Wind force: measurement and use. Classification of wind strength, sea waves and visibility Wind strength is measured using a scale

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

Wind characterized by speed, strength and direction.

Wind speed and strength

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

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

Table 1. Wind strength near the earth's surface on the Beaufort scale (at a standard height of 10 m above an open flat surface)

Beaufort points	Verbal definition of wind strength	Wind speed, m/s	wind action
			Calm. Smoke rises vertically	Mirror-smooth sea
			The direction of the wind is noticeable but the smoke is carried, but not by the weather vane	Ripples, no foam on the ridges
			The movement of the wind is felt on the face, the leaves rustle, the weather vane is set in motion	Short waves, crests do not tip over and appear glassy

			Leaves and thin branches of trees are constantly swaying, the wind is waving the top flags	Short, well defined waves. Combs, tipping over, form a vitreous foam, occasionally small white lambs are formed
	Moderate		The wind raises dust and pieces of paper, sets in motion the thin branches of trees.	The waves are elongated, white lambs are visible in many places
			Thin tree trunks sway, waves with crests appear on the water	Well developed in length, but not very large waves, white lambs are visible everywhere (splashes form in some cases)
			Thick tree branches sway, telegraph wires hum	Large waves begin to form. White foamy ridges take up significant space (probable splashing)
			Tree trunks sway, it's hard to go against the wind	Waves pile up, crests break, foam falls in stripes in the wind
	Very strong		The wind breaks the branches of trees, it is very difficult to go against the wind	Moderately high long waves. On the edges of the ridges, spray begins to take off. Stripes of foam lie in rows in the direction of the wind
			Minor damage; the wind rips off the smoke caps and roof tiles	high waves. Foam in wide dense stripes lays down in the wind. The crests of the waves begin to capsize and crumble into spray that impair visibility.

	Heavy storm		Significant destruction of buildings, trees uprooted. Rarely on land	Very high waves with long downcurving ridges. The resulting foam is blown by the wind in large flakes in the form of thick white stripes. The surface of the sea is white with foam. The strong roar of the waves is like blows. Visibility is poor
	Violent storm		Large destruction over a large area. Very rare on land	Exceptionally high waves. Small to medium sized boats are sometimes out of sight. The sea is all covered with long white flakes of foam, spreading downwind. The edges of the waves are everywhere blown into foam. Visibility is poor
		32.7 and more		The air is filled with foam and spray. The sea is all covered with strips of foam. Very poor visibility

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

Direction of the wind

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

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

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

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

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

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

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

Monsoon

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

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

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

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

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

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

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

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

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

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

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

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.

Max Height waves 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 such weather we tried to sail across the Baltic Sea from Darłowo. (Poland) against the wave. In 30 minutes only approx. 10km. and very wet from the splashes. We returned along the way - och. funny.

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.

bend big trees, the wind breaks tiles from the roofs, very strong sea waves, high waves. It is observed very rarely. Accompanied by destruction in large spaces. At sea, there are 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...

Beaufort scale, sea waves, visibility range

IA site.

Beaufort scale

0 points - calm
A mirror-smooth sea, almost motionless. Waves practically do not run up to the shore. The water is more like a quiet backwater of a lake than a sea coast. Haze may be observed above the surface of the water. The edge of the sea merges with the sky so that the border is not visible. Wind speed 0-0.2 km/h.

1 point - quiet
Light ripples on the sea. The height of the waves reaches up to 0.1 meters. The sea can still merge with the sky. There is a light, almost imperceptible breeze.

2 points - easy
Small waves, no more than 0.3 meters high. The wind speed is 1.6-3.3 m/s, you can feel it with your face. With such a wind, the weather vane begins to move.

3 points - weak
Wind speed 3.4-5.4 m/s. Slight roughness on the water, occasionally lambs appear. The average wave height is up to 0.6 meters. A weak surf is clearly visible. The weather vane spins without frequent stops, the leaves on the trees, flags and so on sway.

4 points - moderate
Wind - 5.5 - 7.9 m / s - raises dust and small pieces of paper. The weather vane spins continuously, the thin branches of the trees bend. The sea is restless, in many places lambs are visible. Wave height up to 1.5 meters.

5 points - fresh
Almost the entire sea is covered with white lambs. Wind speed 8 - 10.7 m/s, wave height 2 meters. Branches and thin tree trunks sway.

6 points - strong
The sea is covered with white ridges in many places. The wave height reaches 4 meters, the average height is 3 meters. Wind speed 10.8 - 13.8 m/s. Thin tree trunks bend, and thick branches of trees, telephone wires buzz.

7 points - strong
The sea is covered with white foamy ridges, which are blown off the surface of the water from time to time by the wind. The wave height reaches 5.5 meters, the average height is 4.7 meters. Wind speed 13.9 - 17.1 m/s. Medium tree trunks sway, branches bend.

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

9 points - storm
High waves on the sea, reaching 10 meters; average height 7 meters. Wind speed 20.8 - 24.4 m/s. Large trees bend, medium branches break. The wind rips off poorly reinforced roof coverings.

10 points - strong storm
Sea white color. Waves crash on the shore or on the rocks with a roar. The maximum wave height is 12 meters, the average height is 9 meters. The wind, at a speed of 24.5 - 28.4 m/s, rips off roofs, significant damage to buildings.

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

12 points - hurricane
Wind speed 32.6 m/s. Serious damage to capital buildings. The wave height is over 16 meters.

Sea wave scale

In contrast to the generally accepted twelve-point system for estimating wind, there are several estimates of sea waves.

British, American and Russian grading systems are generally accepted.

All scales are based on a parameter that determines the average height of significant waves.

This setting is called Significance Wave Height (SWH).

In the American scale, 30% of significant waves are taken, in the British 10%, in the Russian 3%.

