World Ocean: studying ocean currents. Currents of the World Ocean. What is cold and warm current? Description and examples

Sea currents. Sea currents are translational movements of masses of water in the seas and oceans, caused by: - the action of friction between water and air; or - pressure gradients arising in water; or - tidal forces of the Moon and the Sun. Sea currents differ: in origin, in the nature of variability, in location and in physical and chemical properties.

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World ocean currents

Ocean, or sea, currents are the forward movement of water masses in the oceans and seas, caused by various forces. Although the most significant cause of currents is wind, they can also form due to unequal salinity of individual parts of the ocean or sea, differences in water levels, and uneven heating of different areas of water areas. In the depths of the ocean there are eddies created by bottom irregularities; their size often reaches 100-300 km in diameter, they capture layers of water hundreds of meters thick.

If the factors causing currents are constant, then a constant current is formed, and if they are episodic in nature, then a short-term, random current is formed. According to the predominant direction, currents are divided into meridional, carrying their waters to the north or south, and zonal, spreading latitudinally - approx. from geoglobus.ru. Currents in which the water temperature is higher than the average temperature for the same latitudes are called warm, lower ones are called cold, and currents that have the same temperature as the surrounding waters are called neutral.

Monsoon currents change direction from season to season, depending on how the offshore monsoon winds blow. Countercurrents move towards neighboring, more powerful and extended currents in the ocean.

The direction of currents in the World Ocean is influenced by the deflecting force caused by the rotation of the Earth - the Coriolis force. In the Northern Hemisphere, it deflects currents to the right, and in the Southern Hemisphere, to the left. The speed of currents on average does not exceed 10 m/s, and their depth extends to no more than 300 m. In the World Ocean, there are constantly thousands of large and small currents that circle the continents and merge into five giant rings. The system of currents in the World Ocean is called circulation and is associated primarily with the general circulation of the atmosphere. Ocean currents redistribute solar heat absorbed by masses of water. They transport warm water, heated by the sun's rays at the equator, to high latitudes, and cold water from the polar regions flows to the south thanks to currents. Warm currents contribute to an increase in air temperature, and cold currents, on the contrary, reduce it. Territories washed by warm currents are characterized by warm and humid climate, and those near which cold currents pass are cold and dry.

The most powerful current in the World Ocean is the cold Western Wind Current, also called the Antarctic Circumpolar Current (from the Latin cirkum - around - approx. from geoglobus.ru). The reason for its formation is strong and stable westerly winds blowing from west to east over vast areas of the Southern Hemisphere from temperate latitudes to the coast of Antarctica. This current covers an area 2500 km wide, extends to a depth of more than 1 km and transports up to 200 million tons of water every second. There are no large land masses along the path of the Western Winds, and it connects the waters of three oceans - the Pacific, Atlantic and Indian - in its circular flow.

The Gulf Stream is one of the largest warm currents Northern Hemisphere. It passes through the Gulf of Mexico (English Gulf Stream - Gulf Current) and carries warm tropical waters Atlantic Ocean to high latitudes. This gigantic flow of warm water largely determines the climate of Europe, making it soft and warm. Every second, the Gulf Stream carries 75 million tons of water (for comparison: the Amazon, the deepest river in the world, carries 220 thousand tons of water). At a depth of about 1 km, a countercurrent is observed under the Gulf Stream.

UPWELLING

In many areas of the World Ocean, deep waters “float” to the surface of the sea. This phenomenon, called upwelling (from the English up - up and well - gushing - approx. from geoglobus.ru), occurs, for example, if the wind drives away warm surface waters, and colder ones rise in their place. The water temperature in upwelling areas is lower than the average at a given latitude, which creates favorable conditions for the development of plankton, and, consequently, other marine organisms - fish and marine animals that feed on them. Upwelling areas are the most important fishing areas of the World Ocean. They are located off the western shores of the continents: Peruvian-Chilean - near South America, California - y North America, Benguela - in South-West Africa, Canary - in West Africa.

