How to determine a strong wind. Speed, strength and direction of wind

On April 10, 1996, the highest wind speed on Earth was recorded on the island of Barrow in Australia. Then, during the tropical cyclone "Olivia", the wind acted to 408 kilometers per hour. This figure confirmed scientists from the World Meteorological Organization. How exactly they calculated it - I learned Kryptus.

Usually, meteorologists recognize the wind speed using a cup anemometer (another name - veterinary). This is such a measuring device, on the vertical axis of which cups are fixed - hemispheres, which rotate from any, even the easiest, wind. The stronger the wind, the faster the rotation takes place. From the axis of the device there is a transmission to the counter of revolutions. He determines what kind of wind speed is now two, three or four meters per second. To understand the direction, flugers are installed next to the anemometers.

Now every person who wants to always be aware of the wind speed can buy a digital anemometer. They are inexpensive and stand within 25-35 dollars.

By the way, before people learned to measure wind speed in meters per second, they used the Beaufort scale. This English admiral compiled a table in which the characteristics of different winds were reduced to the scores system - from zero (full of calm) to 12 points (hurricane wind, giving up to a speed of 117 km / h).

How to measure speed, wind strength and visibility range.

Determination of strength, speed and direction of wind, visibility range, directions and speeds of flows is extremely important when planning and performing dives in the open sea and coastal zone. Fight with the power of nature is meaningless and sometimes extremely dangerous, so you should always consider the influence natural phenomena, such as the flow and wind, when planning dives. The information below will help you evaluate the strength of some of the phenomena of nature in order to take into account them when planning dives.

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

The wind is characterized speed (strength) and direction. N.eton Determined by the parties of the horizon and is measured by degrees. Wind speed Measured in meters in Speed \u200b\u200band kilometers per hour. Wind power Measured in points.

Beaufort scale - Conditional scale for visual definition and speed recording (strength) of wind in points. Initially, it was developed by the English admiral Francis Beaufort in 1806 to determine the strength of the wind in the nature of its manifestation on the sea. Since 1874, adopted for ubiquitous (on land and at sea) use in international synoptic practice. In subsequent years, changed and specified. For zero points, a full calm condition was taken. Initially, the system was thirteen chibal (0-12). In 1946, the scale was increased to seventeen (0-17). Wind power in the scale is determined by the interaction of wind with various objects. IN last years Wind power is more often evaluated by the speed measured in meters per second in the earth's surface, at an altitude of about 10 meters above the open, smooth surface.

Table 1 shows the scale of Beaufort, adopted in 1963 by the World Meteorological Organization. The excitement scale on the sea is a nine cycle (the excitement parameters are given for a large marine water area, an excitement is less in small waters). The instruments for measuring the wave height does not exist, therefore, the excitement of the sea in points is determined quite conditionally.

The wind force in the ballaves on the Bafort scale and excitement to the sea.

Short, well-pronounced waves. Combs, tilting, form a vitreous foam, occasionally small white lambs are formed. The average wave height is up to 0.6 m., Length is 6 m.

Waves elongated, white lamb are visible in many places. Wave height 1-1,5 m., Length up to 15 m.

Well developed long, but not very large waves, white lambs are visible everywhere (splashes are formed in some cases). Wave height 1.5-2 m., Length - 30 m.

Large waves begin to form. White foam ridges occupy significant areas. Water dust is formed. Wave height - 2-3 m., Length - 50 m.

Waves are prayer, the ridges are broken, foam lies with strips in the wind. The height of the waves is up to 3-5 m., Length - 70 m.

Moderately tall, long waves. At the edges of the ridges begin to take the splashes. Foam strips fall along the wind direction. Wave height 5-7 m., Length - 100 m.

Very high waves with long flexing down crests. The resulting foam is blown by the wind by large flakes in the form of thick white stripes. The surface of the sea is white from foam. A strong crash of waves is like shocks. Visibility is bad. Wave height - 8-11 m., Length - 200 m.

Courts of small and medium sized at times are hidden from the view. The sea is all covered with long white foam flakes located in the wind. The edges of the waves are blown away in a foam. Visibility is bad. Wave height to 16 m., Length up to 250 m.

The air is filled with foam and splashes. The sea is all covered with foam stripes. Very bad visibility. Wave height\u003e 16 m., Length - 300 m.

