Atlantic Ocean: currents and their characteristics. Message about the Atlantic Ocean

In the tropical latitudes of the ocean, trade winds cause powerful surface currents of salt water moving from east to west on either side of the equator called the North and South Trade Wind Currents.

Atlantic currents

The Northern Trade Wind Current, having met the ridge of these islands, also splits into two branches. The northern one continues to go northwest along the northern shores of the Greater Antilles (Antilles Current), and the southern one also enters the Caribbean Sea through the northern straits of the Lesser Antilles, after which it rushes through the Yucatan Strait into the Gulf. In the latter, a huge accumulation of water is created, which, under the influence of the difference in water levels in the Gulf of Mexico and the adjacent part of the ocean, at a speed of up to 9 km/h, exits through the Strait of Florida under the name of the Florida Current into the ocean, where they meet the Antilles Current and give rise to a powerful warm flow

Gulf Stream

The Gulf Stream follows northeast along the coast, taking the influence of westerly winds at 40 s. w. east direction. At approximately 40° W. e. The Gulf Stream deviates to the northeast, at the same time giving a branch to the south along the shores of the Iberian Peninsula and the cold Canary Current. South of the islands Cape Verde, one branch of the current passes into the Northern Trade Wind Current, closing the anticyclonic Northern Hemisphere. The other continues to the south and, gradually warming up, enters the Gulf of Guinea as the warm Guinea Current.

The northeastern branch of the Gulf Stream - the warm North Atlantic Current - as it moves towards it gives a branch to (Irminger Current), which partially continues in the north along the western shores of the island, and partially deviates to the west and, bending around from the south, brings warm water to Baffin Islands bay.

Properties of Atlantic Ocean waters

In general, the temperature of the surface water of the Atlantic decreases from the equator to high latitudes, and the northern part of the ocean, due to the inflow into it large quantity warm waters turn out to be much warmer than the southern ones. The highest is observed in the Northern Hemisphere in August, in the Southern Hemisphere in February, when it varies from + 26 °C at the equator to + 25 °C at 20 ° N. w. and Yu. w. and up to + 10 °C. Most low temperature observed in the Northern Hemisphere in February, in the Southern Hemisphere in August. Only at the equator at this time it rises to + 27 ° C, but with increasing latitude it decreases to + 23 ° C at 20 ° N. w. and up to + 20° C at 20° S. sh.; The water temperature reaches + 6 ° C, but at 60 ° S. sch, it is below - 1 °C.

The latitudinal distribution of water shows the same unevenness as in the distribution. IN Southern Hemisphere, north of 30° S. latitude, the eastern part of the ocean is 10° C colder than the western part, which is explained by the arrival here from high latitudes of more cold water. But south of 30° S. w. difference in temperatures between eastern and western parts The ocean disappears due to the latitudinal direction of the prevailing current here. Particularly sharp changes in temperature are observed in areas where warm and cold waters meet and in places where deep waters rise. For example, at the junction of the cold waters of the East Greenland Current with the warm waters of the Irminger Current, the temperature at a distance of 20-36 km drops from + 10 to + 3 ° C; V coastal strip South West Africa the temperature is 5 °C lower than the surrounding waters.

The distribution generally corresponds to the temperature distribution. High salinity is more than 37.25%o in subtropical latitudes, where evaporation is low and high, and in high latitudes it drops to 35.0%o. The greatest unevenness in the latitudinal distribution of salinity is observed north of 40° N. sh.: in the eastern part of the ocean - 35.5%o, in the western part - 32.0%o (area of ​​the Labrador Current). The average salinity of the Atlantic Ocean is 35.4%o. The highest water salinity in the Atlantic Ocean - 37.5%o - is observed in tropical latitudes in the area of ​​maximum evaporation west of the Azores.

The transparency of the Atlantic Ocean generally decreases from the equator to the poles. The greatest transparency is in the Sargasso Sea, where the white disk is visible at a depth of 65.5 m. The color of the water in the open ocean is dark blue, and in the Gulf Stream region it is pale blue. In coastal areas, greenish hues appear.

