And atmospheric pressure. Atmosphere pressure

Atmosphere pressure belongs to the most important meteorological elements. The change in pressure in space and time is closely related to the development of the main atmospheric processes: the heterogeneity of the pressure field in space is the direct cause of the occurrence of air currents, and pressure fluctuations over time are the main cause of weather changes in a particular area.

Atmospheric pressure is the force with which a column of air extending from the surface of the Earth to the upper boundary of the atmosphere presses on 1 cm 2 of the earth's surface. For a long time, it has been the main instrument for measuring pressure, and the value is usually expressed in millimeters of mercury, balancing the air column.

At the beginning of spring, there is a tendency for the pressure fields to restructure and a general slight decrease in pressure occurs. As the continent warms up, the temperature and air pressure contrasts between land and sea smooth out, the baric field is rebuilt, becoming more uniform. In summer, over the territory of Russia, due to the heating of the mainland, the pressure continues to decrease, the Asian anticyclone collapses and a zone of low atmospheric pressure forms in its place, and over the seas with a relatively cold surface - an area of ​​higher pressure.

The annual course of atmospheric pressure in most of the territory of Russia corresponds to the continental type, characterized by a winter maximum, a summer minimum and a large amplitude. The same annual variation in pressure is observed in the monsoonal region. Far East. The maximum annual pressure amplitude at sea level reaches 45 hPa and is observed in the Tuva Basin. As you move away from it, it sharply decreases in all directions. The smallest annual fluctuations in air pressure take place in the north-west of Russia, where active cyclonic activity is observed throughout the year.

In areas of intense cyclogenesis, the normal annual cycle is often disturbed. Depending on the features, this is expressed in a shift or the appearance of additional highs and lows. Thus, in northwestern Russia, the pressure maximum shifts to May, while secondary maxima and minima appear in the annual course on and in the northern part of Kamchatka.

Purely oceanic type of annual variation of atmospheric pressure, which has a maximum in summer months and a minimum in winter, is observed only in the southern part of the peninsula. In the mountains, up to a certain height, the continental type of the annual pressure variation is preserved. In the high-mountain zone, an annual cycle close to the oceanic one is established. The average annual values ​​of air pressure are highly stable over time and vary slightly from year to year, on average by 1–5 hPa.

Changes in average monthly values ​​from year to year significantly exceed the annual ones. Their range can be judged by the difference between the highest and lowest values ​​of the average monthly pressure. The daily change in pressure in is weakly expressed and is measured only in tenths of hectopascals. A characteristic of the average long-term daily variability of atmospheric pressure is the standard deviation.

The limits of pressure change at each particular point can be judged by its extrema. The largest difference between the absolute maximum and minimum is noted in winter months when the processes of cyclo- and anticyclogenesis are most intense.

In addition to periodic fluctuations, which include annual and daily course, atmospheric pressure experiences non-periodic fluctuations that affect the well-being of weather-dependent people. An example of non-periodic fluctuations is the interdiurnal and intradiurnal pressure variability. AT autumn-winter period during the passage of deep cyclones, the change in pressure between the periods of observation (for three hours) in temperate latitudes can be 10–15 hPa, and between adjacent days reach 30–35 hPa or more. So, in a case was recorded when in three hours the pressure dropped by more than 17 mb, and in the pressure difference between days reached 50 hPa.

Maps of average long-term pressure fields give an idea of ​​some concepts of the total, which is a set of main air currents over the globe that carry out horizontal and vertical exchange of air masses. The structural elements of the general circulation of the atmosphere are air masses, frontal zones, western translation, .

If the surface of the Earth were homogeneous, then in the northern hemisphere there would be a west-east transfer of air masses, and the isobars on the maps of pressure fields would have a latitudinal (zonal) direction. In reality, the zoning is violated in many areas, which can be seen even from the maps of average monthly pressure fields in January and July. With a decrease in the integration period (a decade, a day), the disturbance of the transport increases, and closed areas appear on the pressure maps. The reason for the violation of air currents is the unequal heating and, consequently, the air masses formed above them.

