Wind and its types. What is wind and what is wind power? What are northeast winds
SECTION 3 GEOGRAPHICAL SHELL
Theme 2. Atmosphere
§ 36. Wind. Constant and variable winds
Remember
How do you watch the wind?
Which winds prevail in your area?
Wind is the movement of air in a horizontal or close direction. In this case, air moves from a zone of high atmospheric pressure to an area with low atmospheric pressure. Wind is characterized by speed, strength and direction. Wind speed is measured in meters per second (m / s) or in kilometers per hour (km / h). To convert meters per second to kilometers per hour, you need to multiply the speed in meters per second by 3.6.
The strength of the wind is determined by the pressure of moving air on objects. It is measured in kilograms per square meter (kg / m2). The strength of the wind depends on its speed. So, the wind at a speed of 100 km / h has a force 10 times greater than at a speed of 10 km / h. The greater the difference in atmospheric pressure, the stronger and faster the wind blows. The absence of any signs of wind is called calm.
Modern Facts
The strongest winds. Outlying parts of Antarctica, where the winds blow for 340 days a year, are considered the “Pole of Winds" on Earth. The highest wind speed - 371 km / h - was recorded in 1934 in the United States, on a mountain in the state of New Hampshire. In Ukraine, the strongest wind was in the city of Ai-Petri in the Crimea (its speed reached 180 km / h).
The direction of the wind is determined by the position of the side of the horizon from where it blows. To indicate the direction of the wind in practice, the horizon is divided into eight directions. Of these, four head - north (Mon), south (South), east (Cx) and west (W) and four intermediate - north-east (North-East), north-west (North-West), southeast ( Fd-Cx) and southwestern (Fd-Zx).
For example, when the wind blows from a location located between the south and east, it is called southeastern (PD-Cx). The direction and speed of the wind is determined using a weather vane (Fig. 97). A clear idea of \u200b\u200bthe directions of the winds that prevail in a given area is given by a special diagram - a rose of winds (Fig. 98). This is a graphic representation of the repeatability of wind directions. The length of its rays is proportional to the frequency of winds in a given direction.
Fig. 97. Weather vane
PRACTICAL WORK No. 8(continued)
Weather Observations: composing a wind rose
Using the data in the table, build a wind rose. To do this, first draw the coordinates, indicating four wind directions and four intermediate. At the scale of your choice, set aside the number of lines corresponding to each direction. The ends of the segments are connected in series. Paint the resulting wind rose and indicate which direction the wind prevailed. In Figure 98, note how the winds of various directions denote.
Fig. 98. Wind rose
Direction of the wind |
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Wind repeatability,% |
Constant and variable winds. There are no windless places on the globe. There are many different types of winds. There are winds that blow constantly, and there are those that change their direction during the day or year. Permanent winds — the trade winds — occur between the high tropical and equatorial low atmospheric pressure zones in the Northern and Southern hemispheres of the Earth (Fig. 99). Due to the rotation of the globe, trade winds in the Northern Hemisphere move from the northeast to the southwest, and in the South from the southeast to the northwest. The trade winds hardly change their direction during the year. their speed is on average 5-6 m / s, and the vertical thickness reaches 2-4 km and increases towards the equator.
In temperate latitudes, westerly winds blow. They are also permanent.
Fig. 99. The trade winds
Fig. 100. Education day (a) and night (b) breeze
There are much more variable winds on the globe than constant ones. Distributed only in certain territories, they are called local.
Local winds blow over a relatively small area (from hundreds of meters to tens of kilometers) and significantly affect the weather in this area. An example of a local breeze wind. Translated from French, this word means "a breeze." Its speed is really negligible - up to 4 m / s. The breeze blows with daily intervals on the coast of the seas, large lakes and some large rivers. This wind changes direction twice a day, which is caused by uneven heating of the land surface and the reservoir. The daytime, or sea, breeze moves from the water surface to land, and the night, or coastal, moves from the chilled coast of land to the body of water (Fig. 100).
The breeze occurs mainly in the summer, when the temperature difference between land and water reaches its highest values. In Ukraine, breezes are observed on the coast of reservoirs, the Black and Azov Seas.
