Change in atmospheric pressure with altitude. Atmosphere pressure. Change and impact on the weather

The air surrounding the Earth has mass, and despite the fact that the mass of the atmosphere is about a million times less than the mass of the Earth ( total weight 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 on all objects located on the earth's surface. The force exerted by air on the earth's surface is called atmospheric pressure.

A column of 15 tons of air 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.

Thus, internal and external pressures are balanced.

Barometer

Atmosphere pressure measured in millimeters of mercury (mm Hg). To determine it, they use a special device - a barometer (from the Greek baros - gravity, weight and metreo - I measure). There are mercury and non-liquid barometers.

Liquid-free barometers are called aneroid barometers(from Greek a - negative particle, nerys - water, i.e. acting without the help of a liquid) (Fig. 1).

Rice. 1. Aneroid barometer: 1 - metal box; 2 - spring; 3 - transmission mechanism; 4 - arrow pointer; 5 - scale

normal atmospheric pressure

Air pressure at sea level at a latitude of 45° and at a temperature of 0°C is conventionally taken as normal atmospheric pressure. 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.

The 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 soldered a long glass tube with graduations from one end, filled it with mercury and lowered it into a cup with mercury (this is how the first mercury barometer was invented, which was called the Torricelli tube). The level of mercury 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 pressure of the atmosphere 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 greater than 760 mm Hg. Art., then it is considered increased smaller - lowered.

Since the air becomes more and more rarefied with ascent, atmospheric pressure decreases (in the troposphere, on average, 1 mm for every 10.5 m of ascent). Therefore, for territories located on different height above sea level, the average is its value of atmospheric pressure. 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 falls twice (after noon and after midnight). These changes are associated with 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, a change in pressure.

On the the globe three belts are distinguished with a predominance of low atmospheric pressure (minimums) and four belts with a predominance of high pressure (maximums).

In the equatorial latitudes, the surface of the Earth warms up strongly. The 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, atmospheric pressure is increased by 60-65 ° compared to 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.

The general scheme of atmospheric pressure distribution is as follows (Fig. 3): there is a low-pressure belt along the equator; at 30-40 ° latitude of both hemispheres - belts high pressure; 60-70 ° latitude - low pressure zones; in the polar regions - areas of high pressure.

As a result of the fact that in temperate latitudes In the northern hemisphere in winter, atmospheric pressure over the continents rises sharply, the low pressure belt is interrupted. It persists only over the oceans in the form enclosed areas low pressure - Icelandic and Aleutian lows. Over the continents, on the contrary, winter maxima are formed: Asian and North American.

Rice. 3. General scheme of distribution of atmospheric pressure

In summer, in the temperate latitudes of the Northern Hemisphere, the low atmospheric pressure belt is restored. A huge area of ​​low atmospheric pressure centered in tropical latitudes - the Asian Low - is forming over Asia.

In tropical latitudes, the continents are always hotter than the oceans, and the pressure over them is lower. Thus, over the oceans throughout the year there are maxima: North Atlantic (Azores), North Pacific, South Atlantic, South Pacific and South Indian.

The lines that climate map connecting points of equal atmospheric pressure are called isobars(from the Greek isos - equal and baros - heaviness, weight).

The closer the isobars are to each other, the faster atmospheric pressure changes over 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 the uneven distribution of solar heat and the rotation of the Earth. Depending on the season, both hemispheres of the Earth are heated by the Sun in different ways. This causes some movement of atmospheric pressure belts: in summer - to the north, in winter - to the south.

Atmospheric pressure refers to the pressure 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 basic unit for measuring atmospheric pressure in the SI system is the 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 \u003d 98066 Pa);
• technical atmosphere (1 at = 98066 Pa).

The above units of measurement are used for technical purposes, with the exception of millimeters of mercury, which is used for weather forecasts.

The barometer is the main instrument for measuring atmospheric pressure. Devices are divided into two types - liquid and mechanical. The design of the first is based on a flask filled with mercury and immersed with an open end in a vessel with water. The water in the vessel transmits the pressure of the column of atmospheric air to mercury. Its height acts as an indicator of pressure.

Mechanical barometers are more compact. The principle of their work lies in the deformation metal plate under the influence of atmospheric pressure. The deformable plate presses on the spring, and that, in turn, sets in motion the arrow of the device.

Effect of atmospheric pressure on the weather

Atmospheric pressure and its effect on the state of the weather varies depending on the 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 the weather associated with barometric pressure occur due to movement air masses between areas with different pressures. The movement of air masses form a wind, the speed of which depends on the pressure difference in local areas, their scale and distance from each other. In addition, the movement of air masses leads to a change in temperature.

Standard atmospheric pressure is 101325 Pa, 760 mm Hg. Art. or 1.01325 bar. However, a person can easily endure 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 exactly. A comfortable pressure has a significant range. This value is quite individual and completely depends on the conditions in which a particular person was born and lived. So, a sharp movement from a zone with a relatively high pressure to a lower one can affect the work of the circulatory system. However, with prolonged acclimatization, the negative effect disappears.

High and low atmospheric pressure

In high pressure zones, the weather is calm, the sky is cloudless, and the wind is moderate. High atmospheric pressure in summer leads to heat and droughts. In low pressure zones, the weather is predominantly cloudy with wind and precipitation. Thanks to such zones, cool cloudy weather with rain sets in in summer, and snowfalls occur in winter. The high pressure difference in the two areas is one of the factors leading to the formation of hurricanes and storm winds.

There were fluctuations in atmospheric pressure at sea level in the range of 641 - 816 mm Hg. Art. (inside the tornado, the pressure drops and can reach a value of 560 mm Hg). Under stationary conditions, atmospheric pressure decreases with increasing altitude, since it is created only by the overlying layer of the atmosphere. On maps, atmospheric pressure is depicted using isobars - isolines connecting points with the same surface atmospheric pressure, necessarily reduced to sea level. The height to which one must rise or fall in order for the pressure to change by 1 hPa (hectopascal) is called the "baric (barometric) step". At an air temperature of 0 °C and a pressure of 1000 hPa, the baric level is 8 m/hPa. Therefore, in order for the pressure to decrease by 1 hPa, you need to rise 8 meters.

A person can feel a lower atmospheric pressure when he is on a mountain and takes off on an airplane. The main physiological factor in altitude is reduced atmospheric pressure and, consequently, reduced partial pressure of oxygen. The body reacts to low atmospheric pressure, first of all, by increasing breathing. Thanks to this process, the pulmonary ventilation of a person who experiences low atmospheric pressure increases within the required limits and the body receives a sufficient amount of oxygen.

How to calculate altitude from changes in barometric pressure?

4 - What were the readings of the barometer, if it is known that when you rise by 12 m, atmospheric pressure decreases by 1 mm Hg. Art. (1ft=30.5cm)? Answer: The density of air decreases with height. The higher, the rarer the air. To inhale air, a person expands the chest with the help of muscles.

§ 175. Distribution of atmospheric pressure in height

Plotting the decrease in pressure with height. But as altitude increases, air density decreases.

Atmospheric pressure is measured using barometers. A scale is attached next to the tube, showing the change in pressure. The height of the mercury column changes with pressure.

By different regions the globe, the impact is not the same. The indicators are related to the elevation of the surface above sea level, wind direction, humidity and temperature. environment. Warm air weighs less than cold air. over the area with elevated temperature or moisture, the compression of the atmosphere is always less.