Areas of high pressure, outlined by closed isobars, are called, (Az), and areas of low pressure - (Zn). Cyclones and anticyclones¦ are large-scale eddies that are important structural elements of the general circulation of the atmosphere. Their horizontal dimensions range from several hundred to 1.5–2.0 thousand kilometers. When cyclones and anticyclones move, an interlatitudinal exchange is carried out, and, consequently, heat and moisture, due to which the temperature equalizes between the pole and. If this exchange did not take place, at temperate and high latitudes it would be 10–20° lower than in reality.

From what pressure in the atmosphere on 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 the health and well-being of a person, so scientists of various specialties identify these changes and monitor atmospheric pressure, which is subject to constant fluctuations. In our material, we will tell you what is the normal atmospheric pressure for a person in mm of mercury and pascals.

What does atmospheric pressure depend on?

First, let's look at what atmospheric pressure is. This is the pressure force of the air column on a certain unit of surface area.

The ideal conditions for measuring atmospheric pressure are 45 degrees latitude and 0°C air temperature. The measurement must also be taken at sea level.

But it is worth noting that due to changes in the height of the terrain above sea level, atmospheric pressure will also change. But at the same time, it will also be considered the norm, so each locality has its own normal atmospheric pressure.

Atmospheric pressure also depends on the time of day: at night, atmospheric pressure is always higher, as the air temperature is lower. But a person does not notice this, since the difference is 1-2 mm Hg. In addition, in areas that are close to the poles of the earth, fluctuations in atmospheric pressure become more noticeable. But there are no fluctuations at the equator.

What is normal atmospheric pressure for a person

It is generally accepted that normal atmospheric pressure in mmHg is 760 mmHg. That is, a column of air presses on 1 square centimeter of area with such force as a column of mercury 760 mm high. This is the norm of the Earth's atmospheric pressure, which does not adversely affect 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 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 adaptation of the person. For example, many people can safely climb the top of a mountain without feeling the change in barometric pressure, while others faint from rapid changes in barometric pressure.

Only a sharp fluctuation in blood pressure can significantly affect a person's well-being if atmospheric pressure rises or falls faster than 1 mm Hg. pillar for 3 hours.

Note also that millimeters of mercury is not a standard unit of change in blood pressure. In the world it is customary to recognize the norm of atmospheric pressure in pascals. 100 kPa - normal atmospheric pressure for a person 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 (the maximum point above sea level is 255 meters in Teply Stan, and the average is 130-150 meters above the sea surface).

The norm of atmospheric pressure in Moscow is 746-749 mm Hg. It is very difficult to give an accurate result, since the relief in the capital of Russia is uneven. Also, the normal atmospheric pressure per person in Moscow is affected by the time of year. The norm of atmospheric pressure always rises slightly in spring and summer, and decreases in winter and autumn. If you constantly live in Moscow, then you will feel comfortable with blood pressure in Moscow from 745 to 755 mm Hg. pillar.

Normal pressure in St. Petersburg

Height northern capital above sea level is less than the height of Moscow. That's why Therefore, the norm of blood pressure is slightly higher here. Normal atmospheric pressure in St. Petersburg ranges from 753 to 755 mm Hg.

The most low-lying districts of St. Petersburg are characterized by the "classic" norm of blood pressure. The maximum pressure in St. Petersburg can approach 780 mm Hg - such an increase can lead to a powerful anticyclone.

Atmospheric pressure norm by region

It is known that each specific area corresponds to certain normal indicators of atmospheric pressure. The indicator changes according to the height of the object above sea level. The change in indicators occurs due to the movement of air masses between areas with different pressures. Atmospheric pressure changes due to uneven heating of air above the surface of our planet. A number of factors influence:

• Landscape Features
• Planet rotation
• The difference in heat capacity of water and the earth's surface
• Differences in the reflectivity of water and earth

As a result, cyclones and anticyclones are formed, which form the weather conditions of the area. Cyclone means fast-moving eddies with a low level of blood pressure. The summer cyclone is rainy and cool weather, in winter it is warming and snowing. The anticyclone is characterized by high atmospheric pressure, in summer they bring dry and hot weather, in winter - frosty and clear.