Scale of visibility range.

Visibility - This is the maximum distance in which the items are detected, and at night navigation lights. Visibility is determined by the transparency of the atmosphere depends on weather conditions and is characterized by a visibility range. Below is a table of defining visibility range in the daytime.

Anamometer - device designed to measure wind speed

The device for measuring the wind speed, its strength, as well as determining the direction of its movement in meteorology is called anemometer. Few today know what it is, because the device did not receive widespread In contrast, for example, from a barometer, however, it is still used when measuring wind parameters both on meteorological stations and in some sports, for example, in sailing sports.

It is also used in other scientific fields to measure the speed of movement of gases or air, but the most popular option to use is still operation as a wind speed meter.

Principle of operation of the device

The principle of operation of most such devices is as follows: any rotational element is attached to the meter. When blowing wind moving part of the device It comes to action and the parameters of the exposure to the rotational element are transmitted to the measuring device. So there are mechanical anemometers, including two varieties: a cup and impeller anemometers.

There are also a thermal anemometer based on measuring the temperature shifts of the heating element relative to the initial value under the influence of wind (the higher the speed of the air masses, the less temperature The heating element) and ultrasonic, based on the measurement of shifts in the sound speed indicators relative to the direction of the air masses (if the speed of sound drops relative to its speed in fixed air, it means that it moves against the wind, if it grows in the wind).

Types of devices

The principle of operation consists in measuring the nature of the effects of air masses on special cups fixed on the vertical axis. When the wind breeding occurs, the cups rotate around the axis. The meter fixes The number of revolutions around the axis in time and determines the wind speed. The data is transmitted on the wind speed scale, sometimes an electronic meter is used.

The principle of its work consists in measuring the nature of the impact of wind on a miniature wheel (impeller), fixed on the vertical axis and a fledged metal ring to protect against mechanical damage. When wind movement The impeller rotates, which through the gear system is transmitted to the meter. This device also has two varieties of the meter: manual and electronic.

Based on the change in the number of nusselt, that is, the increase in the heat loss of the heated body is in proportion to an increase in the speed of the air masses. This phenomenon can be observed in life - with an equal air temperature in windy weather becomes colder than in calm. This device represents Heated to a temperature greater than the temperature of the medium, metal wire.

Depending on the current velocity, its density and humidity of the wind of the wire highlights a certain amount of energy, which allows to support one or another temperature of the wire. The meter fixes the heat loss and displays the wind movement parameters on the screen. However, the device has 2 disadvantages:

1. Low strength of the thermal element, as it is represented very thin wire.
2. Accuracy of testimony over time increases due to pollution and wire oxidation.

In view of the above, they are used, as a rule, used in aerodynamics in order to measure the parameters of the movement of air masses, because thermal anemometers, in contrast to mechanical, have imperative, which is a prerequisite for aerodynamic experiments.

The principle of operation lies in the nature of changing the speed of sound when moving relative to the wind. So you can measure not only the current strength of the wind movement, but also the direction of its movement. Since the speed of sound also depends on the air temperature, then this anemometer is equipped As a thermometer, according to the indications of which edits are made to the final results of the parameters of the movement of air masses, issued by anemometer.

To date, the ultrasonic anemometer is the highest and modern device of this category. Among other things, some electronic anemometers can also measure the air temperature at the time of the movement of the air masses, as well as its humidity.

Conclusion

In Russia, multipurpose devices of this category are also produced, combining the functions of various types of anemometers, such as measuring air temperature (thermomemometer), its humidity (gyrometer), as well as calculating the volume flow of air. Such anemometer is, for example, Mess200 meteometer, DMC01m diff pump. These devices are used during examination, repair and verification of ventilation in buildings.

All produced on Russian territory Fixed in the State Register of Measurement Means and are subject to mandatory verification. Therefore, there are no anemometers without calibration.

Consideration of various types of devices called an anemometer intended for measuring wind speed

Description of anemometers, disclosure of this concept, as well as consideration of various types of anemometers, including Russian

Moving air above the surface of the earth in the horizontal direction is called Wind. The wind always blows from the high pressure area into the low area.

Wind characterized by speed, strength and direction.

Wind speed and power

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

The strength of the wind depends on the speed (Table 1). The greater the difference between neighboring grounds of the earth's surface, the stronger the wind.

