How do sea currents affect the weather? The influence of currents on the regime of oceans and seas and on the climate of the earth.
Good day to all! You and I know that everywhere on the planet there is a different climate. And what affects the climate, if you need to know this, then read this article...
We talk about climate if we are interested in what the weather will be like in a resort area during a certain period of time, dry or hot.
The sun's rays, in the region of the poles, overcome thicker layers, which means that the atmosphere receives more solar radiation. In the polar regions, the sun's rays, reaching the Earth's surface, are scattered over much larger area than near the equator.
The altitude above sea level also affects the temperature. For every 1000 m of rise above sea level, the temperature decreases on average by 7°C.
For this reason, in the high mountain regions of the tropics it is much colder on the sea coasts located at the same latitude, and the cold polar climate reigns on the tops of high mountains.
Mountains also influence rainfall.
Moist oceanic winds that rise over the mountain range contribute to the formation, and heavy precipitation falls on the slopes. Winds tend to pick up moisture and become warmer as they cross the ridge and begin to descend.
Therefore, the mountain slopes facing are saturated with moisture, while the leeward ones often remain dry. The rain shadow is considered to be a dry area.
In coastal areas the climate is usually milder than inland. For example, sea and coastal breezes influence climate. heats up more slowly than the earth's surface.
Warm air rises during the day, and cooler air coming from the sea takes its place. But at night the opposite happens. Breezes blow from land to sea because the sea cools more slowly than the land.
Ocean currents affect temperature.
The warm Gulf Stream crosses diagonally the Atlantic Ocean from the northwestern shores to the Gulf of Mexico.
Sea winds blowing along the Gulf Stream towards the coast in this part of Europe provide a much milder climate than on the North American coast located at the same latitude.
Cold currents also affect the climate. For example, off the southwest coast, the Benguela Current and off the west coast South America Peruvian (or Humboldtian) - cools tropical regions, otherwise it would be even hotter there.
Far from the moderating influence of the sea, in the center of the continents, there is a harsh climate with much more cold winter and hotter summers than in the coastal region of the same.
The influence of the sea.
During the warmest time of the year, the average temperature is 15 - 20°C, although away from the coast it is often higher, where the moderating influence of the sea is not felt.
Compared to latitudes located in the same areas, but far from the sea, winter temperatures are unusually high. Usually here average monthly temperature above 0°C.
But sometimes, cold continental or polar air causes the temperature to drop, and snowy weather lasts for several weeks.
There is a big difference in precipitation: there is often a lot of moisture in the coastal mountains, but much drier in the flat eastern part.
Previously, deciduous forests (trees shed their leaves in autumn) covered cold areas. temperate climate. But most of them were cut down, and now large areas of these areas are densely populated.
The western part, with cold winters and warm summers, belongs to the cold temperate climate zones. Subarctic climates with very cold winters and short, cold summers are found in other areas, including Siberia and much of Canada.
In these places, the frost-free period lasts no more than 150 days. Most of this subarctic region is occupied by Taiga - giant coniferous forests.
In conditions of long and harsh winter, learned to survive coniferous trees(larch, fir, spruce and pine). All coniferous trees, with the exception of larch, are evergreen, ready to begin to grow as soon as spring warming arrives.
Such coniferous forests in the southern hemisphere, no, because there, at the corresponding latitudes, there are no large areas of land.
Thus, we learned what affects climate, and what climate is in general. Now you can understand why different places planets have different climates. Apply knowledge🙂
The circulation of the waters of the World Ocean determines the exchange of matter, heat and mechanical energy between the ocean and the atmosphere, surface and deep, tropical and polar waters. Sea currents transport large masses of water from one area to another, often to very remote areas. Currents disrupt the latitudinal zonality in the temperature distribution. In all three oceans - the Atlantic, Indian and Pacific - temperature anomalies arise under the influence of currents: positive anomalies are associated with the transfer of warm waters from the equator to higher latitudes by currents close to meridional direction; negative anomalies are caused by oppositely directed (from high latitudes to the equator) cold currents. Negative temperature anomalies are intensified, in addition, by the rise of deep waters off the western coasts of the continents, caused by the flow of water by trade winds.[...]
