ocean currents

The warm current of the Gulf Stream has long been known and well studied. It runs along the eastern shores North America from southwest to northeast.

The Gulf Stream is warm because its temperature is several degrees higher than the temperature of the surrounding water. This current is formed at the confluence of the waters flowing from the Gulf of Mexico and the waters driven by the wind from the coast of Africa.

Its length is 3,000 km, its width is hundreds of kilometers, and its speed is up to 10 km/h.
Approximately at 45 ° N. sh. The Gulf Stream passes into the North Atlantic Current, part of the waters of which are directed to the Arctic Ocean. Under their influence, the Barents Sea does not freeze and the port of Murmansk is accessible to ships all year round.

From the Arctic Ocean to the Atlantic, along the shores of the Labrador Peninsula, there is a cold Labrador Current . The temperature of this current is lower than the temperature of the surrounding water.

(http://kalach-gimnazia.narod.ru/sites/kuznecov/ocean.htm)

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

If the factors causing the currents are constant, then a constant current is formed, and if they are episodic, then a short-term, random current is formed. According to the prevailing direction, the currents are divided into meridional, carrying their waters to the north or south, and zonal, spreading latitudinally (approx. from geoglobus.ru.) Currents, the water temperature in which is higher than the average temperature for the same latitudes, are called warm below - cold , and currents having the same temperature as the waters surrounding it - neutral .
Monsoon currents change their direction from season to season, depending on how the coastal monsoon winds blow. Countercurrents are moving towards the 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 they extend to a depth of no more than 300 m.

In the World Ocean, there are constantly thousands of large and small currents that go around the continents and merge into five giant rings. The system of currents of the World Ocean is called circulation and is connected, first of all, with the general circulation of the atmosphere. Ocean currents redistribute solar heat absorbed by masses of water. Warm water, heated by the sun's rays at the equator, they carry to high latitudes, and cold water from the polar regions, due to currents, gets to the south. Warm currents increase air temperature, while cold currents, on the contrary, decrease it. Territories washed by warm currents are characterized by a warm and humid climate, and those near which cold currents pass are cold and dry.

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

Gulfstream - one of the largest warm currents in the Northern Hemisphere. It passes through the Gulf of Mexico (Eng. Gulf Stream - the course of the Gulf) and carries warm tropical waters. Atlantic Ocean to high latitudes. This giant stream 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 most full-flowing river in the world, carries 220 thousand tons of water). At a depth of about 1 km under the Gulf Stream, a countercurrent is observed.

(http://www.geoglobus.ru/earth/geo6/earth12.php)

Which moves with a certain cyclicity and frequency. Differs in a constancy of physical and chemical properties and a specific geographical location. It can be cold or warm, depending on belonging to the hemispheres. Each such flow is characterized by increased density and pressure. The flow rate of water masses is measured in sverdrupa, in a broader sense - in units of volume.

Varieties of currents

First of all, cyclically directed water flows are characterized by such features as stability, speed of movement, depth and width, chemical properties, acting forces, etc. Based on the international classification, flows are of three categories:

1. Gradient. Occur when exposed to isobaric layers of water. A gradient ocean current is a flow characterized by horizontal movements of the isopotential surfaces of the water area. According to their initial features, they are divided into density, baric, stock, compensation and seiche. As a result of the runoff flow, precipitation and ice melting are formed.

2. Wind. Determined by the slope of the sea level, the strength of the air flow and fluctuations in mass density. A subspecies is drifting. This is a flow of water caused purely by the action of the wind. Only the surface of the pool is exposed to oscillations.

3. Tidal. They appear most strongly in shallow water, in estuaries and near the coast.

A separate type of flow is inertial. It is caused by the action of several forces at once. According to the variability of movement, constant, periodic, monsoon and trade wind flows are distinguished. The last two are determined by direction and speed seasonally.

Causes of ocean currents

At the moment, the circulation of waters in the world's waters is only beginning to be studied in detail. By and large, specific information is known only about surface and shallow currents. The main snag is that the oceanographic system has no clear boundaries and is in constant motion. It is a complex network of flows due to various physical and chemical factors.