Table 1. Wind power in the earth's surface on the Bafort scale (at a standard height of 10 m above the open level surface)

Balves Beaufort	Verbal definition of wind power	Wind speed, m / s	Wind effect
			Calm. Smoke rises vertically	Mirror smooth sea
			The direction of the wind is noticeable but the following smoke, but not on the fluger	Ripples, foam on the ridges
			The wind movement is felt on his face, leave the leaves, drives in motion.	Short waves, ridges do not overturn and seem to be vitreous

			Leaves and thin branches of trees all the time pegs, wind waves top flags	Short, well-pronounced waves. Combs, tilting, form a glass foam, occasionally small white lambs are formed
	Moderate		The wind raises dust and papers, drives thin branches of trees	Waves elongated, white whiskers are visible in many places
			Thin trunks of trees are swinging, waves appear on the water with ridges	Well developed in length, but not very large waves, white lambs are visible everywhere (in some cases splashes are formed)
			Thick branches of trees are swinging, the telegraph wires are buzzing	Large waves begin to form. White foam ridges occupy significant fasteners (splashes likely)
			Trees trunks are swinging, it's hard to go against the wind	Waves are prayer, the ridges are broken, foam lies with strips in the wind
	Very strong		The wind breaks the bitch of the trees, go against the wind is very difficult	Moderately high long waves. At the edges of the ridges begin to take the splashes. Foam strips fall rows in the direction of wind
			Minor damage; The wind breaks down the smoke caps and tiles	High waves. Foam is widely dense stripes falling around the wind. Combs of the waves begin to overturn and crumble into splashes that worsen visibility

	Heavy storm		Significant destruction of buildings, trees break down with the root. There is rare on land	Very high waves with long-breeding down crests. The resulting foam is blown by the wind by large flakes in the form of thick white stripes. The surface of the sea is white from foam. A strong crash of waves is like shocks. Visibility bad
	Cruel storm		Large destruction at a significant space. On land is very rare	Exceptionally high waves. Courts of small and medium sized at times are hidden from the view. The sea is all covered with long white foam flakes located in the wind. The edges of the waves are blown away in a foam. Visibility bad
		32.7 or more		The air is filled with foam and splashes. The sea is all covered with foam stripes. Very bad appearance

Scale Beaufort - Conditional scale for visual evaluation Forces (speeds) of wind in points in its action on ground items or by wondering on the sea. It was developed by the English admiral F. Beaufort in 1806 and first applied only to them. In 1874, the Permanent Committee of the First Meteorological Congress accepted the Beaufort Scale for use in international synoptic practice. In subsequent years, the scale varied and specified. Beaufort scale is widely used in marine navigation.

Direction of the wind

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

On the climatic map dominant winds Showing arrows (Fig. 1). Winds observed in the earth's surface are very diverse.

You already know that the surface of the sushi and water is heated in different ways. On a summer day, the surface of the sushi is stronger. From heating air over land expands and becomes easier. Over the reservoir at this time, the air is colder and, therefore, harder. If the reservoir is relatively large, in a quiet hot summer day on the shore you can feel a light breeze blowing from water, above which is higher than above the land. Such a light breeze is called daily Breeze (from Franz. Brise is a light wind) (Fig. 2, a). Night breeze (Fig. 2, b), on the contrary, blows from sushi, as the water is cooled much slower and the air over it is warmer. Brist can occur both on the edge of the forest. Briz scheme is presented in Fig. 3.

Fig. 1. The distribution scheme of the dominant winds on the globe

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

Foney - Warm and dry wind blowing from the mountains in the valley.

Bora - Gusty, cold and strong windappearing when cold air turns over low ridges to the warm sea.

Monsoon

If the Breeze changes the direction twice a day - day and night, then seasonal winds - Mussons - Change your direction twice a year (Fig. 4). Summer, the dryer is quickly heated, and the air pressure above its surface. At this time, the cooler air begins to move to the land. In winter, everything is the opposite, so the monsoon blows from sushi to the sea. With the change of winter monsoon on the summer, a change of dry cloudless weather on rainy.

The action of monsoon is very manifested in eastern parts The continents, where the huge spaces of the oceans are adjacent to them, so such winds often bring abundant precipitation on the mainland.