The influence of currents affects not only the magnitude and distribution of average annual temperature values, but also its annual amplitudes. This is especially clearly manifested in areas of contact between warm and cold currents, where their boundaries shift throughout the year, such as, for example, in the Atlantic Ocean in the area of contact of the Gulf Stream and Labrador Currents, in the Pacific Ocean in the area of contact of the Kuroshio and Kuril (Oyashio) currents. .[...]
Currents influence the distribution of other oceanological characteristics: salinity, oxygen content, nutrients, color, transparency, etc. The distribution of these characteristics has a huge impact on the development of biological processes, plant and animal world seas and oceans. The variability of sea currents in time and space, the displacement of their frontal zones affect the biological productivity of the oceans and seas.[...]
Currents have a great influence on the Earth's climate. For example, in tropical regions where eastern transport prevails, significant cloudiness, precipitation, and humidity are observed on the western shores of the oceans, while on the eastern shores, where winds blow from the continents, there is a relatively dry climate. Currents significantly influence pressure distribution and atmospheric circulation. A series of cyclones move above the axes of warm currents, such as the Gulf Stream, North Atlantic, Kuroshio, and North Pacific, which determine the weather conditions of the coastal regions of the continents. The warm North Atlantic Current favors the strengthening of the Icelandic low pressure, and consequently, intense cyclonic activity in the North Atlantic, North and Baltic seas. The influence of Kuroshio on the area of the Aleutian low pressure in the northeastern region is similar Pacific Ocean.[ ...]
In areas where warm and cold currents meet, fog and overcast are often observed.[...]
Where warm currents penetrate deeply into temperate and subpolar latitudes, their influence on the climate is especially pronounced. The moderating influence of the Gulf Stream, the North Atlantic Current and its branches on the climate of Europe, and the Kuroshio Current on climatic conditions northern part of the Pacific Ocean. It should be noted that the North Atlantic Current is more important in this regard than Kuroshio, since the North Atlantic Current penetrates almost 40° north of Kuroshio.[...]
Sharp differences in climate are created when the shores of continents or oceans are washed by cold and warm currents. For example, East Coast Canada is under the influence of the cold Labrador Current, while the western coast of Europe is washed by the warm waters of the North Atlantic Current. As a result, in the zone between 55 and 70° N. w. The duration of the frost-free period on the Canadian coast is less than 60 days, on the European coast - 150-210 days. A striking example of the impact of currents on climatic and weather conditions is the Chilean-Peruvian Cold Current, the water temperature of which is 8-10° lower than the surrounding waters of the Pacific Ocean. Above the cold waters of this current air masses, cooling, form a continuous cover of stratocumulus clouds, as a result, continuous cloudiness and absence of precipitation are observed on the coasts of Chile and Peru. The southeast trade wind creates a surge in this area, i.e. a departure from the coast surface waters and the rise of cold deep waters. When the coast of Peru is only under the influence of this cold current, this period is characterized by the absence of tropical storms, rains and thunderstorms, and in the summer, especially when the oncoming warm coastal current intensifies El Niño currents, tropical storms are observed here, destructive force thunderstorms, downpours that erode the soil, residential buildings, dams, embankments.
The circulation of the waters of the World Ocean determines the exchange of matter, heat and mechanical energy between the ocean and the atmosphere, surface and deep, tropical and polar waters. Sea currents transport large masses of water from one area to another, often to very remote areas. Currents disrupt the latitudinal zonality in the temperature distribution. In all three oceans - the Atlantic, Indian and Pacific - temperature anomalies arise under the influence of currents: positive anomalies are associated with the transfer of warm waters from the equator to higher latitudes by currents that have a direction close to the meridional direction; negative anomalies are caused by oppositely directed (from high latitudes to the equator) cold currents. Negative temperature anomalies are intensified, in addition, by the rise of deep waters off the western coasts of the continents, caused by the movement of water by trade winds.