Nevertheless, the following causes of ocean currents are known today:

1. Cosmic impact. This is the most interesting and at the same time difficult to learn process. In this case, the flow is determined by the rotation of the Earth, the impact on the atmosphere and hydrological system of the planet of cosmic bodies, etc. A striking example is the tides.

2. Wind exposure. The circulation of water depends on the strength and direction of air masses. In rare cases, we can talk about deep currents.

3. Density difference. Streams are formed due to uneven distribution of salinity and temperature of water masses.

atmospheric effect

In the world's waters, this kind of influence is caused by the pressure of heterogeneous masses. Coupled with cosmic anomalies, water flows in the oceans and smaller basins change not only their direction, but also their power. This is especially noticeable in the seas and straits. A prime example is the Gulf Stream. At the beginning of his journey, he is characterized by increased speed.

During the Gulf Stream, it is accelerated simultaneously by opposite and fair winds. This phenomenon forms a cyclic pressure on the layers of the pool, accelerating the flow. From here, in a certain period of time, there is a significant outflow and inflow of a large amount of water. The lower the atmospheric pressure, the higher the tide.

When the water level drops, the slope of the Florida Strait becomes less. Because of this, the flow rate is significantly reduced. Thus, it can be concluded that high blood pressure reduces the flow.

wind impact

The connection between the flows of air and water is so strong and at the same time simple that it is hard not to notice even with the naked eye. Since ancient times, navigators have been able to calculate the appropriate ocean current. This became possible thanks to the work of the scientist W. Franklin on the Gulf Stream, dating back to the 18th century. A few decades later, A. Humboldt indicated precisely the wind in the list of the main extraneous forces affecting the water masses.

From a mathematical point of view, the theory was substantiated by the physicist Zeppritz in 1878. He proved that in the World Ocean there is a constant transfer of the surface layer of water to deeper levels. In this case, the wind becomes the main influencing force on the movement. The current velocity in this case decreases in proportion to the depth. The determining condition for the constant circulation of waters is the infinitely long duration of the action of the wind. The only exceptions are the trade winds of air, which cause the movement of water masses in the equatorial strip of the World Ocean seasonally.

Density difference

The impact of this factor on water circulation is the most important cause of currents in the World Ocean. Large-scale studies of the theory were carried out by the international expedition Challenger. Subsequently, the work of scientists was confirmed by Scandinavian physicists.

The heterogeneity of the densities of water masses is the result of several factors at once. They have always existed in nature, representing a continuous hydrological system of the planet. Any deviation in water temperature entails a change in its density. In this case, an inversely proportional relationship is always observed. The higher the temperature, the lower the density.

Also, the difference in physical indicators is affected by state of aggregation water. Freezing or evaporation increases density, precipitation decreases it. Affects the strength of the current and salinity of water masses. It depends on the melting of ice, precipitation and the level of evaporation. In terms of density, the World Ocean is quite uneven. This applies to both surface and deep layers of the water area.

Currents of the Pacific Ocean

The general scheme of flows is determined by the circulation of the atmosphere. Thus, the east trade wind contributes to the formation of the North Current. It crosses the waters from the Philippine Islands to the coast Central America. It has two branches that feed the Indonesian Basin and the Equatorial Ocean Current of the Pacific Ocean.

The largest currents in the water area are the Kuroshio, Alaska and California currents. The first two are warm. The third stream is the cold ocean current of the Pacific Ocean. The basin of the Southern Hemisphere is formed by the Australian and Tradewind currents. A little to the east of the center of the water area, the Equatorial countercurrent is observed. Off the coast of South America, there is a branch of the cold Peruvian current.

During the summer, the El Niño ocean current operates near the equator. It pushes back the cold masses of water of the Peruvian Stream, forming a favorable climate.

Indian Ocean and its currents

The northern part of the basin is characterized by a seasonal change of warm and cold flows. This constant dynamics is caused by the action of the monsoon circulation.