In the circulation of the waters of the World Ocean, the largest role belongs to currents, which owe their occurrence mainly to the action of constant winds.

Other factors in them, compared to the wind, recede into the background, as a result of which these currents are called drift. Obviously, the beginning of drift currents should be sought in those areas of the ocean where constant or prevailing winds expressed especially well and correctly, that is, primarily in the zone of development of trade winds.

In this zone of the Atlantic Ocean there are two trade wind (equatorial) currents. Deflected from the direction of the corresponding trade winds by 30-40°, both of them carry water from east to west.

South of the equator is the South Trade Wind Current. Its edge, facing the polar latitudes, does not have a clear boundary; the other edge, facing the equator, is more clearly expressed, but its position, in connection with the movement of the trade winds themselves, changes somewhat; yes, in February northern border The Southern Trade Wind Current lies about 2° N. latitude, in August near 5° N. w.

The Southern Trade Wind Current heads from the coast of Africa to the coast of America. At Cape San Roqui it divides into two branches, one of which, under the name of the Guiana Current, heads northwest along the coast of the mainland to the Antilles, and the other, known as the Brazil Current, goes southwest to the mouth of La Plata, where and meets the cold Falkland Current running from Cape Horn along the coast of the continent; here the Brazilian Current turns to the left; water masses rush east, cross the Atlantic Ocean and then, once again deviating to the left, rise from south to north along the west coast of Africa in the form of the cold Benguela Current, merging with the South Trade Wind. This closes the circle of currents in the southern part of the Atlantic, in which water moves counterclockwise - mainly along the periphery of the South Atlantic anticyclone.

The edge of the North Trade Wind Current, facing high latitudes, is as uncertain as the similar edge of the South Trade Wind Current; the southern border is more distinct and in February lies at 3° N. latitude, in August at 13° N. w. The current is caused by the northeast trade wind, begins west of Cape Verde (about 20° W), crosses the ocean and then turns into the slow Antilles Current, washing the garland of the Antilles from the outside. In addition, part of the North Trade Wind Current unites in the area of ​​the Lesser Antilles with the Guiana Current, and this combined stream enters the Caribbean Sea, forming the Caribbean Current here. Between the North and South Trade Wind Currents there is a compensatory countercurrent to the east; its extended continuation is called the Guinea Current and ends in the Gulf of Guinea.

The American semi-enclosed sea and, in particular, its northern part - the Gulf of Mexico - serves as an area where the trade wind, which actually blows here from the east, continuously pushes water. The accumulation of water exits through the Strait of Florida, forming the powerful Florida Current, which occupies the entire width of the strait (150 km) and is felt to a depth of 800 m; its speed is about 130 km per day, and its water consumption is about 90 billion tons per hour; surface water temperature 27-28°; however, this temperature fluctuates somewhat depending on changes in the strength of the trade winds pumping warm water to the Gulf of Mexico.

The Florida Current, upon exiting the strait, rushes north. In the canal between Florida and the Bahamas, its width, equal to the entire width of the canal, is 80 km; Warm (24°) dark blue water is very sharply distinguished by color from the waters of the rest of the sea.

In the area of ​​Cape Hatteras, the Florida Current is joined by the weaker Antilles Current. In the latest oceanographic literature, it is this combined current that is given the name Gulf Stream.

The Gulf Stream differs from the Florida Current in its greater width and lower speed, which is 60 km per day 500 km north of the Bahamas archipelago. The Gulf Stream moves along the coast of America, deviating from them to the right, and nowhere, even at its beginning, does it wash the mainland directly: between it and the coast there is always a strip of colder water. In winter, the difference in temperatures of the Gulf Stream and coastal water reaches 8° near Cape Hatteras, and 12-15° at the latitude of New York and Boston; in the summer, when coastal waters well heated, this difference noticeably weakens, and in some places disappears completely.