The influence of currents affects not only the magnitude and distribution of average annual temperature values, but also its annual amplitudes. This is especially clearly manifested in areas of contact between warm and cold currents, where their boundaries shift throughout the year, such as, for example, in the Atlantic Ocean in the area of contact of the Gulf Stream and Labrador Currents, in the Pacific Ocean in the area of contact of the Kuroshio and Kuril (Oyashio) currents. .
Currents influence the distribution of other oceanological characteristics: salinity, oxygen content, nutrients, color, transparency, etc. The distribution of these characteristics has a huge impact on the development of biological processes, flora and fauna of the seas and oceans. The variability of sea currents in time and space, the displacement of their frontal zones affect the biological productivity of the oceans and seas.
Currents have a great influence on the Earth's climate. For example, in tropical regions where eastern transport prevails, significant cloudiness, precipitation, and humidity are observed on the western shores of the oceans, while on the eastern shores, where winds blow from the continents, there is a relatively dry climate. Currents significantly influence pressure distribution and atmospheric circulation. A series of cyclones move above the axes of warm currents, such as the Gulf Stream, North Atlantic, Kuroshio, and North Pacific, which determine the weather conditions of the coastal regions of the continents. The warm North Atlantic Current favors the strengthening of the Icelandic low pressure, and, consequently, intense cyclonic activity in the North Atlantic, North and Baltic seas. The influence of Kuroshio on the area of the Aleutian low pressure in the northeastern region of the Pacific Ocean is similar. Warm currents penetrating into high latitudes are associated with cyclonic circulation of the atmosphere, which contributes to heavy precipitation. atmospheric precipitation. On the contrary, spurs develop above cold currents high pressure, which causes a decrease in precipitation. In areas where warm and cold currents meet, fog and overcast are often observed.
Where warm currents penetrate deeply into temperate and subpolar latitudes, their influence on the climate is especially pronounced. The moderating influence of the Gulf Stream, the North Atlantic Current and its branches on the climate of Europe, and the Kuroshio Current on the climatic conditions of the northern part of the Pacific Ocean are well known. It should be noted that the North Atlantic Current is more important in this regard than Kuroshio, since the North Atlantic Current penetrates almost 40° north of Kuroshio.
Sharp differences in climate are created when the shores of continents or oceans are washed by cold and warm currents. For example, the eastern coast of Canada is under the influence of the cold Labrador Current, while the western coast of Europe is washed by the warm waters of the North Atlantic Current. As a result, in the zone between 55 and 70° N. w. The duration of the frost-free period on the Canadian coast is less than 60 days, on the European coast - 150-210 days. A striking example of the impact of currents on climatic and weather conditions is the Chilean-Peruvian Cold Current, the water temperature of which is 8-10° lower than the surrounding waters of the Pacific Ocean. Over the cold waters of this current, air masses, cooling, form a continuous cover of stratocumulus clouds, as a result, continuous cloudiness and absence of precipitation are observed on the coasts of Chile and Peru. The southeastern trade wind creates a surge in this area, i.e., the departure of surface waters from the shore and the rise of cold deep waters. When the coast of Peru is only under the influence of this cold current, this period is characterized by the absence of tropical storms, rains and thunderstorms, and in the summer, especially when the warm coastal current El Niño intensifies, tropical storms, destructive thunderstorms, and downpours that erode the soil are observed here , residential buildings, dams, embankments.
