The Gulf Stream in the Atlantic Ocean - Overview The Warm Ocean Current Flows from The Gulf of Mexico into the Atlantic Ocean The Gulf Stream results in beaches with warm water. Stockbyte/ Stockbyte/ Getty Images By Amanda Briney, Contributing Writer The Gulf Stream is a strong, fast moving, warm ocean current that originates in the Gulf of Mexico and flows into the Atlantic Ocean . It makes up a portion of the North Atlantic Subtropical Gyre. The majority of the Gulf Stream is classified as a western boundary current. This means that it is a current with behavior determined by the presence of a coastline - in this case the eastern United States and Canada - and is found on the western edge of an oceanic basin. Western boundary currents are normally very warm, deep, and narrow currents that carry water from the tropics to the poles. The Gulf Stream was first discovered in 1513 by the Spanish explorer Juan Ponce de Leon and was then used extensively by Spanish ships as they travelled from the Caribbean to Spain. In 1786, Benjamin Franklin mapped the current, further increasing its usage.

Path of the Gulf Stream Today, it is understood that the waters feeding into the Gulf Stream begin flowing off the west coast of Northern Africa (map) . continue reading below our video What are the Seven Wonders of the World There, the Atlantic North Equatorial Current flows from that continent across the Atlantic Ocean. Once the current reaches eastern South America, it splits into two currents, one of which is the Antilles Current. These currents are then funneled through the islands of the Caribbean and through the Yucatan Channel between Mexico and Cuba. Because these areas are often very narrow, the current is able to compress and gather strength. As it does so, it begins circulating in the Gulf of Mexico’s warm waters. It is here that the Gulf Stream becomes officially visible on satellite images so it is said that the current originates in this area. Once it gains enough strength after circulating in the Gulf of Mexico, the Gulf Stream then moves east, rejoins the Antilles Current, and exits the area through the Straits of Florida. Here, the Gulf Stream is a powerful underwater river that transports water at a rate of 30 million cubic meters per second (or 30 Sverdrups).

It then flows parallel to the east coast of the United States and later flows into the open ocean near Cape Hatteras but continues moving north. While flowing in this deeper ocean water, the Gulf Stream is its most powerful (at about 150 Sverdrups), forms large meanders, and splits into several currents, the largest of which is the North Atlantic Current. The North Atlantic Current then flows further north and feeds the Norwegian Current and moves the relatively warm water along the west coast of Europe. The rest of the Gulf Stream flows into the Canary Current which moves along the eastern side of the Atlantic Ocean and back south to the equator. Causes of the Gulf Stream The Gulf Stream, like all other ocean currents is mainly caused by wind as it creates friction when moving over the water. This friction then forces the water to move in the same direction. Because it is a western boundary current, the presence of land along the Gulf Stream’s edges also aids in its movement. The northern branch of the Gulf Stream, the North Atlantic Current, is deeper and is caused by thermohaline circulation resulting from density differences in the water.

Impacts of the Gulf Stream Because ocean currents circulate water of different temperatures all over the globe, they often have a significant impact on the world’s climate and weather patterns. The Gulf Stream is one of the most important currents in this regard since it gathers all of its water from the warm tropical waters of the Caribbean and the Gulf of Mexico. As such, it keeps sea surface temperatures warm, causing the areas around it to be warm and more hospitable. Florida and much of the Southeastern United States for instance is mild all year round. The greatest impact the Gulf Stream has on climate is found in Europe. Since it flows into the North Atlantic Current, it too is warmed (though at this latitude the sea surface temperatures are cooled considerably), and it is believed that it helps keep places like Ireland and England much warmer than they would otherwise be at such a high latitude. For example, the average low in London in December is 42°F (5°C) while in St. John’s, Newfoundland, the average is 27°F (-3°C). The Gulf Stream and its warm winds are also responsible for keeping northern Norway’s coast free of ice and snow.

As well as keeping many places mild, the Gulf Stream’s warm sea surface temperatures also aid in the formation and strengthening of many of the hurricanes that move through the Gulf of Mexico. Additionally, the Gulf Stream is important to the distribution of wildlife in the Atlantic. The waters off of Nantucket, Massachusetts for example are incredibly biodiverse because the presence of the Gulf Stream makes it the northern limit for southern species varieties and the southern limit for northern species. The Future of the Gulf Stream Although there are no definitive answers, it is believed that the Gulf Stream could be in the future or is already being impacted by global warming and the melting of glaciers. Some studies suggest that with the melting of ice 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 were to happen, weather patterns worldwide could change. Recently, there has been evidence that the Gulf Stream is weakening and slowing and there is growing concern about what impacts such a change would have on the world’s climate. Some reports suggest that without the Gulf Stream, temperatures in England and northwestern Europe could drop by 4-6°C.