Wave height is measured from the crest (the top of the wave) to the trough (the base of the trough).

Below is a description of the height of the waves:

• 0 points - calm,
• 1 point - ripples (SWH< 0,1 м),
• 2 points - weak waves (SWH 0.1 - 0.5 m),
• 3 points - light waves (SWH 0.5 - 1.25 m),
• 4 points - moderate waves (SWH 1.25 - 2.5 m),
• 5 points - stormy excitement (SWH 2.5 - 4.0 m),
• 6 points - very rough sea (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 sea (SWH > 14.0 m).

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

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

Storm is defined by Beaufort.

For the WH parameter for all scales, it is precisely a part of the waves (30%, 10%, 3%) that is taken because the magnitude of the waves is not the same.

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

Therefore, each scale has its own SWH value, where a certain percentage of the highest waves is taken.

There are no instruments for measuring wave height.

Therefore, there is no exact definition of the score.

The definition is conditional.

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

Visibility scale

Visibility is the maximum distance at which objects are detected during the day and navigation lights at night.

Visibility depends on weather conditions.

In metrology, the influence of weather conditions on visibility is determined by a conditional scale of points.

This scale is a way of indicating the transparency of the atmosphere.

Distinguish between day and night visibility.

Below is a daily scale for determining the visibility range:

Up to 1/4 cable
About 46 meters. Very poor visibility. Thick fog or blizzard.

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

2-3 cables
370 - 550 meters. Bad visibility. Fog, wet snow.

1/2 mile
About 1 km. Haze, thick haze, snow.

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

1 - 2 miles
1.85 - 3.7 km. Haze, mist, rain.

2 - 5 miles
3.7 - 9.5 km. Light haze, haze, light rain.

5 - 11 miles
9.3 - 20 km. Good visibility. Visible horizon.

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

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

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Wind is the movement of air relative to the earth's surface. As you know, the atmosphere is not static, the air in it constantly circulates, moves: it rises and falls.

Differences in the degree of heating of the air contribute to the occurrence of pressure drops in the air masses and set them in motion - air moves from areas of high pressure to areas of low pressure. How more difference temperatures between air masses, the stronger the wind.

Wind speed is measured in meters per second, kilometers per hour or points (1 point equals 2 m/s). The average long-term wind speed near the earth's surface is 4-9 m/s, and the maximum average annual wind speed on the coast of Antarctica reaches 22 m/s. Wind speed of 5-8 m/s is considered moderate, above 14 m/s - strong, above 20-25 m/s - storm, above 30-35 m/s - hurricane.

The direction of air movement is determined by the interaction of several forces. These are the Coriolis force (taking into account the influence of the Earth's rotation on moving air), gravity, pressure gradient force and centrifugal force.

Since the cause of wind is pressure differences at different points on the earth's surface, if you stand with your back to the wind in the northern hemisphere, the high pressure area will be on the right, and the low pressure area will be on the left, that is, low pressure is located to the left of the direction of the air flow, and high pressure on the right. In the southern hemisphere, the opposite is true.

The direction of the wind in meteorology is determined by the side of the horizon from which it blows.

HURRICANE ENERGY

The collective name of hurricanes, storms, typhoons is tropical cyclones.

It's gigantic atmospheric vortices with air pressure decreasing towards the center and air circulation around the center counterclockwise in the Northern Hemisphere and clockwise in the Southern.

Wind speeds in deep cyclones with large baric gradients can reach storm and hurricane levels.

They occur in the oceans in tropical latitudes.

The main energy source of the cyclone is the release of heat during the condensation of water vapor.

A comparison of the amount of energy released during the rampant elements and atomic explosions showed that during a typical summer thunderstorm, thirteen times more energy is released than during an explosion. atomic bomb dropped on Nagasaki.

During a medium-strength hurricane, it is released 500,000 times more.

An atomic explosion on the Bikini Atoll lifted 10 million tons of water into the air, and during a hurricane, 2,500 million tons of rain fell on Puerto Rico in a few hours, i.e. 250 times more.

BREEZES

Why is it quiet on the seashore in summer only early in the morning or in the evening?

This situation occurs quite often, but not always. The reason for this is the fact that water has a higher heat capacity, heats up more slowly and cools down more slowly.

A - Sea breeze (day), B - Coastal breeze (night)

In the early morning hours, when the sun slightly warms the earth, the temperatures of the sea surface and the land are equalized; during the day, the land turns out to be warmer than water, and by the evening, cooling down, it again becomes heated for a while, just like water. When there is no difference in the temperature of water and land, there is no movement of air, the wind subsides, the sea calms down.

During the day, the air that quickly warms up over land rises, and colder air comes to replace it from the sea - a sea breeze blows; at night, the situation changes: the wind blows from land to sea - a coastal breeze.

Pauses are observed in the morning and in the evening - short lulls during periods of change in the direction of the breeze winds. Such an alternation of day and night winds, or the so-called breeze circulation, takes place during the warm season with stable sunny weather and high atmospheric pressure. When a cyclone comes, it brings with it stormy weather and the breezes cease.

