What are monsoons and trade winds in geography? Monsoons: winds, rains, currents. Monsoon climate region, humid and variable humid monsoon forests What are monsoons? in what directions do they blow
Windiness in the modern dictionary is a synonym for inconstancy, changeability. But the trade winds completely break this statement. Unlike breezes, seasonal monsoons, and even more so winds caused by weather cyclones, they are constant. How are the trade winds formed and why do they blow in a strictly defined direction? Where did this word "trade wind" come from in our language? Are these winds 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"
In the days of the sailing fleet, the wind was of paramount importance for navigation. When it always blew steadily in the same direction, one could hope for a successful outcome of a dangerous journey. And the Spanish navigators dubbed such a wind "viento de pasade" - conducive to movement. The Germans and the Dutch included the word "pasade" in their maritime vocabulary of navigational terms (Passat and passaat). And in the era of Peter the Great, this name also penetrated into the Russian language. Although in our high latitudes trade winds are rare. The main place of their "habitat" is between the two tropics (Cancer and Capricorn). 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, over the oceans. There they blow with a force of 3-4 points. Off the coast, the trade winds transform into monsoons. And further from the equator, winds generated by cyclonic activity give way.
How trade winds are formed
Let's do a little experiment. Put a few drops on the ball. Now let's spin it like a top. Look at the drops. Those of them, which are closer to the axis of rotation, remained motionless, and located on the sides of the "spinning tops" spread in the opposite direction. Now imagine that the ball is our planet. It spins from west to east. This movement creates opposite winds. When the point is located close to the poles, it makes a smaller circle per day than the one located at the equator. Therefore, the speed of its movement around the axis is slower. Air currents do not arise from friction with the atmosphere in such subpolar latitudes. Now it is clear that the trade winds are the steady winds of the tropics. At the equator itself, the so-called calm strip is observed.
Direction of the trade winds
Drops on the ball are easy to see that they spread in the opposite direction of 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 a mirror image, on the other side of the equator. That is, in the Southern Hemisphere, the trade winds blow from the southeast to the northwest.
Why is the equator so attractive to air masses? In the tropics, as is known, a constant area of high pressure is established. And at the equator, on the contrary, low. If we answer the children's question, where does the wind come from, then we will state a common natural history truth. Wind is the movement of air masses from layers of high pressure to areas of lower pressure. The periphery of the tropics in science is called “Horse latitudes”. From there, the trade winds blow at a gallop into the "Calm Strip" above the equator.
Constant wind speed
So, we understood the distribution area of the trade winds. They form in both at a latitude of 25-30° and fade near the calm zone around 6 degrees. The French believe that the trade winds are the "correct 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. Born in hot regions and these winds contribute to the development of deserts such as the Kalahari, Namib and Atacama.
Are they permanent?
Over the continents, the 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, the 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 statement that the trade winds are the winds of tropical latitudes is not entirely true. In the Atlantic, for example, in the Northern Hemisphere, they blow in winter and spring within 5-27 ° N, and in summer and autumn 10-30 ° N. This strange phenomenon was given a scientific explanation by John Hadley, a British astronomer, back in the 18th century. The windless band does not stand on the equator, but moves after the Sun. Thus, by the date when our star is at its zenith over the Tropic of Cancer, the trade winds are moving north, and in winter - south. The constant winds are not the same in strength. The Southern Hemisphere trade wind is more powerful. He almost does not meet on his way obstacles in the form of land. There it forms the so-called "roaring" fortieth latitudes.
Trade winds and tropical cyclones
To understand the mechanics of typhoon formation, you need to understand that two constant winds blow in each hemisphere of the Earth. Everything that we have described above refers to the so-called lower trade winds. But the air, as you know, cools when climbing to a height (on average, one degree every hundred meters of ascent). Warm masses are lighter and rush upwards. Cold air tends to sink down. Thus, opposite trade winds arise in the upper layers of the atmosphere. blowing in the Northern Hemisphere from the southwest, and below the equator - from the northwest. inside the trade winds sometimes changes the stable direction of the two layers. There is a zigzag twisting of warm, moisture-saturated and cold air masses. In some cases, tropical cyclones gain hurricane strength. All the same direction vector inherent in the trade winds carries them to the west, where they unleash their destructive force on coastal areas.
The general circulation of the atmosphere includes trade winds, westerly winds of moderate latitudes, easterly (katabatic) winds of the polar regions, as well as monsoons.
Wind is caused by differences in atmospheric pressure. Since there are relatively constant belts on the Earth, they also depend on them. prevailing winds(also called permanent, predominant, dominant or predominant).
Air masses moving with steady winds move in a certain order. They also create a complex system of air currents on a global scale. It is called the general circulation of the atmosphere (from the Latin word circulation- rotation).