In winter, the Southwest Current dominates, which originates in the Bay of Bengal. A little further south is Western. This ocean current of the Indian Ocean crosses the water area from the coast of Africa to the Nicobar Islands.

In summer, the east monsoon contributes to a significant change surface water. The equatorial countercurrent shifts to a depth and noticeably loses its strength. As a result, its place is occupied by powerful warm Somali and Madagascar currents.

Arctic ocean circulation

The main reason for the development of the undercurrent in this part of the World Ocean is a powerful influx of water masses from the Atlantic. The fact is that the centuries-old ice cover does not allow the atmosphere and cosmic bodies to influence the internal circulation.

The most important course of the Arctic Ocean is the North Atlantic. It drives huge volumes of warm masses, preventing the water temperature from dropping to critical levels.

The Transarctic current is responsible for the direction of ice drift. Other major streams include the Yamal, Svalbard, North Cape and Norwegian currents, as well as a branch of the Gulf Stream.

currents of the atlantic basin

The salinity of the ocean is extremely high. The zonality of water circulation is the weakest among other basins.

Here the main ocean current is the Gulf Stream. Thanks to him, the average water temperature is kept at around +17 degrees. This warm ocean warms both hemispheres.

Also the most important streams of the basin are the Canary, Brazilian, Benguela and Tradewind currents.

Many people know about the Gulf Stream, which, carrying huge masses of water from the equatorial latitudes to the polar ones, literally warms the north of Western Europe and Scandinavia. But few people know that there are other warm and cold currents of the Atlantic Ocean. How do they affect the climate of coastal areas? Our article will tell about it. In fact, there are a lot of currents in the Atlantic. We briefly list them for general development. These are the West Greenland, Angola, Antilles, Benguela, Guinea, Lomonosov, Brazilian, Guiana, Azores, Gulf Stream, Irminger, Canary, East Icelandic, Labrador, Portuguese, North Atlantic, Florida, Falkland, North Equatorial, South Equatorial, and also the Equatorial countercurrent . Not all of them have a big impact on the climate. Some of them are generally part or fragments of the main, larger currents. That's about them and will be discussed in our article.

Why do currents form?

In the World Ocean, large invisible "rivers without banks" are constantly circulating. Water in general is a very dynamic element. But everything is clear with rivers: they flow from the source to the mouth due to the difference in heights between these points. But what makes huge masses of water move within the ocean? Of the many reasons, two are the main ones: trade winds and changes in atmospheric pressure. Because of this, the currents are divided into drift and barogradient. The first are formed by trade winds - winds constantly blowing in one direction. Most of these currents Mighty rivers carry into the seas a large amount of water, different from sea water in density and temperature. Such currents are called stock, gravity and friction. Consideration should also be given to the great north-south extent of the Atlantic Ocean. The currents in this water area are therefore more meridional than latitudinal.

What are trade winds

Winds are the main reason for the movement of huge masses of water in the oceans. But what are the trade winds? The answer is to be found in the equatorial regions. The air warms up there more than in other latitudes. It rises and spreads along the upper layers of the troposphere towards the two poles. But already at a latitude of 30 degrees, having cooled thoroughly, it descends. Thus, a circulation of air masses is created. In the equatorial region, a zone of low pressure arises, and in tropical latitudes, a zone of high pressure. And here the rotation of the Earth around its axis manifests itself. If not for it, the trade winds would blow from the tropics of both hemispheres to the equator. But, as our planet rotates, the winds are deflected, becoming westerly. This is how the trade winds form the main currents of the Atlantic Ocean. In the Northern Hemisphere, they move clockwise, and in the Southern Hemisphere, they move counterclockwise. This is because in the first case, the trade winds blow from the northeast, and in the second - from the southeast.