The uneasy nature of the circulation of the atmosphere in different parts of the globe determines differences in the causes and nature of monsoon. As a result, blurred and tropical monsimes distinguish.

Fig. 2. Breeze: a - daily; B - Night

Fig. 3. Briz scheme: a day; B - Night

Fig. 4. Monspi: A - in summer; b - winter

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

Tropical Monsoons - Tropical latitudes monsions. They are due to seasonal differences in heating and cooling the northern and southern hemispheres. As a result, the pressure zone is shifted to seasons relative to the equator to the hemisphere, in which this time is summer. Tropical monsions are most typical and resistant in the northern part of the pool Indian Ocean. This consistently facilitates the seasonal change of atmospheric pressure over the Asian mainland. The indigenous features of the climate of this region are associated with South Asian monscons.

The formation of tropical monsoons in other parts of the globe occurs less characteristic when one of them is more clearly expressed - winter or summer monsoon. Such monsoons are celebrated in Tropical Africa, in Northern Australia and in the having essential areas of South America.

Standing winds of the Earth - Passat and western winds - depend on the position of atmospheric pressure belts. As B. equatorial belt Low pressure prevails, and close to 30 ° C. sh. and Yu. sh. - High, near the surface of the earth, throughout the year, winds blow from thirty latitudes to the equator. These are trade winds. Under the influence of the rotation of the Earth around the axis of the trade winds, they deviate in the northern hemisphere to the west and blow from the northeast to the southwest, and in the southern they are directed from the south-east to the North-West.

From high pressure belts (25-30 ° C. sh. And Yu. Sh.) The winds blow not only to the equator, but also in the side of the poles, since 65 ° C. sh. and Yu. sh. Low pressure prevails. However, due to the rotation of the Earth, they gradually deviate to the east and create air flows moving from the west to the East. Therefore, Western winds prevail in moderate latitudes.

Bafort scale, sea cleansing, visibility range

IA site.

Scale Beaufort

0 points - calm
Mirror smooth sea, almost fixed. Waves practically do not hit the shore. Water looks like a quiet lake plant rather than on the sea coast. A haze can be observed above the surface of the water. The edge of the sea merges with the sky so that the boundaries are not visible. Wind speed 0-0.2 km / h.

1 score - quiet
Easy ripples on the sea. The wave height reaches up to 0.1 meters. The sea can still merge with heaven. It is felt a light, almost imperceptible breeze.

2 points - easy
Small waves, not more than 0.3 meters high. Wind speed 1.6-3.3 m / s, it can be smelted by a face. With this wind, the fluger begins to move.

3 points - weak
Wind speed 3.4-5.4 m / s. Light excitement on the water, races appear occasionally. The average wave height is up to 0.6 meters. Good noticeable weak surf. The fluger is spinning without frequent stops, leaving the leaves on the trees, flags, and so on.

4 points - moderate
Wind - 5.5 - 7.9 m / s - raises dust and small pieces. The fluger is spinning continuously, the thin branches of the trees are rushing. The sea is restless, in many places they are visible lamb. Wave height to 1.5 meters.

5 points - Fresh
Almost all the sea is covered with white lamb. Wind speed 8 - 10.7 m / s, wave height is 2 meters. Drops and thin trees trunks are swinging.

6 points - strong
The sea in many places is covered with white crests. The wave height reaches 4 meters, the average height is 3 meters. Wind speed 10.8 - 13.8 m / s. Torn thin trunks of trees, and thick bumps of trees, buzzing telephone wires.

7 points - strong
The sea is covered with white foam ridges, which from time to time are dried by the wind from the surface of the water. The wave height reaches 5.5 meters, the average height is 4.7 meters. Wind speed 13.9 - 17.1 m / s. The middle trunks of the trees are swinging, bruises bent.

8 points - very strong
Strong waves, on each ridge of foam. The wave height reaches 7.5 meters, the average height is 5.5 meters. Wind speed 17.2 - 20 m / s. It's hard to go against the wind, it is almost impossible to talk. Thin bitching of trees break.

9 points - storm
High waves on the sea reaching 10 meters; The average height of 7 meters. Wind speed 20.8 - 24.4 m / s. Bent big trees, middle branches break. The wind shaves poorly reinforced coating with roofs.

