The Gulf Stream is a strong, fast-moving, warm ocean current that originates and flows into the Atlantic Ocean. The Gulf Stream is part of the subtropical gyre of the North Atlantic Current.
Gulf Stream Current - Warm Ocean
Gulf Stream currents are classified as flowing toward the western boundary. Currently, its coastline begins in the eastern United States and Canada, and the other end of the Gulf Stream is at the western edge of the ocean basin.
Western Boundary Currents are typically very warm, deep and narrow currents that carry water from the tropics to the poles.
The Gulf Stream was first discovered in 1513 by Spanish explorer Juan Ponce de Leon and was widely used by Spanish sailors as they traveled from the Caribbean to Spain. In 1786, Benjamin Franklin mastered a further increase in its use.
Gulf Stream Path
Today it is clear that water is supplied to the Gulf Stream from the west coast of North Africa.
The equatorial current, the flows of which from the continent of Africa through the Atlantic Ocean reach the eastern coast of South America, splits into two currents:
- one of which is the Antilles Current,
- the second is the Gulf Stream Current.
These currents are then routed through the Caribbean islands and then through the Yucatan Channel between Mexico and Cuba.
Because these areas are often very narrow, currents are able to compress and gain strength.
When this happens, warm water begins to circulate in the Gulf of Mexico. This is where the Gulf Stream becomes officially visible on satellite imagery. This is how the opinion came about that the current was formed in this area.
Once the Gulf Stream has gained enough strength from the circulating waters in the Gulf of Mexico, the Gulf Stream begins to move east - returning to the Antilles and exiting this area through the Straits of Florida.
Here, the Gulf Stream is already a powerful underwater river that transports water at a volume of 30 million cubic meters per second (or 30 Sverdrups)
The Gulf Stream then flows parallel to the east coast of the United States, then enters the open sea near Cape Hatteras, and continues to move north.
In this place near the ocean there are deep waters - the Gulf Stream is the most powerful flow, forms large meanders, and breaks up into several currents, the largest of which is the North Atlantic Current.
The North Atlantic Current flows further north and feeds the Norway Current and moves relatively warm water along the western coast of Europe. The rest of the Gulf Stream flows into the Canary Current, which travels along the eastern Atlantic Ocean and back south toward the equator.
The Gulf Stream, like all other ocean currents, is primarily caused by wind as it creates friction as it moves through the water. This friction then causes the water to move in the same direction. Since this is the western limit of the current, along the edge of the Gulf Stream also helps its movement.
The northern branch of the Gulf Stream, the North Atlantic Current, is caused by thermohaline circulation - a result of differences in water densities.
Impact of the Gulf Stream Current
Ocean currents, circulating waters of different temperatures around the world, have a significant impact on the world's climate and weather patterns.
The Gulf Stream is one of the most important currents - it collects all its waters from the warm tropical waters of the Caribbean Sea and the Gulf of Mexico.
As such, the Gulf Stream maintains the surface temperature of a warm sea, causing areas around it to become warmer and more hospitable. For example, Florida and much of the southeastern United States have a mild climate year-round.
The Gulf Stream has the greatest influence on the climate in Europe
The Gulf Stream flows into the current flow of the North Atlantic. Although sea surface temperatures cool significantly at this latitude, the Gulf Stream is thought to help keep countries like Ireland and England much warmer than they would be at such high latitudes.
The average low temperature in London in December is 42°F (5°C), while St. John's, Newfoundland averages 27°F (-3°C). The Gulf Stream and warm winds also keep the northern coast of Norway free of ice and snow.
To maintain mild, warm sea surface temperatures in many places, the Gulf Stream can be responsible for the formation and strengthening of many hurricanes that move through the Gulf of Mexico.
In addition, the Gulf Stream plays an important role in the distribution of wild marine animals in the Atlantic Ocean.
The waters of Nantucket, Massachusetts, for example, contain an incredibly high number of biologically diverse animal species, with the Gulf Stream being the northern limit for southern species and the southern limit for northern species.
The future of the Gulf Stream
Although there is no definitive answer whether the Gulf Stream could disappear in the future or is already disappearing. But this will lead to global climate change.
Some studies suggest that as ice melts in places like Greenland, cold, dense water will flow into the ocean and disrupt the flow of the Gulf Stream and other currents that are part of the global conveyor belt. If this happens, weather patterns around the world could change.
There has been a lot of evidence recently that the Gulf Stream is weakening and slowing down - with growing concern that the impact of such changes will affect the planet's climate.
Some sources suggest that without the Gulf Stream, temperatures in England and northwestern Europe could drop by 4-6°C. These are the most dramatic predictions for the future of the Gulf Stream, but they, like the climate of today's ambient current patterns, show its importance to life in many places around the world.
Having managed to collect a significant amount of heat in the Gulf of Mexico, the Florida Current connects near the Bahamas with the Antilles Current (point 1, Fig. 1) and turns into the Gulf Stream, which flows in a narrow strip along the coast of North America. At North Carolina level (Cape Hatteras, point 2, Fig. 1), the Gulf Stream leaves the coastal zone and turns into the open ocean. The maximum flow rate reaches 85 million m³/s. The continuation of the Gulf Stream southeast of the Great Newfoundland Bank (point 3) is known as the North Atlantic Current, which crosses the Atlantic Ocean in a northeasterly direction, losing much of its energy in branches to the south (point 4), where the Canary Current closes the main cycle North Atlantic currents. Branches to the north into the Labrador Basin (point 5) form the Irminger Current, the West Greenland Current and close with the Labrador Current. At the same time, the main flow of the Gulf Stream can be traced even further to the north (point 6) along the coast of Europe as the Norwegian Current, the North Cape Current and others. Traces of the Gulf Stream in the form of an intermediate current are also observed in the Arctic Ocean.
The Gulf Stream often forms rings - vortices in the ocean. Separated from the Gulf Stream as a result of meandering, they have a diameter of about 200 km and move in the ocean at a speed of 3-5 cm/s.