Climate impact

Based on the fact that the main currents originate in the equatorial and tropical regions, it would be reasonable to assume that they are all warm. But this does not always happen. The warm current in the Atlantic Ocean, having reached the polar latitudes, does not fade away, but, having made a smooth circle, reverses, but has already cooled down considerably. This can be seen in the example of the Gulf Stream. It carries warm masses of water from the Sargasso Sea to northern Europe. Then, under the influence of the rotation of the Earth, it deviates to the west. Under the name of the Labrador Current, it descends along the coast of the North American continent to the south, cooling the coastal regions of Canada. It should be said that these masses of water are called warm and cold conditionally - with respect to temperature environment. For example, in the North Cape current in winter the temperature is only +2 °С, and in summer it is maximum +8 °С. But it is called warm because the water in the Barents Sea is even colder.

Major currents of the Atlantic in the Northern Hemisphere

Here, of course, one cannot fail to mention the Gulf Stream. But other currents passing through the Atlantic Ocean also have an important influence on the climate of nearby territories. Near Cape Verde (Africa), the northeast trade wind is born. It drives huge warm masses of water to the west. Crossing the Atlantic Ocean, they connect with the Antilles and Guiana currents. This enhanced jet moves towards the Caribbean Sea. After that, the waters rush to the north. This continuous clockwise movement is called warm North Atlantic Current. Its edge at high latitudes is indefinite, blurred, and at the equator it is more distinct.

The mysterious "Current from the Gulf" (Golf-Stream)

This is the name of the course of the Atlantic Ocean, without which Scandinavia and Iceland would turn, based on their proximity to the pole, into the land of eternal snows. It used to be thought that the Gulf Stream was born in the Gulf of Mexico. Hence the name. In fact, only a small part of the Gulf Stream flows out of the Gulf of Mexico. The main flow comes from the Sargasso Sea. What is the mystery of the Gulf Stream? The fact that, contrary to the rotation of the Earth, it does not flow from west to east, but in the opposite direction. Its capacity exceeds the discharge of all the rivers of the planet. The speed of the Gulf Stream is impressive - two and a half meters per second on the surface. The current can be traced at a depth of 800 meters. And the width of the stream is 110-120 kilometers. Due to the high speed of the current, the water from the equatorial latitudes does not have time to cool. The surface layer has a temperature of +25 degrees, which, of course, plays a paramount role in shaping the climate of Western Europe. The mystery of the Gulf Stream is also that it does not wash the continents anywhere. There is always a strip of colder water between it and the shore.

Atlantic Ocean: Currents of the Southern Hemisphere

From the African continent to the American continent, the trade wind drives a jet, which, due to low pressure in the equatorial region, begins to deviate to the south. Thus begins a similar northern cycle. However, the South Equatorial Current moves counterclockwise. It also runs across the entire Atlantic Ocean. Currents Guiana, Brazilian (warm), Falkland, Benguela (cold) are part of this cycle.

Rivers in the middle of the ocean

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

It has been established that water flows do not move straight, but deviating slightly to the side, they obey the Coriolis force. In the Northern Hemisphere they almost always move clockwise, in the Southern Hemisphere it is 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 strongest currents were recorded along the eastern coasts of the continents.

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

Of all the 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 a west-east direction. These trade winds form huge streams 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, colliding with the continents and islands, turns to the north or south.

Warm and cold water streams

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

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

• If the temperature indicators of the water flow coincide with the temperature of the waters surrounding it, such a flow is called neutral;
• If the temperature of the currents is lower than the 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 the large flow of rivers, ocean water has a reduced salinity of surface water;
• If the temperature of the currents is warmer than the surrounding water, then they are called warm. They move from the tropics to subpolar latitudes, such as the Gulf Stream.

Main water flows

At the moment, scientists have recorded about fifteen major oceanic water flows in the Pacific, fourteen in the Atlantic, seven in the Indian and four in the Arctic Ocean.

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

But almost all the oceanic currents of the Indian Ocean are warm or neutral, while the Monsoon, Somali, West Australian and the Cape of Needles (cold) move at a speed of 70 cm / s, the speed of the rest varies from 25 to 75 cm / s. The water flows of this ocean are interesting because, along with the seasonal monsoon winds, which change their direction twice a year, ocean rivers also change their course: in winter they mainly flow west, in summer - 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 streams located in the north move clockwise, in the south - against it.

