15 20 m with strong wind. Verbal definition of wind force. There are three types of minima

Wind is a horizontal flow of air that has a number of specific characteristics: strength, direction and speed. It was to determine the speed of the winds that the Irish admiral at the beginning of the 19th century developed a special table. The so-called Beaufort scale is still used today. What is a scale? How to use it correctly? And what does the Beaufort scale not allow you to determine?

What is wind?

The scientific definition of this concept is as follows: wind is an air flow that moves parallel to the earth's surface from an area of ​​high to an area of ​​low atmospheric pressure. This phenomenon is typical not only for our planet. Thus, the strongest winds in the solar system blow on Neptune and Saturn. And the terrestrial winds, in comparison with them, may seem like a light and very pleasant breeze.

The wind has always played an important role in human life. He inspired ancient writers to create mythical stories, legends and fairy tales. It is thanks to the wind that a person has the opportunity to overcome significant distances by sea (with the help of sailboats) and by air (by means of balloons). The wind is also involved in the "building" of many earthly landscapes. So, it transfers millions of grains of sand from place to place, thereby forming unique eolian landforms: dunes, dunes and sandy ridges.

At the same time, winds can not only create, but also destroy. Their gradient fluctuations can provoke a loss of control over the aircraft. Strong winds significantly expand the scale of forest fires, and large reservoirs gives rise to huge waves that destroy houses and claim the lives of people. That is why it is so important to study and measure the wind.

Basic wind parameters

It is customary to distinguish four main wind parameters: strength, speed, direction and duration. All of them are measured using special devices. The strength and speed of the wind is determined using the so-called anemometer, the direction - with the help of a weather vane.

Based on the duration parameter, meteorologists distinguish squalls, breezes, storms, hurricanes, typhoons and other types of winds. The direction of the wind is determined by the side of the horizon from which it blows. For convenience, they are abbreviated with the following Latin letters:

• N (northern).
• S (southern).
• W (western).
• E (eastern).
• C (calm).

Finally, wind speed is measured at a height of 10 meters using anemometers or special radars. Moreover, the duration of such measurements in different countries world is not the same. For example, at American meteorological stations, the average speed of air currents is taken into account for 1 minute, in India - for 3 minutes, and in many European countries - for 10 minutes. The classic instrument for presenting data on wind speed and strength is the so-called Beaufort scale. How and when did she appear?

Who is Francis Beaufort?

Francis Beaufort (1774-1857) - Irish sailor, military admiral and cartographer. He was born in small town An-Waw in Ireland. After graduating from school, the 12-year-old boy continued his studies under the guidance of the famous professor Usher. During this period, he first showed an extraordinary ability to study the "marine sciences". As a teenager, he joined the East India Company and took an active part in filming the Java Sea.

It should be noted that Francis Beaufort grew up as a rather bold and courageous guy. So, during the wreck of the ship in 1789, the young man showed great dedication. Having lost all his food and personal belongings, he managed to save the team's valuable tools. In 1794, Beaufort took part in a naval battle against the French and heroically towed a ship hit by enemy fire.

Development of the wind scale

Francis Beaufort was extremely industrious. Every day he woke up at five o'clock in the morning and immediately set to work. Beaufort was a significant authority among the military and sailors. However, he gained worldwide fame thanks to his unique development. While still a midshipman, the inquisitive young man kept a daily diary of observations of the weather. Later, all these observations helped him to draw up a special scale of winds. In 1838, she was officially approved by the British Admiralty.

In honor of the famous scientist and cartographer, one of the seas, an island in Antarctica, a river and a cape in northern Canada. And Francis Beaufort became famous for creating a polyalphabetic military cipher, also named after him.

Beaufort scale and its features

The scale represents the earliest classification of winds according to their strength and speed. It was developed on the basis of meteorological observations in conditions high seas. Initially, the classic Beaufort wind scale is a twelve-point scale. It was only in the middle of the 20th century that it was expanded to 17 levels in order to distinguish between hurricane-force winds.

Wind strength on the Beaufort scale is determined by two criteria:

1. According to its impact on various ground objects and objects.
2. According to the degree of excitement of the open sea.