Ripple ocean currents, meandering and displacement of their axes to the south or north have a significant impact on the climate of coastal areas. Simultaneous observations of the temperature distribution within such large-scale flows as the Gulf Stream and Kuroshio revealed meanders (meanders) that have a wave-like character. They resemble river meanders and, in the form of condensation of isotherms in the axis of the main flow, move along with the current. For example, the shift of the Kuroshio axis to the south and north reaches 350 miles between 34 and 40 ° N. w. The position of the fronts Kuroshio - Oyashio, Gulf Stream - Labrador and other currents experiences semi-monthly, monthly, semi-annual, annual and long-term fluctuations. In this regard, fluctuations in climatological and meteorological factors on the coasts of nearby continents. Weather Japan is associated with fluctuations of the Kuroshio front, the climatic conditions of the Kuril ridge, about. Hokkaido and the north of. Honshu is influenced by the cold Oyashio Current.
Of particular importance for the formation and change of climate is the interaction between the ocean and the atmosphere, manifested in the exchange of heat, moisture and momentum. The ocean is in continuous interaction with the atmosphere and the earth's crust. It is a huge accumulator of solar heat and moisture, smoothes out sharp temperature fluctuations and moisturizes remote areas of land (through air currents).
The reverse influence of the atmosphere on the ocean is manifested mainly through water circulation, by weakening or strengthening surface (and indirectly deep) currents through the wind regime. Uneven supply of solar heat to the ocean surface and variability atmospheric processes have a direct impact on temperature, salinity and other characteristics of the World Ocean.
Of particular interest is the belt of the World Ocean, where a huge amount of solar radiation is absorbed (the zone between 30° N and 30° S). The heat accumulated there is transferred to higher latitudes, becoming an important factor in moderating the climate of temperate and polar latitudes in the cold half of the year. As a result of evaporation and turbulent heat exchange, about 2 times more heat is transferred from the ocean to the atmosphere per year than from the land surface. It follows that the World Ocean is one of the main factors in shaping climate and weather on Earth.
The climatically significant parameters of the World Ocean are the following: ocean surface temperature, salinity and characteristics of the water column, heat content of the active layer of the ocean, sea currents and ice.
A significant influence on the climate is exerted by sea (ocean) currents, which represent the forward movement of water masses in the seas and oceans, on the surface of which they spread in a wide strip, capturing a layer of water of varying depths. Sea currents are caused by the frictional force between water and air moving over the surface of the sea, pressure gradients arising in the water, as well as the tidal forces of the Moon and the Sun. To the direction of the currents big influence exerts the force of the Earth's rotation, under the influence of which water flows are deflected to the right in the Northern Hemisphere, and to the left in the Southern Hemisphere.
Sea (ocean) currents play important role in the process of interlatitudinal heat transfer. It has been established that about half of the advective heat transfer from low to high latitudes occurs with sea currents, and the remaining half through atmospheric circulation. Accordingly, cold advection occurs in the opposite direction with cold currents. Therefore, sea currents primarily influence air temperature and its distribution.
The stability of currents leads to the fact that their influence on the atmosphere has climatic significance. The ridge of isotherms on average temperature maps clearly shows the warming effect Gulf Stream on the climate of the eastern North Atlantic and Western Europe.
The waters of the Gulf Stream system penetrate 10 thousand km - from Florida to Spitsbergen and Novaya Zemlya. This current transports huge masses of water of varying salinity and density. Having a maximum flow width of up to 120 km and a thickness of 2 km, the Gulf Stream carries 22 times more water than all the rivers on the globe. Crossing the Atlantic Ocean, the Gulf Stream heads northeast (in its delta it divides into several streams). Here it is more correct to call it the North Atlantic Current; it expands significantly and its speed decreases to 0.26–0.32 m/s. The Gulf Stream brings a huge amount of heat to the shores of Western Europe, where it has a temperature of 13–15 °C in summer and 8 °C in winter. Washing the shores of Norway, the North Atlantic Current penetrates further into the Barents Sea to Spitsbergen and partially even into the Kara Sea, significantly warming the climate of the western sector of the Arctic. To the east, due to the high density of water, this current descends into deeper layers of the ocean.
Warm currents are the water heating pipes of the globe.
A. I. Voeikov
The world ocean, or the Earth's hydrosphere, unites almost all oceanic and sea waters having a single surface. It occupies almost three-quarters of the surface of the globe - 361 million km 2, while the land is only 149 million (Fig. 14).