Between the atmospheric pressure belts of the earth, relatively stable prevailing winds, or winds of prevailing directions, are formed.
trade winds
Among the constant winds, the most famous are - trade winds.
trade winds - winds that are stable throughout the year, directed from tropical latitudes to equatorial latitudes and generally have an easterly direction.
The trade winds are formed in a hot thermal zone and blow from an area of high pressure in the region of 30 ° N. sh. and 30°S sh. towards the equator - areas with lower pressure (Fig. 31). If the Earth did not rotate, then the winds in the Northern Hemisphere would blow exactly from north to south. But due to the rotation of the Earth, the winds deviate from the direction of their movement: in the Northern Hemisphere - to the right, and in the Southern Hemisphere - to the left. This phenomenon is called the Coriolis effect - after the French scientist, and it manifests itself in relation not only to winds, but also, for example, to sea currents and the erosion of the corresponding banks of large rivers (in the Northern Hemisphere - right, in the Southern - left).
The Northern Hemisphere trade wind is a northeasterly wind, and the Southern Hemisphere trade wind is a southeasterly wind.
The trade winds blow at a fairly high speed, about 5-6 m / s, and weaken, converging near the equator - a calm zone is formed there. The trade winds over the Ocean are distinguished by a special constancy. This was noted by seafarers of the past, who sailed on sailing ships and were very dependent on the winds. It is believed that the name "trade wind" comes from the Spanish vientedepasada, which means "the wind that favors the move." Indeed, in the days of the sailing fleet, they helped to travel from Europe to America.
Western winds of temperate latitudes
From the area of high pressure of the hot belt, winds blow not only towards the equator, but also in the opposite direction - towards temperate latitudes, where the belt of low pressure is also located. These winds, like the trade winds, are deflected by the rotation of the Earth (the Coriolis effect). In the Northern Hemisphere they blow from the southwest, and in the Southern Hemisphere from the northwest. Therefore these winds are called westerly winds of temperate latitudes or western carry(Fig. 31).
With the western transfer of air masses, we constantly encounter in our latitudes in Eastern Europe. With westerly winds, sea air from temperate latitudes most often comes to us from the Atlantic. In the Southern Hemisphere of latitude, where westerly winds form over the giant continuous surface of the Ocean and reach tremendous speed, they are called "roaring forties". material from the site
Eastern (katabatic) winds of the polar regions
Eastern (katabatic) winds of the polar regions blow towards low pressure belts of temperate latitudes.
Monsoons
Steady winds are often referred to as monsoons. Monsoons arise due to the uneven heating of land and ocean in summer and winter. The land area is much larger in the Northern Hemisphere. Therefore, monsoons are well pronounced here on the eastern coasts of Eurasia and North America, where in the middle latitudes there is a significant contrast in the warming of land and ocean. A special variety is the tropical monsoons that dominate South and Southeast Asia.
Unlike other prevailing winds, monsoons are seasonal winds. They change direction twice a year. The summer monsoon blows from the ocean to the land and brings moisture (rainy season), while the winter monsoon blows from land to the ocean (dry season).
On this page, material on the topics:
Prevailing winds at the equator
What are monsoons? in what directions do they blow?
What are constant winds called?
They helped make the journey from Europe to America they are called
On the map, mark the trade winds iussons zap winds of temperate latitudes
Questions about this item:
Which of us in childhood did not read adventure books about distant wanderings, noble sailors and fearless pirates?
When we pronounce the words "monsoon" and "trade winds", we evoke precisely these romantic pictures: distant tropical seas, uninhabited islands covered with lush greenery, the sound of swords and white sails on the horizon.
Meanwhile, everything is much more prosaic: monsoons and trade winds are well-known names that have a significant impact on the formation of weather not only in tropical areas, but throughout the planet.
Monsoons
Monsoons are called winds with a stable direction, characteristic of the tropical belt and some coastal countries of the Far East. In summer, monsoons blow from the ocean towards land, in winter - in the opposite direction. They form a peculiar type of climate, called monsoon, a characteristic feature of which is a high level of air humidity in the summer.
One should not think that in areas where the monsoon prevails, there are no other winds. But winds of other directions appear from time to time and blow for short periods, while the monsoon is the predominant wind, especially during winter and summer. The autumn-spring periods are transitional, at which time the stable wind regime is disturbed.
Origin of the monsoons
The appearance of monsoons is entirely related to the annual cycles of atmospheric pressure distribution. In summer, the land heats up more than the ocean, and this heat is transferred to the lower atmospheric layer. The heated air rushes up, and a zone of low atmospheric pressure forms over the land.