It is important to note that the Beaufort scale does not allow determining the duration and direction of air flows. It contains a detailed classification of winds according to their strength and speed.

Beaufort scale: table for sushi

Below is a table with a detailed description of the impact of wind on ground objects and objects. The scale, developed by the Irish scientist F. Beaufort, consists of twelve levels (points).

Beaufort table of sea conditions

In oceanography, there is such a thing as the state of the sea. It includes height, frequency and strength. sea ​​waves. Below is the Beaufort scale (table), which will help determine the strength and speed of the wind, based on these signs.

Thus, thanks to the Beaufort scale, people can observe the wind and evaluate its strength. This makes it possible to make the most accurate weather forecasts.

The horizontal movement of air above the Earth's surface is called wind. The wind always blows from an area of ​​high pressure to an area of ​​low pressure.

Wind characterized by speed, strength and direction.

Wind speed and strength

Wind speed measured in meters per second or points (one point is approximately equal to 2 m/s). The speed depends on the baric gradient: the greater the baric gradient, the higher the wind speed.

The force of the wind depends on the speed (Table 1). The greater the difference between adjacent areas of the earth's surface, the stronger the wind.

Beaufort scale- a conditional scale for visual assessment of the strength (speed) of the wind in points according to its effect on ground objects or on waves at sea. It was developed by the English admiral F. Beaufort in 1806 and at first was used only by him. In 1874, the Standing Committee of the First Meteorological Congress adopted the Beaufort scale for use in International synoptic practice. In subsequent years, the scale has changed and refined. The Beaufort scale is widely used in marine navigation.

Direction of the wind

Direction of the wind is determined by the side of the horizon from which it blows, for example, the wind blowing from the south is south. The direction of the wind depends on the pressure distribution and on the deflecting effect of the Earth's rotation.

On the climate map, the prevailing winds are shown by arrows (Fig. 1). The winds observed near the earth's surface are very diverse.

You already know that the surface of land and water heats up in different ways. On a summer day, the land surface heats up more. From heating, the air above the land expands and becomes lighter. Over the pond at this time the air is colder and therefore heavier. If the reservoir is relatively large, on a quiet hot summer day on the shore you can feel a light breeze blowing from the water, above which it is higher than above land. Such a light breeze is called daytime. breeze(from the French brise - light wind) (Fig. 2, a). The night breeze (Fig. 2, b), on the contrary, blows from the land, since the water cools much more slowly and the air above it is warmer. Breezes can also occur at the edge of the forest. The scheme of breezes is shown in fig. 3.

Rice. 1. Scheme of distribution of prevailing winds on the globe

Local winds can occur not only on the coast, but also in the mountains.

Föhn- a warm and dry wind blowing from the mountains to the valley.

Bora- gusty, cold and strong wind that appears when cold air crosses over low ridges to the warm sea.

Monsoon

If the breeze changes direction twice a day - day and night, then seasonal winds - monsoons— change their direction twice a year (Fig. 4). In summer, the land warms up quickly, and the air pressure over its surface hits. At this time, cooler air begins to move to land. In winter, the opposite is true, so the monsoon blows from land to sea. With the change of the winter monsoon to the summer monsoon, dry, slightly cloudy weather changes to rainy.

The action of monsoons is strongly manifested in the eastern parts of the continents, where they are adjacent to vast expanses of oceans, so such winds often bring heavy rainfall to the continents.

The unequal nature of the circulation of the atmosphere in different areas of the globe determines the differences in the causes and nature of the monsoons. As a result, extratropical and tropical monsoons are distinguished.

Rice. 2. Breeze: a - daytime; b - night

Rice. Fig. 3. Scheme of breezes: a - in the afternoon; b - at night

Rice. 4. Monsoons: a - in summer; b - in winter

extratropical monsoons - monsoons of temperate and polar latitudes. They are formed as a result of seasonal fluctuations in pressure over the sea and land. The most typical zone of their distribution is the Far East, Northeast China, Korea, to a lesser extent - Japan and northeast coast Eurasia.

tropical monsoons - monsoons of tropical latitudes. They are due to seasonal differences in the heating and cooling of the Northern and Southern hemispheres. As a result, pressure zones shift seasonally relative to the equator to the hemisphere in which given time summer. Tropical monsoons are most typical and persistent in the northern part of the basin indian ocean. This is largely facilitated by the seasonal change in the atmospheric pressure regime over the Asian continent. The fundamental features of the climate of this region are associated with the South Asian monsoons.