The average depth is relatively small - 3.8 km. Such a thin hydrosphere can be likened to a 1 mm thick film on a globe with a diameter of 3 m. But it plays a huge role in the organic life and climates of the Earth.
The ocean is the cradle of life. In the distant past, in warm and quiet sea lagoons, the first living cells, and then the simplest organisms, arose and developed. If the liquid film had evaporated, then on the dried-out Earth there would not have been a single corner for the modern highly developed organic world. And the thermal regime would be different - in January at the North Pole, instead of the current average temperature of -30°, it would become -80°.
Of all the natural surfaces of the Earth, the ocean surface is the best absorber of solar radiation. But the same surface in a different state of aggregation (ice and snow) is the most perfect reflector. Although the temperature range of the ocean surface and the surface layer of the atmosphere is small, the water in this narrow range changes its state quite often and quickly. This variability has a dramatic effect on the climate.
The ocean is a huge distiller. It evaporates 448,000 km 3 of water annually, while the continents only 71,000. The warmer the ocean, the more moisture it evaporates. Moist air, covering the planet, reduces heat leakage into space, better irrigates the land and makes it easier for the farmer to grow abundant harvests. The ocean is a powerful thermoregulator of the planet. Due to the large mass of water and its high heat capacity (3200 times greater than that of air), it accumulates solar heat and spends it in winter to heat the atmosphere, leveling out interseasonal climate variability. In some cases, the ocean evens out interannual fluctuations. Continents are not capable of accumulating heat, so the continental climate, as a rule, increases with distance from the borders with the ocean.
The waters of the ocean are in constant motion. They absorb solar heat more than land and are the main supplier of energy to global wind systems. Hurricanes and storm winds vigorously mix and move water masses. Thus, the flow of the Western winds in Southern Hemisphere annually transports about 6 million km 3 of water around the Earth, which is equal to two volumes Mediterranean Sea. The surface 100-200 meter layer is especially active. But the subsurface and even bottom layers of the ocean are in perpetual motion. Sea currents bring large masses of heat and cold. A particle of water can make any trip around the world in the World Ocean, changing its state, heating up under the equator and turning into ice in the polar waters of both hemispheres.
Sea currents, together with air currents, equalize the temperature between polar and tropical latitudes and fully fulfill the role noted in the epigraph in the words of A.I. Voeikov.
In table Table 4 shows temperatures by latitude zones, calculated and observed. The difference is the result of heat exchange determined by circulation processes in the atmospheric and hydrosphere shells of the Earth. It is easy to see how strongly interlatitudinal heat exchange affects the Earth’s temperature field. If it weren't for him, then equatorial belt the temperature would rise by 13°, and in latitudes from 60° northern latitude to the Pole the temperature would have dropped by 22° on average. At the latitudes of Moscow and Leningrad, the climate of the modern Central Arctic would dominate, i.e., completely unsuitable for the plant world.
A quantitative idea of the interlatitudinal heat transfer by sea and air circulation processes is given in Table. 5.
As can be seen from the table, the arrival of solar short-wave radiation quickly decreases from the equator to the pole, which is explained by the sphericity of the Earth. Losses through long-wave radiation, on the contrary, remain almost unchanged in all latitude zones, since the spherical surface of the Earth does not matter here. This results in a relative excess of heat in latitudes below 40° and a deficiency above this limit, which gives rise to the temperature contrasts given in Table. 4. In real conditions, as we have seen, excess and deficiency of heat are balanced due to interlatitudinal heat exchange carried out through water and air exchange mechanisms.
Of practical interest is the question: who plays the decisive role in transporting heat from the planetary boiler to the planetary refrigerator, i.e., from equatorial and tropical latitudes to polar ones? Sea or air advection?