Next page “Air temperature. comfort temperature. Thermosphere. Pole of Cold"

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Scale for determining the speed, strength and name of the wind ( Beaufort scale)

Wind force in points	Wind speed m/s (km/h)	wind name	Local signs for determining the strength, speed and name of the wind
0-0,2 (0-0,72)	Calm (calm)	Land (C): leaves are still, smoke rises vertically. Sea (M): mirror sea
0,3-1,5 (1,1-5,4)	Quiet	C: the leaves are motionless, the smoke is deflected, the weather vane is motionless. M: ripples, no foam on the ridges.
1,6-3,3 (5,8-11,9)	Easy	C: the leaves rustle, a slight breath is felt on the face, the weather vane moves. M: short waves, crests do not tip over and appear glassy.
3,4-5,4 (12,2-19,4)	Weak	C: light flags and small branches of trees with leaves are waving. M: short, well-defined waves. The combs tip over, form a vitreous foam, occasionally small white lambs form.
5,5-7,9 (19,8-28,4)	Moderate	C: flags flutter, tree branches without leaves sway, dust and papers rise from the ground. M: the waves are elongated, white lambs are visible in many places.
8-10,7 (28,8-38,5)	Fresh	C: Large flags are raised, large, leafy branches, thin trunks sway. M: well developed in length, but not very large waves, white lambs are visible everywhere (splashes form in some cases)
10,8-13,8 (38,9-49,7)	Strong	S: thick tree branches sway, wind sounds are heard in the building, telegraph wires hum, it is difficult to use an umbrella. M: Large waves begin to form. White foamy ridges occupy large areas (splatter is likely).
13,9-17,1 (50-61,6)	Strong	C: tree trunks sway, it is difficult to go against the wind. M: waves pile up, crests break, foam falls in stripes in the wind.
17,2-20,7 (61,9-74,5)	Very strong	C: the wind breaks thin branches and dry branches of trees, it is noticeably difficult to move against the wind. M: moderately high long waves. On the edges of the ridges, spray begins to take off. Stripes of foam lie in rows in the direction of the wind.
20,8-24,4 (74,9-87,8)	Storm	C: the wind breaks branches on trees, rips off light objects, roofs, knocks down fences, slight damage is observed. M: -//-
24,5-28,4 (88,2-102,2)	Heavy storm	C: the wind bends the trees to the ground, the weak trees are uprooted, the destruction of buildings is observed. Rarely on dry land. M: very high waves with long downward curved crests. The resulting foam is blown by the wind in large flakes in the form of thick white stripes. The surface of the sea is white with foam. The strong roar of the waves is like blows. Visibility is poor.
28,5-32,6 (102,6-117,4)	Violent storm	C: the wind causes great destruction of buildings over a significant area, uproots trees. It is very rare on land. M: exceptionally high waves. Small to medium sized boats are sometimes out of sight. The sea is all covered with long white flakes of foam, spreading downwind. The edges of the waves are everywhere blown into foam. Visibility is poor.
32.7 (117.7) or more	Hurricane	S: Total destruction. It is very rare on land. M: The air is filled with foam and spray. The sea is all covered with strips of foam. Very poor visibility. How and why does wind speed change, wind force parameters

Distinguish smoothed speed over a short period of time and instant, speed at a given time. Velocity is measured with an anemometer using a Wild board.

The highest average annual wind speed (22 m/s) was observed on the coast of Antarctica. The average daily speed there sometimes reaches 44 m / s, and at some moments reaches 90 m / s.

The wind speed has a diurnal variation. It is close to the diurnal variation of temperature. The maximum speed in the surface layer (100 m - in summer, 50 m - in winter) is observed at 13-14 hours, the minimum speed is at night. In higher layers of the atmosphere, the diurnal variation of the velocity is reversed. This is explained by the change in the intensity of vertical exchange in the atmosphere during the day. In the daytime, intense vertical exchange makes it difficult for the horizontal movement of air masses. At night, there is no such obstacle, and Bm move in the direction of the baric gradient.

The wind speed depends on the pressure difference and is directly proportional to it: the greater the pressure difference (horizontal baric gradient), the greater the wind speed. The average long-term wind speed at the earth's surface is 4-9 m/s, rarely more than 15 m/s. In storms and hurricanes (temperate latitudes) - up to 30 m/s, in gusts up to 60 m/s. In tropical hurricanes, wind speeds reach up to 65 m/s, and in gusts they can reach 120 m/s.

Instruments used to measure wind speed are called anemometers. Most anemometers are built on the principle windmill. So, for example, the Fuss anemometer has four hemispheres (cups) at the top, facing the same direction (Fig. 75).

This system of hemispheres rotates about a vertical axis, and the number of revolutions is noted by a counter. The device is exposed to the wind, and when the "mill of the hemispheres" acquires a more or less constant speed, the counter is turned on for exactly certain time. According to the plate, which indicates the number of revolutions for each wind speed, and the speed is determined by the number of revolutions found. There are more complex devices that have a device for automatic recording wind direction and speed. Simple instruments are also used, which can simultaneously determine the direction and strength of the wind. An example of such a device is the Wild weather vane, which is common at all meteorological stations.

The direction of the wind is determined by the side of the horizon from which the wind is blowing. For its designation, eight main directions (rhumbs) are used: N, NW, W, SW, S, SE, B, NE. The direction depends on the pressure distribution and on the deflecting effect of the Earth's rotation.

Rose of Wind. Winds, like other phenomena in the life of the atmosphere, are subject to strong changes. Therefore, here we have to find average values.

To determine the prevailing wind directions for a given period of time, proceed as follows. Eight main directions, or rhumbs, are drawn from some point, and on each, according to a certain scale, the frequency of winds is postponed. In the resulting image, known as wind roses, the prevailing winds are clearly visible (Fig. 76).

The strength of the wind depends on its speed and shows what dynamic pressure the air flow exerts on any surface. Wind strength is measured in kilograms per square meter (kg/m2).

wind structure. The wind cannot be imagined as a uniform air current having the same direction and the same speed throughout its mass. Observations show that the wind blows gusty, as if in separate shocks, sometimes subsides, then regains its former speed. At the same time, the direction of the wind is also subject to change. Observations made in higher layers of air show that gustiness decreases with height. It is also noted that at different times of the year and even at different hours of the day, the gustiness of the wind is not the same. The greatest impetuousness is observed in the spring. During the day, the greatest weakening of the wind is at night. The gustiness of the wind depends on the nature of the earth's surface: the more irregularities, the greater the gustiness and vice versa.