The formation of tropical monsoons in other regions of the globe is less characteristic when one of them, the winter or summer monsoon, is more clearly expressed. Such monsoons are observed in Tropical Africa, in northern australia and in equatorial regions of South America.

Earth's constant winds - trade winds And westerly winds- depend on the position of atmospheric pressure belts. Since low pressure prevails in the equatorial belt, and near 30 ° N. sh. and yu. sh. - high, near the surface of the Earth throughout the year the winds blow from the thirtieth latitudes to the equator. These are trade winds. Under the influence of the rotation of the Earth around its axis, the trade winds deviate to the west in the Northern Hemisphere and blow from the northeast to the southwest, and in the Southern they are directed from the southeast to the northwest.

From the high pressure belts (25-30°N and S), the winds blow not only towards the equator, but also towards the poles, since at 65°N. sh. and yu. sh. low pressure prevails. However, due to the rotation of the Earth, they gradually deviate to the east and create air currents moving from west to east. Therefore, westerly winds prevail in temperate latitudes.

Meteorological hazards are natural processes and phenomena that occur in the atmosphere under the influence of various natural factors or their combinations that have or may have a damaging effect on people, farm animals and plants, economic objects and the natural environment.

Wind - this is the movement of air parallel to the earth's surface, resulting from the uneven distribution of heat and atmospheric pressure and directed from a high pressure zone to a low pressure zone.

The wind is characterized by:
1. Wind direction - determined by the azimuth of the side of the horizon, from where
it blows, and is measured in degrees.
2. Wind speed - measured in meters per second (m/s; km/h; miles/hour)
(1 mile = 1609 km; 1 nautical mile = 1853 km).
3. Wind force - measured by the pressure that it exerts on 1 m2 of surface. The strength of the wind varies almost proportional to the speed,
therefore, the strength of the wind is often estimated not by pressure, but by speed, which simplifies the perception and understanding of these quantities.

Many words are used to indicate the movement of the wind: tornado, storm, hurricane, storm, typhoon, cyclone and many local names. To systematize them, all over the world use Beaufort scale, which allows you to very accurately estimate the strength of the wind in points (from 0 to 12) according to its effect on ground objects or on waves in the sea. This scale is also convenient in that it allows, according to the signs described in it, to fairly accurately determine the wind speed without instruments.

Beaufort scale (Table 1)

Breeze (light to strong breeze) sailors refer to the wind as having a speed of 4 to 31 miles per hour. In terms of kilometers (factor 1.6) it will be 6.4-50 km/h

Wind speed and direction determine weather and climate.

Strong winds, significant changes in atmospheric pressure and a large number of precipitation causes dangerous atmospheric whirlwinds (cyclones, storms, squalls, hurricanes) that can cause destruction and loss of life.

Cyclone - common name eddies with reduced pressure in the center.

An anticyclone is an area of ​​high pressure in the atmosphere with a maximum in the center. In the Northern Hemisphere, the winds in the anticyclone blow counterclockwise, and in the Southern Hemisphere - clockwise, in the cyclone the wind movement is reversed.

Hurricane - wind of destructive force and considerable duration, the speed of which is equal to or exceeds 32.7 m/s (12 points on the Beaufort scale), which is equivalent to 117 km/h (Table 1).
In half of the cases, the wind speed during a hurricane exceeds 35 m/s, reaching up to 40-60 m/s, and sometimes up to 100 m/s.

Hurricanes are classified into three types based on wind speed:
- Hurricane (32 m/s and more),
- strong hurricane (39.2 m/s or more)
- fierce hurricane (48.6 m/s and more).

Cause of these hurricane winds is the occurrence, as a rule, on the line of collision of the fronts of warm and cold air masses, powerful cyclones with a sharp pressure drop from the periphery to the center and with the creation of a vortex air flow moving in the lower layers (3-5 km) in a spiral towards the middle and up, in the northern hemisphere, counterclockwise.