These are the most dramatic of the predictions for the future of the Gulf Stream but they, as well as today’s climate patterns surrounding the current, show its importance to life in many places around the world. Gulf Stream | ocean current | Britannica.com ocean current Alternative Title: Gulf Stream-North Atlantic-Norway Current Related Topics Henry Melson Stommel Gulf Stream, warm ocean current flowing in the North Atlantic northeastward off the North American coast between Cape Hatteras , N.C., U.S., and the Grand Banks of Newfoundland, Can. In popular conception the Gulf Stream also includes the Florida Current (between the Straits of Florida and Cape Hatteras) and the West Wind Drift (east of the Grand Banks). The Gulf Stream is part of a general clockwise-rotating system of currents in the North Atlantic. It is fed by the westward-flowing North Equatorial Current moving from North Africa to the West Indies . Off the northeastern coast of South America , this current splits into the Caribbean Current , which passes into the Caribbean Sea and through the Yucatán Channel into the Gulf of Mexico , and into the Antilles Current , which flows to the north and east of the West Indies.

The Caribbean Current reemerges into the Atlantic through the Straits of Florida between the Florida Keys and Cuba to form the Florida Current. Deflected to the northeast by the submerged Great Bahama Bank southeast of the Florida Peninsula, this swift current is joined by the Antilles Current and flows roughly parallel to the eastern coast of the United States to about Cape Hatteras. There the path of the Gulf Stream becomes twisted as huge swirls of warm water break off. A part of the Gulf Stream forms a countercurrent that flows south and then west. The countercurrent rejoins the Gulf Stream on its seaward side along the coast of Florida and the Carolinas. climate (meteorology): The Gulf Stream The main portion of the Gulf Stream continues north, veering more to the east and passing close to the Grand Banks, south of Newfoundland, where it breaks up into swirling currents. Some of these eddies flow toward the British Isles and the Norwegian seas and form the North Atlantic Current (or Drift). A larger number flow south and east, either becoming part of westward-flowing countercurrents or joining the Canary Current .

History of scientific study Irminger Current The Gulf Stream was first described by the Spanish navigator and explorer Juan Ponce de León early in the 16th century. In the late 1700s Benjamin Franklin produced a map of the current. In 1844 systematic surveying of the stream was begun by the United States Coast and Geodetic Survey. Concentrated modern efforts were inaugurated only in the early 1930s by the ketch Atlantis of the Woods Hole Oceanographic Institution in Massachusetts . Map of the Gulf Stream drawn by Benjamin Franklin. Library of Congress, Washington, D.C. One of the difficulties of scientific study of the Gulf Stream is its extremely complex makeup. It is not a simple ribbon of moving water but rather a complicated network of currents that tend to shift course over time, to disappear and then reappear, and to develop eddies along the margins. Today, orbiting space satellites are utilized to map the path of the Gulf Stream. The satellites are equipped with sensors that can detect temperature and colour variations to trace the changing surface patterns of the current.

Movement and physical features Most of the waters that enter the Gulf Stream system first have been driven westward across the Atlantic by the Northeast Trade Winds . In the Caribbean and the Gulf of Mexico the current is gradually narrowed, and its velocity increases to more than 3.5 knots (4 miles [6.5 km] per hour) as it passes through the Straits of Florida. The volume of flow there has been measured at 1,060,000,000 cubic feet (30,000,000 cubic metres) per second, or many hundreds of times that of the Mississippi River . As it turns north between Florida and the Bahamas, the Florida Current flows at a depth of some 2,600 feet (790 m) and then follows the continental slope beyond the edge of the shelf. Velocities gradually decrease to about one knot off Cape Hatteras. World Tour In the western Atlantic, the current’s deep-blue water, with its higher temperature and salinity, is readily distinguishable from surrounding waters, particularly along its well-defined western margin. The eastern edge gradually moves seaward as the current moves northward.

The water between the current and the North American mainland, with its lower salinity and temperature, forms a boundary known as the Cold Wall. This water, overlying the continental shelf , frequently has a southerly flow, counter to that of the Florida Current. Britannica Stories Scientists Ponder Menopause in Killer Whales Off the coast of the United States, the Gulf Stream system separates the relatively warm and saline waters of the Sargasso Sea in the mid-Atlantic region from the colder waters to the west and north. In winter, for example, average surface temperatures of the Gulf Stream off New England may be 20° F (11° C) higher than those of surface waters only 150 miles (240 km) to the northwest, although there is less than a 10° F (6° C) change in surface-water temperatures over a 1,000-mile (1,600-kilometre) distance to the southeast. Beyond Cape Hatteras the Gulf Stream broadens and moves into deeper water. There it crosses the Western Boundary Undercurrent, which consists of cold, southward-flowing water that sinks to considerable depths in the vicinity of Greenland.