Causes of winds. The air remains at rest as long as the pressure in a given area of ​​the atmosphere is distributed more or less evenly. But as soon as the pressure in any area increases or decreases, air will flow from the place of greater pressure to the side of less. The movement of air masses that has begun will continue until the pressure difference is equalized and equilibrium is established.

Stable equilibrium in the atmosphere is almost never observed, and therefore winds are among the most frequently repeated phenomena in nature.

There are many reasons for disturbing the balance of the atmosphere. But one of the first causes of the pressure difference is the temperature difference. Let's consider the simplest case.

Before us is the surface of the sea and the coastal part of the land. During the day, the land surface heats up faster than the sea surface. Due to this, the lower layer of air over land expands more than over the sea (Fig. 77, I). As a result, an air current is immediately created at the top from a warmer area to a colder one (Fig. 77, II).

Due to the fact that part of the air from the warm region has flowed (above) towards the cold one, the pressure within the cold region will increase, and within the warm region it will decrease. As a result, an air current arises now in the lower layer of the atmosphere from the cold to the warm region (in our case, from the sea to land) (Fig. 77, III).

Such air currents usually occur on the coast or along the shores of large lakes and are called breezes. In our example, the breeze is daytime. At night, the picture is completely opposite, because the surface of the land, cooling faster than the surface of the sea, becomes colder. As a result, in the upper layers of the atmosphere, the air will flow towards the land, and in the lower layers towards the sea (night breeze).

The rise of air from the warm area and the lowering in the cold unites the upper and lower currents and creates a closed circulation (Fig. 78). In these closed circuits, the vertical parts of the path are usually very small, while the horizontal ones, on the contrary, can reach enormous sizes.

Causes of different wind speeds. It goes without saying that the wind speed must depend on the pressure gradient (i.e., be determined primarily by the difference in pressure per unit distance). If, apart from the force due to the gradient, no other forces acted on the mass of air, then the air would move uniformly accelerated. However, this does not work, because there are many reasons that slow down the movement of air. This is primarily friction.

There are two types of friction: 1) the friction of the ground layer of air on the earth's surface and 2) the friction that occurs inside the moving air itself.

The first is directly dependent on the nature of the surface. So, for example, the water surface and the flat steppe create the least friction. Under these conditions, the wind speed always increases significantly. The surface, which has irregularities, creates large obstacles to moving air, which leads to a decrease in wind speed. Urban buildings and forest plantations especially strongly reduce the wind speed (Fig. 79).

Observations made in the forest showed that as early as 50 m from the edge of the wind speed decreases to 60-70% of the original speed, in 100 m up to 7%, in 200 m up to 2-3%.

The friction that occurs between adjacent layers of moving air masses is called internal friction.

Internal friction causes the transfer of motion from one layer to another. The surface layer of air as a result of friction on the earth's surface has the slowest movement. The overlying layer, in contact with the moving lower layer, also slows down its movement, but to a much lesser extent. The next layer is even less affected, and so on. As a result, the speed of air movement gradually increases with height.

Wind direction. If the main cause of wind is pressure difference, then the wind must blow from an area of ​​higher pressure to an area of ​​lower pressure in a direction perpendicular to the isobars. However, this does not happen. In reality (as established by observations) the wind blows mainly along the isobars and only slightly deviates towards low pressure. This is due to the deflecting effect of the Earth's rotation. At one time we have already said that any moving body under the influence of the Earth's rotation deviates from its original path in the northern hemisphere to the right, and in the southern hemisphere to the left. It was also said that the deviating force in the direction from the equator to the poles increases. It is quite clear that the movement of air, which has arisen due to the difference in pressure, immediately begins to experience the influence of this deflecting force. By itself, this power is small. But due to the continuity of its action, in the end the effect is very large. If there were no friction and other influences, then as a result of a continuously acting deflection, the wind could describe a closed curve close to a circle. In fact, due to the influence of various causes, such a deflection does not occur, but nevertheless it is still very significant. It suffices to indicate at least the trade winds, the direction of which, when the Earth is stationary, should coincide with the direction of the meridian. Meanwhile, their direction in the northern hemisphere is northeast, in the south - southeast, and in temperate latitudes, where the force of deviation is even greater, the wind blowing from south to north acquires a west-southwest direction (in the northern hemisphere).

Major systems of winds. The winds observed on the earth's surface are very diverse. Depending on the causes that give rise to this diversity, we will divide them into three large groups. The first group includes winds, the causes of which depend mainly on local conditions, the second - winds due to the general circulation of the atmosphere, and the third - the winds of cyclones and anticyclones. Let's start our consideration with the simplest winds, the causes of which depend mainly on local conditions. Here we include breezes, various mountain, valley, steppe and desert winds, as well as monsoon winds, which already depend not only on local causes, but also on the general circulation of the atmosphere.

Winds are extremely diverse in origin, nature and significance. So, in temperate latitudes, where western transport dominates, winds prevail western directions(NW, W, SW). These areas occupy vast spaces - from about 30 to 60 ° in each hemisphere. In the polar regions, winds blow from the poles to low pressure zones of temperate latitudes. These areas are dominated northeast winds in the Arctic and southeastern in the Antarctic. At the same time, the southeast winds of the Antarctic, in contrast to the Arctic ones, are more stable and have high speeds.

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Signs by which the direction of the wind can be determined in flight are divided into direct and indirect. Direct signs directly indicate the speed and direction of the surface wind. By indirect evidence, one can only assume with some probability that the wind near the earth blows in one direction or another.