Some scientists say that the Gulf Stream is slowing down its waters, and some say that it has stopped completely. It's hard to figure out who's right right now, but the Gulf Stream does have several reasons to slow down.
The first of them is global warming. Since the dynamics of the current are significantly influenced by the salinity of ocean water, which decreases due to melting ice. It is also possible that the decreasing temperature difference between the pole and the equator will influence the greenhouse effect. Thus, “global warming” threatens Europe with a catastrophic cold snap.
The second reason is the very large amount of oil that was spilled in the Gulf of Mexico. This also affects it, disrupting and slowing it down.
Rice. 1. Gulf Stream current system.
Stopping the warm Gulf Stream carries many dangers: cooling of Europe, climate disruption, the emergence of an ice age. It plays a huge role in the life of our planet. In support of the fundamental possibility of such a catastrophe, data on catastrophic climate changes that occurred on our planet previously are provided. Including available evidence of the Little Ice Age or analysis of Greenland ice.
Considering the influence of the Gulf Stream on the climate, it is assumed that in the short-term historical perspective a climate catastrophe associated with disruption of the flow is possible. It has long been one of Hollywood’s favorite themes that, due to global warming and the melting of northern glaciers, waters are desalinated, and since the Gulf Stream is formed by the interaction of salt and fresh water, Europe stops heating and the Ice Age begins.
Currently, there is no sufficiently substantiated data on the influence of the above factors on climate. There are also directly opposite opinions. In particular, according to Doctor of Geographical Sciences, oceanologist Bondarenko A.L., “The operating mode of the Gulf Stream will not change”. This is argued by the fact that no actual water transfer occurs, that is, the flow is a Rossby wave. Therefore, no sudden and catastrophic climate changes in Europe will occur. ( A. L. Bondarenko, “Where does the Gulf Stream flow?”// Oceanology. A popular science blog about the World Ocean and its inhabitants.).
All of the above information can be found on the website “Wikipedia” and “Oceanology. Popular science blog about the World Ocean."
Due to the fact that there is no consensus on the spatiotemporal variability and cause-and-effect relationships of the Gulf Stream current system, we will consider the results of numerous measurements of the speed and direction of currents and the distribution of temperature and salinity in the North Atlantic.
Until now, a large number of measurements of flow parameters have been carried out using different methods. Let's look at some of them produced in various places in the ocean, including in the Gulf Stream current system.
It is advisable to start from the equator. In Fig. Figure 2 (left) shows the meridional component of the equatorial Atlantic current. The flow speed changes periodically (period 20-30 days). These are currents of wave nature. In the literature they are called differently: mslow oscillations; unstable waves; baroclinic coastal jets; topographic waves; continental shelf waves; synoptic eddies in the ocean; baroclinic vortices; ocean vortices; topographic rings; deep jets; equator-trapped Rossby gravitational waves; equatorial long waves; equatorial waves; meanders and long waves; edge waves; double Kelvin waves.
NIt should be noted that the possibility of the formation of long-period waves in the ocean was first shown by theoretical calculations: Kelvin waves (1880), slow large-scale fluctuations (low-frequencycurrent fluctuations) called planetary waves or Rossby waves (1938), topographic, shelf waves (longshelfwaves, continentalshelfwaves) , captured by the shore (coastal-trapped waves), captured by the equator of waves. Waves in the ocean and Great Lakes began to be recorded in the 1960s.
Naturally, they tried to identify the large variability in the speed and direction of currents observed in the ocean with existing models obtained theoretically: with Rossby waves, Kelvin waves, with topographic waves, etc.
The main difference between the observed waves and the theoretically calculated ones is that the observed waves have a large transfer of water masses, while theoretical calculations show that the transfer of water masses in the wave is small. Therefore, in our opinion, it is advisable to call the actual variability in the speed and direction of currents long-period wave currents (LPWT), currents of a wave nature. The necessary features of such currents are: a) periodic variability; b) presence of phase velocity. Moreover, the phase velocity and direction of phase propagation must be shown and calculated from observations.
Long-term instrumental observations of currents of wave nature have become possible with the advent of autonomous current meters.
Figure 2 (left) shows the meridional component of the equatorial current in the form of Rossby waves at a depth of 10 m. (WeisbergR. H.1984), in the same figure on the right - the depth profile of the zonal velocity component (in cm/s) at the point 0°-35°W, in April 1996, received on the voyage of the R/V Elambor 2 (GouriouY., BourlesB., MercierH., ChuchlaR. 1999).It is clearly visible that the current exists to a depth of 4500 m.
Rice. 2. Meridional component of the equatorial current in the form of Rossby waves at a depth of 10 m. (WeisbergR. H.1984) (left); depth profile of the zonal velocity component (in cm/s) at the point 0°-35°W, in April 1996, received on the voyage of the R/V Elambor 2 (GouriouY., BourlesB., MercierH., ChuchlaR. 1999). (right).
There are many measurements of wave nature currents of varying quality, and they are represented in illustrations in different ways. Measurements that lasted 30 years at the equator of the Pacific Ocean are exemplary. (TOGO -TAO) (Fig. 3,4).
In Fig. 3 current of wave nature (period of 20 days), having a constant component, which reaches 150 cm/s in summer, and decreases to 0 cm/s (or has a negative direction) in winter. The amplitude of wave changes is up to 90 cm/s. In Fig. Figure 4 shows the meridional component - fluctuations in current speed in the north-south direction, without a constant component. Packages are visible, i.e. time periods when the amplitude of current variability is large are interspersed with periods when the amplitude of current variability is small.
Rice. 3. An example of measuring the current at the equator of the Pacific Ocean at the point
0°, 110° W, at a depth of 10 m, zonal component (W - E).
Rice. 4. An example of measuring the current at the equator of the Pacific Ocean at the point
0°, 110° W, at a depth of 10 m, meridional component.
The equatorial current reaches the coast of Brazil, and part of the flow flows along the northern coast of Brazil into the Caribbean Sea, the other part turns south (Fig. 5). The results of measuring the speed and direction of currents at 6 horizons to a depth of 3235 m are also presented here. The current changes periodically and has a constant component.
