Beaufort scale - wind strength and sea conditions. What determines the speed and strength of the wind Determining the strength of the wind by external signs

Wind is the horizontal movement (air flow parallel to the earth's surface) resulting from the uneven distribution of heat and atmospheric pressure and directed from the zone high pressure into the low pressure zone

The wind is characterized by speed (strength) and direction. Direction is determined by the sides of the horizon from which it blows, and is measured in degrees. Wind speed measured in meters per second and kilometers per hour. The strength of the wind is measured in points.

Wind in boots, m/s, km/h

Beaufort scale- conditional scale for visual assessment and recording of wind strength (speed) in points. Initially, it was developed by the English admiral Francis Beaufort in 1806 to determine the strength of the wind by the nature of its manifestation at sea. Since 1874, this classification has been accepted for widespread (on land and sea) use in international synoptic practice. In subsequent years, it was changed and refined (Table 2). The state of complete calm at sea was taken as zero points. Initially, the system was thirteen-point (0-12 bft, on the Beaufort scale). In 1946 the scale was increased to seventeen (0-17). The strength of the wind in the scale is determined by the interaction of the wind with various objects. AT last years, wind strength, more often, is estimated by speed, measured in meters per second - at the earth's surface, at a height of about 10 m above an open, flat surface.

The table shows the Beaufort scale, adopted in 1963 by the World Meteorological Organization. The sea wave scale is nine-point (the parameters are given for a large sea area; in small water areas, the wave is less). Action descriptions from move air masses– given "for the conditions earth's atmosphere near the earth or water surface", with an air density of about 1.2 kg / m3 and a positive temperature. On the planet Mars, for example, the ratios will be different.

Wind strength in points on the Beaufort scale and sea waves

To make it easier to remember(compiled by: site author site)

3 - Weak - 5 m / s (~ 20 km / h) - leaves and thin branches of trees continuously sway
5 - Fresh - 10 m / s (~ 35 km / h) - pulls out big flags, whistles in the ears
7 - Strong - 15 m / s (~ 55 km / h) - telegraph wires are buzzing, it is difficult to go against the wind
9 - Storm - 25 m / s (90 km / h) - wind knocks down trees, destroys buildings

* The length of the wind wave on the surface of water bodies (rivers, seas, etc.) is the smallest distance, horizontally, between the tops of adjacent ridges.

Dictionary:

Breeze– a weak coastal wind with a strength of up to 4 points.

normal wind- acceptable, optimal for something. For example, for sports windsurfing, you need sufficient wind thrust (at least 6-7 meters per second), and when parachuting, on the contrary, calm weather is better (excluding lateral drift, strong gusts near the earth's surface and dragging the dome after landing).

storm is called a long and stormy, up to a hurricane, wind with a force of more than 9 points (gradation on the Beaufort scale), accompanied by destruction on land and strong sea waves (storm). Storms are: 1) squall; 2) dusty (sandy); 3) dust free; 4) snow. Squall storms start suddenly and end just as quickly. Their actions are characterized by enormous destructive power (such a wind destroys buildings and uproots trees). These storms are possible everywhere in the European part of Russia, both at sea and on land. In Russia, the northern border of the distribution of dust storms passes through Saratov, Samara, Ufa, Orenburg and the Altai mountains. Snow storms of great strength occur on the plains of the European part and in the steppe part of Siberia. Typically, storms are caused by the passage of an active atmospheric front, a deep cyclone, or a tornado.

Squall- a strong and sharp gust of wind (Peak gusts) with a speed of 12 m / s and above, usually accompanied by a thunderstorm. At a speed of more than 18-20 meters per second, a heavy wind blows away poorly fixed structures, signs and can break billboards and tree branches, cause power lines to break, which creates a danger to people and cars under them. A gusty, squally wind occurs during the passage of an atmospheric front and with a rapid change in pressure in a baric system.

Vortex – atmospheric education With rotational movement air around a vertical or inclined axis.