From the New York parallel, the Gulf Stream goes from west to east. Southeast of Newfoundland about 40° W. d. The Gulf Stream is ending. Here it, expanding greatly, breaks up into a fan of jets directed in a variety of ways; the deflection due to the rotation of the Earth most often gives the jets a direction to the east and south. The area of ​​extinction and branching of the Gulf Stream is called the “Gulf Stream delta.” Delta occupies such large area, What air masses, passing over this part of the ocean in winter, due to the vastness of the warm underlying surface, experience significant heating. The stream, going east from the Azores Islands, approaches the Iberian Peninsula, and then turns along the coasts of Europe and Africa to the south, forming a weak and cold Canary Current, merging in the area of ​​the Cape Verde Islands with the North Trade Wind Current.

This closes the ring of currents in that part of the Atlantic that lies north of the equator. The movement of water in this ring occurs clockwise, mainly along the periphery of the Azores anticyclone.

Inside the North Atlantic ring of currents between 20 and 35° N. w. and 40 and 75° W. There is an extremely unique calm region of the Sargasso Sea, not affected by currents. The surface of the sea is covered with islands, tufts or long strips of floating algae, colored olive green or yellowish at the tops and brown at the base. Most often these are Sargassum bacciferum, S. natans and S. vudgare; they are all pelagic, i.e. characteristic open sea and not connected to the ground. In the western part of the Sargasso Sea, other types of algae related to coastal algae are found. The size of algae ranges from a few centimeters to several decimeters.

Accumulations of algae are very uneven, but they do not interfere with navigation anywhere. A ship can cross the Sargasso Sea and not encounter a single seaweed; sometimes there are so many algae along the way that they occupy the entire visible horizon, and the ocean looks like a green meadow. In summer, when the winds blow from the south, the border of sargassum accumulations reaches 40° N. sh., but the cold waters of the Labrador Current do not allow it further north, since at temperatures below 18° the algae already die.

From the Gulf Stream delta, in addition to its branch, which ultimately forms the Canary Current, another current departs, going to the northeast between 43 and 70 ° N. w. This current is called the Atlantic. It serves as a direct continuation of the Gulf Stream, but genetically it represents a completely new phenomenon, because the impulse that excited the Gulf Stream has already dried up in the Gulf Stream delta and ceased to act. The Atlantic Current is caused by the western and southwestern winds prevailing in the area of ​​its origin and distribution, giving it average speed about 25 km per day. Consequently, the continuity of the transition of the Gulf Stream to the Atlantic Current is purely external and is the result of a kind of relay race, due to which the movement of water was “transferred” from the waste current (Gulf Stream) to the drift current (Atlantic).

Having advanced beyond the 60th parallel, the Atlantic Current begins to give branches to the right and left - the first under the influence of the rotation of the Earth, the second under the influence of the topography of the seabed. Near the underwater ridge connecting Iceland with the Faroe Islands, a branch called the Irminger Current runs to the northwest; west of Iceland it turns sharply to the southwestern tip of Greenland and enters Baffin Bay through Davis Strait in the form of the warm West Greenland Current. From the 70th parallel, approximately at the 15th eastern meridian, two large jets depart: one north to the western shores of Spitsbergen - the Spitsbergen Current, the other east along the northern tip. Scandinavian Peninsula - North Cape Current; minimum temperature its +4°. Having entered the Barents Sea, the North Cape Current, in turn, divides into branches. The southern one - called the Murmansk Current - runs parallel to the Murmansk coast at a distance of 100-130 km from it; Its temperature in August is about 7-8°. The continuation of the Murmansk Current is the Novaya Zemlya Current, heading north along the western shores of the islands of the same name.