Amazing phenomena
Wind from the mountain peaks.
Interesting local winds are fiones, which do not have a certain periodicity. They are not constant and last on average from one to two days.
Fion is a strong, gusty, dry and warm wind blowing from mountain peaks into valleys. It arises when air passes over the crest of a mountain range and, descending the slope, quickly heats up (Fig. 101). In this case, the temperature can reach maximum values \u200b\u200bfor a given time of the year. So, with a strong fion on the icy island of Greenland, the temperature rises by 20-25 ° C. The fion causes snowmelt in the mountains in winter, and droughts and fires in summer. In the mountainous regions of Ukraine, fiones, which blow from the southeastern slopes of the Crimean mountains near Alushta, can suddenly raise the temperature here to 28 ° С. Fioni in the Ukrainian Carpathians have a speed of up to 25 m / s.
Fig. 101. Education fionov
Fig. 102. The movement of monsoons
Monsoons are also attributed to winds changing their direction. The word "monsoon" is translated from Arabic as "season". This name is not accidental, because the monsoon changes its direction twice a year: in winter it blows from land to ocean, and in summer, on the contrary, from ocean to land (Fig. 102). (Think about why the monsoon changes direction in the seasons.) Monsoon winds are best expressed in the south and east of Asia, in the north of the Indian and in the west of the Pacific Ocean. Especially powerful is the Asian summer monsoon. It contains a large amount of moisture and heat, and heavy rainfall is associated with it.
Wind is the horizontal movement of air, resulting from the difference in atmospheric pressure.
Wind is characterized by speed, strength and direction.
Constant winds blow constantly, variable winds change their direction during the day or year.
Questions and tasks for self-testing
Build a wind rose from your observations. Explain which winds prevail in your area. Schematically draw the direction of the wind according to the following data: a) the pressure in point A is 760 mm Hg. Art., and in paragraph B - 784 mm RT. st .; b) on the coast, the pressure is 758 mm Hg. Art., and above the lake - 752 mm RT. Art. In which case will the wind be stronger?
Choose from the listed winds one that almost does not change its direction: a) trade wind; b) monsoon c) breeze.
What is the cause of the wind? What determines the strength and speed of the wind?
Frivolity in the modern dictionary is synonymous with inconstancy, changeability. But the trade winds completely break this statement. Unlike breezes, seasonal monsoons, and especially winds caused by weather cyclones, they are constant. How are the trade winds formed and why are they blowing in a strictly defined direction? Where did the word “trade wind” come from in our language? Are these winds really so constant and where are they localized? You will learn about this and much more from this article.
The meaning of the word "trade winds"
During the sailing fleet, the wind was of paramount importance for navigation. When he always blew exactly in the same direction, one could hope for a successful outcome of a dangerous trip. And such a wind the Spanish sailors dubbed "viento de pasade" - conducive to movement. The Germans and Dutch included the word “Pasade” in their nautical dictionary of navigation terms (Passat and passaat). And in the era of Peter the Great, this name also penetrated the Russian language. Although in our high latitudes the trade winds are a rarity. The main place of their "habitat" is between the two tropics (Cancer and Capricorn). The trade winds are observed and further from them - up to the thirtieth degree. At a considerable distance from the equator, these winds lose their strength and are observed only in large open spaces, above the oceans. There they blow with a force of 3-4 points. Off the coast, trade winds are transformed into monsoons. And even further from the equator give way to the winds generated by cyclonic activity.
How the trade winds are formed
Let's do a little experiment. Put a few drops on the ball. Now spin it like a yule. Take a look at the drops. Those that are closer to the axis of rotation remained immovable, and those located on the sides of the "yule" spread out in the opposite direction. Now imagine that the ball is our planet. It spins from west to east. Opposite winds form from this movement. When the point is close to the poles, it makes a smaller circle per day than the one at the equator. Therefore, the speed of its movement around the axis is slower. Due to friction with the atmosphere, air currents do not arise in such subpolar latitudes. Now it’s clear that the trade winds are the steady winds of the tropics. At the same equator, the so-called calm strip is observed.