Hurricane(typhoon) - a wind of destructive force and considerable duration, the speed of which exceeds 120 km/h. "Lives", i.e. moves, a hurricane usually lasts 9-12 days. Forecasters give it a name. The hurricane destroys buildings, uproots trees, demolishes light structures, breaks wires, and damages bridges and roads. Its destructive force can be compared to an earthquake. Homeland hurricanes - ocean expanses, closer to the equator. Cyclones saturated with water vapor from here leave to the west, more and more twisting and increasing speed. The diameters of these giant whirlwinds are several hundred kilometers. Hurricanes are most active in August and September.
In Russia, hurricanes most often occur in the Primorsky and Khabarovsk Territories, Sakhalin, Kamchatka, Chukotka, and the Kuril Islands.

Tornadoes are vertical vortices; squalls are more often horizontal, included in the structure of cyclones.

The word "tornado" is Russian, and comes from the semantic concept of "twilight", that is, a gloomy, thunderous situation. The tornado is a giant rotating funnel, inside which there is low pressure, and any objects that are in the way of the tornado are sucked into this funnel. As he approaches, a deafening roar is heard. A tornado moves above the ground at an average speed of 50–60 km/h. Deaths are short-lived. Some of them "live" seconds or minutes, and only a few - up to half an hour.

On the North American continent, a tornado is called tornado, and in Europe thrombus. A tornado can lift a car into the air, uproot trees, cripple a bridge, destroy the upper floors of buildings.

The Guinness Book of Records, as the most terrible and destructive in the history of observations, included a tornado in Bangladesh, observed in 1989. Despite the fact that the inhabitants of the city of Shaturia were warned in advance about the approach of a tornado, 1300 people became its victims.

In Russia, tornadoes are more frequent in summer months, in the Urals, Black Sea coast, in the Volga region and Siberia.

Forecasters classify hurricanes, storms and tornadoes as extreme events with a moderate propagation speed, so most often it is possible to announce a storm warning in time. It can be transmitted through civil defense channels: after the sound of sirens " Attention everyone!"must listen to the message of the local television and radio.

Symbols on meteorological maps of weather phenomena associated with wind

In meteorology and hydrometeorology, the direction of the wind ("where it blows from") is indicated on the map in the form of an arrow, the type of plumage of which shows the average speed of the air flow. In air navigation - the name of the direction is different to the opposite. In navigation on the water, the unit of speed (knot) of a vessel is taken to be one nautical mile per hour (ten knots correspond to approximately five meters per second).

On the weather map, a long feather of the wind arrow means 5 m/s, a short one - 2.5 m/s, in the form of a triangular flag - 25 m/s (follows after a combination of four long lines and 1 short one). In the example shown in the figure, there is a wind with a force of 7-8 m/s. With an unstable wind direction, a cross is placed at the end of the arrow.

The picture shows conventions wind directions and speeds used on weather maps, as well as an example of applying icons and fragments from a hundred-cell matrix of weather symbols (for example, snowstorms and blowing snow, when the previously fallen snow rises and redistributes in the surface air layer).

These symbols can be seen on the synoptic map of the Hydrometeorological Center of Russia (http://meteoinfo.ru) compiled as a result of the analysis of current data on the territory of Europe and Asia, which schematically shows the boundaries of the zones of warm and cold atmospheric fronts and the direction of their movements along the earth's surface.

What to do if there is a storm warning?

1. Close and secure all doors and windows tightly. Glue strips of plaster crosswise on the glass (so that fragments do not fly apart).

2. Prepare a supply of water and food, medicines, a flashlight, candles, a kerosene lamp, a battery receiver, documents and money.

3. Turn off gas and electricity.

4. Remove items from balconies (yards) that could be blown away by the wind.

5. From light buildings, move to more durable or civil defense shelters.

6. In a village house, move to the most spacious and durable part of it, and best of all - to the basement.

8. If you have a car, try to drive as far as possible from the epicenter of the hurricane.

Children from kindergartens and schools must be sent home in advance. If the storm warning comes too late, the children should be placed in basements or the center of buildings.

It is best to wait out a hurricane, a tornado or a storm in a shelter, a pre-prepared shelter, or at least in a basement. However, often, a storm warning is given just a few minutes before the arrival of the elements, and during this time it is not always possible to get to the shelter.