Such cyclones, depending on the place of their occurrence and structure, are usually divided into:
- tropical cyclones found over warm tropical oceans, usually moves westward during formation, and curves poleward after formation.
A tropical cyclone that reaches unusual strength is called hurricane if he is born in the Atlantic Ocean and adjacent seas; typhoon - in the Pacific Ocean or its seas; cyclone - in the Indian Ocean region.
mid-latitude cyclones can form both over land and over water. They usually move from west to east. A characteristic feature of such cyclones is their great "dryness". The amount of precipitation during their passage is much less than in the zone of tropical cyclones.
The European continent is affected by both tropical hurricanes that originate in the central Atlantic and cyclones of temperate latitudes.
Storm – a type of hurricane, but has a lower wind speed 15-31
m/sec.

The duration of storms is from several hours to several days, the width is from tens to several hundreds of kilometers.
Storms are divided into:

2. Stream storms – These are local phenomena of small distribution. They are weaker than whirlwinds. They are subdivided:
- stock - the air flow moves down the slope from top to bottom.
- Jet - characterized by the fact that the air flow moves horizontally or up the slope.
Stream storms pass most often between chains of mountains connecting valleys.
Depending on the color of the particles involved in the movement, black, red, yellow-red and white storms are distinguished.
Depending on the wind speed, storms are classified:
- storm 20 m/s and more
- strong storm 26 m/s and more
- severe storm of 30.5 m/s and more.

Squall – a sharp short-term increase in wind up to 20–30 m/s and higher, accompanied by a change in its direction associated with convective processes. Despite the short duration of squalls, they can lead to catastrophic consequences. Squalls in most cases are associated with cumulonimbus (thunderstorm) clouds, either local convection or a cold front. A squall is usually associated with heavy rainfall and thunderstorms, sometimes with hail. Atmospheric pressure during a squall rises sharply due to the rapid precipitation, and then falls again.

If possible, limit the area of ​​impact, all of the listed natural disasters are classified as non-localized.

Dangerous consequences of hurricanes and storms.

Hurricanes are one of the most powerful forces of the elements and, in their detrimental effect, are not inferior to such terrible natural disasters like earthquakes. This is due to the fact that hurricanes carry enormous energy. Its amount released by a hurricane of average power during 1 hour is equal to the energy of a nuclear explosion of 36 Mt. In one day, the amount of energy that would be enough to provide electricity to a country like the United States is released. And in two weeks (the average duration of the existence of a hurricane), such a hurricane releases energy equal to the energy of the Bratsk hydroelectric power station, which it can generate in 26 thousand years. The pressure in the hurricane zone is also very high. It reaches several hundred kilograms per square meter of a fixed surface located perpendicular to the direction of wind movement.

The hurricane destroys strong and demolishes light buildings, devastates sown fields, breaks wires and knocks down poles of power transmission and communication lines, damages highways and bridges, breaks and uproots trees, damages and sinks ships, causes accidents on utility networks, in production. There are cases when hurricane winds destroyed dams and dams, which led to large floods, threw trains off the rails, tore bridges off their supports, knocked down factory pipes, and threw ships onto land. Hurricanes are often accompanied by heavy downpours, which are more dangerous than the hurricane itself, as they cause mudflows and landslides.

Hurricanes vary in size. Usually, the width of the zone of catastrophic destruction is taken as the width of the hurricane. Often, the area of ​​storm force winds with relatively little damage is added to this zone. Then the width of the hurricane is measured in hundreds of kilometers, sometimes reaching 1000 km. For typhoons, the destruction zone is usually 15-45 km. The average duration of a hurricane is 9-12 days. Hurricanes occur at any time of the year, but most often from July to October. In the remaining 8 months they are rare, their paths are short.

The damage caused by a hurricane is determined by a whole complex of various factors, including the terrain, the degree of development and the strength of buildings, the nature of vegetation, the presence of population and animals in its zone of action, the time of year, preventive measures taken and a number of other circumstances, the main of which is velocity head of the air flow q, proportional to the product of the atmospheric air density and the square of the air flow velocity q = 0.5 pv 2.