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 end up in the Barents Sea, they enter the Arctic Ocean, where they cool and turn south in the form of a cold Greenland Current, after which at some stage they deviate to the west and again adjoin the Gulf Stream, forming a vicious circle.

The currents of the Pacific Ocean are mainly latitudinal 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 most of our planet.

For example, trade winds move warm water from the western tropical coasts to the eastern ones, which is why the western part of the Pacific Ocean in the tropical zone 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 the deep ocean waters were almost motionless. But soon, special underwater vehicles discovered both slow and fast-flowing water flows at great depths.

For example, under the Equatorial Pacific Ocean at a depth of about one hundred meters, scientists have identified the Cromwell underwater stream moving eastward at a speed of 112 km / day.

A similar movement of water flows, but already in the Atlantic Ocean, was found by Soviet scientists: 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 that, another underwater stream was discovered in the 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 of which is the question of why they appeared, how they formed, and whether the entire ocean area 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 cannot 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 powered by solar energy. This machine creates a continuous water exchange between the surface and deep layers of the ocean, providing it with oxygen dissolved in water and affecting the life of marine life.

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, as a result of which the food chain is organized. 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, which causes warm tropical showers to fall on the ground, which, once in the ocean, kill fish accustomed to cold temperatures. The result is deplorable - a huge amount of dead small fish ends up in the ocean, large fish leave, fishing stops, birds leave their nests. As a result, the local population is deprived of fish, crops that were beaten by downpours, and profits from the sale of guano (bird droppings) as fertilizer. It can often take several years to restore the former ecosystem.

Where do currents come from?

The causes of water currents may be a sharp change in water temperature due to heating, or, conversely, cooling. They are also affected by different densities, for example, at a place where several flows (marine and oceanic) collide, precipitation, evaporation. But mostly 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 the action of the winds

Trade winds are an example of constantly blowing winds. They start their life from the 30th latitude. The currents that are created by these air masses are called trade winds. Allocate the southern trade wind and the northern trade wind current. In the temperate zone, such water flows are formed under the influence of westerly winds. They form one of the largest currents on the planet. There are two cycles of water flow in the northern and southern hemispheres: cyclonic and anticyclonic. Their formation is influenced by the inertial force of the Earth.

Varieties of currents

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

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

Meaning

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

Examples of warm and cold currents can be given. Let's start with the first variety. The largest are such water flows: Gulf Stream, Norwegian, North Atlantic, North and South Tradewinds, Brazilian, Kurosio, Madagascar and others. The coldest currents of the oceans: Somali, Labrador, California.

major currents

The world's largest warm current is the 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 gets a comfortable mild climate. From this it follows that the cold and warm current largely affects the life of all living organisms on the planet.

From zonal, cold streams, highest value has a westerly wind. In the southern hemisphere, not far from the coast of Antarctica, there are no island or mainland clusters. A large area of ​​the planet is completely filled with water. The Indian, Pacific and Atlantic oceans converge here in one stream, connecting 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 course of the Western winds. Every second it carries a stream of water that is three times the size of the Gulf Stream.

Canary current: warm or cold?

Currents can change their temperature. For example, the flow begins with cold masses. Then it warms up and becomes warm. One of the variants of such a circulating water mass is the Canary Current. It originates in the northeast of the Atlantic Ocean. It is directed by a cold stream along the Iberian Peninsula of Europe. Passing along the western coast of Africa, it becomes warm. This current has long been used by navigators to travel.