About 1,500 miles (2,400 km) northeast of Cape Hatteras, in the area of the Grand Banks, the warm Gulf Stream waters come close to the cold, southward-flowing Labrador Current . The contact of cold, humid air moving over the Labrador Current with the warm surface waters of the Gulf Stream causes widespread condensation. This climatic condition causes the region to have one of the highest incidences of fog in the world. Moving out into the North Atlantic, the current becomes shallower and begins to break down into a meandering pattern of disconnected filaments flowing in the same general direction. Much of the initial force of the current has been dissipated by this time, and momentum is afforded primarily by the westerly winds. Part of the water there is diverted southward into the Sargasso Sea area. Near the middle of the ocean , the North Atlantic Current divides. One branch moves southeast and south as the relatively cool Canary Current, which flows past the Iberian Peninsula and northwestern Africa. The other branch (the balance of the North Atlantic Current) moves toward northwestern Europe.

Effects on marine and human life Connect with Britannica New Simulations Question the Gulf Stream’s Role in Tempering Europe’s Winters - Scientific American Scientific American Sustainability New Simulations Question the Gulf Stream’s Role in Tempering Europe’s Winters It's the flow of warm tropical water across the Atlantic that keeps European winters mild, right? Maybe not Credit: COURTESY OF PETER MINNETT AND BOB EVANS University of Miami/MODIS/NASA Advertisement | Report Ad In Brief Three new climate studies indicate that our long-held belief about the Gulf Stream's role in tempering Europe's winters may not be correct. Yet the studies themselves do not agree. Two of the three studies ascribe a surprisingly large role to the direction of the prevailing winds, and one focuses on the heat lost from the ocean. Many climate models indicate that extensive melting of Arctic ice would not actually shut down the Gulf Stream, as previously thought. The ocean's influence on climate in Europe and elsewhere should become clearer within a decade, now that a global array of more than 3,000 floating ocean sensors called Argo is making near-real-time maps of temperature and salinity down to 2,000 meters.

For a century, schoolchildren have been taught that the massive ocean current known as the Gulf Stream carries warm water from the tropical Atlantic Ocean to northwestern Europe. As it arrives, the water heats the air above it. That air moves inland, making winter days in Europe milder than they are in the northeastern U.S. It might be time to retire that tidy story. The explosion of interest in global climate has prompted scientists to closely study the climatic effects of the Gulf Stream only to discover that those effects are not as clear as conventional wisdom might suggest. Based on modeling work and ocean data, new explanations have emerged for why winter in northern Europe is generally less bitter than winter at the same latitudes in the northeastern U.S. and Canada—and the models differ on the Gulf Stream's role. One of the explanations also provides insight into why winter in the U.S. Northwest is warmer than it is across the Pacific in eastern Russia. At the same time, recent studies have been casting doubt on the popular conjecture made a few years ago that melting of Arctic ice could “shut down” the Gulf Stream, thereby wreaking havoc with Europe's weather.

Yet the studies do suggest that climate change could at least affect the strength of the Gulf Stream, which could lessen the impact of global warming on northern Europe. Competing Theories Climate variations across the globe stem primarily from the earth's spherical shape. Because the sun's rays are more perpendicular to the earth's surface at lower latitudes, they impart more heat per unit area there than at higher latitudes. This differential heating leads to the prevailing atmospheric winds, whose instabilities redistribute that heat from the tropics to the poles. The oceans, covering 70 percent of the earth, also play a major role in this redistribution. The upper two meters of the oceans store more solar heat than the entire atmosphere above the seas because the specific heat (a property that determines the capacity to store heat) of a cubic meter of water is about 4,000 times greater than the same volume of air (and about four times larger than it is for soil). Water temperatures in the upper 100 to 200 meters of the oceans at midlatitudes might vary by 10 degrees Celsius over a year, storing and releasing an immense amount of heat compared with the atmosphere or the land.