The lowest atmospheric pressure is at the equator, and the lowest in the North and south poles. The value of atmospheric pressure fluctuates and 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 mm Hg. And for Central Russia, fluctuations in blood pressure at the level of 730-770 millimeters of mercury. In Mexico City, the capital of Mexico, the atmospheric pressure can drop to 580 mm Hg, 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 mm Hg. pillar. The city is located 3500 meters above sea level.

Normal atmospheric pressure for Russian regions in mmHg

In the winter months, an increased level of atmospheric pressure is observed over most of the territory of the Russian Federation. The highest blood pressure during this period is observed over the Mongolian Altai and Yakutia - about 772 mm Hg. The lowest pressure in the areas over the Barents, Bering and Okhotsk seas is 753 mm Hg. For Vladivostok, normal blood pressure is 761 mm Hg

As we have already said, atmospheric pressure can vary significantly within the same region. Even the indicators of Moscow and the Moscow region may differ, since they have slightly different heights above sea level. Therefore, we provide data on normal atmospheric pressure for Russian cities. But it should be remembered: even within the same city, the data may vary slightly, depending on the elevation of the area.

Video

How to measure atmospheric pressure

Atmospheric pressure in a particular area is measured either with the help of special instruments: a mercury barometer, an aneroid barometer, a liquid and electronic barograph, or by a special formula, if the height 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 free fall acceleration, approximately 9.81 m/s²
• R - universal gas constant - 8.31 J/mol K
• T is the air temperature in Kelvin. Measured by the formula: t Celsius + 273
• h - height above sea level in meters

A mercury barometer is a glass tube, approximately 80 cm long, containing mercury. 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 column of liquid, starting from the level of the cup, will report on the atmospheric pressure at the moment. It is not safe to use such devices, therefore they are used mainly in laboratory conditions, on meteorological stations and in industrial facilities, where measurement accuracy is very important. Electronic barometers are often used in everyday life, digital meteorological stations can be used even in camping and home conditions, and they are inexpensive.

In the event that you have chronic headaches, chest pain, a systematic increase blood pressure, a general deterioration in well-being due to a change in atmospheric pressure, we recommend that you read our article, take care of your health!

In each region of Russia, different atmospheric pressure is considered normal. Therefore, in weather reports, when the number of millimeters of mercury is announced, weather forecasters always say what pressure it is for this area, above or below the norm.

In addition to atmospheric pressure, many factors affect our well-being. About what to do if breathing problems have appeared? Take care of your health, this is the only thing that you can not buy for any money!

You can find out how much air density depends on temperature, it's very interesting!

Moscow is a city located on the Central Russian Upland. As we already know, atmospheric pressure depends precisely on the relief and altitude. If people are above sea level, the atmospheric column presses less.

Therefore, the normal atmospheric pressure in Moscow on the banks of the Moskva River will be guaranteed to be higher than at the source of the Moskva River in the Moscow Region. On the shore we fix a point 168 meters above sea level. And on a hill near the source of the Moscow River - 310. By the way, the most high point in the city itself is located in the area of ​​​​Teply Stan - it is 255 meters.

Meteorologists name a specific figure normal atmospheric pressure for Moscow - 747-748 mm Hg. pillar. It is, of course, like average temperature by hospital. People who permanently live in Moscow feel normal in the range 745-755 mm rt. pillar. The main thing is that the pressure drops are not serious.

Doctors believe that the danger for residents of the metropolis is fraught with, for example, work on the upper floors. If the building's tightness and ventilation system is broken in a high-rise building, then employees of such offices may feel a constant headache and problems with performance. It's all about the abnormal pressure for them.