Direct indications include:

• removal of smoke from fires or chimneys;
• fluttering in settlements flags;
• dust drift behind vehicles moving on country roads;
• movement of waves and ripples on water bodies.

Rice. 161. Determination of wind direction by smoke, flags and dust.

On small ponds and lakes, the water surface is located below the surrounding land. Therefore, the shores can block the wind. As a result, there will be a calm on the water surface near the leeward shore, and then a strip of ripples expanding towards the windward shore ( see fig. 162).

Rice. 162. Determination of wind direction by ripples on water bodies.

In the absence of direct wind indicators, indirect ones should be used. However, remember: indications of indirect signs do not always correspond to reality.

The simplest indirect sign is the wind speed and direction at the start. If you have just started to master thermal flights and were able to fly away from the starting point by only 5-10 km, then it is quite acceptable to assume that during your flight, which is no more than 10-15 minutes, the wind could not have time to change significantly.

What determines the strength and speed of the wind?

In this case, you can well assume that the landing wind will not be much different from the one that blew at the start.

When flying on flat ground, you can also assume that the direction of the wind at altitude is roughly the same as the wind near the ground. You can determine the direction of the wind at a height and approximately estimate its speed by the following features:

• the tops of cumulus clouds are shifted relative to their bases in the "downwind" direction;
• wind at altitude can be estimated from the movement of cloud shadows;
• if you put the paraglider in a gentle spiral, then the direction of the wind will show you the drift of the apparatus.

WARNING
Don't try to use indirect signs determination of wind direction when flying in the mountains. Due to strong temperature contrasts, the speed and direction of the wind in the mountains change very significantly in heights, gorges and valleys.

Article source: http://firstep.ru/kulp/theory/lection-05-12.php

The concept of wind and its features

Wind is the movement of air, and not just movement, but its movement in a horizontal direction above the earth's surface. When the pressure in different points of the globe is different, the air masses tend to be distributed over the earth's surface more evenly and fill the place where the atmosphere is not so dense.

Atmospheric pressure itself is the pressure of air on the earth's surface by the attraction of air masses to the Earth. In this case, the gravitational force acts, which keeps the air near the surface of the Earth, and allows people and objects to come into close contact with the earth, and not fly away into space.

Based on the foregoing, we can conclude that the wind moves not only horizontally above the Earth's surface, but also from the area of ​​high atmospheric pressure to the area of ​​low pressure.

The air heats up extremely unevenly, partly due to the constant presence of winds on the planet.

Most air masses warm up at the Equator - the central latitude of the Earth. From there, the winds are already distributed over the entire earth's surface.

Strength and speed of the wind

The wind cannot be seen, but it can be felt, for example, its strength or the speed with which the wind blows off a hat from the head or ruffles the leaves on the trees. It is not for nothing that the verbal expression “wind knocked down” is sometimes used, meaning that the wind was very strong.

Wind speed is expressed in terms of "meter per second", "kilometer per hour", and its speed can also be expressed on a point scale.

There is a so-called Beaufort scale- a scale with twelve measurements, developed by the World Meteorological Organization to measure wind speed by the waves it creates in open water spaces (most often at sea) and the force of impact on ground objects.

With the Beaufort scale indicator "0", the wind speed reaches about 0-0.2 m/s and is characterized by calmness. The leaves of the trees do not move.

With a Beaufort scale indicator of "4", the wind is considered moderate at a speed of 5.5-7.5 m/s. On the ground, the strength of such a wind is seen as follows: a strong air current raises dust and debris and rolls them along the road, and also sets the branches of trees in motion.

A storm with wind speed on the Beaufort scale occurs at the number "9": trees begin to uproot on the ground and rooftops collapse.

Varieties of wind

There are several types of winds as currents of air masses over giant areas: monsoons, trade winds, foehn, breeze, bora.

Monsoon is a wind with clearly defined periods of activity. Air masses under this name blow from land to sea in winter, and from sea to land in summer. The wind is rich in moisture. Its localization is mainly Asia.

trade wind A type of wind that blows between the tropics. The time of his observation all year round. On a 12-point scale, this wind blows with a force of 3-4.

Breeze- a warm wind with less localization than, for example, a monsoon or a trade wind.

winds. What determines the speed and direction of the wind?

The breeze mainly blows at night from the shore to the sea, during the day from the sea to the shore. The direction can change several times a day.

And finally boron- is a sharp wind, characterized by coldness. Its localization is mountain ranges, from them it blows on the valleys. The wind can develop a fairly high speed (up to 9 points), but has a fickle nature.

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Lexical meaning: definition

The general stock of vocabulary (from the Greek Lexikos) is a complex of all the main semantic units of one language. The lexical meaning of a word reveals the generally accepted idea of ​​an object, property, action, feeling, abstract phenomenon, impact, event, and the like. In other words, it determines what this concept means in the mass consciousness. As soon as an unknown phenomenon gains clarity, specific signs, or an awareness of an object arises, people assign it a name (sound-alphabetic shell), or rather, a lexical meaning. After that, it enters the dictionary of definitions with the interpretation of the content.

