Monsoon is a phenomenon that affects the climate of entire continents. Monsoons: winds, rains, currents

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. AT summer time monsoons blow from the ocean towards the land, in winter - in the opposite direction. They form a peculiar type of climate called monsoon, characteristic feature which is high level air humidity in summer period.

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 annual distribution cycles atmospheric pressure. 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 number 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, southern part mediterranean sea and some other areas, but in a weaker form.

trade winds

Trade winds are called winds that blow steadily in tropical zone all year round thanks to inertial force the rotation of the earth and climatic features 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. In the Age of the Great geographical discoveries when Spain was the queen of the seas, the trade winds served as the main factor favoring the movement sailing ships between the European continent and the New World.

How are trade winds formed?

equatorial zone our planet experiences the strongest heating by the sun's rays, so the air in the lower atmosphere always has enough high temperature. Because of this, in areas close to the equator, there is a stable rising air flow.

The rising air is immediately replaced by colder air. air masses 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 that has risen cools and sinks, but due to the outflow of air in the northern and southern temperate zones he 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 indian ocean where they are in force geographical features coastlines turn into monsoons.

Since ancient times, man has observed nature. Often sailors noticed steady winds blowing towards the continents. The monsoon is the same wind that changes direction twice a year. In summer, it is directed from the ocean to the mainland. It brings with it heavy rains and abundant moisture. It's true life-giving force, which does not allow all living diversity of land to die.

By the onset of winter, the summer monsoon gradually changes its direction, rebuilding into reverse side. Now, from the land, air currents rush to the sea. Such a climate is often characterized as monsoonal. You can observe it in the planets, on Far East and coastal areas, in South Asia, Australia, equatorial Africa, Brazil and the Middle East. The winter period in these areas is characterized by poor rainfall, drought and extremely rare rainfall. Most favorable periods for life in areas with a monsoon climate - spring and autumn. The spring monsoon is a movement of air that brings comfortable temperature and humidity during the off-season. This period is unusually picturesque. One has only to look at the monsoon (pictures below) in order to feel the beauty of a natural phenomenon.

Monsoons are caused by the formation of zones of high and low pressure. If we take into account that in the equatorial regions there are zones of low pressure, and in the subequatorial regions - increased, then the monsoon is a constant movement of cyclones. In addition, the formation of the monsoon wind is influenced by the temperature difference in summer and winter period like, for example, in India. In summer, heated air moves inland. And in winter, stronger winds blow from the continent towards the ocean.

But not always the monsoon is a long-awaited joy. After all, it is known that strong winds bring disaster to entire countries. Often the population of the continents suffers from floods and destructive downpours. Residents of Vietnam, Korea, Thailand often find themselves hostages to the raging elements in the summer. And in winter, a severe drought can turn into fires, outbreaks of epidemics. First of all, African countries suffer from these "charms". The local population is waiting for the onset of the summer monsoon season, since life on this mainland depends entirely on them.

After all, entire rivers dry up in winter, leaving dried-up channels behind them. With the advent of the rainy season, they fill up and life returns to these places.

This phenomenon is practically not observed in European countries. On a vast territory of land, cyclones and anticyclones replace each other, not lingering for a long time in one place. Monsoons are characteristic of coastal regions and are completely atypical for Europe. But in the Far East, you can see their influence on the climate. From June to September, the maximum precipitation falls here. Hence it turns out that it is rainy in summer, but warm weather, and in winter it is quite dry, windy and very cold. And in the driest winter month precipitation is 5 times less than in the rainiest summer. This disproportion is characteristic of the monsoon climate.

SUMMER MOUSSON - A moist wind from the ocean towards a warmer continent. In San Francisco, this is what they call a sea day , penetrating through the Golden Gate, sometimes 150 km deep into the continent, to the confluence of the San Joaquin and Sacramento rivers. It is accompanied by a cold snap of 5-8 "C. It intensifies with the intensive heating of the Big Valley. Brings fog to the continent (see. ), arising over the cold California current, forming a “sea of ​​clouds” over the Golden Gate, while at an altitude of 700 m the slopes of the mountains are brightly lit by the Sun. Thanks to the L. m. in San Francisco, the air temperature in summer is the same as on the pass through the Sierra - Nevada at an altitude of 2140 m. 22 km northwest of San Francisco at an altitude of 730 m in summer 4 ° C warmer than below, due to the presence of a stable monsoon-type temperature inversion.