Mariners learned about the presence of ocean currents almost as soon as they began to plow the waters. True, the public paid attention to them only when, thanks to the movement of ocean waters, many great things were accomplished. geographical discoveries, for example, Christopher Columbus sailed to America thanks to the North Equatorial Current. After this, not only sailors, but also scientists began to pay close attention to ocean currents and strive to study them as best and deeply as possible.

Already in the second half of the 18th century. the sailors studied the Gulf Stream quite well and successfully applied their knowledge in practice: from America to Great Britain they went with the flow, and in reverse direction kept a certain distance. This allowed them to stay two weeks ahead of ships whose captains were not familiar with the area.

Ocean or sea currents are large-scale movements of water masses in the World Ocean at speeds from 1 to 9 km/h. These streams do not move chaotically, but in a certain channel and direction, which is the main reason why they are sometimes called rivers of the oceans: the width of the largest currents can be several hundred kilometers, and the length can reach several thousand.

It has been established that water flows do not move straight, but deviate slightly to the side and are subject to the Coriolis force. In the Northern Hemisphere they almost always move clockwise, in the Southern Hemisphere - vice versa. At the same time, currents located in tropical latitudes (they are called equatorial or trade winds) move mainly from east to west. The most strong currents were fixed along eastern shores continents.

Water flows do not circulate on their own, but are set in motion by a sufficient number of factors - the wind, the rotation of the planet around its axis, the gravitational fields of the Earth and the Moon, the bottom topography, the outlines of continents and islands, the difference in temperature indicators of water, its density, depth in different places in the ocean and even its physical and chemical composition.

Of all types of water flows, the most pronounced are the surface currents of the World Ocean, the depth of which is often several hundred meters. Their occurrence was influenced by trade winds constantly moving in tropical latitudes in the western east direction. These trade winds form the huge flows of the North and South Equatorial Currents near the equator. A smaller part of these flows returns to the east, forming a countercurrent (when the movement of water occurs in the opposite direction from the movement of air masses). Most of them, when colliding with continents and islands, turn to the north or south.

Warm and cold water currents

It must be taken into account that the concepts of “cold” or “warm” currents are conditional definitions. So, despite the fact that the temperature of the water flows of the Benguela Current, which flows along, is 20°C, it is considered cold. But the North Cape Current, which is one of the branches of the Gulf Stream, with temperatures from 4 to 6 ° C, is warm.

This happens because cold, warm and neutral currents got their names based on a comparison of the temperature of their water with the temperature of the surrounding ocean:

If the temperature indicators of the water flow coincide with the temperature of the surrounding waters, such a flow is called neutral;
If the current temperature is lower surrounding water, they are called cold. They usually flow from high latitudes to low latitudes (for example, the Labrador Current), or from areas where, due to high river flows, ocean water has a reduced salinity of surface waters;
If the temperature of the currents is warmer than the surrounding water, then they are called warm. They move from tropical to subpolar latitudes, for example, the Gulf Stream.

Main water flows

On this moment Scientists have recorded about fifteen main ocean water flows in the Pacific, fourteen in the Atlantic, seven in the Indian and four in the Arctic Ocean.

It is interesting that all currents of the Arctic Ocean move at the same speed - 50 cm/sec, three of them, namely the West Greenland, West Spitsbergen and Norwegian, are warm, and only the East Greenland is a cold current.

But almost everything ocean currents The Indian Ocean is classified as warm or neutral, with the Monsoon, Somali, Western Australian and Cape Agulhas current (cold) moving at a speed of 70 cm/sec, the speed of the others varies from 25 to 75 cm/sec. The water flows of this ocean are interesting because, together with the seasonal monsoon winds, which change their direction twice a year, the oceanic rivers also change their course: in winter they mainly flow to the west, in summer - to the east (a phenomenon characteristic only of the Indian Ocean ).

Since the Atlantic Ocean stretches from north to south, its currents also have a meridional direction. Water flows located in the north move clockwise, in the south - counterclockwise.