The most powerful cold current of the West Winds arises, which forms a ring around Antarctica. Also, the direction of the currents is affected by the position, the outlines of their banks. In depth, currents are formed due to the different density of water. More dense waters move towards less dense ones and create powerful currents at depth. The direction of sea currents is greatly influenced by the rotation of the Earth. Ocean currents affect nature and. They redistribute cold and heat between latitudes, as well as gases and dissolved nutrients. With the help of currents, animals and plants move, populate new territories. The Canary Current - the cold current of the Atlantic Ocean, moves from north to south, skirting the Iberian Peninsula and Northwest Africa. The width of the Canary Current is 400-600 km. The Labrador Current is a cold sea current in the North Atlantic Ocean. Mixed with the warm waters of the Gulf Stream, each spring carries icebergs from Greenland to the trans-Atlantic crossing. The Bengal current is a cold current of the Atlantic Ocean off the western coast of Africa. The Falkland current is a cold current of the Atlantic Ocean off the coast of South America, a branch of the West Winds current. Carries a lot of icebergs. The current of the Western Winds is the most powerful cold current of the World Ocean, also called the Antarctic. Crosses three oceans - Atlantic, Indian and Pacific. This current covers the Earth in a continuous ring, the cold Benguela, West Australian and Peruvian currents branch off from it. Its length exceeds 30 thousand km, the average width is about 1000 km. The current of the West Winds penetrates almost to the very bottom of the ocean to a depth of 4.5 km. The current speed is on average 2 km/h. It is characterized by strong bends arising under the influence of the contours of the continents and the bottom topography. The Antarctic Circumpolar Current is a powerful source of energy, it forms cyclones and anticyclones that shape the weather on the entire planet. The Somali current is a cold current of the Indian Ocean, off the eastern coast of the Somali peninsula in Africa. Caused by monsoon winds, it changes its direction depending on the season. The California current is the cold current of the Pacific Ocean. Passes along the coast of California. The Peruvian current is a cold current of the Pacific Ocean that runs from south to north near the western coast of the South American mainland. East Greenland - a cold current of the Arctic Ocean, passing off the eastern coast of Greenland. All year round carries the ice of the Arctic Basin and icebergs in the summer months.

Water masses that continuously move through the oceans are called currents. They are so strong that no continental river can compare with them.

What are the types of currents?

A few years ago, only currents moving along the surface of the seas were known. They are called superficial. They flow at a depth of up to 300 meters. Now we know that deep currents arise in deeper areas.

How do surface currents occur?

Surface currents are caused by constantly blowing winds - trade winds - and reach speeds of 30 to 60 kilometers per day. These include equatorial currents (directed to the west), off the eastern coast of the continents (directed towards the poles) and others.

What are trade winds?

The trade winds are air currents (winds) that are stable throughout the year in the tropical latitudes of the oceans. In the Northern Hemisphere, these winds are directed from the northeast, in the Southern Hemisphere - from the southeast. Due to the rotation of the Earth, they always deviate to the west. The winds that blow in the Northern Hemisphere are called the northeast trade winds, and in the Southern Hemisphere they are called the southeast. Sailing ships use these winds to reach their destination faster.

What are equatorial currents?

Trade winds blow constantly and so strongly that they divide the ocean waters on both sides of the equator into two powerful westerly currents, which are called equatorial. On the way, they have the eastern coasts of parts of the world, so these currents change direction to the north and south. Then they fall into other wind systems and break up into small currents.

How do deep currents form?

Deep currents, unlike surface currents, are not caused by winds, but by other forces. They depend on the density of water: cold and salty water denser than warm water and less salty, and therefore sinks lower to the seabed. Deep currents are caused by the fact that the cooled salt water in the northern latitudes sinks and continues to move above the seabed. A new, warm surface current begins its movement from the south. A cold deep current carries water towards the equator, where it warms up again and rises up. Thus, a cycle is formed. Deep currents move slowly, so it sometimes takes years before they rise to the surface.

What is worth knowing about the equator?

The equator is an imaginary line that passes through the center of the Earth perpendicular to the axis of its rotation, that is, it is equally distant from both poles and divides our planet into two hemispheres - Northern and Southern. The length of this line is about 40,075 kilometers. The equator is located at the zero degree of geographic latitude.

Why does the salt content of sea water change?

The salt content of sea water increases when the water evaporates or freezes. There is a lot of ice in the North Atlantic Ocean, so the water there is saltier and colder than at the equator, especially in winter. However, the salinity of warm water increases with evaporation, as salt remains in it. The salt content decreases when, for example, ice melts in the North Atlantic and fresh water flow into the sea.