10 points - strong storm
Sea white color. Waves fell ashore or about the rocks with a roar. The maximum wave height is 12 meters, the average height of 9 meters. Wind, at a speed of 24.5 - 28.4 m / s, breaks down the roofs, significant damage to the buildings.

11 points - cruel storm
High waves reaches 16 meters, with an average height of 11.5 meters. Wind speed 28.5 - 32.6 m / s. Accompanied by large destruction on land.

12 points - hurricane
Wind speed 32.6 m / s. Serious damage to capital buildings. The height of waves is more than 16 meters.

Scale of unrest of the sea

Unlike the generally accepted twelve ball of the wind assessment, evidence estimates on the sea are several.

Generally accepted are the British, American and Russian estimation systems.

All scales are based on the parameter determining the average height of significant waves.

This parameter is called Significance Wave Height (SWH).

The American scale takes 30% of significant waves, in British 10%, in Russian 3%.

The height of the wave is considered from the crest (the top point of the wave) to the sole (the base of the depression).

Below is a description of the wave height:

• 0 points - calm,
• 1 point - ripples (SWH< 0,1 м),
• 2 points - weak excitement (SWH 0.1 - 0.5 m),
• 3 points - Easy excitement (SWH 0.5 - 1.25 m),
• 4 points - moderate excitement (SWH 1.25 - 2.5 m),
• 5 points - stormy excitement (SWH 2.5 - 4.0 m),
• 6 points - very stormy excitement (SWH 4.0 - 6.0 m),
• 7 points - strong excitement (SWH 6.0 - 9.0 m),
• 8 points - very strong excitement (SWH 9.0 - 14.0 m),
• 9 points - phenomenal excitement (SWH\u003e 14.0 m).

In this scale, the word "storm" is not applicable.

Since it is determined not the strength of the storm, but the wave height.

The storm is determined by Beaufort.

For the WH parameter, part of the waves (30%, 10%, 3%) is taken for all scales because the magnitude of the waves is non-etinak.

At a certain time section, there are waves, for example, 9 meters, as well as 5, 4, etc.

Therefore, it was adopted for each scale its SWH value, where a certain percentage of the highest waves are taken.

Instruments for measuring the wave height does not exist.

Therefore, there is no accurate point defining.

Definition conditionally.

On the seas, as a rule, the wave height reaches 5-6 meters in height, and up to 80 meters in length.

Visibility range scale

Visibility is the limit distance with which the items are detected, and at night navigation lights.

Visibility depends on weather conditions.

In metrology, the influence of weather conditions appreciates the conditional score of the points.

This scale is a way to indicate the transparency of the atmosphere.

There are daily and night visibility range.

Below is a daytime range of visibility range:

Up to 1/4 Cabletov
About 46 meters. Very bad visibility. Thick fog or blizzard.

Up to 1 cable
About 185 meters. Bad visibility. Thick fog or sleet.

2-3 Cabletov
370 - 550 meters. Bad visibility. Fog, sleet.

1/2 Mile
About 1 km. Chimka, thick darkness, snow.

1/2 - 1 mile
1 - 1.85 km. Average visibility. Snow, heavy rain

1 - 2 miles
1.85 - 3.7 km. Cheek, Mist, rain.

2 - 5 miles
3.7 - 9.5 km. Easy flushing, blades, weak rain.

5 - 11 miles
9.3 - 20 km. Good visibility. The horizon is visible.

11 - 27 miles
20 - 50 km. Very good visibility. The horizon is visible sharply.

27 miles
Over 50 km. Exceptional visibility. The horizon is visible clearly, the air is transparent.

The wind is the movement of the air in the 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 discusses issues related to speed and wind direction.

Perhaps the rare phenomenon in nature will be absolutely quiet weather, because you can constantly feel that a light breeze blows. Since ancient times, humanity was interested in the direction of air movement, therefore the so-called vane or anemone was invented. The device is an arrow freely rotating on the vertical axis under the influence of wind power. It indicates his direction. If you determine the point on the horizon, from where the wind blows, then the line spent between this point and the observer will show the direction of air movement.

In order for the observer to convey other people to other people, they use such concepts as the north, south, east, west and the various combinations thereof. Since the totality of all directions form a circle, the verbal wording is also duplicated by the corresponding value in degrees. For example, the North Wind means 0 o (the blue arrow of the compass shows exactly north).