Trade winds
It is not difficult to trace dropwise on the ball that they spread in the direction opposite to rotation. This is called But to say that the trade winds are winds blowing from east to west would be wrong. In practice, the air masses deviate from their main vector to the south. The same thing happens, only in specular reflection, on the other hand from the equator. That is, in the southern hemisphere trade winds blow from the southeast to northwest.
Why is the equator so attractive to air masses? In the tropics, as you know, a constant area of \u200b\u200bhigh pressure is established. And the equator, on the contrary, is low. If we answer the children's question, where does the wind come from, we will state the natural history truth. Wind is the movement of air masses from layers with a high pressure to an area with a lower pressure. The periphery of the tropics in science is called “Horse Latitudes”. From there, the trade winds are galloping into the "Calm Strip" above the equator.
Constant wind speed
So, we understand the area of \u200b\u200bdistribution of the trade winds. They form in both at a latitude of 25-30 ° and decay near the calm zone at about 6 degrees. The French believe that the trade winds are “right winds” (vents alizes), very convenient for sailing. Their speed is small, but constant (five to six meters per second, sometimes it reaches 15 m / s). However, the power of these air masses is so great that they form trade winds. Being born in regions with hot weather, these winds contribute to the development of deserts such as Kalahari, Namib and Atakama.
Are they so constant?
Over the mainland trade winds collide with local winds, sometimes changing their speed and direction. For example, in the Indian Ocean, due to the special configuration of the coast of Southeast Asia and climatic characteristics, trade winds turn into seasonal monsoons. As you know, in summer they blow from the cool sea towards the heated land, and in winter - vice versa. However, the assertion that the trade winds are winds of tropical latitudes is not entirely true. In the Atlantic, for example, in the Northern Hemisphere, they blow in the winter and spring in the range of 5-27 ° N, and in the summer and autumn 10-30 ° N. As early as the eighteenth century, John Gadley, a British astronomer, gave this strange explanation to this strange phenomenon. The band of calm does not stand at the equator, but moves after the Sun. Thus, by the date when our star is at its zenith above the tropic of Cancer, the trade winds are shifting to the north, and in the winter to the south. Constant winds and power are not the same. The trade wind of the southern hemisphere is more powerful. He almost never encounters obstacles in the form of land. There it forms the so-called “roaring” forties.
Trade winds and tropical cyclones
To understand the mechanics of typhoon formation, you need to understand that in each hemisphere of the Earth two constant winds blow. Everything that we described above applies to the so-called lower trade winds. But the air, as you know, cools when climbing to a height (an average of one degree every one hundred meters of ascent). Warm masses are lighter and rush up. Cold air tends to fall down. Thus, in the upper atmosphere arise opposite trade winds. blowing in the Northern Hemisphere from the southwest, and lower from the equator - from the northwest. inside the trade winds sometimes changes the stable direction of two layers. A zigzag twisting of warm, saturated with moisture and cold air masses occurs. In some cases, tropical cyclones gain strength in a hurricane. All the same direction vector inherent in the trade winds carries them to the west, where they bring down their destructive power on the coastal areas.
From the area where the pressure is increased, the air moves, "flows" to where it is lower. Air movement is called by the wind. To observe the wind - its speed, direction and strength - use a weather vane and an anemometer. According to the results of observations of the direction of the wind build wind rose (Fig. 37) per month, season or year. Analysis of the wind rose allows you to establish the prevailing wind directions for a given area.
Fig. 37. Rose of Wind
Wind speed measured in meters per second. At calm wind speed does not exceed 0 m / s. The wind, whose speed is more than 29 m / s, is called a hurricane. The most severe hurricanes were noted in Antarctica, where the wind speed reached 100 m / s.
Wind power measured in points, it depends on its speed and air density. On the Beaufort scale, calm corresponds to 0 points, and for a hurricane the maximum number of points is 12.
Knowing the general laws of atmospheric pressure distribution, it is possible to establish the direction of the main air flows in the lower layers of the Earth’s atmosphere (Fig. 38).
Fig. 38. General atmospheric circulation diagram
1. From the tropical and subtropical areas of high pressure, the main air stream rushes to the equator, in the area of \u200b\u200bconstantly low pressure. Under the influence of the deflecting force of the Earth's rotation, these flows deviate to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. These constantly blowing winds are called trade winds.