The higher the sea level, the lower the air pressure. It decreases, because with the rise, the height of the air column that presses on the earth's surface decreases. The pressure also decreases with altitude because the density of the air itself decreases. Therefore, as the air temperature changes, so does the pressure.

Dependence of pressure on height above sea level

Then the hole was opened, part of the mercury poured out, and a column of mercury of a certain height h remained in the tube, the hydrostatic pressure of which is balanced by atmospheric pressure. Atmospheric pressure decreases with increasing elevation above the Earth. This is due to the fact that with increasing altitude, the thickness of the compressive layer of the atmosphere decreases.

We want to tell you what causes the dependence of pressure on height. Studies have shown that the dependence of atmospheric pressure on altitude differs as follows: an increase of ten meters causes a decrease in the parameter by one unit. The pressure exerted by the air also depends on the temperature, which decreases very much when rising to great height.

Thus, as the distance to the earth increases, the force of gravity acting on the air in the lower parts of the atmosphere increases. Note that the physical nature of the increase in pressure in a liquid with increasing depth is the same as in air. The compressibility of air leads to the fact that the dependence of pressure on the height of the rise above sea level becomes exponential. The Boltzmann distribution, in fact, is directly related to the phenomenon of a drop in air pressure, because this drop leads to the fact that the concentration of particles decreases with height.

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When climbing to a great height, a decrease in atmospheric pressure and rarefied air cause an increase in heart rate, an increase in blood pressure. However, with a further increase in altitude, the level of blood pressure begins to decrease.

Since the air becomes more and more rarefied with ascent, atmospheric pressure decreases (in the troposphere, on average, 1 mm for every 10.5 m of ascent). Therefore, for territories located at different heights above sea level, the average value of atmospheric pressure will be different. Therefore, at the poles, atmospheric pressure is increased by 60-65 ° compared to latitudes. As a result of the fact that in the temperate latitudes of the Northern Hemisphere in winter the atmospheric pressure over the continents greatly increases, the low pressure belt is interrupted. The amount of change in atmospheric pressure per unit distance (100 km) is called the baric gradient.

However, the phenomenon of attraction to the Earth still causes more air molecules to be in the lower atmosphere. However, the decrease in air density with height is significant if we consider the entire atmosphere, which is about 10,000 km in height. In this case, only the change in altitude above sea level affects the change in atmospheric pressure. Then you can easily calculate exactly how atmospheric pressure changes with height.

Under the influence of gravity, the upper layers of air in the earth's atmosphere press on the underlying layers. This pressure, according to Pascal's law, is transmitted in all directions. The highest value is the pressure, called atmospheric, has near the surface of the Earth.

In a mercury barometer, the weight of a column of mercury per unit area (hydrostatic pressure of mercury) is balanced by the weight of a column of atmospheric air per unit area - atmospheric pressure (see figure).

As altitude increases, atmospheric pressure decreases (see graph).

Archimedean force for liquids and gases. Bodies floating conditions

A body immersed in a liquid or gas is subjected to a buoyant force directed vertically upwards and equal to weight liquid (gas) taken in the volume of an immersed body.

The formulation of Archimedes: the body loses in the liquid in weight exactly as much as the weight of the displaced liquid weighs.

The displacing force is applied in the geometric center of the body (for homogeneous bodies - in the center of gravity).

Two forces act on a body in a liquid or gas under normal terrestrial conditions: gravity and the Archimedean force. If the modulus of gravity is greater than the Archimedean force, then the body sinks.

If the modulus of gravity is equal to the modulus of the Archimedean force, then the body can be in equilibrium at any depth.

If the Archimedean force is greater than the force of gravity, then the body floats. The floating body partially protrudes above the surface of the liquid; the volume of the submerged part of the body is such that the weight of the displaced fluid is equal to the weight of the floating body.

The Archimedean force is greater than the force of gravity if the density of the liquid is greater than the density of the immersed body, and vice versa.

• Dizziness;
• Drowsiness;
• Apathy, lethargy;
• joint pain;
• Anxiety, fear;
• Violations of the gastrointestinal tract;

• low physical activity;
• The presence of diseases;
• Fall of immunity;
• Deterioration of the state of the central nervous system;
• Weak blood vessels;
• Age;
• Ecological situation;
• Climate.

• Increased heart rate;
• Weakness;
• Noise in ears;
• redness of the face;

Low atmospheric pressure

• Dizziness;
• Drowsiness;
• Headache;
• Prostration.

• Increased breathing;
• Acceleration of heart rate;
• Headache;
• Asphyxiation attack;
• Nosebleeds.

Meteopathy

1. The concept of atmospheric pressure and its measurement. Air is very light, but it exerts significant pressure on the earth's surface. The weight of air creates atmospheric pressure.

Air exerts pressure on all objects. To verify this, do the following experiment. Pour a full glass of water and cover it with a sheet of paper. Press the palm of the paper against the edges of the glass and quickly turn it over. Take your hand away from the leaf and you will see that the water does not spill out of the glass because the air pressure presses the leaf against the rim of the glass and holds the water.

Atmosphere pressure- the force with which air presses on the earth's surface and on all objects on it. For every square centimeter of the earth's surface, air exerts a pressure of 1.033 kilograms - that is, 1.033 kg / cm2.

Barometers are used to measure atmospheric pressure. Distinguish mercury barometer and metal. The latter is called an aneroid. In a mercury barometer (Fig. 17), a glass tube with mercury sealed from above is lowered with an open end into a bowl with mercury, and an airless space is above the surface of the mercury in the tube. A change in atmospheric pressure on the surface of the mercury in the bowl causes the column of mercury to rise or fall. The value of atmospheric pressure is determined by the height of the mercury column in the tube.

The main part of the aneroid barometer (Fig. 18) is a metal box, devoid of air and very sensitive to changes in atmospheric pressure. When the pressure decreases, the box expands, when the pressure increases, it contracts. With the help of a simple device, changes in the box are transmitted to the arrow, which shows atmospheric pressure on the scale. The scale is divided by the mercury barometer.

If we imagine a column of air from the surface of the Earth to the upper layers of the atmosphere, then the weight of such an air column will be equal to the weight of a column of mercury 760 mm high. This pressure is called normal atmospheric pressure. This is the air pressure at the 45° parallel at 0°C at sea level. If the height of the column is more than 760 mm, then the pressure is increased, less - reduced. Atmospheric pressure is measured in millimeters of mercury (mm Hg).

2. Change in atmospheric pressure. Atmospheric pressure is constantly changing due to changes in air temperature and its movement. When air is heated, its volume increases, density and weight decrease. This causes the atmospheric pressure to drop. The denser the air, the heavier it is, and the pressure of the atmosphere is greater. During the day, it increases twice (morning and evening) and decreases twice (after noon and after midnight). The pressure rises where there is more air and decreases where the air leaves. main reason air movement - its heating and cooling from the earth's surface. These fluctuations are especially pronounced in low latitudes. (What atmospheric pressure will be observed over the land and over the water surface at night?) During the year, the highest pressure in winter months, and the smallest - in the summer. (Explain this distribution of pressure.) These changes are most pronounced at middle and high latitudes and weakest at low latitudes.

Atmospheric pressure decreases with height. Why is this happening? The change in pressure is due to a decrease in the height of the air column that presses on the earth's surface. Also, as altitude increases, air density decreases and pressure drops. At an altitude of about 5 km, atmospheric pressure is reduced by half compared to normal pressure at sea level, at an altitude of 15 km - 8 times less, 20 km - 18 times.

