Is the wind strong 2 m s. On duty. Instrument for measuring wind speed

Wind- this is a horizontal movement (air flow parallel to the earth's surface), resulting from uneven distribution of heat and atmospheric pressure and directed from a high pressure zone to a 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. In recent years, the strength of the wind is more often estimated by the 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 Beaufort scale adopted in 1963 by the World Meteorological Organization. The sea disturbance scale is nine-point (the parameters are given for a large sea area; in small areas - less excitement). Descriptions of the action from the movement of air masses are given "for the conditions of the earth's atmosphere near the earth's or water surface", and above zero temperature. On the planet Mars, for example, the ratios will be different.

Wind strength in points on the Beaufort scale and sea waves

Table 1

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 sway continuously
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 neighboring 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 wind up to a hurricane, with a force of more than 9 points (gradation on the Beaufort scale), accompanied by destruction on land and strong waves at sea (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. Gusty, squally wind occurs during the passage of the atmospheric front and with a rapid change in pressure in the baric system.

Vortex- atmospheric formation with rotational movement of 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 tornado in Bangladesh, observed in 1989, was included in the Guinness Book of Records as the most terrible and destructive tornado in the entire history of observations. Despite the fact that the inhabitants of the city of Shaturia were warned in advance about the approach of a tornado, 1,300 people became its victims.

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

Forecasters classify hurricanes, storms and tornadoes as emergency 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 ship 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 the symbols for the direction and speed of the wind used on weather maps, as well as an example of drawing icons and fragments from a hundred-cell matrix of weather symbols (for example, a snowstorm and a blowing snow, when there is a rise and redistribution of previously fallen snow 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 any shelter (to 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 - a vertical tube (600 mm long) with a welded pointed upper end, 2 - a 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: C - north, south - south, 3 - west, B - east; 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. Board weight - 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 the 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, this is the main drawback of the considered scheme).

Application

Average wind speed on the Beaufort scale in different years 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 maximum wind speeds and includes an estimate of storm waves in each of the five categories. IN 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. When quantifying wind flow 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" factories-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 where 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.

Approximate calculation of dynamic wind pressure per square meter of a 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 (also depends on the height of the support post) and 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 violation of the flight schedule, delay or cancellation of flights - may 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 minimums - may vary for specific aircraft (by their types and models) and airports (by class and the availability of sufficient ground equipment, depending on the features of the terrain surrounding the airfield and the 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, aircraft take off and land against the 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 component of wind speed, for most modern civil aircraft, are values, 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 for Hydrometeorology and Environmental Monitoring). Hydrometeorological Research Center of the Russian Federation.

Www.meteoinfo.ru - new site of the Hydrometeorological Center of the Russian Federation.

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, in American meteorological stations takes into account the average speed of air flows for 1 minute, in India - for 3 minutes, and in many European countries- in 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.

Leading specialist of the Phobos Center Evgeny Tishkovets told REN TV that at the time of the crash of the Boeing-737 in Rostov-on-Don, the weather conditions were critical for landing the aircraft.

"Western-southwest wind, 12-14 m/s, in gusts up to 17 m/s. As for the actual weather, all of the above is not a dangerous weather phenomenon that restricts or prohibits takeoff or landing aircraft. At least - such as Boeing. It remains to understand with what course he went. The fact is that in Rostov-on-Don the direction runway- northeast-southwest. You need to understand what limitations he had. If we draw an analogy with our domestic types of aircraft, then a side wind of 10, maximum 17 m/s is, for example, critical for the Tu-154. Anything above this will disallow landing.", - explained Tishkovets.

An eyewitness to the Boeing crash told REN TV about what the plane had seen coming in to land. According to the man, at that moment he was sitting in the car, which.

Let's remind, Boeing-737-800 of FlyDubai airline crashed today at 3:50 Moscow time. According to preliminary data, the plane caught fire while still in the air. This is confirmed by the frames,. They show how a bright object falls to the ground, after which a powerful explosion is heard.

Before the crash, the liner circled over the airport for about two hours. There were 55 passengers and 7 crew members on board, all of them died.

Boeing-737-800 is one of the latest models in the 737th line, the most widely used passenger aircraft throughout the history of civil aviation. The Boeing-737 is so widely used that 1,200 aircraft of this family are in the air at the same time, and one 737 takes off or lands every 5 seconds. Over the entire history of operation, more than 170 liners of this type have been lost, almost 4,000 people have died in accidents.

In Russia, four such aircraft were lost, and all the crashes occurred during landing. The first disaster occurred in Perm in September 2008. Then 88 people died, among the victims of the crash were Hero of Russia Colonel-General Gennady Troshev, First Vice-President of the All-Russian Sambo Federation Vladimir Pogodin. The second incident in Kaliningrad in October of the same 2008 was without casualties - during landing, the crew forgot to release the landing gear. There were 144 people on board, all of them survived. The disaster on November 17, 2013 in Kazan claimed the lives of 50 people. Boeing-737 crashed while entering the second circle. Everyone on board died, including the son of Tatarstan President Rustam Minnikhanov and the head of the local FSB Alexander Antonov.

Wind is the movement of air in a horizontal direction along the earth's surface. In which direction it blows depends on the distribution of pressure zones in the planet's atmosphere. The article deals with issues related to the speed and direction of the wind.

Perhaps, absolutely calm weather will be a rare phenomenon in nature, since you can constantly feel that a light breeze is blowing. Since ancient times, mankind has been interested in the direction of air movement, so the so-called weather vane or anemone was invented. The device is an arrow freely rotating on a vertical axis under the influence of wind force. She points his direction. If you determine the point on the horizon from which the wind blows, then the line drawn between this point and the observer will show the direction of air movement.