According to building codes and regulations, the maximum normative value of wind pressure is q = 0.85 kPa, which, at an air density of r = 1.22 kg/m3, corresponds to wind speed.

For comparison, we can cite the calculated values ​​of the velocity head used for the design of nuclear power plants for the region Caribbean: for buildings of category I - 3.44 kPa, II and III - 1.75 kPa and for open installations - 1.15 kPa.

Every year, about a hundred powerful hurricanes march across the globe, causing destruction and often claiming human lives (Table 2). June 23, 1997 over for the most part A hurricane swept through the Brest and Minsk regions, as a result of which 4 people died, 50 were injured. IN Brest region 229 settlements were de-energized, 1071 substations were put out of action, roofs were torn off from 10-80% of residential buildings in more than 100 settlements, up to 60% of agricultural production buildings were destroyed. In the Minsk region, 1,410 settlements were de-energized, hundreds of houses were damaged. Broken and uprooted trees in forests and forest parks. At the end of December 1999 from hurricane wind swept through Europe, Belarus also suffered. Power lines were cut, many settlements were de-energized. In total, 70 districts and more than 1,500 settlements were affected by the hurricane. Only in the Grodno region, 325 transformer substations failed, in the Mogilev region even more - 665.

table 2
Impact of some hurricanes

Tornado (tornado)- whirlwind movement of air, propagating in the form of a giant black column with a diameter of up to hundreds of meters, inside which there is a rarefaction of air, where various objects are drawn.

Tornadoes occur both over the water surface and over land, much more often than hurricanes. Very often they are accompanied by thunderstorms, hail and showers. The speed of air rotation in the dust column reaches 50-300 m/s and more. During its existence, it can travel up to 600 km - along a strip of terrain several hundred meters wide, and sometimes up to several kilometers, where destruction occurs. The air in the column rises in a spiral and draws in dust, water, objects, people.
Dangerous factors: buildings caught in a tornado due to a vacuum in the air column are destroyed from the pressure of air from the inside. It uproots trees, overturns cars, trains, lifts houses into the air, etc.

Tornadoes in Belarus occurred in 1859, 1927 and 1956.

Each a natural phenomenon having different degrees severity, it is customary to evaluate in accordance with certain criteria. Especially if information about it must be transmitted quickly and accurately. For wind strength, the Beaufort scale has become a single international benchmark.

Developed by the British rear admiral, a native of Ireland, Francis Beaufort (stress falls on the second syllable) in 1806, the system, improved in 1926 by adding information about the equivalence of wind strength in points of its specific speed, allows you to fully and accurately characterize this atmospheric process, while remaining relevant and to this day.

What is wind?

Wind is the movement of air masses parallel to the surface of the planet (horizontally above it). This mechanism is caused by pressure difference. The direction of movement always comes from the higher area.

To describe the wind, it is customary to use the following characteristics:

• speed (measured in meters per second, kilometers per hour, knots and points);
• wind strength (in points and m.s. - meters per second, the ratio is approximately 1:2);
• direction (according to cardinal directions).

The first two parameters are closely related. They can be mutually denoted by each other's units of measurement.

The direction of the wind is determined by the side of the world from where the movement began (from the north - North wind and so on.). Velocity determines the pressure gradient.

Baric gradient (otherwise - barometric gradient) - change in atmospheric pressure per unit distance along the normal to a surface of equal pressure (isobaric surface) in the direction of decreasing pressure. In meteorology, the horizontal barometric gradient is usually used, that is, its horizontal component (Great Soviet Encyclopedia).

The speed and strength of the wind cannot be separated. A large difference in indicators between atmospheric pressure zones generates a strong and rapid movement of air masses above the earth's surface.

Features of wind measurement

In order to correctly correlate the data of meteorological services with their real situation or correctly measure, you need to know what standard conditions professionals use.

• The measurement of the strength and speed of the wind takes place at a height of ten meters on an open flat surface.
• The name of the wind direction is given by the cardinal direction from which it blows.