Near the earth's surface, it decreases by approximately 10 mm of mercury per 100 m of elevation (Fig. 19).

At an altitude of 3000 m, a person begins to feel unwell, he has signs of altitude sickness: shortness of breath, dizziness. Above 4000 m, blood from the nose may bleed, as small blood vessels are torn, loss of consciousness is possible. This happens because with height the air becomes rarefied, both the amount of oxygen in it and the atmospheric pressure decrease. The human body is not adapted to such conditions.

On the earth's surface, pressure is distributed unevenly. At the equator, the air gets very hot (Why?), and the atmospheric pressure is lower throughout the year. In the polar regions, the air is cold and dense, and the atmospheric pressure is high. (Why?)

? check yourself

Practicalande tasks * At the foot of the mountain, air pressure is 740 mm Hg. Art., at the top 340 mm Hg. Art. Calculate the height of the mountain. * Calculate the force with which the air presses on the palm of a person if its area is approximately 100 cm2. * Determine the atmospheric pressure at an altitude of 200 m, 400 m, 1000 m, if at sea level it is 760 mm Hg. Art. It is interesting The highest atmospheric pressure is about 816 mm. Hg - registered in Russia, in the Siberian city of Turukhansk. The lowest (at sea level) atmospheric pressure was recorded in the region of Japan during the passage of Hurricane Nancy - about 641 mm Hg. Connoisseur Contest Surface human body the average is 1.5 m2. This means that air exerts a pressure of 15 tons on each of us. Such pressure can crush all living things. Why don't we feel it?

If the weather changes, patients with hypertension also feel bad. Consider how atmospheric pressure affects hypertensive patients and meteorologically dependent people.

Weather dependent and healthy people

Healthy people do not feel any changes in the weather. Weather dependent people experience the following symptoms:

• Dizziness;
• Drowsiness;
• Apathy, lethargy;
• joint pain;
• Anxiety, fear;
• Violations of the gastrointestinal tract;
• fluctuations in blood pressure.

Often, health worsens in the fall, when there is an exacerbation of colds and chronic diseases. In the absence of any pathologies, meteosensitivity is manifested by malaise.

Unlike healthy people, weather-dependent people react not only to fluctuations in atmospheric pressure, but also to increased humidity, sudden cooling or warming. The reason for this is often:

• low physical activity;
• The presence of diseases;
• Fall of immunity;
• Deterioration of the state of the central nervous system;
• Weak blood vessels;
• Age;
• Ecological situation;
• Climate.

As a result, the ability of the body to quickly adapt to changes deteriorates. weather conditions.

High atmospheric pressure and hypertension

If the atmospheric pressure is elevated (above 760 mm Hg), there is no wind and precipitation, they speak of the onset of an anticyclone. During this period, there are no sudden changes in temperature. The amount of harmful impurities in the air increases.

The anticyclone has a negative effect on hypertensive patients. An increase in atmospheric pressure leads to an increase in blood pressure. Working capacity decreases, pulsation and pains in the head, heart pains appear. Other symptoms of the negative influence of the anticyclone:

• Increased heart rate;
• Weakness;
• Noise in ears;
• redness of the face;
• Flashing "flies" before the eyes.

The number of white blood cells in the blood decreases, which increases the risk of infections.

Elderly people with chronic cardiovascular diseases are especially susceptible to the effects of the anticyclone.. With an increase in atmospheric pressure, the likelihood of a complication of hypertension increases - a crisis, especially if blood pressure rises to 220/120 mm Hg. Art. It is possible to develop other dangerous complications (embolism, thrombosis, coma).

Low atmospheric pressure

Poor effect on patients with hypertension and low atmospheric pressure - a cyclone. It is characterized cloudy weather, precipitation, high humidity. The air pressure drops below 750 mm Hg. Art. The cyclone has the following effect on the body: breathing becomes more frequent, the pulse quickens, however, the strength of heart beats is reduced. Some people experience shortness of breath.

With low air pressure, blood pressure also drops. Taking into account the fact that hypertensive patients take drugs to reduce pressure, the cyclone has a bad effect on well-being. The following symptoms appear:

• Dizziness;
• Drowsiness;
• Headache;
• Prostration.

In some cases, there is a deterioration in the functioning of the gastrointestinal tract.

With an increase in atmospheric pressure, patients with hypertension and weather-dependent people should avoid active physical exertion. Need more rest. Recommended low calorie diet containing an increased amount of fruit.

Even "neglected" hypertension can be cured at home, without surgery and hospitals. Just don't forget once a day...

If the anticyclone is accompanied by heat, it is also necessary to exclude physical activity. If possible, stay in an air-conditioned room. Will be relevant low calorie diet. Increase the amount of foods rich in potassium in your diet.

See also: What are the complications of hypertension

To normalize blood pressure at low atmospheric pressure, doctors recommend increasing the amount of fluid consumed. Drink water, infusions of medicinal herbs. It is necessary to reduce physical activity, more rest.

Good sleep helps. In the morning, you can allow a cup of a drink containing caffeine. During the day, you need to measure the pressure several times.

Influence of pressure and temperature change

A lot of health problems can be delivered to hypertensive patients and changes in air temperature. During the anticyclone period, combined with heat, the risk of cerebral hemorrhages and heart damage increases significantly.

Because of high temperature and high humidity the oxygen content in the air decreases. This weather is especially bad for the elderly.

The dependence of blood pressure on atmospheric pressure is not so strong when heat is combined with low humidity and normal or slightly elevated air pressure.

However, in some cases, such weather conditions cause blood clotting. This increases the risk of blood clots and the development of heart attacks, strokes.

The well-being of hypertensive patients will worsen if atmospheric pressure rises simultaneously with a sharp decrease in ambient temperature. With high humidity, strong winds, hypothermia (hypothermia) develops. Excitation of the sympathetic division of the nervous system causes a decrease in heat transfer and an increase in heat production.

The reduction in heat transfer is caused by a decrease in body temperature due to vasospasm. The process contributes to an increase in the thermal resistance of the body. To protect against hypothermia of the extremities, the skin of the face constricts the vessels that are in these parts of the body.

Change in atmospheric pressure with height

As you know, the higher from sea level, the lower the air density and the lower the atmospheric pressure. At an altitude of 5 km, it decreases by about 2 r. The influence of air pressure on the blood pressure of a person located high above sea level (for example, in the mountains) is manifested by such signs:

• Increased breathing;
• Acceleration of heart rate;
• Headache;
• Asphyxiation attack;
• Nosebleeds.

Also read: What causes high eye pressure?

At the core negative impact reduced air pressure lies oxygen starvation, when the body receives less oxygen. In the future, adaptation occurs, and well-being becomes normal.

A person who permanently lives in such an area does not feel the effect of low atmospheric pressure in any way. You should know that in hypertensive patients, when climbing to a height (for example, during flights), blood pressure can change dramatically, which threatens with loss of consciousness.

Under ground and water, air pressure is increased. Its effect on blood pressure is directly proportional to the distance one has to descend.

The following symptoms appear: breathing becomes deep and rare, heart rate decreases, but only slightly. The skin becomes slightly numb, the mucous membranes become dry.

The body of a hypertensive person, like an ordinary person, adapts better to changes in atmospheric pressure if they occur slowly.

Much more severe symptoms develop due to a sharp drop: increase (compression) and decrease (decompression). Under conditions of high atmospheric pressure, miners and divers work.

They descend and rise underground (under water) through locks, where the pressure rises / falls gradually. At elevated atmospheric pressure, the gases contained in the air dissolve in the blood. This process is called "saturation". When decompressed, they come out of the blood (desaturation).