The northern branch of the current passes through the Caribbean Sea, the Gulf of Mexico and flows in a powerful jet through the Strait of Florida into the Atlantic Ocean. (shown using drifter trajectories in Fig. 6 left).
Rice. 5. Variability of current speed off the coast of Brazil (Fischer J ., Schott F . A . 1997).
Rice. 6. Trajectories of drifters in the Caribbean Sea and the Gulf of Mexico and the beginning of the Gulf Stream (left), 240 trajectories of SOFAR (SoundFixingAndRanging) neutral buoyancy floats in the North Atlantic at depths from 700 to 2000 m (Philip L. Richardson 1991) (right).
Very interesting results of drifters passing along their trajectories are presented in Fig. 6 (right). There are 240 trajectories presented here. The author (Philip L. Richardson 1991) begins the article with the phrase “We will show you something amazing.” Of course, for many it is surprising even now, more than 20 years after the publication of this article. Most people still believe that the Gulf Stream is a geostrophic jet current. The author of the article believes that the currents in the Gulf Stream and in adjacent areas are of a vortex nature (Fig. 6 on the right). The text of the article states that some of the vortices are cyclonic in nature, some are anticyclonic. Such a current cannot be geostrophic. And cannot be formed by uneven density.
Rice. 7. Three medium-scale eddies that followed in the eastern Atlantic for a long time (PhilipL. Richardson. 1991).
The same work presents the trajectories of drifters carried away by medium-scale eddies in the eastern Atlantic (Fig. 7). Three vortices were tracked over a period of two years, a year, and a year and a half (MEDDY 1,2,3, respectively).
Rice. 8. Spatial distribution of current velocity vectors in the wave (a) and in the vortex (b), which move with phase velocities of 2 cm/s.
But there are different opinions about the nature of the observed vortex movements in the ocean.
Zakharchuk (2010) shows the spatial distribution of current velocity vectors in a wave and in a vortex (Fig. 8). In a wave, the vectors are located along the direction of movement of the wave. In a vortex, the vectors are located tangent to the circular motion.
In Fig. Figure 9 shows the variability of current speed in the Gulf Stream. The nature of variability convinces us that the Gulf Stream has a wave nature. It is not jet, not geostrophic. And clearly not thermohaline. Velocity of a mass of water measuring 500 × 100 × 1 km. first increases, reaches a maximum, then decreases, sometimes almost to zero. And it increases again. Such a process can only occur in a wave.
Rice. 9. Variability of the speed of movement of drifter No. 12046 in the Gulf Stream. (Bondarenko A. L. 2009).
Thus, along the entire perimeter of the large-scale circulation, wave currents are observed throughout its entire length. You can say more specifically: “The flow of large-scale circulation (and the Gulf Stream too) is the averaged movement of a current of wave nature.”
This conclusion is confirmed by numerous observations. “From 1959 to 1971, there were 350 ABS productions in the Western Atlantic Ocean of the United States. Of particular interest are long-term (with interruptions) observations on the section 70° W. d. Detected period of speed fluctuations in the bottom and surface layers equal 30 days. Apparently, these fluctuations are caused topographic Rossby waves. It is interesting to note that the position of the Gulf Stream changes with the same periodicity.” (Baranov E.I. 1988).
“Drifter observations have become widespread over the past 30 years.
A long-term experiment to determine the trajectory of current speed in the Gulf Stream core was carried out in June-November 1975. During this experiment, the trajectory and drift speed from Florida to 45° W were reliably determined. In this section of the trajectory, the buoy was located within the core of the Gulf Stream, somewhat to the right of the Gulf Stream front. From Florida to Cape Hatteras, speeds were within 200 cm/s. High velocities in the core, more than 100 cm/s, were observed up to 55° W. d. Further, the nature of the drift, the value of the velocities changes sharply, which could be the reason for the release of the buoy from the core of the Gulf Stream-North Atlantic Current system and its entry into one of the southern branches of this system.” (Baranov E.I. 1988).
“Before approaching Cape Hatteras, the Florida Current follows from the Straits of Florida along the continental slope and crosses the Blake Plateau (Fig. 10, between 72° and 65°W). Depths in this area are 700-800m. Propagating to the bottom, the current moves the entire mass of water from the surface to the bottom. The addition of the Antilles Current to the Florida Current increases the flow of the Gulf Stream.
In the Cape Hatteras region, two processes occur that qualitatively and quantitatively change transport. In this area, the Gulf Stream turns away from the edge of the continental shelf towards the open ocean. The ocean depths along the trajectory at the turning point increase at a distance of 20 km. from 1000 to 2000 m (bottom slope here is 5%, and then at a distance of 150 km, from 2000 to 3000 m (bottom slope 1.5%).
After passing through the region 60-78° W, where flow rates reach maximum values, a sharp decrease is observed. In the 0-2000 m layer, flow rates decrease from 89 sv. at 68-70° W up to 49 St. at 60°W This sharp decrease can be explained by the following factors. In the area between 60-65° passes underwater mountain range New England (Fig. 10)." (Baranov E. I. 1988).
Rice. 10. Relief of the ocean bottom in the Gulf Stream area after the passage of Cape Hatteras.
“The area located south and southeast of the Great Newfoundland Bank is called the Gulf Stream delta. Moving east of 50° W. The Gulf Stream meets in its path the southeastern Newfoundland submarine ridge, which stretches from northwest to southeast from the edge of the Great Newfoundland Bank to 39°N, 44°W. This ridge, like the New England underwater mountain range, acts as a barrier to the Gulf Stream, which extends to the bottom here. Here the Gulf Stream itself begins to branch into a number of branches - the northern, central and southern branches of the North Atlantic Current. The southern branch of the Gulf Stream (Canary Current) extends to the south.