And because ocean currents, such as the Gulf Stream, move water around the globe, heat gained in the summer at one locale can later be released to the atmosphere thousands of kilometers away. Given that movement and the oceans' ability to store heat, it is easy to hypothesize that ocean currents might be responsible for the fact that winter air temperatures in Ireland, at about 50 degrees north latitude, are nearly 20 degrees C warmer than they are at the same latitude across the Atlantic in Newfoundland. Similarly, air temperatures at 50 degrees north latitude in the eastern Pacific, near Vancouver, are about 20 degrees C warmer than they are at the same latitude at the southern tip of Russia's Kamchatka Peninsula. In the 19th century geographer and oceanographer Matthew Fontaine Maury was the first to attribute the relatively mild climate of northwestern Europe to the Gulf Stream. This powerful ocean current flows northward along the southeastern U.S. coast, a product of warm waters from the subtropics and tropics. At about the latitude of Cape Hatteras, N.C., the Gulf Stream turns to the northeast and flows out into the Atlantic.

Maury surmised that the Gulf Stream supplies heat to the overlying westerly winds that move across the Atlantic toward northwestern Europe. He also speculated that if the Gulf Stream were somehow diminished in strength, the winter winds would be much colder and that Europe would experience Arctic-style winters. Over the years Maury's idea became almost axiomatic—and until recently, it also remained largely untested. [break] A decade ago, however, Richard Seager of Columbia University's Lamont-Doherty Earth Observatory and his colleagues produced an explanation for Europe's warmer winter that had nothing to do with the Gulf Stream. Seager's modeling study indicated that when the atmospheric jet stream, which flows around the earth from west to east, hits the Rocky Mountains, it begins to oscillate north and south. The oscillation produces winds that flow from the northwest over the western side of the Atlantic basin and from the southwest over the Atlantic's eastern side. The northwesterly winds bring cold continental air to the northeastern U.S., whereas the southwesterly ones bring warm maritime air to northwestern Europe. In this view, it is not heat carried by the Gulf Stream that moderates the European climate.

Instead heat that is stored off the shores of Europe, in the upper 100 meters of the ocean during the summer, is released to the atmosphere in winter when the southwesterly winds mix the surface ocean waters. In this scenario, the classic conjecture of Maury is incorrect: large-scale wind patterns directed by mountain ranges, plus local storage of heat by the ocean near Europe, set the temperature differences between the western and eastern sides of the Atlantic [see box on next two pages]. It is important to keep in mind that Seager's model simulations did not explicitly take into consideration the transport of heat by the ocean, a point addressed in a study released soon after Seager's by Peter Rhines of the University of Washington and Sirpa Häkkinen of the NASA Goddard Space Flight Center. They put forth a counterargument that offered some modern support for Maury's historical ideas. After examining archived sea-surface temperature data, the two oceanographers concluded that the amount of heat stored in the upper layer of the eastern Atlantic Ocean at the latitudes of northern Europe is enough to maintain mild air temperatures only through December of an average year. The additional heat required to moderate the climate over the remainder of the winter had to be imported from elsewhere.

The most likely source: the northeastward-flowing Gulf Stream. Measurements showed that at 35 degrees north latitude—roughly the latitude of North Carolina—the North Atlantic transports about 0.8 petawatt of heat northward, mostly by the Gulf Stream. Yet at 55 degrees north latitude—the latitude of Labrador in Canada—this poleward heat transport is negligibly small. Where does all the heat go? Rhines and Häkkinen suggested that it is released by the ocean into the atmosphere along the path of the Gulf Stream. The prevailing winds then carry the heat eastward, where it moderates the European climate. Rhines and Häkkinen essentially argued for Maury's Gulf Stream conjecture, and Seager argued against it, focusing on the role of the atmospheric jet stream. In 2011 Yohai Kaspi, now at the Weizmann Institute of Science in Rehovot, Israel, and Tapio Schneider of the California Institute of Technology unveiled a third idea, based on novel numerical experiments of the atmosphere and the ocean. They suggested a degree of truth in both the Seager and Rhines scenarios but concentrated mostly on patterns of atmospheric pressure.

Kaspi and Schneider's model indicated that the loss of heat from the ocean to the atmosphere along the path of the Gulf Stream where it leaves the U.S. East Coast generates a stationary, atmospheric low-pressure system to the east—on the European side of the Atlantic. It also creates a stationary high-pressure system to the west—over the eastern edge of the North American continent. For complex reasons, the net result of this pattern is that the stationary low-pressure system delivers warm air to western Europe via the jet stream's southwesterly winds, which pick up heat released all winter long by the Gulf Stream. The stationary high pulls in cold air from the Arctic, cooling eastern North America and increasing the contrast in temperature between North America and Europe. [break] Thus, the difference in the climate across the Atlantic arises not only because western Europe warms but also because eastern North America gets colder. Both regions have their characteristic temperatures because of the atmospheric circulation pattern established by heat loss from the ocean in the vicinity of the Gulf Stream. The amount of heat loss from the Gulf Stream that is required to establish this circulation cannot be sustained only from heat that the mid-Atlantic gains during the summer, however.