If a person descends to a great depth underground or under water in violation of the sluice regime, the body will be oversaturated with nitrogen. Decompression sickness will develop, in which gas bubbles penetrate the vessels, causing multiple embolisms.

The first symptoms of the pathology of the disease are muscle and joint pain. In severe cases, eardrums burst, dizziness, labyrinthine nystagmus develops. Decompression sickness sometimes ends in death.

Meteopathy

Meteopathy is a negative reaction of the body to changes in the weather. Symptoms range from mild malaise to severe myocardial dysfunction that can cause permanent tissue damage.

The intensity and duration of manifestations of meteopathy depend on age, build, and the presence of chronic diseases. Some ailments last up to 7 days. According to medical statistics, 70% of people with chronic ailments and 20% of healthy people have meteopathy.

The reaction to a change in the weather depends on the degree of sensitivity of the body. The first (initial) stage (or meteosensitivity) is characterized by a slight deterioration in well-being, not confirmed by clinical studies.

The second degree is called meteorological dependence, it is accompanied by changes in blood pressure and heart rate. Meteopathy is the most severe third degree.

With hypertension, combined with meteorological dependence, the cause of deterioration of health can be not only fluctuations in atmospheric pressure, but also other environmental changes. Such patients need to pay attention to weather conditions and weather forecasts. This will allow you to take the measures recommended by the doctor in time.

The cardiovascular system can often fail Changes in weather conditions have a significant impact on the health and well-being of people. Meteopaths can be not only sick, but also healthy people. Let's consider what types of dependence on weather conditions are distinguished, who suffers at the same time, at what atmospheric pressure the head hurts. In addition, we will find out what measures will help prevent the deterioration of well-being in case of meteorological dependence.

• joint pain;
• unreasonable concern;
• decrease in working capacity;
• depression;
• body weakness;
• deterioration of the digestive tract;

Atmospheric pressure is the force with which the air column exerts an effect on 1 cm2 of the surface. The normal level of atmospheric pressure is 760 mm Hg. Art. Even minimal deviations from this value to one of the sides can lead to a deterioration in well-being. The following symptoms may appear:

• headache and dizziness;
• joint pain;
• unreasonable concern;
• decrease in working capacity;
• depression;
• body weakness;
• deterioration of the digestive tract;
• difficulty breathing, shortness of breath.

Atmospheric pressure is the force with which the air column exerts an effect on 1 cm2 of the surface. The normal level of atmospheric pressure is 760 mm Hg. Art. Even minimal deviations from this value to one of the sides can lead to a deterioration in well-being. The following symptoms may appear:

• headache and dizziness;
• joint pain;
• unreasonable concern;
• decrease in working capacity;
• depression;
• body weakness;
• deterioration of the digestive tract;
• difficulty breathing, shortness of breath.

Changes in atmospheric pressure can cause whole line reasons. Let's consider them in more detail:

• Cyclones, in which the pressure of the atmosphere decreases, there is an increase in air temperature, cloudiness, it may rain. Scientists have proven the effect of atmospheric pressure on human blood pressure. Hypotension suffers especially at this time, as well as those who have vascular pathologies and malfunctions. respiratory system. They lack oxygen, they become short of breath. A person with high intracranial pressure has a headache at low atmospheric pressure.
• Anticyclones, in which the weather is clear outside. In this case, the atmospheric pressure, on the contrary, increases. Allergy sufferers and asthmatics suffer from anticyclones. Hypertensive patients have a headache at high atmospheric pressure.
• High or low humidity causes the most inconvenience for allergy sufferers and people with respiratory disorders.
• Air temperature. The most comfortable indicator for a person is +16 ... +18 Co, since in this mode the air is most saturated with oxygen. When the temperature rises, people with diseases of the heart and blood vessels suffer.

There are such degrees of dependence on atmospheric pressure:

• the first (light) - there is a slight malaise, anxiety, irritability, working capacity decreases;
• the second (middle) - there are shifts in the work of the body: blood pressure changes, the heart rhythm goes astray, the content of leukocytes in the blood increases;
• the third (severe) - requires treatment, can lead to temporary disability.

There are such degrees of dependence on atmospheric pressure:

• the first (light) - there is a slight malaise, anxiety, irritability, working capacity decreases;
• the second (middle) - there are shifts in the work of the body: blood pressure changes, the heart rhythm goes astray, the content of leukocytes in the blood increases;
• the third (severe) - requires treatment, can lead to temporary disability.

Scientists distinguish the following types of meteorological dependence:

• cerebral - the appearance of pain in the head, dizziness, tinnitus;
• cardiac - the occurrence of pain in the heart, heart rhythm disturbance, increased breathing, feeling of lack of air;
• mixed - combines the symptoms of the first two types;
• asthenoneurotic - the appearance of weakness, irritability, depression, decreased performance;
• indefinite - the appearance of a feeling of general weakness of the body, pain in the joints, lethargy.

The sharper the weather changes, the stronger the reaction of the human body will be. Even healthy people get headaches when the atmospheric pressure changes.

The human body most often reacts to changing weather conditions with the appearance of a headache. This is due to the fact that when the pressure of the atmosphere decreases, the vessels expand. Conversely, when enlarged, contraction occurs. That is, one can clearly trace the influence of atmospheric pressure on human blood pressure.

There are special baroreceptors in the human brain. Their function is to catch changes in blood pressure and prepare the body for changes in the weather. In healthy people, this happens imperceptibly, but with minor deviations from the norm, symptoms of meteorological dependence begin to appear.

Most people get headaches when the barometric pressure is too low or too high. What to do in this case? The best solution in the presence of meteorological dependence is a healthy sleep, bringing the lifestyle in order and maximizing the body's ability to adapt. In particular, you need:

• Rejection bad habits.
• Minimize the consumption of tea and coffee.
• Hardening, contrast shower.
• Formation of a normal daily routine and compliance with a full sleep regimen.
• Reducing stress.
• Moderate physical activity, breathing exercises.
• Walking on fresh air(can be combined with exercise therapy).
• The use of adaptogens, such as ginseng, eleutherococcus, lemongrass tincture.
• Taking courses of multivitamins.
• Healthy and nutritious food. It is advisable to consume more foods containing vitamin C, potassium, iron and calcium. Recommended fish, vegetables and dairy products. Hypertensive patients should not consume salt.

Meteorological dependence can be manifested by many symptoms. However, one of the most common manifestations of the influence of weather on the body is pain in the head. It can be observed both with an increase in atmospheric pressure and with a decrease. In these two cases, different categories of people feel the influence. With an increase in pressure, hypertensive patients suffer more from headaches, and with a decrease, hypotension. For them, weather changes can lead to serious consequences, up to a heart attack and stroke.

Why does my head hurt with high atmospheric pressure? This is because the blood vessels dilate. Blood pressure rises, heart rate increases, tinnitus appears.

If a person has a headache at high atmospheric pressure, you need to carefully consider your condition. This is necessary, since there is a high risk of a hypertensive crisis, stroke and heart attack, coma, thrombosis, and embolism.

High atmospheric pressure, headache... What should I do? When such a situation arises, it is necessary to limit physical activity, take a contrast shower, drink more fluids, cook low-calorie foods (eat more fruits and vegetables), try not to go out in the heat, but stay in a cool room.