A striking example of the flow of the Atlantic Ocean is the Gulf Stream, which, starting in the Caribbean Sea, carries warm waters to the north, breaking up into several side streams along the way. When the waters of the Gulf Stream find themselves in the Barents Sea, they enter the Arctic Ocean, where they cool and turn south in the form of the cold Greenland Current, after which at some stage they deviate to the west and again join the Gulf Stream, forming a vicious circle.

The currents of the Pacific Ocean are mainly in a latitudinal direction and form two huge circles: northern and southern. Since the Pacific Ocean is extremely large, it is not surprising that its water flows have a significant impact on much of our planet.

For example, trade wind water flows transport warm waters from the western tropical shores to the eastern ones, which is why in the tropical zone West Side The Pacific Ocean is much warmer than the opposite side. But in the temperate latitudes of the Pacific Ocean, on the contrary, the temperature is higher in the east.

Deep Currents

For quite a long time, scientists believed that deep ocean waters were almost motionless. But soon special underwater vehicles discovered both slow and fast-flowing water streams at great depths.

For example, under the Equatorial Current of the Pacific Ocean at a depth of about one hundred meters, scientists have identified the underwater Cromwell Current, moving eastward at a speed of 112 km/day. Soviet scientists found a similar movement of water flows, but in the Atlantic Ocean: the width of the Lomonosov Current is about 322 km, and the maximum speed of 90 km/day was recorded at a depth of about one hundred meters. After this, another underwater flow was discovered in Indian Ocean, however, its speed turned out to be much lower - about 45 km/day.

The discovery of these currents in the ocean gave rise to new theories and mysteries, the main one of which is the question of why they appeared, how they were formed, and whether the entire area of the ocean is covered by currents or there is a point where the water is still.

The influence of the ocean on the life of the planet

The role of ocean currents in the life of our planet can hardly be overestimated, since the movement of water flows directly affects the planet’s climate, weather, and marine organisms. Many compare the ocean to a huge heat engine, which is set in motion. This machine creates a constant exchange of water between the surface and deep layers of the ocean, providing it with oxygen dissolved in the water and influencing the life of marine inhabitants.

This process can be traced, for example, by considering the Peruvian Current, which is located in Pacific Ocean. Thanks to the rise of deep waters, which lift phosphorus and nitrogen upward, animal and plant plankton successfully develop on the ocean surface, resulting in the organization of a food chain. Plankton is eaten by small fish, which, in turn, becomes a victim of larger fish, birds, marine mammals, which, with such food abundance, settle here, making the region one of the most highly productive areas of the World Ocean.

It also happens that a cold current becomes warm: the average ambient temperature rises by several degrees, causing warm tropical showers to fall on the ground, which, once in the ocean, kill fish accustomed to cold temperatures. The result is disastrous - it ends up in the ocean great amount dead small fish, big fish goes away, fishing stops, birds leave their nesting grounds. As a result local population deprived of fish, crops destroyed by rainfall, and profits from the sale of guano (bird droppings) as fertilizer. It can often take several years to restore the previous ecosystem.

They play a big role in shaping the climate on planet Earth, and are also largely responsible for the diversity of flora and fauna. Today we will get acquainted with the types of currents, the reasons for their occurrence, and consider examples.

It's no secret that our planet is washed by four Atlantic, Indian and Arctic seas. Naturally, the water in them cannot be stagnant, since this would long ago lead to environmental disaster. Thanks to the fact that it constantly circulates, we can live fully on Earth. Below is a map of ocean currents; it clearly shows all the movements of water flows.

What is an ocean current?

The current of the World Ocean is nothing more than the continuous or periodic movement of large masses of water. Looking ahead, let’s say right away that there are many of them. They differ in temperature, direction, depth penetration and other criteria. Ocean currents are often compared to rivers. But the movement river flows occurs only downward under the influence of gravity. But the circulation of water in the ocean occurs due to many different reasons. For example, wind, uneven density of water masses, temperature differences, the influence of the Moon and the Sun, changes in pressure in the atmosphere.

Causes

I would like to start my story with the reasons that give rise to the natural circulation of water. Even now there is practically no accurate information. This can be explained quite simply: the ocean system does not have clear boundaries and is in constant motion. Now the currents that are closer to the surface have been studied in more depth. Today, one thing is known for sure: the factors influencing water circulation can be both chemical and physical.