If you were outside during a hurricane

2. You can not be on bridges, overpasses, overpasses, in places where flammable and toxic substances are stored.

3. Hide under the bridge, reinforced concrete canopy, in the basement, cellar. You can lie down in a hole or any depression. Protect eyes, mouth and nose from sand and earth.

4. You can not climb onto the roof and hide in the attic.

5. If you are driving in a flat area, stop but do not leave the vehicle. Close its doors and windows more tightly. Cover the radiator side of the engine during a snow storm. If the wind is not strong, you can shovel the snow from the car from time to time so as not to be buried under a thick layer of snow.

6. If you are in public transport, leave it immediately and seek shelter.

7. If the elements caught you on an elevated or open place, run (crawl) towards some shelter (to the rocks, forest) that could extinguish the force of the wind, but beware of falling branches and trees.

8. When the wind has died down, do not immediately leave the shelter, as a squall may repeat in a few minutes.

9. Stay calm and don't panic, help the injured.

How to behave after natural disasters

1. Leaving the shelter, look around for overhanging objects and parts of structures, broken wires.

2. Do not light gas and fire, do not turn on electricity until special services check the state of communications.

3. Do not use the elevator.

4. Do not enter damaged buildings, do not approach broken electrical wires.

5. The adult population provides assistance to rescuers.

Devices

The exact wind speed is determined using an instrument - an anemometer. If there is no such device, you can make a home-made wind-measuring "Wild board" (Fig. 1), with sufficient measurement accuracy for wind speeds up to ten meters per second.

Rice. 1. Homemade Wind Measuring Board-Wild Vane:
1 - vertical tube (600 mm long) with a welded pointed upper end, 2 - front horizontal weather vane rod with a counterweight ball-weight; 3 – weather vane impeller; 4 - upper frame; 5 - horizontal axis of the board hinge; 6 - wind board (weighing 200 g). 7 - lower fixed vertical rod with indicators of the cardinal points fixed on it, in eight points: N - north, south - south, 3 - west, B - east, NW - northwest, NE - northeast, SE - southeast, SW - southwest; No. 1 - No. 8 - wind speed indicator pins.

The weather vane is installed at a height of 6 - 12 meters, above an open flat surface. Under the weather vane, arrows indicating the direction of the wind are fixedly fixed. Above the weather vane to the tube 1 on the horizontal axis 5 is hinged to the frame 4 wind board 6 measuring 300x150 mm. The weight of the board is 200 grams (adjusted according to the reference device). Extending back from frame 4 is an arc segment attached to it (with a radius of 160 mm) with eight pins, of which four are long (140 mm each) and four are short (100 mm each). The angles at which they are fixed are with the vertical for the pin No. 1-0 °; №2 - 4°; No. 3 - 15.5°; #4 - 31°; No. 5 - 45.5 °; #6 - 58°; #7 - 72°; No. 8-80.5°.
The wind speed is determined by measuring the angle of deflection of the board. Having determined the position of the wind board between the arc pins, refer to Table. 1, where this position corresponds to a certain wind speed.
The position of the board between the pins gives only an approximate indication of the wind speed, especially since the wind strength changes quickly and often. The board never remains long in any one position, but constantly fluctuates within certain limits. Observing the changing inclination of this board for 1 minute, its average inclination is determined (calculation by averaging maximum values) and only after that the average minute wind speed is judged. For a high wind speed exceeding 12-15 m/s, the readings of this device have low accuracy (in this limitation - the main drawback of the considered scheme)...

Application

average speed winds on the Beaufort scale in different years of its application

table 2

The Hurricane Scale was developed by Herbert Saffir and Robert Simpson in the early 1920s to measure the potential damage from a hurricane. It is based on numerical values maximum wind speed and includes an assessment of storm waves in each of the five categories. AT Asian countries, given a natural phenomenon called a typhoon (translated from Chinese - "great wind"), and in the North and South America is called a hurricane. At quantification wind speed, the following abbreviations apply: km/h / mph– kilometers / miles per hour, m/s- meters per second.

table 3

tornado scale

The tornado scale (Fujita-Pearson scale) was developed by Theodore Fujita to classify tornadoes according to the degree of damage caused by wind. Tornadoes are typical mainly for North America.

table 4

Glossary of terms:

Leeward side of the object (protected from the wind by the object itself; an area of ​​increased pressure, due to strong flow deceleration) faces where the wind blows. In the picture, on the right. For example, on the water, small ships approach larger ships from their leeward side (there they are protected by the hull of a large ship from waves and wind). "Smoking" plants-enterprises should be located, in relation to residential urban buildings - on the leeward side (in the direction of the prevailing winds) and separated from these areas by fairly wide sanitary protection zones.


windward side object (hill, sea vessel) - on the side from which the wind blows. On the windward side of the ridges, ascending movements of air masses occur, and on the leeward side, a downward airfall occurs. Most of the precipitation (in the form of rain and snow), due to the barrier effect of mountains, falls on their windward side, and on the leeward side, a collapse of colder and drier air begins.

In meteorology, when indicating the direction of the wind, the division of the circle into sixteen parts is used, according to 16-beam rhumb rose(after 22.5 degrees). For example, north-northeast is designated as NNE (the first letter is the main direction, to which the rhumb is closer). Four main directions: North, East, South, West.

Approximate calculation of dynamic wind pressure on the square meter billboard (perpendicular to the plane of the structure) installed near the road of the carriageway. In the example, expected in this place, the maximum storm wind speed, is assumed to be 25 meters per second.

Calculations are carried out according to the formula:
P = 1/2 * (air density) * V^2 = 1/2 * 1.2 kg/m3 * 25^2 m/s = 375 N/m2 ~ 38 kilograms per square meter (kgf)

Note that the pressure increases with the square of the speed. Take into account and include in the construction project sufficient margin of safety, stability (depends on the height of the support post, and on the critical angles of inclination of each particular column), resistance to strong gusts of wind and precipitation, in the form of snow and rain.

At what wind force cancel flights civil aviation

The reason for the violation of the flight schedule, delays or cancellation of flights can be a storm warning from weather forecasters, at the airports of departure and destination.

The meteorological minimum required for a safe (regular) takeoff and landing of an aircraft is the allowable limits for changes in a set of parameters: wind speed and direction, line of sight, the state of the airfield runway and the height of the cloud base. Bad weather, in the form of intense precipitation (rain, fog, snow and blizzard), with extensive frontal thunderstorms, can also cause cancellation of flights from the air harbor.

The values ​​of meteorological minima may differ for specific aircraft (by their types and models) and airports (by class and availability of sufficient ground equipment, depending on the features of the terrain surrounding the airfield and existing high mountains), as well as due to the qualifications and flight experience of the crew pilots , commander of the ship. The worst minimum is taken into account and for execution.

Departure ban - possible in case of bad weather at the destination airport, if there are not, nearby, two alternative air harbors with acceptable weather conditions.

In strong winds, planes take off and land against air flow(by taxiing, for this, to the appropriate lane). In this case, not only safety is ensured, but also the takeoff run and landing run are significantly reduced. Limitations on the lateral and tailwind components of wind speed, for most modern civil aircraft, are approximately: 17-18 and 5 m/s, respectively. The danger of a large roll, demolition and reversal of an airliner, during its takeoff and landing, is represented by an unexpected and strong gusty wind (squall).

https://www.meteorf.ru - Roshydromet ( federal Service on hydrometeorology and environmental monitoring). Hydrometeorological Research Center of the Russian Federation.

Www.meteoinfo.ru is a new website of the Hydrometeorological Center of the Russian Federation.

193.7.160.230/web/losev/osad.gif - Watch a video animation with a predictive synoptic weather map - precipitation, dynamics of cyclones and anticyclones for the coming days, showing the horizontal movements of isobars (atmospheric pressure isolines) of the calculated weather model.

Www.ada.ru/Guns/ballistic/wind/index.htm - For hunters about the effect of wind on bullet flight, ballistic calculator.

Directory ru.wikipedia.org/wiki/ Climate_of Moscow - metropolitan weather stations and statistical data on the average monthly values ​​of the main weather parameters (temperature, wind speed, cloudiness, precipitation in the form of rain and snow), days when absolute temperature records were noted, as well as the coldest and warmest years in Moscow and the region.

Https://meteocenter.net/weather/ - Russian weather from the Meteocenter.