Thus, there is a negative effect of high atmospheric pressure on the vessels of the head. In addition, the load on the heart and the entire cardiovascular system increases. Therefore, if it became known about the increase in atmospheric pressure, you need to prepare in advance for this, putting aside all minor matters and providing the body with rest from stress.

Why do headaches appear at low atmospheric pressure? This is due to the fact that the vessels narrow. Blood pressure decreases, pulse weakens. Breathing becomes difficult. Intracranial pressure increases, which contributes to spasm and headache. Mostly suffer from hypotension. This can lead to serious consequences. For hypotension in this situation, the danger lies in the onset of a hypertensive crisis and coma.

Low atmospheric pressure, headaches… What should I do? In this case, it is recommended to get enough sleep, drink more water, drink coffee or tea in the morning, and also take a contrast shower.

So, a decrease in atmospheric pressure for hypotensive patients is fraught with headaches and can lead to disturbances in the functioning of body systems. Therefore, such people are recommended to regularly harden, give up bad habits, and normalize their lifestyle as much as possible.

Summarizing all of the above, we will following output: an increase or decrease in atmospheric pressure negatively affects the human body. In particular, the nervous system, hormonal levels and the circulatory system suffer. Meteorological dependence is mainly affected by hypertensive and hypotensive patients, allergy sufferers, heart patients, diabetics, asthmatics. But sometimes healthy people also become meteorologists. Moreover, women feel weather changes better than men. To the question of at what atmospheric pressure the head hurts, one can answer that at any other than ideal. The joints are also sensitive to weather changes.

Meteorological dependence is not treated, it is impossible to completely get rid of it. However, timely prevention of diseases and normalization of lifestyle will minimize the occurrence of painful reactions to any sudden changes in the weather.

All bodies in the universe have the property of being attracted to each other. Large and massive have a higher force of attraction compared to small ones. This law is also inherent in our planet.

The earth attracts to itself any objects that are on it, including the gaseous shell surrounding it - the atmosphere. Although the air is much lighter than the planet, it has a lot of weight and presses on everything that is on the earth's surface. This creates atmospheric pressure.

Atmospheric pressure is understood as the hydrostatic pressure of the gas envelope on the Earth and objects located on it. At different heights and in different parts of the world, it has different indicators, but at sea level, 760 mm of mercury is considered standard.

This means that an air column of mass 1.033 kg exerts pressure on a square centimeter of any surface. Accordingly, there is a pressure of more than 10 tons per square meter.

People learned about the existence of atmospheric pressure only in the 17th century. In 1638, the Duke of Tuscany decided to embellish his gardens in Florence with beautiful fountains, but he suddenly discovered that the water in the constructed structures did not rise above 10.3 meters.

Deciding to find out the reason for this phenomenon, he turned to the Italian mathematician Torricelli for help, who, through experiments and analysis, determined that air has weight.

Atmospheric pressure is one of the most important parameters of the Earth's gaseous envelope. Since it varies in different places, a special device is used to measure it - a barometer. An ordinary household appliance is a metal box with a corrugated base, in which there is no air at all.

When the pressure increases, this box contracts, and when the pressure decreases, on the contrary, it expands. Along with the movement of the barometer, a spring attached to it moves, which affects the arrow on the scale.

On the meteorological stations using liquid barometers. In them, pressure is measured by the height of a mercury column enclosed in a glass tube.

Since the atmospheric pressure is created by the overlying layers of the gaseous envelope, as the height increases, it changes. It can be influenced by both the density of the air and the height of the air column itself. In addition, the pressure varies depending on the place on our planet, since different regions of the Earth are located at different heights above sea level.

From time to time over earth's surface slowly moving areas of high or low pressure are created. In the first case, they are called anticyclones, in the second - cyclones. On average, sea level pressures range from 641 to 816 mmHg, although inside a tornado it can drop to 560 mm.

The distribution of atmospheric pressure over the Earth is uneven, which is primarily due to the movement of air and its ability to create the so-called baric vortices.

In the northern hemisphere, clockwise rotation of air leads to the formation of descending air currents (anticyclones), which bring clear or slightly cloudy weather to a particular area with a complete absence of rain and wind.

If the air rotates counterclockwise, then ascending vortices are formed above the ground, characteristic of cyclones, with heavy precipitation, heavy winds, and thunderstorms. In the southern hemisphere, cyclones move clockwise, anticyclones move against it.

An air column weighing from 15 to 18 tons presses on each person. In other situations, such a weight could crush all living things, but the pressure inside our body is equal to atmospheric pressure, therefore, when normal at 760 mmHg we do not experience any discomfort.

If the atmospheric pressure is higher or lower than normal, some people (especially the elderly or sick) feel unwell, have a headache, and notice an exacerbation of chronic diseases.

Most often, a person experiences discomfort at high altitudes (for example, in the mountains), since in such areas the air pressure is lower than at sea level.

The human body is very sensitive to changes in atmospheric pressure (especially during periods of its fluctuation). Reduced or increased atmospheric pressure disrupts some individual functions of the body, which leads to poor health or even the need to take medication.

High blood pressure is considered to be higher than 755 mmHg. This increase in atmospheric pressure primarily affects people prone to mental illness, as well as those with asthma. People with various cardiac pathologies also feel uncomfortable. This is especially pronounced at the moment when jumps in atmospheric pressure occur quite sharply.

In people with hypotension, an increase in atmospheric pressure also causes an increase in blood pressure. If a person is healthy, in such a situation in the atmosphere, only his upper systolic pressure rises, and if a person is hypertensive, his blood pressure decreases with an increase in atmospheric pressure.

At low atmospheric pressure, the partial pressure of oxygen decreases. In human arterial blood, the tension of this gas is noticeably reduced, which stimulates special receptors in the carotid arteries. The impulse from them is transmitted to the brain, resulting in rapid breathing. Thanks to enhanced pulmonary ventilation, the human body is able to fully provide oxygen at altitude (when climbing mountains).

The overall performance of a person at reduced atmospheric pressure is reduced by the following two factors: increased activity of the respiratory muscles, which requires the provision of additional oxygen, and the leaching of carbon dioxide from the body. A large number of people, with low atmospheric pressure, feel problems with some physiological functions, which leads to oxygen starvation of tissues and manifests itself in the form of shortness of breath, nausea, nosebleeds, suffocation, pain and changes in smell or taste, as well as arrhythmic heart function.

How atmospheric pressure affects blood pressure

• Headache.
• Nose bleed.
• Nausea, bouts of vomiting.
• Joint and muscle pain.
• Sleep disorders.
• Psycho-emotional disorders.

With a change in altitude, significant changes in temperature and pressure can be observed. The terrain can greatly influence the formation of the mountain climate.

It is customary to distinguish between mountainous and alpine climates. The first is typical for heights less than 3000-4000 m, the second - for more high levels. It should be noted that the climatic conditions on high vast plateaus differ significantly from the conditions on mountain slopes, in valleys or on individual peaks. Of course, they differ from climatic conditions characteristic of the free atmosphere over the plains. Humidity, atmospheric pressure, rainfall and temperature change quite strongly with altitude.

As the height increases, the air density and atmospheric pressure decrease, in addition, the content of dust and water vapor in the air decreases, which significantly increases its transparency for solar radiation, its intensity increases significantly compared to the plains. As a result, the sky looks bluer and denser, and the light level increases. On average, atmospheric pressure decreases by 1 mmHg for every 12 meters of ascent, but specific indicators always depend on the terrain and temperature. The higher the temperature, the slower the pressure decreases as it rises. Untrained people begin to experience discomfort due to reduced pressure already at an altitude of 3000 m.