Heat transported by the Gulf Stream, from lower latitudes, is also needed. In this sense, Kaspi and Schneider lend some credence to Maury's earlier ideas. Although the atmospheric low- and high-pressure systems are created without any need to invoke the influence of the Rockies on the jet stream, this new work does highlight the importance of the southwesterly winds in bringing warmth to Europe. Interestingly, the Kaspi-Schneider model can also explain why western Oregon, Washington State and British Columbia have much milder winters than what Kamchatka endures. This transpacific contrast has never been attributed to the presence of the Kuroshio, the counterpart of the Gulf Stream in the Pacific, primarily because the Pacific is a much larger ocean and the Kuroshio is a considerably weaker current than the Gulf Stream across much of it. Yet the Kaspi-Schneider result would suggest that heat lost over the Kuroshio could induce a stationary, atmospheric-pressure system similar to the one near the Gulf Stream in the Atlantic. The system would deliver cold polar air to northwestern Asia via northwesterly winds there, and southwesterlies would deliver warmer air to the northern U.S. Pacific Coast.

Shutting Down the Gulf Stream The jury is still out on which model is correct, although the Kaspi-Schneider scenario seems plausible. The second part of Maury's conjecture—that a cessation of the Gulf Stream would lead to more intense winters over northwestern Europe—has also recently generated considerable interest. For many years the nature of the Gulf Stream's role in climate change has been framed as this question: If a warmer climate melts Arctic ice, will the excess freshwater that enters the ocean in the northern Atlantic decrease the overturning circulation there, shut down the Gulf Stream and rob northwestern Europe of an important source of heat? The overturning circulation consists of warm upper waters in the North Atlantic that move northward toward the pole and of cold deep waters that move southward toward the equator. These shallow and deep currents link to form something of a conveyor belt by the sinking, or downwelling, of surface waters at high latitudes in the Labrador and Nordic seas and by deep water elsewhere in the global basin that rises, or upwells, to the surface. In essence, the cold waters that sink in the northern North Atlantic are replaced by relatively warm surface waters that upwell elsewhere in the global ocean.

In many climate-warming scenarios, the melting of Arctic ice would add a large quantity of freshwater to the ocean at high latitudes. Because freshwater is less salty (and thus less dense) than seawater, it might not sink—so the downwelling that feeds the deep currents of the overturning circulation would be inhibited. In this case, there would be no physical requirement for warm deep waters to rise up elsewhere because there would be no downwelling to compensate for; in consequence, with no new warm water rising to the surface, the northward flow of such water—the Gulf Stream—might be diminished. Alternative scenarios hold that freshwater additions at high latitudes would divert the Gulf Stream farther south or diminish its strength. In either case, a weakened or diverted Gulf Stream would provide less heat for European winters. Many models strongly predict that a decrease in the overturning circulation correlates with a subsequent cooling in the North Atlantic and northwestern Europe. [break] Yet recent modeling studies with higher resolution of ocean currents suggest that fresh Arctic meltwater may pour mostly into currents that are more restricted to the coastlines and therefore have less influence on the open ocean, where downwelling primarily occurs.

Even if freshwater significantly affected the amount of waters downwelled in the North Atlantic, it turns out to be highly unlikely that this change would effectively shut down the Gulf Stream. A shutdown is unlikely because the path and the strength of the Gulf Stream depend largely on the speed and direction of the large-scale midlatitude winds. In most climate change scenarios, the general direction of the large-scale winds does not change significantly as Arctic ice melts, so the general path and strength of the Gulf Stream do not change much either. The northeastward extension of the Gulf Stream—the relatively small branch that brings the warm upper waters to the subpolar regions—could potentially be disrupted, however. Thus, the weight of evidence indicates that the Gulf Stream would persist, but it is unclear how much Gulf Stream water would be carried northward under different climate scenarios. More Data, Better Resolution At present, answers to how climate change would affect Europe's weather come largely from modeling experiments. Still, the experiments have considerable uncertainties that can be reconciled only with more extensive data from the oceans. Few observations from the open oceans are older than a century, and we have satellite data for just the past 30 years or so.

Scientists have recently been making considerable progress in improving the oceanic database through the Argo project, an ongoing global collection of temperature and salinity measurements from more than 3,000 floating sensors scattered worldwide. The Argo array, deployed and operated by the U.S. and more than 30 other countries, allows scientists to make near-real-time maps of temperature and salinity in the upper 2,000 meters of the world's oceans. The complete array has been in place for less than a decade, and we are just beginning to use it to effectively examine the connection between atmospheric variability and changes in the large-scale ocean. For example, a comparison of the Argo data with ocean observations from the 1980s, carried out by Dean Roemmich and John Gilson of the Scripps Institution of Oceanography, shows that the upper few hundred meters of the oceans have warmed by about 0.2 degree C in the past 20 years. Upper-ocean salinity also increased globally by a small 0.1 percent—yet below a few hundred meters, ocean waters appear to be considerably fresher than in previous decades.