At different times, the contribution of each of these advections is different. In modern conditions and in colder conditions in the past, when the Arctic basin is largely covered with drifting ice all year round, marine advection is relatively small, but as Atlantic waters are forced into the Arctic basin, its role increases. The current ratio of sea and air advection is defined differently by individual researchers: from 1:2 in favor of air exchange to 1:1.5 in favor of sea advection. We will not take air advection into account in our calculations, since its relative and absolute significance in acryogenic conditions naturally decreases. We will reserve the relatively small contribution of heat that air advection makes as a “safety margin”.
A.I. Voeikov, calling sea currents temperature regulators, believed that “air currents do not contribute to the equalization of temperatures between the equator and the pole to the same extent as sea currents, and in terms of their direct influence in this regard they cannot be equal to the latter. But their indirect influence is very great.”
P.P. Lazarev in 1927 built a model of oceanic and atmospheric circulation. This model showed that ocean currents passing through North Pole and bringing to the polar region a large number of heat, warm it up. Paying tribute to the Soviet experimenter, the Englishman Brooks noted: “When the model reflected the modern distribution of land and sea, the currents that arose in the basin to the smallest detail turned out to be similar to the current currents... In models that reproduced the conditions of warm periods, ocean currents passed through the pole, while in models of cold periods, not a single current crossed the poles.”
Brooks rejected the self-sufficient role of atmospheric circulation and believed that its possible changes are not capable of causing major climate changes on their own, without the involvement of other factors. “The role of atmospheric circulation,” he wrote, “should be considered as regulating, sometimes perhaps enhancing, but not generating major climate fluctuations.” If sea currents, according to the apt definition of A.I. Voeikov, serve as climate thermoregulators, then the same cannot be said about macrocirculations of the atmosphere. Of all the climate-forming factors, as noted by B.L. Dzerdzeevsky, they, despite their dynamism, are the least constant factor.
Analysis of bottom sediments in the Arctic basin also confirmed that it is sea currents, compared to air currents, that play a decisive role in climate formation. In cases where warm Atlantic waters penetrated weakly into the Arctic basin, temperatures in the polar latitudes fell. Low temperatures led not only to the restoration of the ice cover of the basin, but also to the revival of ice sheets on the continents.
Attaching great importance to the directions of sea currents in climate formation, A.I. Voeikov wrote: “Don’t we have the right to say, having weighed the main conditions influencing the climate: without any change in the mass of current currents, without changes in the average air temperature on globe Temperatures in Greenland similar to those there in the Miocene period are again possible, and glaciers are again possible in Brazil. This requires only certain changes that direct the currents in a different way than now.” Many years later, Academician E.K. Fedorov pointed out the need for a thorough study of possible climate changes in connection with the deviation of some sea currents, believing that it should become one of the most important directions in our research.
Therefore, it will be useful to recall brief characteristics of modern ocean currents (Fig. 15).
The most powerful warm current in the World Ocean, which has a decisive impact on the climate of the Northern Hemisphere, is the system of North Atlantic currents under common name Gulf Stream. The system covers a vast area from the Gulf of Mexico to the shores of Spitsbergen and the Kola Peninsula. Actually, the Gulf Stream is the area from the confluence of the Florida Current with the Antilles (30° north latitude) to the island of Newfoundland. At latitude 38°, the thickness reaches 82 million km 3 /sec, or 2585 thousand km 3 /year.
In the area of Nova Scotia and the southern edge of the Newfoundland Bank, the Gulf Stream comes into contact with the cold, desalinated waters of the Cabot Current, and then with the waters of the cold Labrador Current. The thickness of Labrador is approximately 4 million m 3 /sec. It, together with cold waters, carries sea ice and icebergs to the Big Bank area.
Ice marine origin usually stay above the bank itself and, falling into the waters of the Gulf Stream, quickly melt. Icebergs have a longer life. Once in the waters of the Gulf Stream, they drift to the northeast and even north again, and often make a long voyage throughout the North Atlantic. In exceptional cases, they are carried to the south, almost to 30° north latitude, and to the east almost to Gibraltar.