For Petersburgers, the situation is different. Due to the fact that St. Petersburg is lower above sea level than Moscow, the norm is more high pressure. Average, normal atmospheric pressure for St. Petersburg is 753-755 mm Hg. pillar. However, in some sources you can see another figure - 760 mm Hg. pillar. However, it is valid only for low-lying districts of St. Petersburg.

Due to its location, the Leningrad region has unstable climatic indicators, and atmospheric pressure can fluctuate significantly. For example, it is not uncommon for it to rise to 780 mm Hg during an anticyclone. pillar. And in 1907, a record atmospheric pressure was recorded - 798 mm Hg. pillar. This is 30 mm more than normal.

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We are used to measuring atmospheric pressure in millimeters of mercury. However international system defines the pressure in Pascals. So, standard atmospheric pressure, according to IUPAC requirements, is 100 kPa.

Let's translate our measurement of mercury barometers into pascals into pascals. So, 760 mmHg a column is 1013.25 mb. According to the SI system, 1013.25 mb is equal to 101.3 kPa.

But still, measuring pressure in Russia in pascals is a rarity. Like the standard 760 mm Hg. pillar. An ordinary resident of Russia just needs to remember what pressure is the norm for his region.

Let's summarize.

1. Normal atmospheric pressure - 760 mm Hg. pillar. However, it rarely occurs. It is quite comfortable for a person to live in the range from 750 to 765 mm Hg. pillar.
2. In each region of the country, different pressure is considered normal for this region. If a person lives in a low pressure zone, he gets used to it and adapts to it.
3. Normal atmospheric pressure for Moscow is 747-748 mm Hg. pillar, for St. Petersburg - 753-755 mm.
4. The value of normal pressure in pascals will be 101.3 kPa.

If you want to measure the atmospheric pressure in your region and find out how it corresponds to the norm, we recommend using the most modern device - an electronic barometer. In the event that you are weather dependent and suffer from a sharp change in atmospheric pressure, it is recommended to use a tonometer to check the quality of your own health.

A short video about atmospheric pressure

Approximately one third of the population of our planet is sensitive to changes environment. Most of all, human well-being is affected by atmospheric pressure - the attraction of air masses to the Earth. What atmospheric pressure is considered normal for a person depends on the area in which he stays most of the time. Everyone will feel comfortable in the conditions familiar to him.

What is atmospheric pressure

The planet is encircled air mass, which, under the influence of gravity, presses on any object, including the human body. The force is called atmospheric pressure. A column of air weighing approximately 100,000 kg presses on each square meter. Atmospheric pressure is measured with a special device - a barometer. It is measured in pascals, millimeters of mercury, millibars, hectopascals, atmospheres.

The normal atmospheric pressure is 760 mm Hg. Art., or 101 325 Pa. The discovery of the phenomenon belongs to the famous physicist Blaise Pascal. The scientist formulated the law: at the same distance from the center of the earth (does not matter, in the air, at the bottom of the reservoir), the absolute pressure will be the same. He was the first to propose measuring heights by barometric equalization.

Atmospheric pressure norms by region

It is impossible to find out what atmospheric pressure is considered normal for a healthy person - there is no definite answer. By different regions the globe the impact is not the same. Within a relatively small area, this value can vary markedly. For example, in Central Asia, slightly elevated figures are considered standard (average 715-730 mm Hg). For middle lane Russia's normal atmospheric pressure is 730-770 mm Hg. Art.

The indicators are related to the elevation of the surface above sea level, wind direction, humidity and ambient temperature. Warm air weighs less than cold air. over the area with elevated temperature or moisture, the compression of the atmosphere is always less. People living in high mountain areas are not sensitive to such barometer readings. Their body was formed in these conditions, and all organs underwent appropriate adaptation.

How pressure affects people

The ideal value is 760 mm Hg. Art. What awaits when the mercury column fluctuates:

1. A change in optimal performance (up to 10 mm/h) already leads to a deterioration in well-being.
2. With a sharp increase, decrease (on average by 1 mm / h), even in healthy people there is a significant deterioration in well-being. Appears headache, nausea, loss of working capacity.