Managers of water transport, as well as lovers of spending time in nature, often purchase anemometers that determine the speed, which is easy to correlate with the wind force in points. There are waterproof models. For convenience, devices of various compactness are produced.

In the Beaufort system, the description of the height of the waves, correlated with a certain force of wind in points, is given for the open sea. It will be much less in shallow water areas and coastal zones.

From personal to global use

Sir Francis Beaufort not only had a high military rank in the navy, but was also a successful practical scientist who held important posts, a hydrographer and cartographer, who brought great benefits to the country and the world. One of the seas in the North bears his name. Arctic Ocean bordering Canada and Alaska. An Antarctic island is named after Beaufort.

A convenient system for estimating wind strength in points, available for fairly accurate determination of the severity of the phenomenon "by eye", Francis Beaufort created for his own use in 1805. The scale had a gradation from 0 to 12 points.

In 1838, the system of visual assessment of weather and wind strength in points began to be officially used by the British Navy. In 1874 it was adopted by the international synoptic community.

In the 20th century, several more improvements were made to the Beaufort scale - the ratio of points and a verbal description of the manifestation of the elements with wind speed (1926), and five more divisions were added - gradation points for the strength of hurricanes (USA, 1955).

Criteria for estimating wind strength in Beaufort points

IN modern form The Beaufort scale has several characteristics that allow, in combination, to most accurately correlate a specific atmospheric phenomenon with its indicators in points.

• First, it is verbal information. Verbal description of the weather.
• Average speed in meters per second, kilometers per hour and knots.
• The impact of moving air masses on characteristic objects on land and sea is determined by typical manifestations.

Non-dangerous wind

Safe wind is determined in the range from 0 to 4 points.

A wind of 5 points, characterized as "fresh", or fresh breeze, can be called borderline. Its speed ranges from 8 to 10.7 meters per second (29-38 km/h, or 17 to 21 knots). Thin trees sway along with the trunks. Waves rise up to 2.5 (average up to two) meters. Sometimes there are splashes.

Wind that brings trouble

With a wind force of 6 points, strong phenomena begin that can cause damage to health and property.

Dangerous force of the wind

Wind force from ten to twelve points is dangerous and is characterized as a strong (storm) and severe storm (violent storm), as well as a hurricane (hurricane).

Wind uproots trees, damages buildings, destroys vegetation, destroys buildings. The waves make a deafening noise from 9 meters and above, long. At sea, they reach a dangerous height even for large ships - from nine meters and above. Foam covers the water surface, visibility is zero or close to such an indicator.

The speed of movement of air masses is from 24.5 meters per second (89 km / h) and reaches from 118 kilometers per hour with a wind force of 12 points. Violent storms and hurricanes (winds of magnitudes 11 and 12) are very rare.

Additional five points to the classical Beaufort scale

Since hurricanes are also not identical to each other in terms of intensity and degree of damage, in 1955 the United States Weather Bureau adopted an addition to the standard Beaufort classification in the form of five scale units. Wind strength from 13 to 17 points inclusive - these are clarifying characteristics for destructive hurricane winds and related phenomena environment.

How to protect yourself when the elements are raging?

If the storm warning of the Ministry of Emergency Situations catches in an open area, it is better to follow the advice and reduce the risk of accidents.

First of all, you should pay attention to warnings every time - there is no guarantee that the atmospheric front will come to the area where you are, but you also cannot be sure that it will bypass it again. All items should be removed or securely fastened, to protect pets.

If a heavy wind catches in a fragile structure - a garden house or other light structures - it is better to close the windows from the air movement side, and if necessary, strengthen them with shutters or boards. On the leeward, on the contrary, slightly open and fix in this position. This will eliminate the danger of an explosive effect from the pressure difference.

It is important to remember that any strong wind can bring unwanted precipitation - in winter it is snowstorms and snowstorms, in summer dust and sand storms are possible. It should also be borne in mind that strong winds can occur even in absolutely clear weather.

Takeoff is the most difficult part of flying. Of course, the automatic takeoff mode after the release of the brakes is not difficult, but the crew of the aircraft, led by the commander, must be tuned to critical moments. Can a flight be canceled due to rain? ? You will find out in the process of reading the article.