None of the listed warm currents goes into the Arctic Ocean along its surface further than the area of ​​Franz Josef Land, since their waters here, due to their higher density (salinity) compared to the density of the waters Arctic Ocean, sink below the surface of the sea and penetrate into the Polar Basin in the form of a warm deep current. The deep current, subject to the deflecting effect of the Earth's rotation, follows to the east, presses against the northern edge of the Eurasian shelf, but, due to the high density of its waters, does not spread to the surface of the shelf. The main stream flows along the continental shelf, but warm Atlantic waters also fill the entire Polar Basin. In many of its deep places it was observed that upper layer water with a thickness of 200-250 m, having negative temperature(up to -1°.7), is then replaced to a depth of 600-800 m by a layer of water with positive (up to +2°) temperatures, and below, to the very bottom, lies again a layer of cold (up to -0°.8) water. The warm “layer” is a warm current that has disappeared from the surface of the ocean.

The numerous currents of the Atlantic Ocean are very heterogeneous in their origin, although they are mutually closely related. Both equatorial currents, which arose under the influence of trade winds, are drift currents; The Florida Current, as a result of the surge of water into the Gulf of Mexico, is a waste stream; its continuation - the Gulf Stream - waste and drift; The Atlantic current is predominantly drift; Guinean - compensatory and partly drift, since the southwest monsoon also takes part in its formation; Canary - compensatory, compensating for the loss of water created off the coast of Africa by the North Trade Wind Current, etc.

Using the example of Atlantic Ocean currents, we also became familiar with the factors that influence the direction of currents: the deflecting effect of the Earth's rotation and the importance of underwater relief and coastal configuration (division of the South Trade Wind Current).

A message about the Atlantic Ocean for children can be used in preparation for the lesson. A story about the Atlantic Ocean for children can be supplemented with interesting facts.

Report on the Atlantic Ocean

Atlantic Ocean second by size ocean on our planet. The name probably originated from the legendary lost continent of Atlantis.

In the west it is limited by the shores of the Northern and South America, in the east - the shores of Europe and Africa to Cape Agulhas.

The area of ​​the Atlantic Ocean with its seas is 91.6 million km2, the average depth is 3332 m.

Maximum depth - 8742 m in the trench Puerto Rico.

The Atlantic Ocean is located in almost all climatic zones, except for the Arctic, but its largest part lies in the areas of equatorial, subequatorial, tropical and subtropical climate.

A distinctive feature of the Atlantic Ocean is a small amount of islands, as well as the complex bottom topography, which forms many pits and gutters.

Well expressed in the Atlantic Ocean currents, directed almost in the meridional direction. This is due to the great elongation of the ocean from north to south and its outlines coastline. The most famous warm current Gulf Stream and its continuation - North Atlantic flow.

Salinity of Atlantic Ocean waters generally higher than the average salinity of the waters of the World Ocean, and organic world poorer in terms of biodiversity compared to the Pacific Ocean.

The Atlantic is an important sea route connecting Europe and North America. Shelves North Sea and the Gulf of Mexico - places of oil production.

Plants presented wide range green, brown and red algae.

The total number of fish species exceeds 15 thousand, the most common families being nanothenia and white-blooded pike. Large mammals most widely represented: cetaceans, seals, seals etc. The amount of plankton is insignificant, which causes migration of whales to feeding fields to the north or to temperate latitudes, where there is more of it.

Almost half of the world's fish catch is caught in the seas of the Atlantic Ocean. Today, unfortunately, stocks of Atlantic herring and cod have sharply decreased, sea ​​bass and other types of fish. Today the problem of preserving biological and mineral resources is particularly acute.

We hope the information presented about the Atlantic Ocean has helped you. You can supplement the report on the Atlantic Ocean through the comment form.

The Atlantic Ocean, or Atlantic, is the second largest (after the Pacific) and the most developed among other water areas. From the east it is limited by the coast of South and North America, from the west - Africa and Europe, in the north - Greenland, in the south it merges with the Southern Ocean.

Distinctive features of the Atlantic: a small number of islands, complex bottom topography and a highly indented coastline.

Characteristics of the ocean

Area: 91.66 million sq. km, with 16% of the territory falling on seas and bays.

Volume: 329.66 million sq. km

Salinity: 35‰.