2. Part of the tropical air moves to temperate latitudes. This movement is especially active in the summer when lower pressure prevails there. These air flows in the Northern Hemisphere also deviate to the right and initially take the south-west, and then the west direction, and in the South - the north-west, turning into the west. Thus, in the temperate latitudes of both hemispheres prevails western air transport.
3. From the polar regions of high pressure, air moves to temperate latitudes, taking a northeastern direction in the North and southeast in the Southern Hemispheres.
Trade winds, temperate westerly winds and polar winds are called planetary and distributed zonally.
4. This distribution is disturbed on the eastern coasts of the continents of the Northern Hemisphere in temperate latitudes. As a result of seasonal changes in pressure over land and the adjacent water surface of the ocean in winter, winds blow from land to sea, and in summer from sea to land. These seasons changing winds are called monsoons. Under the influence of the deflecting effect of the rotating Earth, summer monsoons take a southeast direction, and winter monsoons take a northwest direction. Monsoon winds are especially characteristic of the Far East and East China, to a lesser extent they appear on the east coast of North America.
5. In addition to planetary winds and monsoons, there are local so called local winds. They arise due to the features of the relief, uneven heating of the underlying surface.
Breezes - coastal winds observed in clear weather on the banks of water bodies: oceans, seas, large lakes, reservoirs and even rivers. During the day they blow from the water surface (sea breeze), at night - from land (coastal breeze). In the afternoon, the land warms up more than the sea. Air rises above the land, air streams from the sea rush to its place, forming a daytime breeze. In tropical latitudes, daytime breezes are quite strong winds that bring moisture and coolness from the sea.
At night, the surface of the water is warmer than land. The air rises, and in its place rush air from land. A night breeze forms. By force, it is usually inferior to daylight.
In the mountains are observed hair dryers - warm and dry winds blowing along the slopes.
If low mountains rise in the path of moving cold air like a dam, it may occur boron. Having overcome a low barrier, cold air collapses with tremendous force, and at the same time there is a sharp drop in temperature. Bora is known under different names: on Lake Baikal it is Sarma, in North America - Chinook, in France - Mistral, etc. In Russia, boron reaches a special strength in Novorossiysk.
Dry winds - These are dry and sultry winds. They are characteristic of the arid regions of the globe. In Central Asia, the dry wind is called the sumum, in Algeria - the sirocco, in Egypt - the hatsin, etc. The wind-dry wind speed reaches 20 m / s, and the air temperature is 40 ° C. Relative humidity with a drier temperature drops sharply and drops to 10%. Plants, evaporating moisture, dry on the vine. In deserts, dry winds are often accompanied by dust storms.
The direction and strength of the wind must be taken into account in the construction of settlements, industrial enterprises, and dwellings. Wind is one of the most important sources of alternative energy, it is used to generate electricity, as well as for the operation of mills, water pumps, etc.
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§ 35. Atmospheric pressure§ 37. Weather and its forecasting
Wind - air movement is usually in the horizontal direction relative to the earth's surface. Air moves out. The cause of the wind is the uneven heating of various parts of the Earth. Over the vast territories of our planet, systems of constant and variable winds - air currents - are forming.
Permanent winds (air currents):
Trade winds. They blow from the tropics of the Northern and Southern Hemispheres, where high-pressure regions, located in the low-pressure region, are formed. As a result of the Earth's rotation around its axis, these winds deviate: in the Northern Hemisphere they blow from the northeast to the southwest, in the Southern Hemisphere from the southeast to the northwest. the eastern coast, Africa, is year-round under the influence of trade winds, which arise over the oceans and bring throughout the year. The North is influenced by the trade winds, which originate at 30 ° latitudes of the Northern Hemisphere in central Asia. These winds do not bring precipitation: they come dry and hot. The influence of these winds can explain the location in the largest world -.
Westerly winds. These are the winds prevailing in the troposphere and stratosphere of the middle latitudes of the Earth. They blow from the tropics of the Northern and Southern Hemisphere, where a high-pressure region forms, towards 60 ° latitudes, where low-pressure regions form. Due to the rotation of the Earth, they constantly deviate to the east (to the right in the Northern Hemisphere, to the left in the Southern Hemisphere) and create air flow from west to east.