The main, central branch of the North Atlantic Current crosses the Newfoundland Ridge and, turning sharply to the north, follows the 4500 m isobath. Having reached a latitude of 50° N. w. on the meridian 40° W. d., the central branch turns to the northeast. At the latitude of Scotland, this branch, together with the northern branch, forms the Irminger Current. The main part of it, having crossed the Whyville-Thomson threshold, passes into the Norwegian Sea under the name of the Norwegian Current.
The southern branch of the North Atlantic Current is formed from that part of the Gulf Stream that bends around the Newfoundland Ridge from the south and follows east along 42-45° N. w. After crossing the Mid-Atlantic Ridge, this branch deviates to the right and continues in the form of an unstable flow to the south between the Azores and Spain and, under the name of the Portuguese Current, gives rise to the Canary Current” (Baranov E.I. 1988).
Rice. 11. Drifter trajectories in the northern Atlantic (ArturMoriano website)
Due to the widespread occurrence of drifter observations, attempts were made to trace all of the above-described currents (a continuation of the Gulf Stream) along drifter trajectories. According to one data (Bondarenko A.L.), out of 100 drifters launched in the Strait of Florida, only one reached the shores of Iceland. The rest, a small part, went to the left, into the Labrador Current, the majority deviated to the right and headed south and southeast. According to other sources, out of 400 drifters, only one reached the shores of England. It was even concluded that the Gulf Stream does not transport water masses, and heat is transferred by turbulence.
Data from drifter observations on the website oceancurrents.rsmas.miami.edu/at helped clarify the situation.
In Fig. 11 vectors and colors indicate current speeds. From the color scale you can see that near the Straits of Florida the speeds are close to 70 cm/s, from Cape Hatteras to the Newfoundland Bank the speeds are about 100 cm/s. Further, the width of the flow increases and the speed decreases to 20 cm/s. That is, the location and color of the vectors confirms the patterns of current movement described above and its deviation to the right near Cape Hatteras. And then a significant expansion of the flow. Formation of the southern branch (Fig. 11). The color turns blue (20 cm/s). Vectors are spaced less frequently.
Rice. 12. Transition from the Gulf Stream to the North Atlantic Current (left). Trajectories of drifters in the North Atlantic.
Rice. 13. Area of the Irminger Current (near Iceland) (left), drifters from the North Atlantic Current in the Irminger Current (right).
In Fig. 11 the current is presented up to 23° W. e. We see the continuation of the flow in the next Fig. 12 (right). From the area 30-25° W. d., 54°N. The Irminger current begins in the northwest direction (Fig. 13). From latitude 20°W (Fig. 12 on the right) a branch of the North Atlantic Current has been formed, which passes past England to the shores of Norway (Fig. 14).
Figure 14 shows the trajectories of three drifters launched at longitude 37° W. and 52° N. w. Two of them reached the prime meridian, and one passed along the coast of Norway.
So, we traced the path of drifters from the Strait of Florida to the coast of Norway, a branch to the south, to the northwest (Irminger Current), and into the North Atlantic Current.
How can we explain that out of hundreds (100, 400) drifters launched in the area of the Strait of Florida, only a few reach the end of the North Atlantic Current? It's very simple to explain. Even if you launch drifters in a river (jet current), as a result of turbulence and friction against the banks, the drifters will approach the banks, and gradually everyone will end up on the shore.
Rice. 14. Trajectories of drifters in the North Atlantic and Norwegian Currents.
Meanwhile, ALL the water passes downstream. The Gulf Stream has a wave nature and great variability in speed. The influence of bottom irregularities and the deep western countercurrent (Labrador Current), as well as the wave nature, is great. Drifters, reaching the edge of the current, the liquid banks, easily cross the boundaries of the current and leave it. In order to trace the flow further, it is possible to propose launching the same number in the section where approximately half of the drifters remain. Of course, one must take into account the obvious fact that the volume of water in the North Atlantic Current is a small part of the Gulf Stream, since a significant amount of water goes into branches to the south, then to the left (Irmingham Current). It is difficult to specifically quantify the proportion of water directly from the Gulf Stream in different branches of the North Atlantic Current. To qualitatively represent the distribution of Gulf Stream waters among its branches, you can use maps of the distribution of heat in the North Atlantic (Fig. 16 a, b, c) carried by different branches.
Data on the distribution of temperature on three horizons of the North Atlantic can be found in the atlas of the Atlantic Ocean:
AtlanticOcean. WOCE Hydrographic Atlas and Global Climatology. N3. CD.
Let us consider the heat distribution at a horizon of 200 m along the path of the Gulf Stream (Fig. 15a). In the Straits of Florida, the water temperature is 20°C. After passing Cape Hatteras, the temperature is 18°C. At the Newfoundland Bank the water temperature is 14.5° - 17°C (along the north-south section). At the Whyville-Thomson rapids (along the line from Ireland to England) the water temperature is 8.5° -10°C (across the current). And then, in a narrow stream, water with a temperature of 8.5° -10°C flows to the shores of Norway.
A). Temperature at hl. 200 meters
b). Temperature at hl. 500 m.
Figure 15. Temperature distribution at a depth of 200 m. a), at a depth of 500 m. b).
At a depth of 500 m, water with a temperature of 15°-16.5°C comes out of the Strait of Florida in a very thin stream. On the left along the shore is the cold water of the Labrador Current. After passing Cape Hatteras, the temperature is 18°C. At the Newfoundland Bank, the water temperature is 4.5° - 12°C (along the north-south section). Before the Whyville-Thomson rapids (perpendicular to the line from Ireland to England) the water temperature is 7° -9°C (along the current). Warm water at depth does not pass beyond the Whyville-Thomson threshold. It is located in the area south of Iceland to Ireland, and further south. Beyond the Thomson threshold, the water temperature is from 2° to 5°C. That is, we see that the warm water of the Gulf Stream-North Atlantic Current at a horizon of 500 m does not pass beyond the Thomson threshold.