Whether these changes are enough to alter the climate in Europe or anywhere else remains an open question, but the data we are now getting from Argo offer some clues. For the earth to neither warm nor cool, the input of heat from the sun must equal the amount of heat radiated from the earth back into space. Accumulating greenhouse gases in the atmosphere are apparently upsetting this equilibrium. The observed warming of 0.2 degree C in the upper ocean is consistent with an excess of incoming solar radiation over outgoing radiation of approximately one watt per square meter. Early results from our improved ocean observatory provide a powerful input for climate theories and models. The results also offer a hint at what will be possible in the coming decades. In the next 10 years, as scientists examine, in tandem, the sea-surface data from satellites, computer models and longer, subsurface data records from Argo, they should be able to assess the role of the ocean in climate with new precision. At that point, we may finally be able to determine how the Gulf Stream will affect climate change on our watery planet.

This article was originally published with the title "Rethinking the Gulf Stream" Gulf Stream (Global Warming) In Depth Tutorials and Information Gulf Stream (Global Warming) Ocean currents Affect not only the temperature, but also the precipitation on land areas adjacent to the ocean. A cold ocean current near land causes the air just above the water to be cold, while the air above is warm. There is very little opportunity for convection, thus denying moisture to nearby land. Coastal des erts of the world usually border cold ocean currents. Contrary to this, warm ocean currents, such as Gulf Stream, bring moisture to the adjacent land areas. The Gulf Stream, together with its northern extension towards Europe, the North Atlantic Drift, is a powerful, warm, and swift Atlantic Ocean current that originates in the Gulf of Mexico, exits through the strait of Florida, and follows the eastern coastlines of the United States and Newfoundland (Canadian island) before crossing the Atlantic Ocean. It carries a huge amount of warm water to northerly lands, which has enormous significance to inhabitants of those areas; without it, northern Europe would be much colder and drier.

At about 30 degrees W, 40 degrees N, it splits into two, with the northern stream crossing northern Europe, and the southern stream (Canary Current) recirculating off western Africa. The Gulf Stream influences the climate of the east coast of North America from Florida to Newfoundland, and the west coast of Europe. Warm water brought to Europe’s shores raises the temperature by as much as 18 degrees F (10 degrees C) in some places. A NASA satellite image shows the Atlantic Ocean, off the shore of Georgia and the Carolinas, where the Gulf Stream current curves out to sea away from the North American continent. Gulf stream origins The origin of the Gulf Stream is debatable. One group of scientists believes that the Gulf Stream is driven both by the rotation of the Earth and by a deep-water current called the thermohaline circulation. Another group of scientists accept the theory propounded by Henry Stomme in 1948, that the Gulf Stream is a wind-driven phenomenon. Heating and cooling affect its temperature and other properties, but not its basic existence or structure.

Stomme theorized that as long as the sun heats the Earth and the Earth spins, there will be winds, and there will be a Gulf Stream. There is some speculation that global warming could decrease or shut down thermohaline circulation, and therefore reduce the North Atlantic Drift. The time frame for this might happen is unclear; estimates range from few decades to a few hundred years. This could trigger localized cooling in the north Atlantic and lead to cooling (or lesser warming) in that region, particularly affecting areas such as the Scandinavian countries and the United Kingdom. The slowdown, which climate modelers have predicted will follow global warming, has been confirmed by the most detailed study yet of ocean flow in the Atlantic. Most alarmingly, the new research reveals that a part of the current, which is usually 60 times more powerful than the Amazon River of South America, came to a temporary halt during November 2004. Recent research has shown that changes are occurring in the Gulf Stream. According to scientists, in the absence of the Gulf Stream and its two northern branches, the north Atlantic Drift and the Canary Current, the weather in the United Kingdom could be more like that of Siberia, which lies on the same latitude.

According to Peter Wadhams of the University of Cambridge, changes are occurring in the water of the Greenland Sea. Historically, large columns of very cold, dense water in the Greenland Sea, known as chimneys, sink from the surface of the ocean to about 9,000 ft. (2,743 m.) below, to the seabed. As that water sinks, it interacts with the warm Gulf Stream current flowing from the south. However, the number of those chimneys, according to Wadhams, has decreased from about a dozen to just two. That is causing a weakening of the Gulf Stream, Wadham asserts, which could mean less heat reaching northern Europe. It is possible that the coastal areas of western Europe could be converted into deserts. However, this would require much more extensive research on changing land use patterns in coastal areas. Harry Bryden, of the National Oceanography Centre in Southampton, presented his findings to a conference in Birmingham on rapid climate change. Bryden’s research group stunned climate researchers in 2006, with data suggesting that the flow rate of the Atlantic circulation had dropped by about 6 million tons of water a second 1957-98.