Objective assessment

Do planes fly in the rain? Yes. But in order for the flight to be successful, there are strict regulations for pilots and controllers who allow the aircraft to fly and land. For each side and airfield, the rules are individual, but with similar indicators:

• minimal visibility. Determined both vertical and horizontal visibility with the level of illumination;
• runway coverage. Ice on the airfield is unacceptable;
• the ability of pilots to receive instrument signals of adverse weather conditions.

Normally, the weather forecast should correspond to the meteorological minimum so that the pilot has the opportunity to take emergency action in the event of a critical situation.

Paramount parameters

What is meant by meteorological minimum? These are the conditions that apply in relation to visibility, cloudiness, wind speed and direction. These criteria can be dangerous when flying, especially when it comes to thunderstorms, downpours and severe turbulence. Of course, most thunderclouds can be bypassed, but frontal thunderstorms stretching for hundreds of kilometers are almost impossible to bypass.

If we are talking about minima, then the criteria for visibility at the aerodrome and the decision height (CHL) are determined. What is this indicator? This is the level of altitude at which the aircraft crew is required to make an additional turn when the runway is not defined.

There are three types of minima:

• air transport - acceptable criteria for the safe flight of an aircraft under adverse weather conditions, established by the manufacturer;
• airfield - depends on the type of installed navigation and technical systems on the runway and in the surrounded area;
• crew - the admission of pilots in accordance with their training program under specific weather conditions and practical flight skills.

Do planes fly in the rain? To allow an aircraft to take off or not, is determined only by the aircraft commander. To make a decision, you should first familiarize yourself with the provided meteorological data for the destination aerodromes, as well as alternate ones, and evaluate them.

Thunderstorm is not a hindrance to flight

A thunderstorm is a rather dangerous phenomenon, but for modern liner it is not the cause of the disaster. Technique and people have learned to overcome huge distances safely in all weather conditions.

In his practice, every experienced pilot has repeatedly encountered thunderclouds, which significantly complicate the landing and takeoff of an aircraft in the rain. During the "entry" into the clouds, the crew loses the visual perception of the machine in space. Therefore, flight in "non-flying" weather can only be carried out according to technical instruments. In some cases, an unpleasant situation may arise - the electrification of the aircraft. Here, radio communication deteriorates sharply, which causes great inconvenience even to professional pilots.

But most of all, "non-flying" weather complicates the landing of liners. In such a crew is maximally loaded. The captain, even in modern rain, glances at aviation equipment up to 200 times per minute, focusing on each fixture up to 1 second. Low cloud cover in combination with a thunderstorm is a serious obstacle to the correct movement of the aircraft. Therefore, it is extremely important to have a good knowledge of the clouds, their state and the nearest changes. The deterioration of the weather begins if there is:

• accelerated drop in atmospheric pressure;
• a sharp change in the direction and speed of the wind;
• an increase in various types of cloudiness and its rapid movement;
• "growth" of cumulus clouds in the evening;
• the formation of colored circles around the satellites of the Earth.

You can’t play with a thunderstorm, you need to bypass it as far as possible, according to the regulations. In addition, when climbing or descending, the pilot must correlate information on the development of the elements with the capabilities of the aircraft.

When there are clouds in the sky

Is it dangerous to fly in the rain on an airplane? The passenger liner passes the way along the given air routes. In case of bad weather, the coordinates may change upon agreement with the controller at the flight control center. The flight altitude is about 11,000 meters. For this reason, it becomes comfortable due to the greater It is this flight altitude that allows aircraft rise above the clouds - sources of rain or snow. Therefore, the movement of the aircraft at high altitude is completely independent of weather conditions. Often you can observe how the rays of the sun enter the window of the liner, and when landing it is dark and it is raining.

Do planes fly in the rain? Yes. Theoretically, raindrops can affect aircraft engine performance. But rain is not the amount of water that can provoke a short circuit. In tests, the engine compressors are subjected to a good "gulf", which is not compared with natural phenomena.