So, let's look at the main reasons for the occurrence of ocean currents. The first thing I want to highlight is the impact of the wind. It is thanks to him that surface and shallow currents function. Of course, wind has nothing to do with water circulation at great depths. The second factor is also important: the impact of outer space. In this case, currents arise due to the rotation of the planet. And finally, the third main factor that explains the causes of ocean currents is different densities of water. All ocean currents are different temperature conditions, salinity and other indicators.

Directional factor

Depending on the direction, ocean water circulation flows are divided into zonal and meridional. The first ones move west or east. Meridional currents go south and north.

There are also other types that are caused by such ocean currents called tidal currents. They are most powerful in shallow waters in the coastal zone, at river mouths.

Currents that do not change strength and direction are called stable, or established. These include the Northern Trade Wind and Southern Trade Wind. If the movement of a water flow changes from time to time, then it is called unstable, or unsteady. This group is represented by surface currents.

Surface currents

The most noticeable of all are surface currents, which are formed due to the influence of wind. Under the influence of the trade winds that constantly blow in the tropics, huge flows of water are formed in the equator region. They form the Northern and Southern Equatorial (trade wind) currents. A small part of these turns back and forms a countercurrent. The main flows are diverted to the north or south when colliding with continents.

Warm and cold currents

The types of ocean currents play a critical role in the distribution of climate zones on Earth. Warm streams are usually called water streams that carry water with temperatures above zero. Their movement is characterized by a direction from the equator to high latitudes. These are the Alaska Current, the Gulf Stream, Kuroshio, El Niño, etc.

Cold currents transport water in the opposite direction compared to warm ones. Where a current with a positive temperature occurs on their path, an upward movement of water occurs. The largest are considered to be Californian, Peruvian, etc.

The division of currents into warm and cold is conditional. These definitions reflect the ratio of the water temperature in the surface layers to the ambient temperature. For example, if the flow is colder than the rest of the water mass, then such a flow can be called cold. If on the contrary, then it is considered a warm current.

Ocean currents determine many things on our planet. By constantly mixing the water in the World Ocean, they create conditions favorable for the life of its inhabitants. And our lives directly depend on this.

As a rule, their movement occurs in a strictly defined direction and can have a large extent. The current map below displays them in full.

Water flows are of considerable size: they can reach tens or even hundreds of kilometers in width, and have greater depth(hundreds of meters). The speed of ocean and sea currents varies - on average, it is 1-3 thousand m/hour. But there are also so-called high-speed ones. Their speed can reach 9,000 m/hour.

Where do currents come from?

The causes of water currents can be a sharp change in water temperature due to heating, or, conversely, cooling. They are also affected by different densities, for example, in a place where several currents (sea and ocean) collide, precipitation, evaporation. But basically, cold and warm currents arise due to the action of winds. Therefore, the direction of the largest oceanic water flows depends mainly on the air currents of the planet.

Currents formed by winds

An example of constantly blowing winds is the trade winds. They begin their life from 30 latitudes. The currents created by these air masses are called trade winds. There are the Southern Trade Wind and Northern Trade Wind Currents. In the temperate zone, such water flows are formed under the influence of They form one of the largest currents on the planet. In the northern one there are two water flow circulations: cyclonic and anticyclonic. Their formation is influenced by the inertial force of the Earth.

Types of currents

Mixed, neutral, cold and warm currents are types of circulating masses on the planet. When the temperature of the stream water is lower than the temperature of the surrounding water, this is If, on the contrary, this is its warm variety. Neutral currents do not differ from the temperature of surrounding waters. And mixed ones can change throughout their entire length. It is worth noting that there is no constant temperature indicator for currents. This figure is very relative. It is determined by comparing the surrounding water masses.

In tropical latitudes, warm currents circulate along the eastern edges of the continents. Cold ones - along the western ones. In temperate latitudes, warm currents pass through western shores, and cold ones - according to the east. The variety can be determined by another factor. So, there is an easier rule: cold currents go towards the equator, and warm currents - from it.