A significant part of the icebergs spread along the outskirts of the Big Bank, especially along the northern ones, where, running aground, they remain until they melt so much that their reduced draft allows them to continue their drift further.
In addition to sea ice and icebergs, in the area of Newfoundland, as well as off the coast of Labrador, there is also bottom ice, which floats to the surface as it forms and participates in the general drift of ice. Since the temperature difference between the Gulf Stream and Labrador is very large, the waters of the Gulf Stream are greatly cooled.
After passing the Great Newfoundland Bank, the Gulf Stream, called the North Atlantic Current, moves east from average speed 20-25 km/day and, as it moves towards the shores of Europe, it takes a north-eastern direction. Behind the banks of Newfoundland, it separates branch-sleeves that are lost in the whirlpools. At about 25° west longitude, a large branch of the Canary Current departs from its southern edge to the Iberian Peninsula.
When approaching the British Isles, a large branch separates from the North Atlantic Current on the left side - the Irminger Current, heading north towards Iceland; the main mass, crossing the Whyville-Thomson threshold, passes in the strait between the Shetland and Faroe Islands and enters the Norwegian Sea.
The line of Wyville-Thomson rapids, and then the Greenland-Iceland rapids, form a clear boundary between the Atlantic and Arctic oceans. At a depth of 1000 m south of the Faroe-Shetland Sill, which is less than 500 m deep, the water temperature is almost 8° higher than to the north. Salinity at the same depth on the southern side of the threshold is higher by 0.3 ppm. The explanation for this exceptional contrast lies in the deflection of deep layers of warm water to the west on the southern side, while on the northern side of the threshold cold water is deflected to the east. As a result, to the north of the threshold, the entire deep-water part of the Greenland and Norwegian seas is filled with very cold and dense water. This system of thresholds also demarcates areas dominated by Atlantic and Arctic waters on the surface.
The North Atlantic Current, bypassing the strait between the Faroe and Shetland Islands, called the Norwegian warm current runs along the western coast of the Scandinavian Peninsula. In the area where the Arctic Circle intersects, a branch of an independent flow of warm waters departs from the left side of it, which has a stable direction to the north in all seasons of the year.
To the west of the North Cape, from the Norwegian Current on the right side, the North Cape Current departs east into the Barents Sea. East of the 35th meridian, although it breaks up into small jets, it plays a noticeable role in the term Barents Sea. Thus, the small Murmansk branch makes the Murmansk port open all year round for the free navigation of ships of any type.
Due to the greater density, Atlantic waters in a significant part of the Barents Sea are submerged under light layers of local water. Part of the Atlantic waters penetrates the Kara Sea. At the same time, warm Atlantic water under a layer of local polar water also enters the Barents Sea from the north, from the Arctic Basin along deep trenches west and east of Franz Josef Land, where it enters as a branch from the already deep Spitsbergen Current.
The left branch of the Norwegian Current, after the North Cape branch departs from it, goes north under the name of the Spitsbergen Current. Its main flow, upon entering the Spitsbergen-Greenland strait, loses part of its kinetic and thermal energy due to the fact that the strait reflects part of the water masses and due to lateral mixing with the waters of the oncoming cold East Greenland Current. The reflected water masses move first in the western and then in south direction, wedge into the cold jets of the East Greenland Current and, mixing with them, form circular currents in the region of the prime meridian and 74-78° north latitude.
The Spitsbergen Current passes along the Western shores of Spitsbergen at a speed of about 6 km per day, with average temperature water 1.9° and salinity 35 ppm. North of Spitsbergen, due to the difference in densities, it sinks under arctic waters and continues its path in the Central Arctic in the form of a deep warm current. But it is not the only place, where the warm waters of Svalbard are submerged under the cold Arctic ones. In the Greenland eastern shallow waters, high positive temperatures prevail everywhere at depths of more than 200 m. These warm waters can penetrate deep into bays and fiords. Of course, such deep penetration under the oncoming desalinated waters, quickly moving southward, carrying with them not only pack ice with deep draft, but also icebergs, cannot occur without a large loss of kinetic energy and heat. The work of the North Pole-1 station has established a very active role of Atlantic waters in warming the upper cold layer. Even in winter, despite the low winter air temperatures, the Atlantic waters, acting on the ice from below, weaken it all the time. This also applies to local ice, and to ice carried from the Central Arctic to the Greenland Sea.