Meteorological dependence

Human sensitivity to weather conditions - wind changes, geomagnetic storms - is called meteorological dependence. The influence of atmospheric pressure on is not yet fully understood. It is known that when changing weather conditions internal tension is created inside the vessels and cavities of the body. Meteorological dependence can be expressed:

• irritability;
• pains of various localization;
• exacerbation of chronic diseases;
• general deterioration of well-being;
• vascular problems.

In most cases, weather dependence affects people with the following diseases:

• disease respiratory tract;
• hypo- and hypertension.

Response to high blood pressure

A decrease in barometer readings by at least 10 units (770 mm Hg and below) has Negative influence on health. Particularly affected by weather changes are people with long-standing diseases of the cardiovascular and digestive system. Doctors on such days recommend reducing physical exercise, less to be on the street, do not abuse junk food and alcohol. Among the main reactions:

• feeling of congestion in the ear canals;
• decrease in the number of leukocytes in the blood;
• decreased activity of intestinal motility;
• functionality violation of cardio-vascular system;
• poor ability to concentrate.

Reaction to reduced atmospheric pressure

Lowering the compression of the atmosphere to 740 mm or less causes opposite shifts in the body. At the heart of all adverse changes is oxygen starvation. A rarefaction of air is created, a low percentage of oxygen molecules: it becomes harder to breathe. Arise.

Atmospheric pressure is the force with which the air around us presses on the earth's surface. The first person to measure it was Galileo Galilei's student Evangelista Torricelli. In 1643, together with his colleague Vincenzo Viviani, he conducted a simple experiment.

The Torricelli Experience

How could he determine atmospheric pressure? Taking a meter tube, sealed at one end, Torricelli poured mercury into it, closed the hole with his finger and, turning it over, lowered it into a bowl also filled with mercury. At the same time, part of the mercury spilled out of the tube. The mercury column stopped at 760 mm. from the surface level of mercury in the bowl.

Interestingly, the result of the experiment did not depend on the diameter, inclination, or even the shape of the tube - the mercury always stopped at the same level. However, if the weather suddenly changed (and the atmospheric pressure fell or rose), the mercury column fell or rose by a few millimeters.

Since then, atmospheric pressure has been measured in millimeters of mercury, and the pressure is 760 mm. rt. Art. considered equal to 1 atmosphere and called normal pressure. So the first barometer was created - a device for measuring atmospheric pressure.

Other ways to measure atmospheric pressure

Mercury is not the only liquid that can be used to measure atmospheric pressure. Many scientists in different time water barometers were built, but since water is much lighter than mercury, their tubes rose to a height of up to 10 m. In addition, water already turned into ice at 0 ° C, which created certain inconveniences.

Modern mercury barometers use Torricelli's principle, but are somewhat more complex. For example, a siphon barometer is a long glass tube bent into a siphon and filled with mercury. The long end of the tube is sealed, the short one is open. A small weight floats on the open surface of the mercury, balanced by a counterweight. When the atmospheric pressure changes, the mercury moves, dragging the float along with it, and that, in turn, sets in motion a counterweight associated with the arrow.

Mercury barometers are used in stationary laboratories and meteorological stations. They are very accurate, but quite cumbersome, so at home or in the field, atmospheric pressure is measured using a liquid-free or aneroid barometer.

How an aneroid barometer works

In a liquidless barometer, fluctuations in atmospheric pressure are perceived by a small round metal box with rarefied air inside. The aneroid box has a thin corrugated membrane wall, which is pulled back by a small spring. The membrane bulges outward when atmospheric pressure falls and pushes inward when it rises. These movements cause deviations of the arrow moving along a special scale. The scale of the aneroid barometer is aligned with the mercury barometer, but it is still considered a less accurate instrument, since over time the spring and membrane lose their elasticity.