Meaning

It’s worth talking about it in more detail. Cold and warm currents play an important role on planet Earth. The significance of circulating water masses is that due to their movement, solar heat is redistributed on the planet. Warm currents increase the air temperature of nearby areas, while cold currents lower it. Formed on water, water flows have a serious impact on the mainland. In areas where warm currents constantly pass, the climate is humid, where there are cold currents, on the contrary, it is dry. Ocean currents also contribute to the migration of oceanic ichthyofauna. Under their influence, plankton moves, and fish migrate after them.

We can give examples of warm and cold currents. Let's start with the first variety. The largest water flows are: Gulf Stream, Norwegian, North Atlantic, Northern and Southern Trade Winds, Brazilian, Kuroshio, Madagascar and others. The coldest ocean currents: Somali, Labrador, California.

Major currents

The most close-up of the planet- Gulf Stream. This is a meridional circulating flow that carries 75 million tons of water every second. The width of the Gulf Stream is from 70 to 90 km. Thanks to him, Europe receives a comfortable mild climate. It follows from this that cold and warm currents largely affect the life of all living organisms on the planet.

Of the zonal, cold watercourses, the flow of the Western winds is of greatest importance. In the southern hemisphere, off the coast of Antarctica, there are no island or continental clusters. A large area of the planet is completely filled with water. The Indian and Quiet streams converge here into one stream and unite into a separate huge body of water. Some scientists recognize its existence and call it Southern. It is here that the largest flow of water is formed - the current of the Western Winds. Every second it carries a flow of water that is three times larger than the Gulf Stream.

Canary Current: warm or cold?

Currents can change their temperature. For example, the flow starts from cold masses. Then it warms up and becomes warm. One of the options for such a circulating water mass is the Canary Current. It originates in the northeast Atlantic Ocean. It is directed by a cold stream along Europe. Walking along west coast Africa is getting warm. This current has long been used by sailors to travel.

4. Ocean currents.

The constant and continuous movement of water masses is the eternal dynamic state of the ocean. If rivers on Earth flow to the sea along their inclined channels under the influence of gravity, then currents in the ocean are caused by various reasons. The main causes of sea currents are: wind (drift currents), unevenness or changes in atmospheric pressure (barogradient), attraction of water masses by the Sun and Moon (tidal), differences in water densities (due to differences in salinity and temperature), differences in levels created by influx of river water from continents (runoff).

Not every movement of ocean water can be called a current. In oceanography, sea currents are the forward movement of water masses in the oceans and seas..

Two physical forces cause currents - friction and gravity. Excited by these forces currents are called frictional And gravitational.

Currents in the World Ocean are usually caused by several reasons. For example, the mighty Gulf Stream is formed by the merger of density, wind and discharge currents.

The initial direction of any flow soon changes under the influence of the rotation of the Earth, frictional forces, configuration coastline and bottom.

According to the degree of stability, currents are distinguished sustainable(for example, North and South trade wind currents), temporary(surface currents of the North Indian Ocean caused by monsoons) and periodic(tidal).

Based on their position in the ocean water column, currents can be superficial, subsurface, intermediate, deep And bottom. Moreover, the definition of “surface current” sometimes refers to a fairly thick layer of water. For example, the thickness of inter-trade wind countercurrents in the equatorial latitudes of the oceans can be 300 m, and the thickness of the Somali Current in the northwestern part of the Indian Ocean reaches 1000 meters. It is noted that deep currents are most often directed in the opposite direction compared to the surface waters moving above them.

Currents are also divided into warm and cold. Warm currents move water masses from low latitudes to higher ones, and cold- in the opposite direction. This division of currents is relative: it characterizes only the surface temperature of moving waters in comparison with the surrounding water masses. For example, in the warm North Cape Current (Barents Sea) the temperature of the surface layers is 2–5 °C in winter and 5–8 °C in summer, and in the cold Peruvian Current (Pacific Ocean) - all year round from 15 to 20 °C, in the cold Canary Current (Atlantic) – from 12 to 26 °C.