The passage of Gulf Stream waters from the Strait of Florida to Thomson's Threshold takes 11 months, and from Thomson's Threshold to Spitsbergen about 13 months.
The Irminger Current, having separated from the North Atlantic Current when approaching the northern shores of the British Isles, takes on a northward direction towards Iceland. At approximately 63° north latitude the current bifurcates. Its right part goes into the Denmark Strait and with its warm waters washes not only the western shores of Iceland, but also the northern ones. In this area it comes into contact with the Icelandic branch of the East Greenland Current and, mixing with its waters, cools and moves to the southeast. The left, more powerful part of the Irminger, after branching, turns southwest and then south, under an oblique section it meets the flow of water and ice of the East Greenland Current. At the junction of the waters, the temperature at a distance of 20 to 36 km drops from 10 to 3°.
In the area of the southern tip of Greenland, the Irminger and East Greenland currents concentrically go around Cape Farwell and the entire southwestern part of the island and, under the name of the West Greenland Current, pass through Davis Strait to Baffin Bay.
The East Greenland Cold Current, which serves as the main route for water flow and ice removal from the Arctic Basin, originates on the continental shelf of Asia. With a gradual movement from the mainland to the north, the current in the Pole region bifurcates: one branch goes to the American sector of the Arctic, the other - towards the Greenland Sea. Off the northeastern coast of Greenland, the waters of a cold current flowing from the west along the northern coast of Greenland join the East Greenland Current. The width of the East Greenland Current at 75-76° north latitude is 175-220 km, the speed increases from two miles per day at a latitude of 80° to 8 miles at 75°, up to 9 miles at 70° and up to 16-18 miles at 65 -66° north latitude; The water temperature is below 0° everywhere. Having passed the Gulf of Denmark, it comes into contact with the warm Irminger, and with it it goes around Cape Farwell. In this area, sea ice and icebergs, falling into currents of warm water, quickly melt. Cape Farwell has a belt width floating ice in some months it reaches 250-300 km, but thanks to the warm waters of Irminger, north of Cape Desolation (62° north latitude), the ice never forms a closed cover here, and the width of its belt does not exceed several tens of kilometers.
The Labrador Current is a continuation of the cold Baffin Island Current, which originates at Smith Strait. It runs along the shores of the Labrador Peninsula and further south along the eastern coast of Newfoundland; its capacity is approximately 130,000 km 3 /year. It carries sea ice and icebergs and, as already noted, greatly cools the waters of the Gulf Stream. The waters of Labrador remain cold all year round, cooling the entire coastline it washes. Tundra vegetation in Newfoundland owes its existence to the cold waters of Labrador. It is noteworthy that at almost the same latitude, but on the other side of the Atlantic, in France, they grow the best varieties grapes
Looking at the current paths of the North Atlantic, we are convinced how right A.I. Voeikov was when he said that the direction of sea currents plays a huge role in climate formation. On the same meridian, the ice-free port of Murmansk is located far beyond the Arctic Circle, and the Azov ports, located 2,500 km to the south, freeze for several months every year. And finally, the North Atlantic Basin can be likened to a bathtub into which water flows through two taps. cold water(Labrador and East Greenland Currents) and after one - warm water Gulf Stream. By adjusting the taps, we can change the temperature of the Atlantic, and with it the climate of the surrounding continents. Recognition of the large role of sea currents in climate formation has determined, since the end of the last century, ways of regional improvements in the climate regime, changing the directions of warm and cold currents. Along with this, projects of large hydraulic engineering measures to regulate and transfer river flow were developed. Let us dwell on the main hydraulic engineering projects for the reclamation of natural conditions.