Dictionary of winds. - Leningrad: Gidrometeoizdat. L.Z. Proh . 1983

See what "SUMMER MOUSSON" is in other dictionaries:

Monsoon off the northeast coast of Africa. See Tropical monsoons ... Dictionary of winds

Monsoon- This term has other meanings, see Monsoon (meanings). Monsoon (from Arabic "موسم" (mysem), season) steady winds that periodically change their direction; in summer they blow from the ocean, in winter from land; characteristic of tropical regions ... Wikipedia

- (from Arab, mausim season) large-scale air flow with a corresponding weather complex. A seasonal wind that occurs at the border of the sea and the continent as a result of their unequal heating and changes its direction twice a year to ... ... Dictionary of winds

Refers to extratropical. Winter weather is due to the strong cooling of continental air under anticyclonic conditions. In the Amur Region and the Khabarovsk Territory, in winter, the air temperature drops to 40 ° C with a clear sky, frosts are kept ... Wind Dictionary

MONSOON- Origin: from the Arab, mausim season is a steady system of winds that act between land and ocean and change direction twice a year by 120 180 °. The main reason for M. is seasonal temperature contrasts between the surface of the ocean and the adjacent ... ... Marine encyclopedic reference book

Cold autumn winds from the mountain coasts towards the unfrozen lake (sarma, kultuk, barguzin, etc.). Before freezing, the temperature differences between the surface of the lake and the shores reach 40 ° C, which is the reason for the monsoon intensification of coastal ... ... Dictionary of winds

Summer oceanic tropical monsoon in the northern Indian Ocean. See Tropical Monsoon ... Wind Dictionary

We invite you to embark on an unusual journey. Let us follow the winds of the seasons today. "Mausim" - in Arabic - the season, the season, it was from there that the word "monsoon" came from. The winds of the seasons that blow from opposite directions in winter and summer.

Let's go first consider the situation in the summer: there is a lot of sun and it heats the land to a greater extent. But why? Everything is not so complicated, firstly, water has the property that it is difficult to heat it and difficult to cool. Water, of all substances, is the most difficult to heat, so they say that its heat capacity is one. The volumetric heat capacity of air is 0.000307, ​​i.e., in order to heat the air, it is necessary to apply 3257 times less heat than is required for water. Conversely, it is 3257 times easier to cool air than water.

Plus, water, unlike land, is also transparent, which means that the sun's rays penetrate the water column and warm it up, and not just the surface layers.

So, we settled on the fact that in summer the sun heats the land more than the ocean. Therefore, over land, the air is warmed up and rises, leaving behind an area of ​​low pressure. Over the ocean, the air is colder and, therefore, is located closer to the earth, and here a region arises high pressure. That's almost all!!! A holy place is never empty and cold air is sent from the ocean to land to fill the "empty" space. Or, in other words, high pressure pushes air into areas of lower pressure.

Why is the air humid in summer? Here, too, everything is simple, he came from the ocean, and there is a lot of water 🙂 In summer, under the influence of the sun, it evaporates and saturates the air.

Now consider, what happens in winter. Here the sun is already scarce and it does not play an important role. But again, everything happens thanks to amazing properties water discussed earlier. Per long summer, the water has absorbed a lot of heat, and in winter it begins to slowly give it away, while the air over the land cools almost as soon as the sun goes down. Therefore, now, all the air that is above the ocean is heated due to the heat accumulated in the water, and the air above the land cools down without the sun.

And again, where the air is warm, the pressure is low, where it is cold, the pressure is high. And the wind blows from an area of ​​high pressure to an area of ​​low pressure. Those. in our case, in winter, monsoon winds blow from land to the ocean, and I think it’s clear why they are dry :-).

For a better understanding, see also the video: “Why does the wind blow?”

Monsoon climate areas.

Summer monsoons come from the sea and bring rain and dampness, in winter the wind blows from the land and gives dry and clear weather.

India is a classic monsoon territory. It has long been a natural phenomenon known to navigators, because the correct change of winds was very important for shipping.

What does spring mean to us? Awakening of nature, rebirth. The beginning of the rainy summer monsoon carries the same meaning on the Indian mainland. Many poets sang this season in their works. The South Asian monsoon captures, in addition to India, Indo-China, and then China.

And finally, the Australian monsoons cover the northern part of Australia and the Malay Archipelago. These are the territories of the country of monsoons.

Modern Russian physical map world with sea currents. In particular, you can find the monsoon current enveloping India.

And now, we offer to get acquainted with humid and variable-humid monsoon forests.

Permanently wet forests. Huge humidity and always hot air temperature. vegetable and animal world very rich. These forests are impenetrable jungle, the presence of several tiers of plants that never shed their leaves. Animals are usually small in size, since large individuals could hardly make their way through difficult areas. For humans, these forests are also difficult. Even today you can find places untouched and unexplored by us.

Variably moist forests. Precipitation does not occur all year round, but only during the rainy season. Plants have to shed their leaves to protect themselves from excessive evaporation. Animals also have to adapt, so the diversity of flora and fauna here is inferior to constantly wet forests.

Unfortunately, these forests are increasingly threatened by our civilization. And the restoration of the former species requires a very long time. Therefore, it is worth thinking again about how to preserve this wonderful splendor of nature.

And finally, I suggest watching a video film: BBC: The Natural World. Monsoon / Natural World. Monson.