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Wind Raz

Alexey Bakaldin

Lenya ran up to his ninth floor. The elevator in the building of the military camp worked, one might say, on holidays, but not for everyone and not every year. But it was a great boost. After all, at sea, submarine officer Leonid Bystrykin is not physically tense, but there are many “seas” (exits to the sea)! And now the boat has returned from a week-long voyage, and the commander released the senior lieutenant in order to prepare for the entry into service, the submarine duty officer.
The door of the apartment was opened by Antonina's wife, beloved Tonechka. And the three-year-old Verunchnik was delighted: “Daddy sat down!” - and hung on her leg.
— Hello, My, good ones! How I missed you! - taking his daughter in his arms and kissing her, the happy father of the family tried to hug Tonya. She somehow strangely pulled away, and on her face there was not a trace of the joy of her husband's return.
“Vera, go finish painting your cat,” said the wife, removing her daughter from her father’s arms, “are you making a gift for dad?”
- Meow! Kittens! - the daughter squealed and disappeared into the room.
- Something happened? - carefully studying the face of his wife, the husband asked, - do you have such a face, as if someone had died again?
The fact is that a month ago, Bystrykin's father died. Leonid had to fly to the funeral, and because of his sick daughter, he traveled alone on this trip. On his return, he went to sea on his ship the next day. Tonya reported about the telegram with the news of the death of a loved one. It was then that she had such a sad, tense face as she does today.
“Yes!” the answer was not loud. - I fell in love with another person. I cheated on you and I'm leaving you!
There were tears in her eyes. Leonid was taken aback! At some point, it began to seem that this was not reality!
- Wait a minute! Wait a minute! How come? And our family, and the daughter?
"I'll take my daughter with me!"
They went into the kitchen. The news was like a tub cold water! Thoughts fled, it is almost impossible to collect them together.
- Wait a minute! Tonya, Tonya, how are you? We are such a friendly, happy family! We are fine! – in fact it was true. They got married when he was in his fourth year of college. Both friends and parents admired the young couple. In love, a sweet daughter was born! Then there was a move to the place of service, to the North. Getting the long-awaited housing and happiness in a single officer's family!
- I've made up my mind! It's my fault, I'm sorry! - burst his wife, - I fell in love with him more than you and we have already slept. You won't forgive me! I'm leaving! She turned to the window.
— Wait! I have to go on duty now. We must prepare for the intercession. Let's move the conversation to tomorrow, after the shift, okay?
- It will not change anything!
- But still! - Bystrykin left the kitchen, his wife remained standing at the window.
As if in a fog, he began to prepare for duty. The time when it was necessary to arrive for a divorce, to enter the service, was already short, but here it flew at the speed of sound! Lenya went into the room to change, his uniform smelled like a boat. The daughter at the children's table diligently covered her drawing with a pen from her father.
- Draw, draw, baby, I'm not peeping!
He threw off his uniform, took a dressing gown and went to the bath. In the head, like a hammer beats the brain! “Leave! No! What's wrong?!" After a quick shower, he began to shave. Blood rushed to his face. "What to do?" Lenya covered his cheeks with foam. “We need to save the family, I can’t live without my daughter.” He makes a movement with a razor and a cut appears on his face. “I can’t do without Antonina” - a cut on my neck. Having shaved and stopped the blood, Leonid returned to the room. He began to dress in a fresh set of uniforms.
- Dad! Where are you going? The daughter had anxiety in her eyes.
- Bunny! My! I'll be back tomorrow and we'll play again. Here's a present for you. - He pulled out a bar of boat chocolate and handed it to Verunchik. He usually gave chocolate to his wife. And the wife gave it to the child in portions, fearing diathesis.
Today the rule could be broken.

§ 5. Wind. Wind direction and speed. The power of the wind.

- Thank you! - the girl rustled the wrapper.
- Smart girl! Goodbye! - pressing and kissing his daughter, the assembled dad went out into the corridor.

The wife did not leave the kitchen. She did not come out, and when Leonid fully gathered himself, he opened the door and, standing on the threshold, said loudly:
- I'm all gone! Bye!
- Bye! - a child's voice from the daughter's room. The wife was not heard.
Closing the door behind him, the officer quickly began to go downstairs. His face was on fire. All his thoughts were still in the apartment, in his World, which was collapsing!

Before the intercession, it was necessary to run into the boat. Get a service weapon - a pistol with equipment and two clips with cartridges. Bystrykin went to the piers where the boats were moored. As if sensing his mood, the weather began to deteriorate. The sky turned black and the wind blew. "This is not good!" - Lenya had time to think before he went down into the boat. On duty on the ship, his friend, Marat Batyev. Together they came to the fleet on the same boat as lieutenants and were friends!
- ABOUT! Change, creep! - cheerfully welcomed, Marat. After arriving from the sea, he took over on duty and, naturally, wanted to change as quickly as possible in order to also come home. Meet my wife and son. And also take a bath, wash off the boat load like that! Marat in anticipation of this action was in a very good mood.
- Come on trunk! Bystrykin muttered.
- Get out and sign in the magazine. - Marat pointed to the console where she lay
ammunition with prepared weapons and a carefully opened magazine for issuing weapons.
Weapons are always kept in a safe, but before the shift, so as not to delay, they usually always get it for their colleague.
- E! What is it, evil?
- Yes, so! - Checking the weapon, Lenya left the direct answer. His thoughts were far from the service.
Having signed for the weapon, he took the holster and met Marat's gaze.
“Your face is full of cuts and irritation. Why are you so shaved?
- I know!

I was nervous,” Bystrykin replied in a calm voice. - The wife left, changed.
He turned around and began to climb out of the central post along the ladder, to the top.
- How? - Marat was amazed. Their families were friends. And the first moments he could not drive in response to a friend. Believe in what is said. A good mood from the fact that he will change this hour, hand over his weapon, come home ... Stop! Weapon! Marat had cold sweat running down his back. He just gave out a pistol with cartridges to a man whose wife cheated! The hand reached for the shore telephone. You have to report to the commander.

Leonid did not think of shooting anyone. The routine and frequency of duty in the base did their job. He acted like a programmed automaton. Without thinking about a divorce, he gathered the personnel of the sailors interceding with him, checked their knowledge and arrived at the place of construction. The brigade duty officer conducted a briefing and examination of the interceders. Routine as a whole, as usual. However, also at the divorce, it was noted that the wind is expected to increase, “Wind Two” has already been announced and possibly the announcement of “Wind Raz”. This meant that the navigator and one of the mechanics should already arrive on the boat. This was done so that in the event of a separation of the boat from the pier, the boat would have working navigation equipment and powered power point. If “Wind Raz” is announced, the entire composition of the ship must be in a strong hull.
In the head of the officer, a detached flash flashed: “Bad luck, guys. From the seas and again to the "iron".