The main source of data is ARGO buoys. The fields were obtained using optimal analysis.

Some ocean currents combine with other currents to form a basin-wide gyre.

In general, the constant movement of water masses in the oceans is complex system cold and warm currents and countercurrents, both surface and deep.

The most famous for residents of America and Europe is, of course, the Gulf Stream. Translated from English, this name means Current from the Bay. Previously, it was believed that this current begins in the Gulf of Mexico, from where it rushes through the Strait of Florida into the Atlantic. Then it turned out that the Gulf Stream carries only a small fraction of its flow from this bay. Having reached the latitude of Cape Hatteras at Atlantic coast USA, the current receives a powerful influx of water from the Sargasso Sea. This is where the Gulf Stream itself begins. A peculiarity of the Gulf Stream is that when it enters the ocean, this current deviates to the left, whereas under the influence of the Earth’s rotation it should deviate to the right.

The parameters of this powerful current are very impressive. The surface speed of water in the Gulf Stream reaches 2.0–2.6 meters per second. Even at a depth of 2 km, the speed of the water layers is 10–20 cm/s. When leaving the Strait of Florida, the current carries out 25 million cubic meters of water per second, which is 20 times more than the total flow of all the rivers of our planet. But after adding the flow of water from the Sargasso Sea (Antilles Current), the power of the Gulf Stream already reaches 106 million cubic meters of water per second. This powerful stream moves northeast to the Great Newfoundland Bank, and from here it turns south and, together with the Slope Current that separated from it, is included in the North Atlantic water cycle. The depth of the Gulf Stream is 700–800 meters, and its width reaches 110–120 km. The average temperature of the surface layers of the current is 25–26 °C, and at depths of about 400 m it is only 10–12 °C. Therefore, the idea of the Gulf Stream as a warm current is created precisely by the surface layers of this stream.

Let us note another current in the Atlantic – the North Atlantic. It runs across the ocean to the east, towards Europe. The North Atlantic Current is less powerful than the Gulf Stream. The water flow here is from 20 to 40 million cubic meters per second, and the speed is from 0.5 to 1.8 km/h, depending on the location. However, the influence of the North Atlantic Current on the climate of Europe is very noticeable. Together with the Gulf Stream and other currents (Norwegian, North Cape, Murmansk), the North Atlantic Current softens the climate of Europe and the temperature regime of the seas washing it. The warm Gulf Stream current alone cannot have such an impact on the climate of Europe: after all, the existence of this current ends thousands of kilometers from the shores of Europe.

Now let's return to the equatorial zone. Here the air heats up much more than in other areas of the globe. The heated air rises and reaches upper layers troposphere and begins to spread towards the poles. Approximately in the area of 28-30° northern and southern latitudes, the cooled air begins to descend. More and more new air masses flowing from the equator region create excess pressure in subtropical latitudes, while above the equator itself, due to the outflow of heated air masses, the pressure is constantly reduced. From areas of high pressure, air rushes to areas of low pressure, that is, to the equator. The rotation of the Earth around its axis deflects the air from the direct meridional direction to the west. This creates two powerful flows of warm air, called trade winds. In the tropics of the Northern Hemisphere, trade winds blow from the northeast, and in the tropics of the Southern Hemisphere - from the southeast.

For simplicity of presentation, we do not mention the influence of cyclones and anticyclones in the temperate latitudes of both hemispheres. It is important to emphasize that the trade winds are the most stable winds on Earth; they blow constantly and cause warm equatorial currents that move huge masses of ocean water from east to west.

Equatorial currents benefit navigation by helping ships cross the ocean from east to west more quickly. At one time, H. Columbus, without knowing anything in advance about the trade winds and equatorial currents, felt their powerful effect during his sea voyages.