Air temperature also decreases with height in the troposphere. Moreover, it depends not only on the height of the area, but also on the exposure of the slopes - on the northern slopes, where the influx of radiation is not so large, the temperature is usually noticeably lower than on the southern ones. At high altitudes (in high mountain climate) the temperature is influenced by firn fields and glaciers. Firn fields are areas of special granular perennial snow (or even a transitional stage between snow and ice) that form above the snow line in the mountains.

In the inner regions of the mountain ranges in winter time stagnant air may occur. This often leads to temperature inversions, i.e. rise in temperature as altitude increases.

The amount of precipitation in the mountains up to a certain level increases with height. It depends on the slope exposure. The largest number precipitation can be observed on those slopes that face the main winds, this amount is further increased if the prevailing winds carry moisture-containing air masses. On the leeward slopes, the increase in precipitation as one ascends is not so noticeable.

Most scholars agree that optimum temperature for normal human well-being is from +18 to +21 degrees, when relative humidity air does not exceed 40-60%. When these parameters change, the body reacts with a change in blood pressure, which is especially noticed by persons with hypertension or hypotension.

Weather fluctuations with a significant change in temperature regimes, when the differences are more than 8 degrees Celsius in one day, negatively affect people with unstable blood pressure.

With a significant increase

temperature vessels

expand dramatically so that the blood circulates faster and cools the body. The heart begins to beat much faster. All this leads to drastic change blood pressure. At

hypertensive patients

with insufficient compensation for the disease, a sharp jump can occur, which will lead to a hypertensive crisis.

Hypotonic patients feel dizzy when the air temperature rises, but at the same time

heartbeat

becomes much faster, which somewhat improves well-being, especially if hypotension occurs against the background of bradycardia.

A decrease in air temperature leads to vasoconstriction,

pressure

decreases somewhat, but against this background there may be a strong headache, since vasoconstriction can lead to spasm. With hypotension, blood pressure can drop to critical levels.

As the weather becomes stable, the autonomic nervous system adjusts to temperature regime, the state of health is stabilized in persons who do not have serious deviations in the state of health.

Patients with chronic diseases with strong fluctuations in air temperature and atmospheric pressure should carefully monitor their health, more often measure blood pressure using

tonometer accept

prescribed by a doctor

drugs

If in the background

the usual dose of pharmaceuticals, unstable blood pressure is still observed, it is necessary to consult a doctor to reconsider tactics

or changing doses of prescribed drugs.

• how the air temperature changes in 2017

Temperature (t) and pressure (P) are two interconnected physical quantities. This relationship is manifested in all three aggregate states of substances. Most natural phenomena depend on fluctuations in these values.

A very close relationship can be found between liquid temperature and atmospheric pressure. Inside any liquid there are many small air bubbles that have their own internal pressure. When heated, saturated vapor from the surrounding liquid evaporates into these bubbles. All this continues until the internal pressure becomes equal to the external (atmospheric) one. Then the bubbles do not withstand and burst - a process called boiling occurs.

A similar process occurs in solids during melting or during the reverse process - crystallization. A solid is made up of crystalline

Which can be destroyed when the atoms are separated from each other. The pressure, while increasing, acts in the opposite direction - it presses the atoms to each other. Accordingly, in order for the body to melt,

more needed

energy and temperature rises.

The Clapeyron-Mendeleev equation describes the temperature dependence

from pressure

in gas. The formula looks like this: PV = nRT. P is the pressure of the gas in the vessel. Since n and R are constants, it becomes clear that pressure is directly proportional to temperature (when V=const). This means that the higher P, the higher t. This process is due to the fact that when heated, the intermolecular space increases, and the molecules begin to move quickly in a chaotic manner, which means that they collide more often

vessel walls

in which the gas is located. The temperature in the Clapeyron-Mendeleev equation is usually measured in degrees Kelvin.

There is the concept of standard temperature and pressure: the temperature is -273 ° Kelvin (or 0 ° C), and the pressure is 760 mm

mercury column

note

Ice has a high specific heat capacity of 335 kJ/kg. Therefore, to melt it, you need to spend a lot of heat energy. For comparison: the same amount of energy can heat water up to 80 °C.

The decrease in air pressure with increasing altitude is a well-known scientific fact that justifies a large number of phenomena associated with low pressure on high altitude above sea level.

You will need

• Physics textbook grade 7, textbook on molecular physics, barometer.

Read in a physics textbook

definition of the concept of pressure. Regardless of what kind of pressure is considered, it is equal to the force acting on a unit area. Thus, the greater the force acting on a certain area, the greater the pressure value. If a we are talking about air pressure, then the force under consideration is the force of gravity of air particles.

Note that each layer of air in the atmosphere makes its own contribution to the air pressure of the lower layers. It turns out that with an increase in the height of the rise above sea level, the number of layers that press on the lower part of the atmosphere increases. Thus, as the distance to the earth increases, the force of gravity acting on the air in the lower parts of the atmosphere increases. This leads to the fact that the layer of air located near the surface of the earth experiences the pressure of all the upper layers, and the layer located closer to the upper boundary of the atmosphere does not experience such pressure. Accordingly, the air of the lower layers of the atmosphere has a pressure much greater than the air of the upper layers.

Remember how the pressure of a liquid depends on the depth of immersion in the liquid. The law describing this regularity is called Pascal's law. He argues that the pressure of a liquid increases linearly with increasing depth of immersion in it. Thus, the tendency for the pressure to decrease with increasing height is also observed in the liquid, if the height is counted from the bottom of the container.

Note that the physical nature of the increase in pressure in a liquid with increasing depth is the same as in air. The lower the liquid layers lie, the more they have to bear the weight of the upper layers. Therefore, in the lower layers of the liquid, the pressure is greater than in the upper ones. However, if in a liquid the pattern of pressure increase is linear, then in air this is not the case. This is justified by the fact that the liquid is not compressible. The compressibility of air leads to the fact that the dependence of pressure on the height of the rise above sea level becomes exponential.

Recall from the course of the molecular-kinetic theory of an ideal gas that such an exponential dependence is inherent in the distribution of particle concentration with the Earth's gravity field, which was revealed by Boltzmann. The Boltzmann distribution, in fact, is directly related to the phenomenon of a drop in air pressure, because this drop leads to the fact that the concentration of particles decreases with height.

A person spends his life, as a rule, at an altitude of the Earth's surface, which is close to sea level. The organism in such a situation experiences the pressure of the surrounding atmosphere. The normal value of pressure is considered to be 760 mm of mercury, this value is also called "one atmosphere". The pressure we experience from the outside is balanced by the internal pressure. In this regard, the human body does not feel the gravity of the atmosphere.

Atmospheric pressure can change during the day. Its performance also depends on the season. But, as a rule, such pressure surges occur within no more than twenty to thirty millimeters of mercury.

Such fluctuations are not noticeable to the body of a healthy person. But in people suffering from hypertension, rheumatism and other diseases, these changes can cause disturbances in the functioning of the body and deterioration in general well-being.

A person can feel a lower atmospheric pressure when he is on a mountain and takes off on an airplane. The main physiological factor in altitude is reduced atmospheric pressure and, consequently, reduced partial pressure of oxygen.

The body reacts to low atmospheric pressure, first of all, by increasing breathing. Oxygen at altitude is discharged. This causes excitation of the chemoreceptors of the carotid arteries, and it is transmitted to the medulla oblongata to the center, which is responsible for increased breathing. Thanks to this process, the pulmonary ventilation of a person who experiences low atmospheric pressure increases within the required limits and the body receives a sufficient amount of oxygen.