Marat did not find a place for himself in the central post. He himself to a friend, in this state, put a pistol in his hands. He reported to the commander. He shortly replied: “Understood!” and hung up. Batiev ordered to report to the top watchman as soon as he saw the approaching shift. When a report was made on "Larch" (communication system):
I see a change!
- Who is leading? Marat asked almost immediately.
- Senior Lieutenant Bystrykin. - answered the top watchman.
- Wow! - Marat caught his breath.
With the arrival of the shift, the routine procedure for handing over the duty began. Leonid did not want to develop the theme of his family relations. All attempts by Marat, he interrupted. Like, none of your business. Leonid tried to get on duty as quickly as possible, stay with his subordinates and completely immerse himself in the duties of a submarine duty officer. The old shift has gone to base! The routine began. Checking the pressure hull for tightness, working off the watch, checking the compartments, filling out magazines. After dinner, the boat was informed that with the worsening weather, "Wind Raz" was announced.

Wind Raz. This a storm warning. On the roadstead of the Kola flotilla, a cross of four red lights was lit. All personnel must arrive on the ship. All systems are being launched and the personnel should be ready at any moment for the actions prescribed according to the staffing table ..

Somewhere, after 21.00, everyone arrived on the boat, including the commander, captain of the second rank Zaletsky Vladimir Vladimirovich. Leonid reported, according to the form to the commander, about the measures taken. In the meantime, the personnel were stationed in the compartments according to their combat schedules. The officers and midshipmen, cut off from their families in the evening, frowned and scolded the North, for the winds, snowstorms, and cold. And so the rest is small between the "seas", and then at the pier you will have to spend the whole night on the "iron" and it's not a fact that you can get enough sleep. The exit to the service tomorrow half an hour before the flag was raised, no one, by the way, did not cancel! Yes, if "Wind Raz" is cancelled.

After the life of the ship entered the normal mode, the commander called Leonid to his cabin.
- Well, tell me, Lenya.
-What to tell, comrade commander?
-All! You to me, Greens podkilnaya! We need a full-fledged fighter! With a strong back! And not with thoughts about ... Fuck knows what! Zaletsky said sharply.
-Wife cheated, loves and goes to another! - Leonid tried to hold on.
-It's clear! - Cap, reached out to the "Larch" - Central, Senior Lieutenant Batyev, to me!
- There is! - answered central!
- Lenya! - forget it, - the cap put his hand on Leonid's shoulder!
-How? I have a daughter? I love them?
-Lenya! It hurts. You can't fix a broken plate! Remember, you can forgive a lot, but not betrayal. You will no longer have a life. You are a military man, your daughter will stay with her, and you will not do anything! Consider that both your wife and daughter have died for you today.
- No! Tears ran treacherously down her cheeks.
- Allow me!?? - Marat entered the cabin. Leonid turned away, wiping his tears.
- Come in, Batiev! - Vladimir Vladimirovich, took out a canister with an awl (nautical alcohol). His voice was harsh again - Marat! Hear the order!
Meanwhile, the cap filled two bottles of awl.
- The task, you and senior lieutenant Bystrykin, take it, this is the first bottle was in the hands of Marat, - stomp to, Zaletsky nodded towards Lenya, - to his apartment! Today he must get drunk! Take the third, a miner, it's useless, downwind, anyway! - The second bottle was in the hands of Marat.
-Comrade Commander! I'm on duty on the ship! Bystrykin remembered!
-What the hell!? Duty? Cap looked sternly! - carry a magazine and hand over your weapons! The captain of the second rank Zaletsky is on duty! All the same, everyone sit still for a long time! Yes, Bystrykin has a day off tomorrow, not you! - Cap killed Marat's smile with a look. “You tick-like creatures, don’t be late for raising the flag!”

Having taken Kostya, the miner, the company went to Bystrykin's house! Already from afar, it was clear that the light in Leonid's one-room apartment was not on ...

Five years have passed. Antonina filed for divorce and got married. Leonid, went to sea trying to forget himself in the service. Without which, he indulged in all the hard ... Time heals. Lieutenant Commander Bystrykin found his half. The date of the wedding was set, and at the appointed time, a red cross caught fire on the roadstead of the Kola Flotilla. Wind One! Of the guests, there were only Marat and the miner Kostya! True, the occasion was much happier! The family took place and this time very, very strong!

Copyright: Alexey Bakaldin, 2015
Publication Certificate No. 215120401334

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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 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). 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", with an air density of about 1.2 kg / m3 and positive 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