Based on the constancy of equatorial currents, the Norwegian ethnographer and archaeologist Thor Heyerdahl put forward a theory about the initial settlement of the Polynesian islands by the ancient inhabitants of South America. To prove the possibility of sailing on primitive ships, he built a raft, which, in his opinion, was similar to the watercraft that the ancient inhabitants of South America could use when crossing the Pacific Ocean. On this raft, called Kon-tiki, Heyerdahl, along with five other daredevils, made a perilous voyage from the coast of Peru to the Tuamotu archipelago in Polynesia in 1947. In 101 days, he swam a distance of about 8 thousand kilometers along one of the branches of the southern equatorial current. The brave men underestimated the power of the wind and waves and almost paid for it with their lives. Up close, the warm equatorial current, driven by the trade winds, is not at all gentle as one might think.

Let us briefly look at the characteristics of other currents in the Pacific Ocean. Part of the waters of the North Equatorial Current in the area of the Philippine Islands turns north, forming the warm Kuroshio Current (in Japanese, “Dark Water”), which in a powerful stream flows past Taiwan and the southern Japanese islands to the northeast. The width of Kuroshio is about 170 km, and the penetration depth reaches 700 m, but in general, in terms of fashionability, this current is inferior to the Gulf Stream. About 36°N Kuroshio turns into the ocean, moving into the warm North Pacific Current. Its waters flow east, cross the ocean approximately at the 40th parallel and warm the coast of North America all the way to Alaska.

The turn of Kuroshio from the coast was noticeably influenced by the influence of the cold Kuril Current, approaching from the north. This current is called Oyashio (“Blue Water”) in Japanese.

There is another remarkable current in the Pacific Ocean - El Niño (Spanish for “The Baby”). This name was given because the El Niño current approaches the shores of Ecuador and Peru before Christmas, when the arrival of the baby Christ into the world is celebrated. This current does not occur every year, but when it nevertheless approaches the shores of the mentioned countries, it is not perceived as anything other than a natural disaster. The fact is that too warm El Niño waters have a detrimental effect on plankton and fish fry. As a result, the catches of local fishermen are reduced tenfold.

Scientists believe that this treacherous current can also cause hurricanes, rainstorms and other natural disasters.

In the Indian Ocean, waters move along an equally complex system of warm currents, which are constantly influenced by monsoons - winds that blow from the ocean to the continent in summer, and in the opposite direction in winter.

In the strip of forties latitudes of the Southern Hemisphere in the World Ocean, winds constantly blow in the direction from west to east, which gives rise to cold surface currents. The largest of these currents, with almost constant waves, is the Western Wind Current, which circulates in a direction from west to east. It is no coincidence that sailors call the strip of these latitudes from 40° to 50° on both sides of the equator the “Roaring Forties”.

Arctic Ocean for the most part covered with ice, but this did not make its waters motionless at all. The currents here are directly observed by scientists and specialists from drifting polar stations. Over the course of several months of drift, the ice floe on which the polar station is located sometimes travels many hundreds of kilometers.

The largest cold current in the Arctic is the East Greenland Current, which carries the waters of the Arctic Ocean into the Atlantic.

In areas where warm and cold currents meet, phenomenon of rising deep waters (upwelling), in which vertical water flows bring deep water to the ocean surface. Together with them, nutrients that are contained in the lower water horizons rise.

In the open ocean, upwelling occurs in areas where currents diverge. In such places, the ocean level drops and deep water inflows. This process develops slowly - a few millimeters per minute. The most intense rise of deep waters is observed in coastal areas(10 – 30 km from the coastline). There are several permanent upwelling areas in the World Ocean that affect the overall dynamics of the oceans and affect fishing conditions, for example: the Canary and Guinea upwellings in the Atlantic, the Peruvian and California upwellings in the Pacific Ocean, and the Beaufort Sea upwelling in the Arctic Ocean.

Deep currents and rises of deep waters are reflected in the nature of surface currents. Even such powerful currents as the Gulf Stream and Kuroshio sometimes wax and wane. The temperature of the water changes in them and deviations from a constant direction and huge eddies are formed. Similar changes in sea currents influence the climate of the corresponding land regions, as well as the direction and distance of migration of certain species of fish and other animal organisms.

Despite the apparent chaos and fragmentation of sea currents, in fact they represent a certain system. Currents ensure that they have the same salt composition and unite all waters into a single World Ocean.