If the current remained that weak, Bryden predicted, it would lead to a one degree C drop in the United Kingdom in the next decade. A complete shutdown would lead to a 7-11 degree F (4-6 degree C) cooling over 20 years. Bryden’s study prompted the United Kingdom’s National Environment Research Council to set up an array of 16 submerged stations spread across the Atlantic, from Florida to northern Africa, to measure the flow rate and other variables at different depths. Data from these stations confirmed the slowdown in 1998 was not a "freak observation," although the current does seem to have picked up slightly since then. Richard Seager, who presented his research to the New York Academy of Sciences on "The Gulf Stream: European Climate and Abrupt Climate Change," expressed similar views. Seager states that a slowdown of the Gulf Stream and ocean circulation in the future, induced by freshening of the waters caused by anthropogenic climate change (via melting of glaciers and increased water vapor transport into high latitudes) or simply by warming, would introduce a modest cooling tendency. This would leave the temperature contrast across the Atlantic unchanged.

In fact, the cooling tendency would probably be overwhelmed by the direct radia-tively driven warming from rising greenhouse gases. Untitled Document TOPIC 4 - Ocean Circulation Surface Ocean Circulation - This model for surface ocean circulation was first developed by Ekman and is termed the Ekman model. a. Atmospheric Circulation and Coriolis Force Prevailing winds develop waves and push them in one predominant direction forming surface ocean currents. This produces strong Equatorial Currents due to the trade winds and mid-latitude Easterly Currents due to the prevailing westerly winds. Ocean currents moving north or south in the northern hemisphere are deflected to the right by the Coriolis force forming Ekman spirals. Ekman spiraling and the Coriolis force also cause ocean currents to spiral toward the right with increasing water depth while the current velocities decrease. At depth, surface ocean currents die out just like particle motion associated with wave motion dies out. As a result of the Coriolis force, the Trade winds (tropical easterly winds) push surface water to the west and north while the mid-latitude westerlies push water to the east and south.

This forms a dome of water near 30° latitude (on average) between the two wind belts. As the dome builds, it sets up a pressure gradient and water attempts to flow away from the dome. As it flows away, it is deflected by Coriolis force and ends up flowing in the same direction as the prevailing winds on either side of the bulge. b. Continental Effects As currents flow west under the trade winds, they strike continental barriers. The currents are then deflected mostly northward (southward) in the northern (southern) hemisphere by the Coriolis effect forming Western Boundary Currents. The Gulf Stream in the North Atlantic Ocean is a prime example of this process. Some water, however, is deflected southward towards the equator where it meets some water deflected northward in the southern hemisphere. These currents meet and slowly flow eastward in the Doldrums forming Equatorial Counter-Currents. At mid latitudes, currents moving eastward under the influence of the prevailing westerlies may also strike a continental barrier where they are primarily deflected toward the right (left) in the northern hemisphere. These currents as a group are called Eastern Boundary Currents. c.

Currents and Upwelling As currents move north as western boundary currents or south as eastern boundary currents (in the northern hemisphere), they are deflected by the Coriolis force toward the open ocean. This allows deeper water to rise to the ocean surface to replace it producing upwelling. This can also occur if there are strong prevailing winds blowing from the continent toward the ocean. Large-scale upwelling occurs near the equator where northern and southern hemisphere eastern boundary currents meet and turn westward as equatorial currents. Large-scale upwelling can also occur when two currents pass one another going in opposite directions. As the currents pass, Coriolis forces will cause them to either converge (causing downwelling), or diverge (causing upwelling). 2. Distribution of Surface Currents in the World's Oceans A. Westerly Flowing Surface Currents: In all of the Equator-crossing oceans (Atlantic, Pacific, Indian), there are strong westerly flowing currents in the Tropics driven by the Trade winds. In each ocean basin, these currents are called North or South Equatorial Currents depending on whether they are north or south of the equator.