The resulting lack of air is immediately filled with a colder air mass located above the ocean surface. It contains a large amount of moisture evaporated from the water surface.
Moving in the direction of land, the air from the sea carries this moisture and spills it onto the surface of coastal areas. Therefore, the monsoonal climate is more humid in summer than in winter.
With the onset of the winter period, the winds change their direction, since at this time the land surface warms up less actively, and the air above it turns out to be colder than over the sea surface, which explains the change in the direction of the monsoon at this time.
Monsoon geography
The monsoon climate is most typical for the equatorial regions of Africa, the northern coast of Madagascar, many states of Southeast and South Asia, as well as the equatorial part of the Southern Hemisphere, including the northern coast of Australia.
The influence of the monsoons is experienced by the states of the Caribbean, the southern Mediterranean Sea and some other areas, but in a weaker form.
trade winds
Trade winds are called winds that blow steadily in the tropical zone all year round due to the inertial force of the Earth's rotation and the climatic features of the tropics. 
In the Northern Hemisphere, the trade winds blow from the northeast, and in the Southern Hemisphere, from the southeast. The trade winds are most stable above the sea surface, while the land relief introduces certain changes in their direction.
The name "trade wind" comes from the Spanish expression "viento de pasada" - a wind that favors movement. During the Age of Discovery, when Spain was the queen of the seas, the trade winds served as the main factor favoring the movement of sailing ships between the European mainland and the New World.
How are trade winds formed?
The equatorial zone of our planet experiences the strongest heating by the sun's rays, so the air in the lower atmosphere always has a fairly high temperature. Because of this, there is a stable updraft in areas close to the equator.
In place of the rising air, colder air masses immediately rush from both subtropical zones - northern and southern. Due to the Coriolis force - the inertial force of the Earth's rotation - these air currents do not move strictly in the south and north directions, but are deflected, acquiring a southeast and northeast direction. 
The cold air rising up cools and sinks down, but due to the outflow of air in the northern and southern temperate zones, it rushes there and also experiences the action of the Coriolis force. These winds blowing in the upper atmosphere are called the upper trade winds, or counter trade winds.
Geography of the trade winds
The trade winds are the prevailing winds along the entire equatorial belt, except for the coastal zone of the Indian Ocean, where, due to the geographical features of the coastline, they turn into monsoons.
The air is constantly moving, it goes up and down all the time, and it also moves horizontally. We call the horizontal movement of air wind. The wind is characterized by such quantities as speed, force, direction. The average wind speed near the earth's surface is 4-9 meters per second. The maximum wind speed -22 m/s - was recorded off the coast of Antarctica, with gusts up to 100 m/s.
The wind arises due to the difference in pressure, moving from an area of high pressure to an area of low pressure along the shortest path, deviating, according to the direction of flow, to the left in the Southern Hemisphere, and to the right in the Northern Hemisphere (Coriolis force). At the equator, this deviation is absent, and in the region of the poles, on the contrary, it is maximum.
Constant winds
The main directions of winds at different latitudes determine the distribution of atmospheric pressure. In each of the hemispheres, air moves in two directions: from areas of a tropical climate, in which high pressure reigns, to temperate latitudes and to the equator. At the same time, it deviates to the right in the Northern Hemisphere, and to the left in the Southern, in the direction of the flow.
In the region between the equator and the tropics, the trade winds blow - easterly winds that are constantly directed towards the equator.
In regions of temperate latitudes, on the contrary, westerly winds, which are called westerly transfer, predominate.
These winds determine the main constant movement of air masses, which interacts with anticyclones and cyclones, and on which regional winds are then superimposed.
Regional winds
On the border of land and ocean water, due to the displacement of high and low pressure zones, monsoons arise, as a result of which intermediate belts appear that change the direction of the winds seasonally. There are no huge land masses in the Southern Hemisphere, so the monsoons dominate the Northern Hemisphere. In summer, they blow towards the mainland, and in winter - towards the ocean. Most often, this wind occurs on the Pacific coast of Eurasia (northeast China, Korea, the Far East), in North America (Florida). It is these winds that also blow in Vietnam, which is why there is such a stable wind regime here.
Tropical monsoons are a cross between trade winds and monsoons. They originated like trade winds due to differences in pressure across different climates, but like monsoons, they change direction with the seasons. This wind can be encountered on the shores of the Indian Ocean and the Gulf of Guinea.
The sirocco, a wind that originates in the Mediterranean, also belongs to the regional winds. It is the western transport which, having passed through the tops of the mountains, heats up and becomes dry, since it has given all its moisture to the windward slopes. Sirocco brings to the regions of Southern Europe a lot of dust from the deserts of North Africa, as well as the Arabian Peninsula.
local winds
These are winds on the coasts, arising from the difference in the rate of heating and cooling of the sea and land, and acting in the area of the first tens of kilometers of the coast.