In order for an observer to convey information about the wind to other people, concepts such as north, south, east, west and their various combinations are used. Since the totality of all directions forms a circle, the verbal formulation is also duplicated by the corresponding value in degrees. For example, North wind means 0 o (the blue compass needle points due north).

The concept of the wind rose

Speaking about the direction and speed of movement of air masses, a few words should be said about the wind rose. It is a circle with lines showing how air flows. The first mention of this symbol was found in the books of the Latin philosopher Pliny the Elder.

The entire circle, reflecting the possible horizontal directions of the forward movement of air, is divided into 32 parts on the wind rose. The main ones are north (0 o or 360 o), south (180 o), east (90 o) and west (270 o). The resulting four parts of the circle are divided further, forming the northwest (315 o), northeast (45 o), southwest (225 o) and southeast (135 o). The resulting 8 parts of the circle are again divided in half each, which forms additional lines on the wind rose. Since the result is 32 lines, the angular distance between them is equal to 11.25 o (360 o /32).

Note that distinctive feature The wind rose is an image of a fleur-de-lis located above the north icon (N).

Where does the wind blow from?

Horizontal movements of large air masses are always carried out from areas of high pressure to areas of lower air density. At the same time, you can answer the question of what wind speed is by studying the location on geographical map isobars, that is, broad lines within which air pressure is constant. The speed and direction of movement of air masses is determined by two main factors:

• The wind always blows from the areas where the anticyclone stands to the areas covered by the cyclone. This can be understood if we remember that in the first case we are talking about zones of high pressure, and in the second case - low pressure.
• Wind speed is in direct proportion to the distance that separates two adjacent isobars. Indeed, the greater this distance, the weaker the pressure drop will be felt (in mathematics they say a gradient), which means that the forward movement of air will be slower than in the case of small distances between isobars and large pressure gradients.

Factors affecting wind speed

One of them, and the most important one, has already been voiced above - this is the pressure gradient between neighboring air masses.

Besides average speed wind depends on the topography of the surface over which it blows. Any irregularities in this surface significantly hinder the forward movement of air masses. For example, everyone who has been in the mountains at least once should have noticed that the winds are weak at the foot. The higher you climb the mountainside, the stronger the wind is felt.

For the same reason, winds blow stronger over the sea than over land. It is often eroded by ravines, covered with forests, hills and mountain ranges. All these heterogeneities, which are not over the seas and oceans, slow down any gusts of wind.

High above the earth's surface (on the order of several kilometers) there are no obstacles to the horizontal movement of air, so the wind speed in the upper troposphere is high.

Another factor that is important to consider when talking about the speed of movement of air masses is the Coriolis force. It is generated due to the rotation of our planet, and since the atmosphere has inertial properties, any movement of air in it is deflected. Due to the fact that the Earth rotates from west to east around its own axis, the action of the Coriolis force leads to the deviation of the wind to the right in the northern hemisphere, and to the left in the southern.

Curiously, this effect of the Coriolis force, which is negligible at low latitudes (tropics), has a strong influence on the climate of these zones. The fact is that the slowdown in wind speed in the tropics and at the equator is compensated by increased updrafts. The latter, in turn, lead to the intense formation of cumulus clouds, which are sources of strong tropical showers.

Instrument for measuring wind speed

It is an anemometer, which consists of three cups located at an angle of 120 o relative to each other, and fixed on a vertical axis. The principle of operation of an anemometer is quite simple. When the wind blows, the cups experience its pressure and begin to rotate on the axis. The stronger the air pressure, the faster they spin. By measuring the speed of this rotation, one can accurately determine the wind speed in m/s (meters per second). Modern anemometers are equipped with special electrical systems that independently calculate the measured value.

The instrument of wind speed based on the rotation of the cups is not the only one. There is another simple tool called the pitot tube. This device measures the dynamic and static wind pressure, the difference between which can accurately calculate its speed.

Beaufort scale

Information about wind speed, expressed in meters per second or kilometers per hour, for most people - and especially for sailors - says little. Therefore, in the 19th century, the English admiral Francis Beaufort proposed to use some empirical scale for evaluation, which consists of a 12-point system.

The higher the Beaufort scale, the stronger the wind blows. For example:

• The number 0 corresponds to absolute calm. With it, the wind blows at a speed not exceeding 1 mph, that is, less than 2 km / h (less than 1 m / s).
• The middle of the scale (number 6) corresponds to a strong breeze, the speed of which reaches 40-50 km/h (11-14 m/s). Such a wind can lift big waves on the sea.
• The maximum on the Beaufort scale (12) is a hurricane whose speed exceeds 120 km/h (more than 30 m/s).

Major winds on planet Earth

They are usually classified into one of four types in the atmosphere of our planet:

• Global. They are formed as a result of the different ability of continents and oceans to heat up from the sun's rays.
• Seasonal. These winds change with the season of the year, which determines how much solar energy a certain area of ​​the planet receives.
• Local. They are associated with features geographical location and topography of the area in question.
• Rotating. These are the strongest movements of air masses that lead to the formation of hurricanes.

Why is it important to study the winds?

In addition to the fact that information about wind speed is included in the weather forecast, which every inhabitant of the planet takes into account in his life, air movement plays an important role in a number of natural processes.

So, he is a carrier of plant pollen and is involved in the distribution of their seeds. In addition, wind is one of the main sources of erosion. Its destructive effect is most pronounced in deserts, when the terrain changes dramatically during the day.

It should also not be forgotten that the wind is the energy that people use in economic activity. According to general estimates, wind energy makes up about 2% of all solar energy falling on our planet.

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.