Https:// www.ecomos.ru/kadr22/ postyMeteoMoskwaOblast.asp - Meteorological network (stations and posts) on the territory of the Moscow region. and in neighboring regions (Vladimir, Ivanovo, Kaluga, Kostroma, Ryazan, Smolensk, Tver, Tula and Yaroslavl regions)

Https:// www.ecomos.ru/kadr22/ sostojanieZagrOSnedelia.asp - environmental reports on the state of environmental pollution in Moscow (VDNH, Balchug and Tushino weather stations) and the region for the past week.

In 1963, the World Meteorological Organization clarified Beaufort scale and it was adopted for an approximate estimate of wind speed by its effect on ground objects or by waves on the high seas. The average wind speed is indicated at a standard height of 10 meters above an open flat surface.

The smoke (from the captain's pipe) rises vertically, the leaves of the trees are motionless. Mirror-like sea.

Wind 0 - 0.2m/s

The smoke deviates from the vertical direction, there are light ripples on the sea, there is no foam on the ridges. Wave height up to 0.1m.

The wind is felt in the face, the leaves rustle, the weather vane starts to move, the sea has short waves with a maximum height of up to 0.3 m.

Wind 1.6 - 3.3m/s.

Leaves and thin branches of trees sway, light flags sway, slight excitement on the water, occasionally small lambs form.

The average wave height is 0.6 m. The wind is 3.4 - 5.4 m/s.

The wind raises dust, pieces of paper; thin branches of trees sway, white lambs on the sea are visible in many places.

Maximum wave height up to 1.5 m. Wind 5.5 - 7.9 m/s.

Branches and thin tree trunks sway, the wind is felt by hand, white lambs are visible everywhere.

The maximum wave height is 2.5 m, the average is 2 m. The wind is 8.0 - 10.7 m/s.

In this weather, we tried to leave by Baltic Sea from Darlowo. (Poland) against the wave. In 30 minutes only approx. 10km. and very wet from the splashes. We returned along the way - och. fun.

The thick branches of the trees sway, the thin trees bend, the telephone wires hum, the umbrellas are hardly used; white foamy ridges occupy large areas, water dust is formed. The maximum wave height is up to 4m, the average is 3m. Wind 10.8 - 13.8m/s.

Such weather was caught on boats in front of Rostock. The navigator was afraid to look around, the most valuable thing was stuffed into his pockets, the radio was tied to his vest. Spray from the side waves constantly covered us. For a water-powered fleet, not to mention a simple motorboat, this is probably the maximum ...

Tree trunks sway, large branches bend, it is difficult to go against the wind, the crests of the waves are torn off by the wind. The maximum wave height is up to 5.5m. wind 13.9 - 17.1 m/s.

Thin and dry branches of trees break, it is impossible to speak in the wind, it is very difficult to go against the wind. Strong storm at sea.

The maximum wave height is up to 7.5 m, the average is 5.5 m. The wind is 17.2 - 20.7 m / s.

Large trees are bending, the wind is tearing tiles from the roofs, very strong sea waves, high waves. It is observed very rarely. Accompanied by destruction in large spaces. At sea, exceptionally high waves (maximum height - up to 16m, average - 11.5m), small vessels are sometimes hidden from view.

Wind 28.5 - 32.6m/s. Violent storm.

The sea is all covered with strips of foam. The air is filled with foam and spray. Visibility is very poor. Full p ... ts small-sized ships, yachts and other ships - it's better not to get hit.

Wind 32.7 m/s or more...

Each natural phenomenon, which has different degrees of severity, is usually evaluated 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 (emphasis 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 - the north wind, etc.). 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 your real position or to correctly measure, you need to know which standard conditions used by professionals.

• Measurement of the force 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 wind strength 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 wind force in points, is given for an open maritime space. 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 Arctic Ocean, washing Canada and Alaska, bears his name. An Antarctic island is named after Beaufort.

A convenient system for estimating the strength of the wind 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 - points for grading the strength of hurricanes (USA, 1955).

Criteria for estimating wind strength in Beaufort points

AT modern form The Beaufort scale has several characteristics that allow, in combination, to most accurately correlate a specific atmospheric phenomenon with his scores.

• 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 their accompanying environmental phenomena.