A breeze is a wind that occurs at the border of the coast and the water area and changes its direction twice a day: during the day it blows from the water area to land, at night - vice versa. Breezes blow along the banks of large lakes and rivers. A change in the direction of this wind occurs due to a change in temperature and, accordingly, in pressure. During the day on land it is much warmer, the pressure is lower than over water, while at night it is vice versa.
Bora (Mistral, Bizet, Nord-Ost) is a cold hurricane-force wind. It is formed on narrow sections of the shores of warm seas during the cold season. Bora is directed from the leeward slopes of the mountains towards the sea. These winds blow, for example, in the mountainous regions of Switzerland and France.
Pampero is a cold stormy, southerly or southwesterly wind from Argentina and Uruguay, sometimes with rain. Its formation is associated with the invasion of cold air masses from the Antarctic.
Thermal wind is a general name for the winds associated with the temperature difference that occurs between the hot desert and the relatively cold sea, the Red Sea, for example. This is the difference between the conditions of Dahab and Hurghada in Egypt, which is not far away, but the wind blows there with less force. The fact is that the city of Dahab lies at the exit from the canyon formed by the Sinai and Arabian Peninsulas. The wind accelerates in the canyon itself, the effect of a wind tunnel appears, but, going out into the open space, the wind force gradually decreases. With distance from the coast, the speed of such winds fades. As we move towards the open ocean, global atmospheric winds have a greater influence.
Tramontana is a hurricane north wind of the Mediterranean, generated by the collision of the atmospheric currents of the Atlantic with the air of the Gulf of Lion. After their meeting, a violent squall is formed, which can exceed the speed of 55 m / s and be accompanied by a loud whistle and howl.
Another group of local winds depends on the local topography.
Föhn - a warm dry wind directed from the lee slopes of the mountains to the plain. The air gives up moisture as it rises up the windward slopes, and this is where precipitation falls. When the air descends from the mountains, it is already very dry. A kind of foehn - wind garmsil - blows mainly in summer from the south or southeast in the area of the foothills of the Western Tien Shan.
Mountain-valley winds change their direction twice: during the day they are directed up the valley, at night, on the contrary, they blow down. This happens because the lower part of the valley warms up more intensively during the day.
There are also winds that arise in large areas of deserts and steppes.
Samoom is a hot dry wind of tropical deserts, which has a stormy, squall character. Gusts accompany dust and sand storms. You can meet him in the deserts of the Arabian Peninsula and North Africa.
Dry wind is a warm dry wind in the steppe regions, which is formed in the warm season under anticyclone conditions and contributes to the appearance of droughts. These winds are found in the Caspian Sea and Kazakhstan.
Khamsin is a dry hot and dusty wind, usually southerly, blowing in northeastern Africa and the eastern Mediterranean. Khasmin blows in the spring for about 50 days, bringing with it a lot of dust and sand. It reaches its greatest strength in the afternoon, fading away by sunset. Often found in Egypt.
Thus, each point on Earth has its own different features that affect wind conditions, for example, we will give some of them.
Anapa is one of the few places in Russia where the climate is subtropical Mediterranean and very pleasant for water sailing. In winter, it is humid but not cold, and in summer, a cool sea breeze softens the intense heat. The most favorable period for skiing is the season from July to November. Wind strength in summer averages 11-15 knots. After mid-October and in November, the wind intensifies and can reach 24 knots.
The Canarian archipelago has a tropical trade wind climate, moderately dry and hot. From the coast of Africa to the islands of Fuerteventura and Lanzarote comes "harmattan", bringing the heat and sand of the Caxapa desert. The main wind that dominates these islands is the trade wind, which blows for half a year and almost constantly in the summer. The wind force is 10-20 knots, in October and November it increases to 25-35.
The Philippines are islands with a tropical monsoon climate. Temperatures on the coast are about 24-28 degrees. The rainy season here begins in November and lasts until April, when the northeast monsoon blows, and from May to October the southwest monsoon blows. Tsunamis and typhoons often occur in the northern regions of the country. The average wind force is 10-15 knots.
So, on a specific territory, the influence of various types of winds is simultaneously manifested: global, depending on areas of high or low pressure, and local, blowing only in this territory, due to its physical and geographical features. This means that for a certain place the wind system can be predictable to some extent. For a long time, scientists have created special maps, with the help of which it became possible to learn and trace the wind regimes of different regions.
Internet users often find out the features of the winds in a particular area with the help of resources and where you can quite accurately check whether there is wind at a particular point in the world or not.