We take into account

Do planes fly in thunderstorms? The precipitation itself does not pose any danger to the flight. Another thing is visibility. But when it rains, windshield wipers come to the rescue. Aircraft windshield wipers are different from car wipers. First, they have a completely different design. Secondly, the windshield wipers operate at a very high rate, which provides a perfect view.

How do planes land when it rains? The most critical in bad weather are "atmospheric disturbances". The landing aircraft has a low speed and can easily be affected by the movement of air masses. To overcome the adverse effects during this phenomenon, pilots spend a lot of time "in simulators", honing their skills. If in such weather the danger of an accident is great, then the landing is postponed or the ship is sent to another airfield.

Another important factor in rain is traction. Wet coating reduces its coefficient, but this situation is not recognized as critical. It is much more dangerous if the water on the asphalt freezes, and the value of the coefficient decreases. In most of these cases, the airport does not allow aircraft to take off or land.

Other natural barriers

In addition to the main weather phenomena, there are other important criteria that limit the capabilities of aviation:

• wind - requires special care and dexterity from the pilot, especially on the runway;
• remu - vertical movement of air, throwing up an aircraft, forming "air pockets";
• fog is a real enemy during flights, limiting visibility and forcing pilots to navigate by compasses;
• glaciation - on the ice-covered runway, the movement of aircraft is strictly prohibited.

Thanks to the developed electronic devices and systems, she is ready to overcome any weather conditions. The movement on the runway is safe, because in critical situations the liner simply does not depart for the flight or remains in certain waiting areas.

Heavy flight criteria

Cumulus clouds in cold weather and at high altitude in summer can be a hazard to aircraft. It is here that the probability of aircraft icing is quite high. In cumulus clouds, the flight of heavy aircraft is complicated by turbulence. If the likelihood of adverse events persists, the flight is postponed for several hours.

Indicators of bad stable weather are:

• atmospheric pressure with low rates, which practically do not change or even decrease;
• high wind speed;
• clouds in the sky are predominantly of a scatter or scatter-rain type;
• prolonged precipitation in the form of rain or snow;
• small fluctuations in temperature during the day.

If the problem with rain can be solved more quickly, then heavy precipitation, especially in the form of drizzle, will create difficulties. They occupy very large areas, and it is almost impossible to bypass them. In such a zone, visibility is significantly reduced, and at low temperatures, icing of the aircraft body occurs. Therefore, at low altitude in such situations, flight is classified as difficult.

On duty

In order not to expose themselves and passengers on board to danger and fear, the crew of the aircraft must perform a number of important actions before departure:

• listen to information from the duty meteorologist about the upcoming weather conditions along the established route: cloudiness data, wind speed and direction, the presence of dangerous zones and ways to bypass them;
• receive a special bulletin containing information about the state of the atmosphere, the weather forecast along the route and at the landing site;
• if the flight is delayed by more than an hour and a half, the pilot must receive new information about the state of the weather.

However, the duties of the crew do not end there.

Additional terms of commitment

During the flight, the pilot must carefully monitor the weather, especially if the route passes near dangerous areas or worsening weather is expected soon. The attentiveness and professionalism of the navigator will allow you to correctly assess the state of the atmosphere and, in which case, make the right decision.

In addition, a few hundred kilometers before the landing point, an inquiry should be made about the meteorological situation at the aerodrome and the safety of the landing should be assessed.

The natural "opponent" of the flight

It's great when the flight takes place in a clear sunny weather. But if it snows or rains, and overboard low temperature? Here begins the icing of the body of the aircraft.

Ice, like armor, increases the weight of an aircraft, reducing its lift by several times and reducing engine power. If suddenly the crew captain, studying the meteorological situation, determined that the hull of the liner was covered with a crust, then a command comes to clean the ship. The processing of the aircraft is carried out. Moreover, attention is paid to the entire hull of the vessel, and not just the wings and nose.

Reliability above all

Thunderstorm or rain is a romantic phenomenon only in literature. Aviation considers a natural phenomenon as an emergency. The elements can bring great human casualties, so it is extremely important to approach flights with high accuracy and literacy. A flight in adverse conditions is a great responsibility and great worries not only for your life, but also for the life of hundreds of passengers.