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 direction of air movement, 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 with it - in winter it is blizzards and snowstorms, in summer dust and sandstorms. It should also be borne in mind that strong winds can occur even in absolutely clear weather.

The wind as a natural phenomenon is known to everyone since early childhood. He pleases with a fresh breath on a hot day, drives ships across the sea, and can bend trees and break roofs on houses. The main characteristics that determine the wind are its speed and direction.

From a scientific point of view, the movement of air masses in a horizontal plane is called wind. This movement occurs because there is a difference in atmospheric pressure and heat between two points. Air moves from areas of high pressure to areas of lower pressure. The result is wind.

Wind characteristics

In order to characterize the wind, two main parameters are used: direction and speed (force). The direction is determined by the side of the horizon from which it blows. It can be indicated in rhumbs, in accordance with the 16-rhumb scale. According to her, the wind can be north, southeast, north-northwest, and so on. can also be measured in degrees, relative to the meridian line. This scale defines north as 0 or 360 degrees, east as 90 degrees, west as 270 degrees, and south as 180 degrees. In turn, they are measured in meters per second or in knots. A knot equals approximately 0.5 kilometers per hour. Wind strength is also measured in points, in accordance with the Beaufort scale.

According to which the strength of the wind is determined

This scale was put into circulation in 1805. And in 1963, the World Meteorological Association adopted a gradation that is valid to this day. Within its framework, 0 points corresponds to a calm, in which the smoke will rise vertically upwards, and the leaves on the trees remain motionless. A wind force of 4 points corresponds to a moderate wind, in which small waves form on the surface of the water, thin branches and leaves on trees can sway. 9 points correspond to a gale, in which even large trees can bend, roof tiles can be torn off, high waves can rise on the sea. And the maximum wind force in accordance with this scale, namely, 12 points, falls on a hurricane. This is a natural phenomenon, in which the wind causes serious damage, even capital buildings can collapse.

Using the power of the wind

The power of the wind is widely used in the energy sector as one of the renewable natural sources. Since time immemorial, mankind has used this resource. Suffice it to recall or sailing ships. Windmills, with the help of which the wind is converted for further use, are widely used in places that are characterized by constant strong winds. Of the various fields of application of such a phenomenon as wind power, it is also worth mentioning the wind tunnel.

Wind is a natural phenomenon that can bring pleasure or destruction, as well as be beneficial to mankind. And its specific action depends on how large the force (or speed) of the wind will be.

The direction and speed of the wind is one of best performance weather changes. There are 16 wind directions (rhumbs), indicated by the cardinal points. The names of these sixteen points, or directions from which the wind blows, are given in the following table:

The wind is named after the part of the horizon from which it blows. Sailors say that the wind "blows into the compass". This expression will make it easier to remember the above table.

In addition to these names, there are also local ones. For example, on the coast White Sea and in the region of Murmansk, local fishermen call the northeast wind "night owl", the south - "letnik", the southeast - "lunch", the southwest - "shelkovnik", the northwest - "coastal wind". There are also names of winds on the Black, Caspian Seas and on the Volga. Great importance to determine the weather have local winds that need to be known and taken into account.

To determine the direction of the wind, you need to moisten your index finger and raise it vertically upwards. It will feel cold on the side facing the wind.

The direction of the wind can also be determined by the pennant, smoke and compass. Facing the wind and holding a compass in front of you, the zero division of which is brought under the northern end of the arrow, they put a match or a thin straight stick on its center, pointing it in the direction in which the observer is facing, that is, towards the wind.

Pressing a match or stick in this position to the glass of the compass, you need to look at what division of the scale it falls on. This will be the part of the horizon where the wind blows from.

An indication of the direction of the wind is the landing of birds. They always land against the wind.

Wind speed is measured by the distance (in meters or kilometers) over which the mass of air moves in 1 second. (hours), as well as in points according to the twelve-point Beaufort system. The wind speed is constantly changing, and therefore more often take into account its average value over 10 minutes. The wind speed is determined special devices, but it can be determined quite accurately by eye, using the table below.

Determination of wind speed (according to K.V. Pokrovsky):

The strength of the waves of the sea (lake) is determined according to the following table (according to A.G. Komovsky):