere acting on all objects in it and the earth's surface. Atmospheric pressure is equal to the weight of an overlying column of air with a base area equal to one. The presence of atmospheric pressure led people to confusion in 1638, when the Duke of Tuscany's idea to decorate the gardens of Florence with fountains failed - the water did not rise above 10.3 meters.
Together with V. Viviani, Torricelli conducted the first experiment in measuring atmospheric pressure, inventing the first mercury barometer - a glass tube in which there is no air. Under stationary conditions, atmospheric pressure decreases as altitude increases, since it is created only by the overlying layer of the atmosphere.
Atmospheric pressure and our well-being
On maps, atmospheric pressure is depicted using isobars - isolines connecting points with the same surface atmospheric pressure, necessarily reduced to sea level. In chemistry, the standard atmospheric pressure since 1982, according to IUPAC recommendations, has been considered to be a pressure of 100 kPa. Atmospheric pressure is one of the most significant characteristics of the state of the atmosphere.
The height to which one must rise or fall for the pressure to change by 1 hPa (hectopascal) is called the pressure level.
What is normal atmospheric pressure for a person?
The reciprocal of the pressure level is the vertical pressure gradient, that is, the change in pressure when rising or falling by 100 meters. Many weather stations send out so-called “synoptic telegrams”, which indicate the pressure normalized to sea level (see KN-01, METAR). This is done so that the pressure is comparable at stations located at different heights, as well as for aviation needs.
Pressure converter
At low altitudes, every 12 m of ascent reduces atmospheric pressure by 1 mm Hg. Art. At high altitudes this pattern is broken. Weather forecasts and reports disseminated to the public via the Internet and radio use unreduced pressure, that is, the actual pressure at the local level. The force with which air presses on the earth's surface is called atmospheric pressure.
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. 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.
High and low atmospheric pressure
The value of 760 mm was first obtained in 1644 by Evangelista Torricelli (1608-1647) and Vincenzo Viviani (1622-1703) - students of the brilliant Italian scientist Galileo Galilei. The mercury level in the tube dropped as some of the mercury spilled into the cup and settled at 760 millimeters.
Normal atmospheric pressure for St. Petersburg
IN international system units (SI) 1 atm. = 101,325 Pascals (Pa). Blaise Pascal (1623-1662) was a French scientist after whom the pressure unit is named. Air pressure on our planet can vary widely. If the air pressure is more than 760 mm Hg. Art., then it is considered increased, less - decreased. 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).
Atmospheric pressure rises twice during the day (morning and evening) and decreases twice (after noon and after midnight). The distribution of atmospheric pressure over the earth's surface has a pronounced zonal character.
On the globe there are three zones with a predominance of low atmospheric pressure (minimums) and four zones with a predominance of high atmospheric pressure (maxima). Heated air expands, becomes lighter and therefore rises. As a result, low atmospheric pressure is established near the earth's surface near the equator.
Pressure - physical quantity, which characterizes the state of a continuous medium and is numerically equal to the force acting per unit surface area perpendicular to this surface. Fluctuations in atmospheric pressure at sea level were noted within the range of 641 - 816 mm Hg. Art. (inside the tornado the pressure drops and can reach 560 mmHg).
Pressure is a physical quantity that shows the acting force per unit area of a surface perpendicular to this surface.
Pressure is defined as P = F / S, where P is pressure, F is pressure force, S is surface area. From this formula it is clear that pressure depends on the surface area of the body acting with a certain force. The smaller the surface area, the greater the pressure.
The unit of measurement for pressure is newton per square meter(H/m2). We can also convert pressure units N/m 2 to pascals, units named after the French scientist Blaise Pascal, who developed the so-called Pascal's Law. 1 N/m 2 = 1 Pa.
What's happened???
Pressure measurement
Pressure of gases and liquids - manometer, differential pressure gauge, vacuum gauge, pressure sensor.Atmospheric pressure - barometer.
Blood pressure - tonometer.
And so, once again the pressure is defined as P = F / S. The force in the gravitational field is equal to the weight - F = m * g, where m is the mass of the body; g is the acceleration of free fall. Then the pressure is
P = m * g / S . Using this formula, you can determine the pressure exerted by the body on the surface. For example, a person to the ground.
Atmospheric pressure decreases with altitude. The dependence of atmospheric pressure on altitude is determined barometric formula
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P = Po*exp(- μgh/RT) . Where, μ = 0.029 kg/m3 - molecular mass gas (air); g = 9.81 m/s2 - free fall acceleration; h - h o - difference in altitude above sea level and the accepted altitude at the beginning of the report (h=h o); R = 8.31 - J/mol K - gas constant; Po - atmospheric pressure at the height taken as the reference point; T - temperature in Kelvin.
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