Depth: average - 3736 m, greatest - 8742 m (Puerto Rico Trench).

Temperature: in the very south and north - about 0°C, at the equator - 26-28°C.

Currents: conventionally there are 2 gyres - Northern (currents move clockwise) and Southern (counterclockwise). The gyres are separated by the Equatorial Intertrade Current.

Main currents of the Atlantic Ocean

Warm:

Northern trade wind - begins off the west coast of Africa, crosses the ocean from east to west and meets the Gulf Stream near Cuba.

Gulf Stream- the most powerful current in the world, which carries 140 million cubic meters of water per second (for comparison: all the rivers of the world carry only 1 million cubic meters of water per second). It originates near the coast of the Bahamas, where the Florida and Antilles currents meet. Having united, they give rise to the Gulf Stream, which flows into the Atlantic Ocean through the strait between Cuba and the Florida Peninsula. The current then moves north along the US coast. Approximately off the coast of North Carolina, the Gulf Stream turns east and enters open ocean. After approximately 1,500 km, it meets the cold Labrador Current, which slightly changes the course of the Gulf Stream and carries it to the northeast. Closer to Europe, the current splits into two branches: Azores and North Atlantic.

Only recently it became known that 2 km below the Gulf Stream flows reverse current, heading from Greenland to Sargasso Sea. This thread ice water called the Anti-Gulf Stream.

North Atlantic- a continuation of the Gulf Stream, which washes the western coast of Europe and brings the warmth of southern latitudes, providing a mild and warm climate.

Antilles- begins east of the island of Puerto Rico, flows north and joins the Gulf Stream near the Bahamas. Speed ​​- 1-1.9 km/h, water temperature 25-28°C.

Interpass countercurrent - current encircling Earth along the equator. In the Atlantic, it separates the North Trade Wind and South Trade Wind Currents.

South Passat (or South Equatorial) - passes through the southern tropics. average temperature water - 30°C. When the South Trade Wind Current reaches the coast of South America, it divides into two branches: Caribbean, or Guiana (flows north to the coast of Mexico) and Brazilian— moving south along the coast of Brazil.

Guinean - located in the Gulf of Guinea. It flows from west to east and then turns south. Together with the Angolan and South Equatorial currents, it forms the cyclic current of the Gulf of Guinea.

Cold:

Lomonosov countercurrent - discovered by a Soviet expedition in 1959. It originates off the coast of Brazil and moves north. The 200 km wide stream crosses the equator and flows into the Gulf of Guinea.

Canary- flows from north to south, towards the equator along the coast of Africa. This wide stream (up to 1 thousand km) near Madeira and Canary Islands meets the Azores and Portuguese Currents. Approximately around 15°N latitude. joins the Equatorial Countercurrent.

Labrador - begins in the strait between Canada and Greenland. It flows south to the Newfoundland Bank, where it meets the Gulf Stream. The waters of the current carry cold from the Arctic Ocean, and along with the flow, huge icebergs are carried south. In particular, the iceberg that destroyed the famous Titanic was brought precisely by the Labrador Current.

Benguela- is born near the Cape of Good Hope and moves along the coast of Africa to the north.

Falkland (or Malvinas) branches off from the West Wind Current and flows north along east coast South America to La Plata Bay. Temperature: 4-15°C.

Current of the westerly winds encircles the globe in the region of 40-50°S. The flow moves from west to east. In the Atlantic it branches off South Atlantic flow.

Underwater world of the Atlantic Ocean

The underwater world of the Atlantic is poorer in diversity than in Pacific Ocean. This is due to the fact that the Atlantic Ocean was more frozen during ice age. But the Atlantic is richer in the number of individuals of each species.

Flora and fauna underwater world clearly distributed among climatic zones.

The flora is represented mainly by algae and flowering plants (Zostera, Poseidonia, Fucus). IN northern latitudes Laminaria predominates; in temperate areas, red algae predominates. Throughout the ocean, phytoplankton actively thrives at depths of up to 100 m.