Let's consider the distribution of water temperature at a depth of 1000 m. Along the northern coast of the Gulf of Mexico, in the Strait of Florida and further along the coast of America to M. Hatteras on the map (Fig. 16 c. - blue), which corresponds to cold water of 3.5 ° C. But the fact is that from the Strait of Florida to Cape Hatteras the depth is 700-800 m (Blake Plateau). The bottom is practically marked here. In Hatteras, the Gulf Stream turns away from the edge of the continental shelf toward the open ocean. The ocean depths along the trajectory at the turning point increase at a distance of 20 km. from 1000 to 2000 m (the bottom slope here is 5%, and then at a distance of 150 km, from 2000 to 3000 m the bottom slope is 1.5%). From Cape Hatteras further than the Newfoundland Bank, the water temperature at a horizon of 1000 m is 7°-12°C, and near the Whyville-Thomson threshold the water temperature increases to 13-14°C. Beyond Thomson's threshold the water is cold.
The results of this analysis are shown in Table 1.
IN). Temperature at hl. 1000 m.
Rice. 15th century Temperature distribution at a depth of 1000 m.
Table 1.
|
Straits of Florida |
Cape Hatteras |
Newfoundland Jar |
At the threshold Thomson |
Beyond the threshold Thomson |
|
Horizon 200 m. 20° Horizon 500 m. 15°-16.5°С Gor. 1000 m. No (depth 700-800 m). |
18° 18° 7°-12°С |
14.5° - 17°C 4.5° - 12°С 7°-12°С |
8.5° -10°С 4.5° - 12°С 13-14°С |
8.5° -10°С 2° to 5°C 2° to 5°C |
“On the left side of the Gulf Stream there is a cold Labrador Current. “In October 1962, in the area of Cape Hatteras at a depth of 800-2500 m, a flow directed to the south was instrumentally recorded. To the north and south of Cape Hatteras, the deep western boundary current (WBC) was located at some distance from the Gulf Stream. In the area of Cape Hatteras, the WBC was located directly near with the core of the Gulf Stream.
Long-term series of measurements of bottom currents along the 70° W meridian. Averaging over 240 days. Gor. 200 and 1000 m. Average speeds 2.5-4.9 m/sec.
The water mass of the GZPT south of Cape Hatteras is identical to the deep flow from the Labrador Basin to the Cape Hatteras area and further south.
There is still an unresolved problem associated with HRT. According to all the data presented, the Florida Current and the Gulf Stream near Cape Hatteras, as well as to the south and northeast of it, extend to the ocean floor. At the same time, the GZPT also spreads to the ocean floor. To the northeast of Cape Hatteres, the GZPT is located on the left flank of the Gulf Stream, and to the south it is on its right flank. According to (KnaussJ. A. 1969), the GZPT passes through the Gulf Stream in the area of Cape Hatteras"(Baranov E.I. 1988).
This gives reason to assume that the beginning of the Antilo-Guiana deep countercurrent, the continuation of which is the Equatorial countercurrent, was recorded here. Essentially these are the components cyclonic large-scale circulation in the North Atlantic. Similar circulations exist separately in the northern and southern parts of the three oceans.
So, analysis of observations, instrumental and drift, shows the same picture of the Gulf Stream current system, which is given in Equipedia.
Why does the Gulf Stream exist? There are different opinions.
Some believe “that the hot and cold waters of the Atlantic Ocean form a kind of conveyor belt. Hot equatorial waters rise to the top and form a current, and when they reach the end of the path, they cool. At the same time, they sink down into the water column and move back to the beginning of the flow. This is how the warm Gulf Stream exists.” (Wikipedia).
Others believe that “on a planetary scale, the Gulf Stream, like any global current, is determined primarily by the rotation of the Earth, which accelerates the tropical trade winds, trade wind currents, including the Northern Trade Wind Current, pushes an excess amount of water into the Caribbean Sea, determines the Coriolis force, pressing the current towards the eastern coast of the American continent. Locally, in each individual region, the direction and nature of the current is also determined by the outline of the continents, temperature conditions, salinity distribution and other factors.” (Wikipedia).
Due to the fact that there are serious disagreements about the basic laws of formation and existence of the Gulf Stream, it is advisable to consider the data of numerous instrumental observations. This will allow you to choose the one that most likely corresponds to reality from various points of view.
The first important note: the Gulf Stream is not the only, unique current in the Ocean. There are 5 more such currents, 2 in each ocean - the Atlantic, Pacific and Indian Oceans. In the Atlantic, the Gulf Stream flows to the north and the Brazil Current to the south. In the Pacific Ocean, the Kuro-Sio Current goes to the north, the Australian Current goes to the south, in the Indian Ocean the Somali Current goes to the north, and the Cape Verde Current (Mozambique) goes to the south. That is, separate large-scale anticyclonic circulations are formed in the northern and southern parts of the three oceans, and the Gulf Stream and similar currents are part of these circulations. The diagram of ocean currents in the Atlantic Ocean is shown in Fig. 16 (Dobrolyubov A.I. 1996).
Rice. 16. Structural similarity of large-scale currents in the Pacific,
Atlantic and Indian oceans. (Dobrolyubov A.I. 1996).
“The pattern of ocean currents is in full accordance with air currents - by the winds. Extensive oceanic water cycles, which originate from trade winds currents, respond both in the direction of movement and in the position of the anticyclonic air movement over the oceans in the Northern Hemisphere clockwise, in the Southern Hemisphere counterclockwise.” (Brief geographical encyclopedia. Publishing house "Soviet Russia" M. 1962.).
But there are also doubts about the wind nature of ocean circulation. Nikiforov E.G. (Institute of the Arctic and Antarctic) at the First Congress of Soviet Oceanologists (1977) said: “The problem of explaining modern water circulation cannot be considered satisfactorily resolved even at the level of qualitative hypotheses. Hypotheses about the wind origin of water circulation do not explain deep circulation, and the hypothesis about the thermohaline nature of water circulation is based mainly on the existing density field. Therefore, it is also impossible to draw any conclusions about the nature of water circulation based on calculations made using the actual density field.”