Concept about wind rose

Speaking about the direction and speed of the air masses, a few words about the wind rose should be said. It is a circle on which lines showing how air flows are moving. The first mentions of this symbol were found in the books of the Latin philosopher Pole senior.

The entire circle, reflecting the possible horizontal directions of the translational movement of air, on the wind rose is divided into 32 parts. The main ones are North (0 o or 360 o), south (180 o), East (90 o) and West (270 o). The resulting four stakes of the circle are submitted further, forming the North-West (315 o), northeast (45 o), south-west (225 o) and southeast (135 o). The resulting 8 parts of the circle are again divided by each in half, which forms additional lines on the wind rose. Since the end is obtained 32 lines, the angular distance between them turns out to be 11.25 o (360 o / 32).

Note that the distinguishing feature of the wind roses is the image of a heraldic lily located above the north icon (N).

Where does the wind blow?

Horizontal movements of large air masses are always carried out of high pressure areas in a zone with less air density. At the same time answer the question of what speed of the wind can, by studying the location on the geographical map of the isobar, that is, wide lines, within which air pressure is unchanged. The speed and direction of movement of the air masses is determined by two main factors:

• The wind always blows out of the areas where the anticyclone is, in the area that covers the cyclone. It is possible to understand this if you remember that in the first case we are talking about the zones of increased pressure, and in the second case - reduced.
• The wind speed is in direct proportionality from the distance that separates two neighboring isobars. Indeed, the larger the distance, the pressure drop will be felt (the gradient is said in mathematics), which means that the translational movement of the air will be slower than in the case of small distances between isobami and large pressure gradients.

Factors affecting wind speed

One of them and the most important was already voiced above - this is a pressure gradient between adjacent air masses.

In addition, the average wind speed depends on the surface relief on which it blows. Any irregularities of this surface significantly restrain the translational movement of air masses. For example, everyone who at least once was in the mountains should have noticed that the foot of the wind was weak. The higher the mountain slope, the stronger the wind felt.

For the same reason, the wind blew more over the sea smoothness than above the land. It is often made by ravines, covered with forests, hills and mountain chains. All these inhomogeneities, which are not over the seas and oceans, slow down any gusts of the wind.

It is high above the surface of the Earth (about a few kilometers) there are no obstacles to the horizontal movement of air, so the wind speed in the upper layers of the troposphere is large.

Another factor that is important to take into account when talking about the ambassadors of the mass movement of the air, it is the power of Coriolis. It is generated by the rotation of our planet, and since the atmosphere has inertial properties, then any movement in it is deviated. Due to the fact that the Earth rotates from the west to the east around its own axis, the effect of the coriolism force leads to the rejection of the wind to the right in the northern hemisphere, and left in South.

Curious, but the specified coriolism force effect, which is insignificant in low latitudes (tropics), has a strong influence on the climate of these zones. The fact is that the slowdown of the wind speed in the tropics and at the equator is compensated by the amplification of ascending flows. The latter, in turn, lead to the intensive formation of cumulus clouds, which are sources of strong tropical rainfall.

Wind speed measurement device

It is an anemometer, which is three cups located at an angle of 120 o relative to each other, and fixed on the vertical axis. The principle of an anemometer is quite simple. When the wind blows, the cups are tested on themselves and begin to rotate on the axis. The stronger the air pressure, the faster they rotate. Measuring the speed of this rotation, you can accurately determine the wind speed in M \u200b\u200b/ C (meters per second). Modern anemometers are equipped with special electrical systems that independently calculate the measured value.

The wind speed device based on the rotation of the cups is not the only one. There is another simple tool called Pito tube. This device measures the dynamic and static wind pressure, by the difference of which it is possible to accurately calculate its speed.

Scale Beaufort

Information about wind speed, expressed in meters per second or kilometers per hour, for most people - and especially for sailors - there is little about what. Therefore, in the XIX century, English Admiral Francis Beaufort proposed to evaluate the use of some empirical scale, which consists of a 12-point system.

The higher the score on the Bafort scale, the stronger the wind blows. For example:

• Figure 0 corresponds to the absolute calm. With it, the wind blows at a rate not exceeding 1 mile per hour, that is less than 2 km / h (less than 1 m / s).
• The middle of the scale (digit 6) corresponds to a strong breeze, the speed of which reaches 40-50 km / h (11-14 m / s). Such a wind is able to raise big waves on the sea.
• Maximum on the Bafort scale (12) is a hurricane whose speed exceeds 120 km / h (more than 30 m / s).