What are deep currents?

Deep currents carry cold water from the polar regions to warm tropical countries, where the water masses mix. The rise of cold water affects the coastal climate: rain falls directly on the cold water. The air comes to the warm mainland almost dry, so the rains stop and deserts appear on the coastal shores. This is how the Namib Desert on the South African coast arose.

What is the difference between cold and warm currents?

temperature dependent sea ​​currents divided into warm and cold. The first appear near the equator. They carry warm waters through cold waters located near the poles and heat the air. Counter sea currents flowing from the polar regions towards the equator transport cold waters through the surrounding warm ones, and as a result, the air cools. Sea currents are like a huge air conditioner that distributes cold and warm air around the globe.

What are burs?

Bors are called tidal waves, which can be observed in those places where rivers flow into the sea - that is, at the mouths. They arise when so many waves running towards the shore accumulate in a shallow and wide funnel-shaped mouth that they all suddenly pour into the river. In the Amazon, one of the South American rivers, the surf raged so much that a five-meter wall of water advanced more than a hundred kilometers deep into the mainland. Bors also appear in the Seine (France), the Ganges Delta (India) and on the coast of China.

Alexander von Humboldt (1769-1859)

German naturalist and scientist Alexander von Humboldt traveled extensively in Latin America. In 1812, he discovered that a cold deep current moves from the polar regions to the equator and cools the air there. In his honor, the current that carries water along the coasts of Chile and Peru was named the Humboldt Current.

Where are the largest warm sea currents on the planet?

The largest warm sea currents include the Gulf Stream (Atlantic Ocean), Brazilian (Atlantic Ocean), Kuroshio (Pacific Ocean), Caribbean (Atlantic Ocean), North and South Equatorial Currents (Atlantic, Pacific and Indian Oceans), as well as Antilles (Atlantic ocean).

Where are the biggest cold sea currents located?

The largest cold sea currents are Humboldt (Pacific Ocean), Canary (Atlantic Ocean), Oyashio, or Kuril (Pacific Ocean), East Greenland (Atlantic Ocean), Labrador (Atlantic Ocean) and California (Pacific Ocean).

How do sea currents affect climate?

Warm sea currents primarily affect the surrounding air masses and, depending on geographical location continent, warm the air. So, thanks to the Gulf Stream in the Atlantic Ocean, the temperature in Europe is 5 degrees higher than it could be. Cold currents, which are directed from the polar regions to the equator, on the contrary, lead to a decrease in air temperature.

What is affected by changes in the sea current?

Sea currents can be affected by sudden events such as volcanic eruptions or changes associated with El Niño. El Niño is a warm water current that can displace a cold current off the coast of Peru and Ecuador in the Pacific Ocean. Although the influence of El Niño is limited to certain areas, its effects affect the climate of outlying regions. It calls heavy showers off the coasts of South America and East Africa, resulting in devastating floods, storms and landslides. In the tropical rain forests around the Amazon, on the contrary, a dry climate prevails, which reaches Australia, Indonesia and South Africa contributing to the occurrence of droughts and the spread of forest fires. Off the Peruvian coast, El Niño is leading to mass extinction of fish and corals, as plankton, which lives predominantly in cold water, suffers when it is heated.

How far can sea currents carry objects out to sea?

Sea currents can carry objects that have fallen into the water for great distances. So, for example, in the sea you can find wine bottles that 30 years ago were thrown from ships in the ocean between South America and Antarctica and carried away for thousands of kilometers. The currents carried them across the Pacific and Indian oceans!

What is worth knowing about the Gulf Stream?

The Gulf Stream is one of the most powerful and famous sea currents that originates in the Gulf of Mexico and carries warm waters to the Svalbard archipelago. Thanks to the warm waters of the Gulf Stream, northern Europe has a mild climate, although it should be much colder here, since this area is located as far north as Alaska, where it is freezing cold.

What are sea currents - video