An important physiological mechanism that starts at low atmospheric pressure is the increased activity of the organs responsible for hematopoiesis. This mechanism manifests itself in an increase in the amount of hemoglobin and red blood cells in the blood. In this mode, the body is able to transport more oxygen.

Boiling is the process of vaporization, that is, the transition of a substance from a liquid state to a gaseous state. It is very different from evaporation. more speed and violent flow. Any pure liquid boils at a certain temperature. However, depending on the external pressure and impurities, the temperature boiling may change significantly.

You will need

• - flask;
• - test liquid;
• - cork or rubber stopper;
• - laboratory thermometer;
• - bent tube.

As the simplest instrument for determining temperature

boiling

you can use a flask with a capacity of about 250-500 milliliters with a round bottom and a wide neck. Pour the test into it

liquid

(preferably within 20-25%

from volume

vessel), plug the neck with a cork or rubber stopper with two holes. Insert into one of the holes

laboratory thermometer, into the other - a curved tube that plays the role of a safety

to remove vapors.

If to be determined temperature boiling clean liquid - the tip of the thermometer should be close to it, but not touching. If you need to measure temperature boiling solution - the tip should be in the liquid.

What heat source can be used to heat a flask with liquid? It can be a water or sand bath, electric stove, gas burner. The choice depends on the properties of the liquid and its expected temperature. boiling.

Immediately after the process starts

boiling

write down

temperature

Which shows the mercury column of the thermometer. Observe the thermometer readings for at least 15 minutes, recording the readings every few minutes at regular intervals. For example, measurements were taken immediately after the 1st, 3rd, 5th, 7th, 9th, 11th, 13th and 15th

experience. There were 8 in total. After

graduation

experience calculate the arithmetic mean

temperature boiling

according to the formula: tcp = (t1 + t2 +… + t8)/8.

At the same time, it is necessary to take into account important point. In all physical, chemical, technical reference books

temperature indicators boiling liquids

given at normal atmospheric pressure (760 mm Hg). It follows from this that, simultaneously with the measurement of temperature, it is necessary to measure with the help of a barometer

atmospheric

pressure and make the necessary adjustments to the calculations. Exactly the same amendments are given

in tables

temperatures

boiling

for a wide variety of liquids.

• how will the boiling point of water change in 2017

How temperature and atmospheric pressure change in the mountains

When a head starts to hurt before a thunderstorm, and every cell of the body feels the approach of rain, you begin to think that this is old age. In fact, this is how millions of people around the globe react to changeable weather.

This process is called meteorological dependence. The first factor that directly affects well-being is the close relationship between atmospheric and blood pressure.

Atmospheric pressure is a physical quantity. It is characterized by the action of the force of air masses per unit surface. Its value is changeable, depends on the height of the area above sea level, geographical latitude and is associated with the weather. Normal atmospheric pressure is 760 mm Hg. It is at this value that a person experiences the most comfortable state of health.

The deviation of the barometer needle by 10 mm in one direction or another is sensitive to humans. And pressure drops occur for several reasons.

In summer, when the air warms up, the pressure on the mainland drops to a minimum. AT winter period, due to the heavy and cold air, the values ​​of the barometer needle reach a maximum.

In the morning and in the evening, the pressure usually rises slightly, after noon and midnight it becomes lower.

Atmospheric pressure also has a pronounced zonal character. On the globe, areas with a predominance of high and low pressure are distinguished. This happens because the surface of the Earth warms up unevenly.

At the equator, where the land is very hot, warm air rises and areas are formed where the pressure is low. Closer to the poles, cold heavy air descends to the ground, presses on the surface. Accordingly, a high pressure zone is formed here.

Recall the geography course for high school. As the altitude increases, the air becomes thinner and the pressure decreases. Every twelve meters of ascent reduce the barometer reading by 1 mmHg. But at high altitudes, the patterns are different.

See the table for how air temperature and pressure change with climb.

0	15	760
500	11.8	716
1000	8.5	674
2000	2	596
3000	-4.5	525
4000	-11	462
5000	-17.5	405

So, if you climb Mount Belukha (4,506 m), from the foot to the top, the temperature will drop by 30 ° C, and the pressure will drop by 330 mm Hg. That's why high-altitude hypoxia, oxygen starvation, or a miner occurs in the mountains!

Man is so arranged that over time he gets used to new conditions. Stable weather has set in - all body systems work without failures, the dependence of arterial pressure on atmospheric pressure is minimal, the condition is normalizing. And during periods of change of cyclones and anticyclones, the body does not quickly succeed in switching to a new mode of operation, the state of health worsens, it can change, jump blood pressure.

Arterial, or blood, is the pressure of blood on the walls of blood vessels - veins, arteries, capillaries. It is responsible for the uninterrupted movement of blood through all the vessels of the body, and directly depends on the atmospheric pressure.

First of all, people with chronic heart diseases and of cardio-vascular system(perhaps the most common disease is hypertension).

Also at risk are:

• Patients with neurological disorders and nervous exhaustion;
• Allergy sufferers and people with autoimmune diseases;
• Patients with mental disorders obsessive fears and anxiety;
• People suffering from lesions of the articular apparatus.

A cyclone is an area with low atmospheric pressure. The thermometer falls to the level of 738-742 mm. rt. Art. The amount of oxygen in the air decreases.

In addition, the following signs distinguish low atmospheric pressure:

• High humidity and air temperature,
• cloudy,
• Precipitation in the form of rain or snow.

People with diseases of the respiratory system, cardiovascular system and hypotension suffer from such a change in the weather. Under the influence of a cyclone, they experience weakness, lack of oxygen, shortness of breath, shortness of breath.

In some weather-sensitive people, intracranial pressure rises, a headache occurs, and disorders of the gastrointestinal tract occur.

How does a cyclone affect people with low blood pressure? With a decrease in atmospheric pressure, arterial pressure also becomes lower, the blood is saturated with oxygen worse, the result is headaches, weakness, a feeling of lack of air, a desire to sleep. Oxygen starvation can lead to a hypotensive crisis and coma.

We will tell you what to do at low atmospheric pressure. Hypotension patients with the onset of a cyclone need to control blood pressure. It is believed that pressure from 130/90 mm Hg, increased for hypotension, may be accompanied by symptoms of a hypertensive crisis.

Therefore, you need to drink more fluids, get enough sleep. In the morning you can drink a cup of strong coffee or 50 g of cognac. To prevent meteorological dependence, you need to harden the body, take strengthening nervous system vitamin complexes, tincture of ginseng or eleutherococcus.

With the onset of an anticyclone, the barometer needles creep up to the level of 770-780 mm Hg. The weather changes: it becomes clear, sunny, a light breeze blows. The amount of industrial impurities harmful to health is increasing in the air.

High blood pressure is not dangerous for hypotensive patients.

But, if it rises, then allergy sufferers, asthmatics, hypertensive patients experience negative manifestations:

• Headaches and heartaches
• Decreased performance,
• increased heart rate,
• Redness of the face and skin,
• flies flickering before my eyes,
• An increase in blood pressure.

Also, the number of leukocytes in the blood decreases, which means that a person becomes vulnerable to diseases. With blood pressure of 220/120 mm Hg. high risk of developing a hypertensive crisis, thrombosis, embolism, coma.