The fauna is rich in species. Almost all species and classes of marine animals live in the Atlantic. From commercial fish Herring, sardine, and flounder are especially prized. There is an active catch of crustaceans and mollusks, and whaling is limited.

The tropical zone of the Atlantic amazes with its abundance. There are a lot of corals and a lot amazing views animals: turtles, flying fish, several dozen species of sharks.

The name of the ocean first appears in the works of Herodotus (5th century BC), who calls it the Sea of ​​Atlantis. And in the 1st century AD. The Roman scientist Pliny the Elder writes about a vast expanse of water called Oceanus Atlanticus. But official name The “Atlantic Ocean” was established only in the 17th century.

The history of Atlantic exploration can be divided into 4 stages:

1. From antiquity to the 15th century. The first documents that talk about the ocean date back to the 1st millennium BC. The ancient Phoenicians, Egyptians, Cretans and Greeks knew the coastal zones of the water area well. Maps of those times have been preserved with detailed depth measurements and indications of currents.

2. Time of the Greats geographical discoveries(XV-XVII centuries). The development of the Atlantic continues, the ocean becomes one of the main trade routes. In 1498, Vasco de Gama, having circumnavigated Africa, paved the way to India. 1493-1501 - Columbus's three voyages to America. The Bermuda anomaly was identified, many currents were discovered, and detailed maps depths, coastal zones, temperatures, bottom topography.

Expeditions of Franklin in 1770, I. Kruzenshtern and Yu. Lisyansky of 1804-06.

3. XIX - first half of the XX century - the beginning of scientific oceanographic research. Chemistry, physics, biology, ocean geology are studied. A map of currents has been compiled, and research is being carried out to lay an underwater cable between Europe and America.

4. 1950s - present day. A comprehensive study of all components of oceanography is being carried out. Priority: climate research different zones, identification of global atmospheric problems, ecology, mining, ensuring ship traffic, seafood production.

In the center of the Belize Barrier Reef there is a unique underwater cave - the Great Blue Hole. Its depth is 120 meters, and at the very bottom there is a whole gallery of smaller caves connected by tunnels.

The Atlantic is home to the only sea in the world without shores - the Sargasso. Its boundaries are formed by ocean currents.

Here is one of the most mysterious places on the planet: Bermuda Triangle. The Atlantic Ocean is also home to another myth (or reality?) - the continent of Atlantis.

Ocean water is on the move, affecting your climate, your local ecosystem and the seafood you eat. Ocean currents, abiotic features environment, are continuous and directed movements ocean water. These currents are found in the depths of the ocean and on its surface, flowing both locally and globally.

The most important and unique currents of the Atlantic Ocean

• Equatorial north current. This current is created by the rise of cold water near the African west coast. Warm current also moves westward with the cool Canary Current.
• Equatorial south current flows from the west coast of Africa to the coast of South America between the equator and latitude 20°. This current is more constant, stronger and more to a greater extent than the north equatorial current. In fact, this current is a continuation of the Benguela current.
• The Gulf Stream consists of several currents that flow in a northeasterly direction. This current system originates in the Gulf of Mexico and reaches the western shores of Europe near 70°N latitude.
• The Florida Current is a continuation of the well-known equatorial current in the north. This current flows through the Yucatan Channel into the Gulf of Mexico, after which the current moves forward through the Straits of Florida and reaches 30° north latitude.
• The Canary Current is the coolest current that flows along the western coast of North Africa between Madeira and Cape Verde. In fact, this current is a continuation of the North Atlantic drift, which turns south near the Spanish coast and flows south along the coast of the Canary Islands. Approximate current speed ranges from 8 to 30 nautical miles.
• The Labrador Current, an example of a cold current, originates in Baffin Bay and Davis Strait and after flowing through the coastal waters of Newfoundland and the Grand Banks merges with the Gulf Stream around 50°W longitude. The flow rate is 7.5 million m3 of water per second.