Indeed, trade winds only affect the upper layer of the water mass (up to 200 m). Whereas the current in equatorial regions is observed to a depth of 4–5 km. Similarly, the wind influence (vorticity) on the entire northern (southern) part of the three oceans is limited to the upper horizons up to 200 m, while currents are observed to depths of 3000-4000 m.
Regarding the thermohaline nature of the Gulf Stream, Stommel wrote: “It was also established that density differences across the Gulf Stream have nothing to do with the driving force of the Gulf Stream, but simply represent part of the equilibrium caused indirectly by the action of the wind” (Stommell 1963, p. 27).
Ferronsky V.I. (Dynamics of the Earth) put forward a hypothesis according to which the water masses of the oceans lag behind the speed of rotation of the Earth, the movement of water reaches the western shores of the oceans, the current deviates to the north and south, and large-scale anticyclonic circulations arise. Previously, such a hypothesis was expressed by I. Kepler.
And finally, the most physically substantiated hypothesis regarding the cause of the emergence and existence of equatorial currents was expressed by I. Kant (1744). Astronomical observations have shown that the Earth's rotation speed is slowing down (the theory of the evolution of the Earth's rotation speed) (Monin, Shishkov). Various explanations have been put forward for the reason for this process. I. Kant suggested that the Moon (and the Sun) drags water along the equator, a current arises from east to west, which, by friction with the bottom, slows down the rotation speed. Subsequently (Broche P., Sundermann J. Die Gezeiten des Meeres und die Rotation der Erde. PureAppl. Geophys., 86, 95-117, 1971) suggested that the deceleration occurs due to viscous negative torques.
It can also be assumed that equatorial currents, having high kinetic energy, create a negative torque when they act on the eastern shores of the continents and turn north and south. This assumption is more physically reliable.
Immanuel Kant's hypothesis was not recognized for 100 years under the influence of Laplace. At present, there is no doubt that it is the impact of the forces of the Moon and the Sun on water masses in the equator region that leads to the formation of equatorial currents. This point of view is shared by about 20 researchers: Avsyuk Yu. N., Suvorova I., Svetlozanova I.; Dobrolyubov A. I. 1996, Garetsky R. G.; Monin A. S., Shishkov Y.; KantI.; LeBlondP. H., MysakL. A., Broche, SündermannJ.; GrovesG. V.; MornerN. A.; MunkW., WunschC.; EgbertG. D., RayR. D.
In the Encyclopedia of Geography (1960), in the article “Tidal Friction,” Juan J. Pattullo writes, “Harold Jeffreys estimated that each day about half of all tidal energy is wasted by friction on the bottom in shallow seas, such as the shallow Bering Sea. In theory, this friction should gradually slow down the Earth's rotation. There is some evidence (from the daily growth rings of corals) that 400 million years ago the number of days in a year was more than 400; in addition, there is some astronomical data indicating the same thing.”
“Has the Earth undergone some changes in its rotation around its axis, due to which the change of day and night occurs, since its origin?” I. Kant asks the question in an article in which he substantiated the slowdown of the Earth’s axial rotation by tidal friction of the waters of the World Ocean.
Thoughts of the philosopher: “Under the influence of lunar gravity, sea tides move from east to west and slow down the earth’s rotation... True, notes I. Kant, if we compare the slowness of this movement with the speed of the earth’s rotation, the insignificance of the amount of water with the enormous size of the globe, it may seem, that the effect of such a movement should be considered equal to zero. But if, on the other hand, we take into account that this process is carried out tirelessly and eternally, that the rotation of the Earth is a free movement, the slightest loss of which remains unrecovered, then it would be a completely unbecoming prejudice for a philosopher to declare this small effect of no importance.” (I. Kant, 1754).
So, the most physically substantiated reason for the formation and existence of large-scale anticyclonic circulations (and, consequently, the Gulf Stream, Kuroshio, etc.) is the daily impact of the tidal forces of the Moon and the Sun on water masses in equatorial regions. It is quite clear that the magnitude of the forces (annual average) does not change due to changes in average temperature or any other reasons. The average speed of equatorial currents remains constant, and therefore the speed of the Gulf Stream and similar currents cannot slow down or stop completely. But since the Gulf Stream determines the climate of Europe, it is necessary to understand the patterns of variability of this current along its route from the Strait of Florida to the coast of Norway, which is one of the reasons for changes in the transfer of heat and its influence on weather and climate.
Literature
Baranov E.I. Structure and dynamics of waters of the Gulf Stream system. M. Gidrometeoizdat, 1988.
Dobrolyubov A.I. Traveling tidal waves of deformation as a generator of global geophysical processes. // Litasfera No. 4, 1996, p. 22-49. Minsk.
Zakharchuk E. A. Synoptic variability of level and currents in the seas washing the northwestern Arctic coast of Russia. St. Petersburg 2008. 358 p.
Brief geographical encyclopedia. Publishing house "Soviet Russia" M. 1962.
Stommel G. Gulf Stream. Physical and dynamic description. 1963 M.I.L.
Ferronsky V.I., Ferronsky S.V. Earth dynamics. M. Scientific world. 2007 335 p.
Shokalsky Yu. M. Oceanography.L. Gidrometeoizdat. 1959 537 p.
Shchevyev V. A. Physics of currents in oceans, seas and lakes. A history of searches, reflections, misconceptions, discoveries. 2012 312 p. LAMBERTAcademic Publishing.
ISNB: 978-3-8484-1929-6
Shchevyev V. A. Physics of currents in oceans, seas and lakes.
Broche P., Sundermann J. Die Gezeiten des Meeres und die Rotation der Erde. PureAppl. Geophys., 86, 95-117, 1971).
Kant I. Study of the question of whether changes could have occurred in the rotation of the Earth around its axis, causing the change of day and night, from the first days of its appearance and how this can be found out. 1754 g.
Knauss J. A. A note on the transport of the Golfstream. – Deep-Sea Res., 1969, vol. 16, p. 117-123.
Website oceancurrents.rsmas.miami.edu/at ... orida.html (Artur Moriano).