Doctors advise patients with blood pressure above normal to alleviate the condition to carry out gymnastics complexes, arrange contrast water procedures, eat vegetables and fruits containing potassium. These are: peaches, apricots, apples, Brussels sprouts and cauliflower, spinach.

It is also worth avoiding serious physical exertion, try to get more rest.. When the air temperature rises, drink more liquid: clean drinking water, tea, juices, fruit drinks.

Can weather sensitivity be reduced?

It is possible to reduce weather dependence if you follow the simple but effective recommendations of doctors.

1. banal advice, follow the daily routine. Go to bed early, sleep at least 9 hours. This is especially true for days when the weather changes.
2. Before bedtime drink a glass of mint or chamomile tea. It's calming.
3. Do a light workout in the morning, stretch, massage your feet.
4. After gymnastics take a contrast shower.
5. Get in a positive mood. Remember that a person cannot influence the increase or decrease in atmospheric pressure, but help the body cope with its fluctuations in our strength.

Summary: meteorological dependence is typical for patients with pathologies of the heart and blood vessels, as well as for elderly people suffering from a bunch of diseases. At risk for allergies, asthma, hypertension. The most dangerous for weather-sensitive people are sharp jumps in atmospheric pressure. Hardening of the body and a healthy lifestyle saves from unpleasant sensations.

ATMOSPHERE PRESSURE

Since air has mass and weight, it exerts pressure on the surface in contact with it. It is calculated that a column of air from sea level to the upper limit of the atmosphere presses on an area of ​​1 cm with the same force as a weight of 1 kg 33 g. Man and all other living organisms do not feel this pressure, since it is balanced by their internal air pressure. When climbing in the mountains, already at an altitude of 3000 m, a person begins to feel bad: shortness of breath and dizziness appear. At an altitude of more than 4000 m, nosebleeds can bleed, as blood vessels burst, sometimes a person even loses consciousness. All this happens because atmospheric pressure decreases with height, the air becomes rarefied, the amount of oxygen in it decreases, and the internal pressure of a person does not change. Therefore, in aircraft flying at high altitude, the cabins are hermetically sealed, and the same air pressure is artificially maintained in them as at the surface of the Earth. Pressure is measured using a special device - a barometer - in mmHg.

It has been established that at sea level at the 45° parallel at an air temperature of 0°C, atmospheric pressure is close to the pressure produced by a mercury column 760 mm high. The air pressure under these conditions is called normal atmospheric pressure. If the pressure indicator is greater, then it is considered increased, if it is less, it is considered reduced. When climbing mountains, for every 10.5 m, the pressure decreases by about 1 mmHg. Knowing how pressure changes, using a barometer, you can calculate the height of a place.

Pressure doesn't just change with height. It depends on the air temperature and on the influence of air masses. Cyclones lower atmospheric pressure, while anticyclones increase it.

First, let's remember the physics course high school, which explains why and how atmospheric pressure changes with altitude. The higher the area above sea level, the lower the pressure there. The explanation is very simple: atmospheric pressure indicates the force with which a column of air presses on everything that is on the surface of the Earth. Naturally, the higher you rise, the lower will be the height of the air column, its mass and the pressure exerted.

In addition, at a height the air is rarefied, it contains a much smaller number of gas molecules, which also instantly affects the mass. And we must not forget that with increasing altitude, the air is cleared of toxic impurities, exhaust gases and other "charms", as a result of which its density decreases, and atmospheric pressure indicators fall.

Studies have shown that the dependence of atmospheric pressure on altitude differs as follows: an increase of ten meters causes a decrease in the parameter by one unit. As long as the height of the terrain does not exceed five hundred meters above sea level, changes in the pressure of the air column are practically not felt, but if you rise five kilometers, the values ​​\u200b\u200bare half the optimal ones. The strength of the pressure exerted by the air also depends on the temperature, which decreases very much when ascending to a great height.

For blood pressure and general condition human body the value of not only atmospheric, but also partial pressure, which depends on the concentration of oxygen in the air, is very important. In proportion to the decrease in air pressure values, the partial pressure of oxygen also decreases, which leads to an insufficient supply of this necessary element to the cells and tissues of the body and the development of hypoxia. This is explained by the fact that the diffusion of oxygen into the blood and its subsequent transportation to the internal organs occurs due to the difference in the values ​​of the partial pressure of the blood and the pulmonary alveoli, and when ascending to a great height, the difference in these readings becomes significantly smaller.

How does altitude affect a person's well-being?

Main negative factor that affects the human body at altitude is the lack of oxygen. It is as a result of hypoxia that acute disorders of the heart and blood vessels, increased blood pressure, digestive disorders and a number of other pathologies develop.

Hypertensive patients and people prone to pressure surges should not climb high into the mountains and it is advisable not to make many hours of flights. They will also have to forget about professional mountaineering and mountain tourism.

The severity of the changes occurring in the body made it possible to identify several height zones:

• Up to one and a half - two kilometers above sea level is a relatively safe zone in which there are no special changes in the functioning of the body and the state of vital systems. Deterioration of well-being, a decrease in activity and endurance is observed very rarely.
• From two to four kilometers - the body tries to cope with oxygen deficiency on its own, thanks to increased breathing and deep breaths. Heavy physical work, which requires a large amount of oxygen consumption, is difficult to perform, but the light load is well tolerated for several hours.
• From four to five and a half kilometers - the state of health noticeably worsens, the performance of physical work is difficult. Psycho-emotional disorders appear in the form of elation, euphoria, inappropriate actions. With a long stay at such a height, headaches, a feeling of heaviness in the head, problems with concentration, and lethargy occur.
• From five and a half to eight kilometers - it is impossible to engage in physical work, the condition deteriorates sharply, the percentage of loss of consciousness is high.
• Above eight kilometers - at such a height a person is able to maintain consciousness for a maximum of several minutes, followed by a deep fainting and death.

For the flow of metabolic processes in the body, oxygen is needed, the deficiency of which at altitude leads to the development of mountain sickness. The main symptoms of the disorder are:

• Headache.
• Shortness of breath, shortness of breath, shortness of breath.
• Nose bleed.
• Nausea, bouts of vomiting.
• Joint and muscle pain.
• Sleep disorders.
• Psycho-emotional disorders.

At high altitude, the body begins to experience a lack of oxygen, as a result of which the work of the heart and blood vessels is disturbed, arterial and intracranial pressure rises, and vital organs fail. internal organs. To successfully overcome hypoxia, you need to include nuts, bananas, chocolate, cereals, fruit juices in your diet.

Influence of height on the level of blood pressure

When climbing to a great height, a decrease in atmospheric pressure and rarefied air cause an increase in heart rate, an increase in blood pressure. However, with a further increase in altitude, the level of blood pressure begins to decrease. A decrease in the oxygen content in the air to critical values ​​\u200b\u200bcauses oppression of cardiac activity, a noticeable decrease in pressure in the arteries, while in the venous vessels the indicators increase. As a result, a person develops arrhythmia, cyanosis.

Not so long ago, a group of Italian researchers decided for the first time to study in detail how altitude affects blood pressure levels. To conduct research, an expedition to Everest was organized, during which the pressure indicators of the participants were determined every twenty minutes. During the hike, an increase in blood pressure during ascent was confirmed: the results showed that the systolic value increased by fifteen, and the diastolic value by ten units. It was noted that the maximum values ​​of blood pressure were determined at night. The effect of antihypertensive drugs at different heights was also studied. It turned out that the studied drug effectively helped at a height of up to three and a half kilometers, and when climbing above five and a half it became absolutely useless.