Basic winds on planet Earth

Their in the atmosphere of our planet is customary to attribute to one of the four types:

• Global. They are formed as a result of various abilities of continents and oceans to heat up from sunlight.
• Seasonal. These winds vary depending on the season of the year, which determines how many solar energy receives a certain area of \u200b\u200bthe planet.
• Local. They are associated with features geographic location and the relief of the area under consideration.
• Rotating. These are the strongest movements of the air masses, which lead to the formation of hurricanes.

Why is it important to study wind?

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

So, he is a carrier of pollen plants and participates in the spread of their seeds. In addition, the wind is one of the main sources of erosion. Its destroying effect is stronger than all in the deserts, when the terrain relief changes radically.

Should also not forget that the wind is the energy that people use in economic activity. By general estimates, Wind energy is about 2% of all solar energy falling on our planet.

Wind (The horizontal component of the air movement relative to the earth's surface) is characterized by direction and speed.
Wind speed It is measured in meters per second (m / s), kilometers per hour (km / h), nodes or fabala points (wind power). The node is a marine velocity measure, 1 sea mile per hour, approximately 1 node is 0.5 m / s. Bafort's scale (Francis Beaufort, 1774-1875) was created in 1805.

Direction of the wind (where it blows) is indicated either in Rumbach (at a 16-rumbic scale, for example, the north wind - C, northeast - sv, etc.), or in the corners (relative to the meridian, north - 360 ° or 0 °, East - 90 °, South - 180 °, west - 270 °), Fig. one.

Wind name	Speed, m / s	Speed, km / h	Knots	Wind power, points	Wind effect
Calm	0	0	0	0	Smoke rises vertically, trees leaves still. Mirror smooth sea
Quiet	1	4	1-2	1	Smoke deviates from the vertical direction, the sea light ripples, there is no foam on the ridges. Wave height to 0.1 m
Easy	2-3	7-10	3-6	2	The wind is felt face, leaves rustle, the fluger begins to move, the sea short waves with a maximum height up to 0.3 m
Weak	4-5	14-18	7-10	3	Leaves and thin branches of trees pegs, disgusted light flags, light excitement on the water, occasionally small "lambs" are formed. Average wave height 0.6 m
Moderate	6-7	22-25	11-14	4	The wind raises dust, paper; Thin branches of trees are swinging, white "lamb" on the sea are visible in many places. Maximum wave height to 1.5 m
Fresh	8-9	29-32	15-18	5	The branches and subtle trunks of trees are swinging, the wind is felt by hand, white "lames" are visible on the water. Maximum wave height 2.5 m, average - 2 m
Strong	10-12	36-43	19-24	6	Thick buccias are swinging, the thin trees are bent, the telephone wires are buzzing, umbrellas are used with difficulty; White foam ridges occupy significant areas, water dust is formed. Maximum wave height - up to 4 m, average - 3 m
Strong	13-15	47-54	25-30	7	Trees trunks are swinging, large branches are rushing, it is difficult to go against the wind, the ridges of the waves are drunk by the wind. Maximum wave height to 5.5 m
Very strong	16-18	58-61	31-36	8	Thin and dry buccias break, it is impossible to speak in the wind, it is very difficult to go against the wind. Strong excitement on the sea. Maximum wave height to 7.5 m, average - 5.5 m
Storm	19-21	68-76	37-42	9	Big trees are bent, the wind breaks off the roofs, very strong excitement on the sea, high waves ( maximum height - 10 m, average - 7 m)
Heavy storm	22-25	79-90	43-49	10	There is rare on land. Significant destruction of buildings, the wind shakes the trees and pulls them down with the root, the surface of the sea is white from foam, a strong crash of the waves is similar to shocks, very high waves (maximum height - 12.5 m, average - 9 m)
Cruel storm	26-29	94-104	50-56	11	Observed very rarely. Accompanied by destruction on large spaces. At sea Exceptionally high waves (maximum height - up to 16 m, average - 11.5 m), units of small sizes are hiding out of sight
Hurricane	More than 29.	More than 104.	More than 56.	12	Serious destruction of capital buildings