AtlanticOcean. WOCE Hydrographic Atlas and Global Climatology. N3. CD.
Warm Current Gulf Stream is a huge current in the Atlantic Ocean, with a fairly high temperature. In more specific terms, the Gulf Stream is a current flowing along the entire east coast of North America, extending from the Straits of Florida to the Newfoundland Bank. And in a broad sense, the Gulf Stream is the general name for the system of warm currents in the North Atlantic Ocean.
This is a fairly powerful jet current, approximately 70-90 km wide and deep almost to the very bottom. The maximum current speed varies from several meters per second on the surface to 10-20 centimeters at the bottom. The total water consumption of the Gulf Stream is 50,000,000 m3 every second, which is more than all existing rivers combined. Only thanks to the warm Gulf Stream, all European countries adjacent to the Atlantic Ocean have a milder climate than Southern Siberia, located at the same latitude.
At the same time, the winds passing through this current bring such an amount of heat to Northern Europe that in winter it is about 15-20 degrees higher than it should be. That's why seaports in Norway, as well as our port in Murmansk, are not covered in ice all year round. During the Cold War, and particularly tense relations with the Old World, the United States developed European freeze plan. According to their idea, it was necessary to adjust the current so that the Gulf Stream sailed back along the east coast, rather than crossing the Atlantic Ocean. Nothing came of this, and the current gives warmth as before.
What is noteworthy is that the first mention of this movement was the story of Christopher Columbus, and it was then that Europeans paid attention to it. He encountered it in 1492 while sailing to the lands of the New World. The next conquistador was the Spaniard Ponce de Leon, who attempted to pass through the Gulf of Mexico, past peninsula florida, and discovered an amazing thing: his ship was under full sail, and was moving in the opposite direction with a fair wind.
Previously, sailors had repeatedly noted a similar fact, without finding an explanation for it, but indicated on the maps the fact that the current helps to return home to Europe faster than to fight this obstacle on the way to America. But the scientific study of the current was first undertaken by the American scientist, and later US President Benjamin Franklin, in 1770. It was he who noted its approximate course along the entire length of the route, and gave it the name now known to the whole world.
Everyone knows from school that the Gulf Stream warms entire continents. So imagine what will happen when it completely changes direction. Now this process is underway and this explains many natural disasters...
Scientists have confirmed that the famous ocean current, the Gulf Stream, has finally changed its direction. Now it does not reach Spitsbergen, but turns towards Greenland, which contributes to warmer weather on the American continent, but “freezes” northern Siberia.
The shutdown of the Gulf Stream was first reported by Dr. Dr. Gianluigi Zangari, a theoretical physicist at the Frascati Institute in Italy, in a journal article on June 12, 2010. The article is based on satellite data from the Colorado Aerodynamic Research Center, coordinated with the US Navy's National Oceanic and Atmospheric Administration . The author pointed out the stopping of the rotation of water flows in the Gulf of Mexico and the breaking of the Gulf Stream into parts. Subsequently, the images were changed on the server of the Colorado Aerodynamic Research Center and now it is difficult to say by whom and when.
How did the current go?
The cold and denser Labrador Current “dived” under the warm and lighter Gulf Stream, without preventing it from warming Europe, reaching Murmansk. Then the Labrador Current “surfaced” off the coast of Spain under the name of the cold Canary Current, crossed the Atlantic, reached the Caribbean Sea, heated up and, passing through a loop in the Gulf of Mexico, already under the name of the Gulf Stream, freely rushed back to the North.
The Gulf Stream was part of the thermohaline circulation system, a key element in the planet's thermal regulation. It separated England and Ireland from becoming a glacier. Smoothed out the climate in the Scandinavian countries.
After Dr. Zangari's message, the Canadian Parliament created a commission to find out the real state of affairs with the Gulf Stream near the coast of the state. It was headed by the famous US oceanologist Ronald Rabbit, a technologist for processing the biomass of the World Ocean and improving the environment. A special dye that does not harm the flora and fauna of the ocean was poured into containers that exploded at a certain depth and, thus, the flow of movement of water masses was tracked. The Gulf Stream was not discovered as an existing current.
But, as it turned out, the self-regulating system called “worked” this time too. According to research, the current “crept” 800 miles (1,481 kilometers) east of the former Gulf Stream zone. According to satellite images, the temperature of this current has increased relative to the Gulf Stream. This means that the evaporation rate in the warm zone above the ocean has increased.
A small digression: most people believe that moist air is heavier than dry air, but this is not true. Molecules of oxygen O2, carbon dioxide CO2 and nitrogen N2 are heavier than water molecules H2O.
What does this change mean for us?
Presumably, a very cold winter of up to -45 degrees and little snow in the European part of Russia, Western Europe will be covered with snow, and hurricane winds will rage on the border of the fronts. In mid-February 2011, instead of frost, spring came in Canada with a temperature of +10. America, apparently, will also not be left without a “carrot”. This is confirmed by the recent cold weather in Montana, South Dakota, Texas, Arkansas and Tennessee.
Main world ocean currents. The Gulf Stream originates in the Gulf of Mexico, heads towards Europe (dark color of the “river”), turns towards Greenland, cools (gray, light color of the “river”), sinks to depth, and flows south. According to new data, the channel of the Gulf Stream (surface warm flow) has recently deviated towards Greenland by 800 km.
If you liked this material, then we offer you a selection of the best materials on our site according to our readers. You can find a selection of TOP interesting facts and important news from around the world and about various important events where it is most convenient for youIn Western Europe, as well as on the east coast of the United States, the climate is quite mild. Thus, on the coast of Florida, the average water temperature is very rarely below 22° Celsius. This is during the winter months. In summer, the air heats up to 36°-39° Celsius with humidity reaching 100%. This temperature regime extends far to the east and north. It covers the states: Arkansas, Alabama, Mississippi, Tennessee, Texas, Kentucky, Georgia, Louisiana, as well as North and South Carolina.
All these administrative entities lie in an area of humid subtropical climate, where the summer average daily temperature does not fall below 25° Celsius, and in the winter months it very rarely drops to 0° Celsius.