Points	Verbal designation of wind power	Wind speed, m/s	Wind speed km/h	wind action
				on the land	at sea (points, excitement, characteristics, height and wavelength)
0	Calm	0-0,2	Less than 1	Complete absence of wind. The smoke rises vertically, the leaves of the trees are motionless.	0. No excitement Mirror-smooth sea
1	Quiet	0,3-1,5	2-5	The smoke deviates slightly from the vertical direction, the leaves of the trees are motionless	1. Weak excitement. There are light ripples on the sea, there is no foam on the ridges. The height of the waves is 0.1 m, the length is 0.3 m.
2	Easy	1,6-3,3	6-11	The wind is felt in the face, the leaves rustle faintly at times, the weather vane begins to move,	2. Weak excitement The ridges do not tip over and appear glassy. At sea, short waves are 0.3 m high and 1-2 m long.
3	Weak	3,4-5,4	12-19	Leaves and thin branches of trees with foliage fluctuate continuously, light flags sway. The smoke, as it were, licks off the top of the pipe (at a speed of more than 4 m / s).	3. Light excitement Short, well defined waves. The ridges, overturning, form a vitreous foam, occasionally small white lambs are formed. The average wave height is 0.6-1 m, length - 6 m.
4	Moderate	5,5-7,9	20-28	The wind raises dust and papers. Thin branches of trees sway without foliage. The smoke is mixed in the air, losing its shape. This is the best wind for the operation of a conventional wind generator (with a wind wheel diameter of 3-6 m)	4. Moderate excitement The waves are elongated, white lambs are visible in many places. The height of the waves is 1-1.5 m, the length is 15 m. Sufficient wind thrust for windsurfing (on a board under sail), with the ability to enter the planing mode (with a wind of at least 6-7 m / s)
5	Fresh	8,0-10,7	29-38	Branches and thin tree trunks sway, the wind is felt by hand. Pulls out big flags. Whistling in the ears.	4. Troubled sea Well developed in length, but not very large waves, white lambs are visible everywhere (in some cases splashes are formed). Wave height 1.5-2 m, length - 30 m
6	Strong	10,8-13,8	39-49	Thick branches of trees sway, thin trees bend, telegraph wires hum, umbrellas are used with difficulty.	5. Big commotion Large waves begin to form. White foamy ridges occupy large areas. Water mist is generated. Wave height - 2-3 m, length - 50 m
7	Strong	13,9-17,1	50-61	Tree trunks sway, large branches bend, it is difficult to go against the wind.	6. Strong excitement Waves pile up, crests break, foam falls in strips in the wind. Wave height up to 3-5 m, length - 70 m
8	Very strong	17,2-20,7	62-74	Thin and dry branches of trees break, it is impossible to speak in the wind, it is very difficult to go against the wind.	7. Very strong excitement Moderately high, long waves. On the edges of the ridges, spray begins to take off. Stripes of foam lie in rows in the direction of the wind. Wave height 5-7 m, length - 100 m
9	Storm	20,8-24,4	75-88	Big trees bend, big branches break. The wind blows the tiles off the roofs	8. Very strong excitement high waves. Foam in wide dense stripes lays down in the wind. The crests of the waves begin to capsize and crumble into spray, which impair visibility. Wave height - 7-8 m, length - 150 m
10	Strong storm	24,5-28,4	89-102	Rarely on dry land. Significant destruction of buildings, the wind fells trees and uproots them	8. Very strong excitement Very high waves with long downward curved crests. The resulting foam is blown by the wind in large flakes in the form of thick white stripes. The surface of the sea is white with foam. The strong roar of the waves is like blows. Visibility is poor. Height - 8-11 m, length - 200 m
11	Cruel storm	28,5-32,6	103-117	It is observed very rarely. Accompanied by large destruction in large areas.	9. Exceptionally high waves. Small to medium sized boats are sometimes out of sight. The sea is all covered with long white flakes of foam, which are located in the wind. The edges of the waves are everywhere blown into foam. Visibility is poor. Height - 11m, length 250m
12	Hurricane	>32,6	>117	Devastating destruction. Individual gusts of wind reach speeds of 50-60 m.sec. A hurricane can happen before a major thunderstorm	9. Exceptional excitement The air is filled with foam and spray. The sea is covered with strips of foam. Very poor visibility. Wave height >11m, length - 300m.

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 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. 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 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 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, the 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 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, where the boundaries of warm and cold zones are schematically shown. 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 country 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 - 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 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 - the main drawback of the considered scheme) ...

Application

Average wind speed on the Beaufort scale in different years its application

table 2

score	verbal characteristic	Average wind speed (m/s) as recommended
		Simpson	Koeppen	International Meteorological Committee
		1906	1913	1939	1946	1963
0	Calm	0	0	0	0	0
1	Quiet wind	0,8	0,7	1,2	0,8	0,9
2	Light breeze	2,4	3,1	2,6	2,5	2,4
3	weak wind	4,3	4,8	4,3	4,4	4,4
4	moderate wind	6,7	6,7	6,3	6,7	6,7
5	Fresh breeze	9,4	8,8	8,7	9,4	9,3
6	Strong wind	12,3	10,8	11,3	12,3	12,3
7	strong wind	15,5	12,7	13,9	15,5	15,5
8	Very strong wind	18,9	15,4	16,8	18,9	18,9
9	Storm	22,6	18,0	19,9	22,6	22,6
10	Heavy storm	26,4	21,0	23,4	26,4	26,4
11	Violent storm	30,0		27,1	30,6	30,5
12	Hurricane			29,0	33,0	32,7
13					39,0
14					44,0
15					49,0
16					54,0
17					59,0

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, this 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 the wind. Tornadoes are typical mainly for North America.

table 4

Category	Speed, km/h	Damage
F0	64-116	destroys chimneys, damages tree crowns
F1	117-180	Breaks prefabricated (panel) houses from the foundation or turns them over
F2	181-253	Significant destruction. Prefabricated houses collapse, trees are uprooted
F3	254-332	Destroys roofs and walls, scatters cars, overturns trucks
F4	333-419	Breaks down fortified walls
F5	420-512	Lifts houses and carries them over a considerable distance

Glossary of terms:

Leeward side object (protected from the wind by the object itself; area high blood pressure, due to the strong deceleration of the flow) 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 per square meter of a billboard (perpendicular to the plane of the structure) installed near the road of the carriageway. In the example, the maximum storm wind speed expected at a given location 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 (depending 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 strength cancel flights of civil aviation aircraft

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.

At strong wind, airplanes 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 components of the 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 for Hydrometeorology and Monitoring environment). 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 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_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 recorded, 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.