There are also local winds:
Breeze (French brise - light breeze). This is a local wind of low speed, changing its direction twice a day. It occurs on the shores of the seas, lakes. In the afternoon, the land warms up faster than water. An area of \u200b\u200blow pressure is established above the land, and high above the water, and the daytime breeze blows from the sea or lake on the coast. At night, the picture changes. The land cools faster than water, and the night breeze blows from the chilled coast, over which the high pressure region is established, to be warmed up.
In the era of sailing, breezes were used to start sailing.
Bora (Italian: bora; Greek. boreas - north wind). It is a strong, gusty wind blowing from coastal mountains towards the sea, mainly in the cold season. Boron occurs when cold air above land is separated from warm air above water by a low ridge. Cold air gradually accumulates in front of the ridge and then slides down to the sea with great speed, so the temperature on the coast drops sharply. Bora is especially typical for the coast. The set leads to icing of coastal buildings, to capsizing of ships.
A variety of bora is the Sarma wind, the name of which comes from the name of the river flowing into. This, flying suddenly and raising steep on the lake. It occurs during transshipment through the mountain ranges. As this wind approaches, meteorologists broadcast a storm warning.
Fyon.It is a warm and dry gusty wind from the mountains. It often blows in winter and spring and causes rapid snowmelt. Fen is very common in the mountains of Central Asia,.
Simoom (Arabic) - a sultry wind in the deserts and North Africa, carrying hot sand and dust. This wind occurs during strong warming of the Earth in
PERMANENT WIND - a wind that maintains its direction and speed over time if within two minutes its direction changes by no more than one rumba. There are winds of different constancy: in speed - smooth, gusty (by spirits), squally (holomyany); in the direction-constant (trade wind, strip,) or variable, changing, transitional (variable, rickety) and vortex, circular (vortex,).
Dictionary of the winds. - Leningrad: Hydrometeoizdat. L.Z. Proh. 1983.
See what is "PERMANENT WIND" in other dictionaries:
WIND - WIND, wind husband. movement, flow, flow, current, air flow. By its strength, the wind happens: a hurricane, a cav. bora: storm, storm (usually thunderstorm and rain are connected with the storm), cruel, strong, winds: medium, weak, quiet wind or breeze, wind, ... ... Dahl's Explanatory Dictionary
WIND - (Wind) the movement of air masses in the horizontal direction or, in other words, the horizontal flow of air. Each V. is characterized by two elements: the direction in which the air moves, and the speed with which it ... ... Marine dictionary
Constant wind blowing without interruption for several days and nights on the lake. Seliger. Wed Married wind ... Dictionary of winds
sunny wind - This term has other meanings, see Solar wind (film) ... Wikipedia
SUNNY WIND - constant radial plasma flux of the sun. corona in interplanetary right The flow of energy coming from the bowels of the Sun heats the plasma of the corona to 1.5 2 million K. heating is not balanced by the loss of energy due to radiation, because the density of the corona is low. ... ... Physical Encyclopedia
sunny wind - represents a constant radial outflow of the plasma of the solar corona (see. Solar corona) into interplanetary space. Education S. century due to the flow of energy entering the corona from the deeper layers of the sun. Apparently ... ... Great Soviet Encyclopedia
Conditional (calculated, fictitious) wind, constant throughout the trajectory of a flying projectile, rocket or other object. It has the same effect on the flight as the actual wind (changing along the trajectory). B. century simplifies calculations of wind action ... Dictionary of winds
STAND - where, to stand sometimes, at times, often. We stand at the gate, look at the passers-by. Hold on and wait. Stand, stand a few times in different I stood at the matins and my legs hurt. The ship anchored and left. The regiment stood at ... ... Dahl's Explanatory Dictionary
Sea currents * - The progressive movement of water in the oceans and seas is called the current. The currents are divided, in 1 x, into constant, periodic and random, or irregular; in 2 x, on surface and underwater and, in 3 x, on warm and cold. Constant currents are not ... ...
Sea currents - … Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron
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