If we take Western Europe, then the Iberian, Apennine and Balkan peninsulas, as well as the entire southern part of France, are located in the subtropical zone. Summer temperatures there range from 26°-28° Celsius. In winter, these indicators drop to 2°-5° Celsius, but almost never reach 0°.
In Scandinavia, the average winter temperature ranges from minus 4° to 2° Celsius. In the summer months it rises to 8°-14°. That is, even in the northern regions the climate is quite acceptable and suitable for comfortable living.
Gulf Stream Current
This temperature bliss occurs in a vast region for a reason. It is directly connected with the Gulf Stream ocean current. It is what shapes the climate and gives people the opportunity to enjoy warm weather almost all year round.
The Gulf Stream is a whole system of warm currents in the North Atlantic Ocean. Its full length covers a distance of 10 thousand kilometers from the sultry shores of Florida to the ice-covered islands of Spitsbergen and Novaya Zemlya. Huge masses of water begin to move in the Strait of Florida. Their volume reaches 25 million cubic meters per second.
The Gulf Stream moves slowly and majestically along the east coast of North America and crosses 40° N. w. Near the island of Newfoundland it meets the Labrador Current. The latter carries cold waters to the south and forces warm water flows to turn east.
After such a collision, the Gulf Stream splits into two currents. One rushes north and turns into the North Atlantic Current. This is what shapes the climate in Western Europe. The remaining mass reaches the coast of Spain and turns south. Off the coast of Africa, it meets the North Trade Wind Current and deviates to the west, ending its journey in the Sargasso Sea, from which it is a stone's throw to the Gulf of Mexico. Then the cycle of huge masses of water repeats.
This has been going on for thousands of years. Sometimes a powerful warm current weakens, slows down, reduces heat transfer, and then cold falls on the ground. An example of this is the Little Ice Age. Europeans observed it in the XIV-XIX centuries. Every heat-loving resident of Europe has experienced first-hand what a real frosty, snowy winter is like.
True, before this, in the 8th-13th centuries there was a noticeable warming. In other words, the Gulf Stream was gaining power and releasing a very large amount of heat into the atmosphere. Accordingly, on the lands of the European continent the weather was very warm, and snowy, cold winters had not been observed for centuries.
Nowadays, powerful warm streams of water also influence the climate as in former times. Nothing has changed under the sun, and the laws of nature remain the same. But man has come very far in his technological progress. His tireless activities triggered the Greenhouse Effect.
The result was the melting of the ice of Greenland and the Arctic Ocean. Huge masses of fresh water poured into the salt waters and rushed south. Nowadays, this situation is already beginning to affect the powerful warm current. Some experts predict an imminent stop of the Gulf Stream, since it will not be able to cope with the influx of incoming waters. This will entail a sharp cooling in Western Europe and the east coast of North America.
The situation was aggravated by the largest accident at the Tiber oil field in the Gulf of Mexico. Underwater in the bowels of the earth, geologists have found huge oil reserves, estimated at 1.8 billion tons. Experts drilled a well, the depth of which was 10,680 meters. Of these, 1259 meters were in the ocean water column. In April 2010, a fire broke out on an oil platform. It burned for two days and claimed the lives of 11 people. But it was, although tragic, a prelude to what happened after that.
The burnt platform sank, and oil began to flow from the well into the open ocean. According to official sources, 700 tons of oil entered the waters of the Gulf of Mexico per day. However, independent experts gave a different figure - 13.5 thousand tons per day.
The oil film, huge in its area, hindered the movement of Atlantic waters, and this, accordingly, began to negatively affect heat transfer. Hence, there was a disruption in the circulation of Atlantic air flows. They no longer had the strength to move east and create the usual mild climate there.
The result was a terrible heat wave in Eastern Europe in the summer of 2010, when air temperatures rose to 45° Celsius. This was caused by winds from North Africa. They, without encountering any resistance on their way, brought a hot and dry cyclone to the north. It hovered over a vast territory and stayed above it for almost two months, destroying all living things.
At the same time, Western Europe was shocked by terrible floods, as heavy, moisture-filled clouds coming from the Atlantic did not have enough strength to break through the dry and hot front. They were forced to dump tons of water onto the ground. All this provoked a sharp rise in river levels and, as a result, various disasters and human tragedies.
What are the immediate prospects, and what awaits old Europe in the near future? Experts say that dramatic climate changes will begin to be felt as early as 2020. Western Europe faces cooling and rising sea levels. This will provoke impoverishment of the middle class, since its money is invested in real estate, which will sharply fall in price.
From here, political and social tension will arise in all layers of society. The consequences of this can be the most tragic. It is simply impossible to predict anything specific, since there are many scenarios for the development of events. Only one thing is clear: difficult times are coming.
The Gulf Stream, nowadays, thanks to global warming and the disaster in the Gulf of Mexico, is practically closed in a ring and does not provide sufficient thermal energy to the North Atlantic Current. Accordingly, air flows are disrupted. Completely different winds are beginning to dominate over European territory. The usual climate balance is being disrupted - this is already noticeable with the naked eye.
In such a situation, anyone can be overwhelmed by a feeling of anxiety and hopelessness. Of course, not for the fate of hundreds of millions of people, since this is too vague and unclear, but for the specific fate of their relatives and friends. But it is premature to despair, let alone panic. Nobody knows how it will actually be there.
The future is full of surprises. It is entirely possible that global warming is not global warming at all. This is a normal increase in temperatures as part of the climate cycle. Its duration is 60 years. That is, for six decades the temperature on the planet has been steadily increasing, and over the next 60 years it has been slowly decreasing. The beginning of the last cycle dates back to the end of 1979. It turns out that half the journey has already been completed and we only have to wait 30 years.
The Gulf Stream is too powerful a stream of water to simply change direction or disappear. There may be some failures and deviations, but they will never turn into global and irreversible processes. There are simply no prerequisites for this. At least these days they are not observed.
Yuri Syromyatnikov