These currents usually flow westward to continental boundaries and form easterly flowing Equatorial Counter currents which separate the North And South Equatorial Currents. B. Western Boundary Currents: When the Equatorial Currents become blocked by continents which sit astride the equator, the currents are deflected northward and southward along the western boundaries of the ocean basins. The best known western boundary surface currents are the Gulf Stream in the western North Atlantic Ocean, the Kuroshio Current in the western North Pacific, and the Brazil Current in the South Atlantic Ocean. C. Easterly Surface Currents: As western boundary currents reach latitudes of the prevailing westerly winds, they become easterly currents. The best known examples are the continuation of the Gulf Stream as it moves toward Europe and the North Pacific Current. D. Eastern Boundary Currents: As westerly currents are blocked by continents, they are deflected toward the equator forming eastern boundary currents on the western margins of continents. The best examples are the California Current off North America, the (Pacific) Peru or Humbolt Current off South America, and the (Atlantic) Benguela Current off Africa. E.

The Antarctic Circumpolar Current flows easterly all the way around Antarctica. F. All of these surface current systems form continental-scale gyres, or zones of coherent cyclonic circulation (either clockwise or counter-clockwise) in all of the major ocean basins. At the centers of these gyres, are saline subtropical surface waters that underlie atmospheric high pressure systems. These zones of surface water are not as well mixed as the rest of the surface ocean. The best known of these regions in the Sargasso Sea within the North Atlantic Ocean gyre. 3. Thermohaline Circulation A. Changes in water temperature and salinity alter water mass density and cause them to move vertically to reach water masses of comparable density. B. Water masses become more dense at the ocean's surface due to cooling or increased salinity. These masses sink so that the ocean maintains a stable density stratification (less dense water above more dense water). C. Thermohaline circulation primarily affects water in the deep oceans below the zone of surface ocean circulation. It produces nutrient-rich waters that rise to the surface during upwelling. D. Source Water Masses for Deep Ocean Circulation.

North Atlantic Deep Water (NADW) The Gulf Stream and North Atlantic Current carry relatively saline surface water from the equatorial Atlantic Ocean into the high-latitude North Atlantic Ocean. NADW is formed by cooling relatively saline surface water in the Greenland Sea between Greenland and Great Britain. High salinity and cold temps yield a very dense water mass. (open ocean process of deep water formation). NADW is created in large volumes and as it sinks to the ocean bottom it slowly flows southward underneath the Gulf Stream and North Atlantic Current. Antarctic Bottom Water (AABW) AABW forms along the continental shelf of Antarctica by the process of freezing new ice onto the margins of the Antarctic ice sheet. The water is already quite cold and the increase in density which occurs as salts are expelled from the freezing ice produce an even denser water mass. This process of deep water formation is called the near-boundary process. The AABW water mass is the densest water mass in the world's oceans and its large volume fills most of the southern Atlantic, Pacific, and Indian oceans. Mediterranean Intermediate Water (MIW) MIW forms by evaporation of relatively-warm water in the semi-enclosed Mediterranean Sea.

Increased salinity results and the water sinks to the bottom of the Sea. Less saline surficial water from the Atlantic Ocean flows into the Mediterranean Sea to replace the lost surface water while the deep warm and salty MIW flows over the sill at Gibraltar and sinks into the eastern North Atlantic Ocean. MIW then continues to flow westward at depths of 1-2 km reaching as far as the island of Bermuda in the western North Atlantic Ocean. Antarctic Intermediate Water (AAIW) As ice flows out from the Antarctic continent it melts forming a low-salinity very cold surface current. As that cold low-salinity water mixes with AABW that is sinking to the ocean bottom, AAIW is formed. This water mass is less dense than AABW and NADW which comes to the surface in the Antarctic, but denser than surface water and flows underneath it. 4. The Overall Thermohaline Circulation System a. Atlantic Ocean NADW forms in the high north Atlantic Ocean and flows southward underneath surface water mass and intermediate water masses until it is diverted to the surface in the Antarctic. AABW forms in coastal Antarctica, sinks to the bottom, and flows northward underneath all other water masses.

It reaches the mid-latitude North Atlantic Ocean where the water is entrained with NADW and swings back southward. THE AABW is so dense that it underlies NADW and deflects NADW to the surface near Antarctica. MIW flows westward above NADW and AABW and reaches the western North Atlantic Ocean. AAIW flow northward above NADW and AABW but underneath surface water masses. The surface water is thickest in the central ocean gyres like the Sargasso Sea. The central gyres are warm, saline, low-nutrient waters with low biological productivity. b. Pacific Ocean AABW flows northward into the Pacific Ocean basin. Since there is no other source of deep water, AABW flows far into the north Pacific. AAIW flows northward into the Pacific Ocean where it meets North Pacific IW near the equator. The cores of the northern and southern gyres have warm, saline, nutrient-poor pools of surface water. c. Indian Ocean as a whole, the Indian Ocean deep circulation looks very much like the Pacific Ocean. Here too, there is no northern source of deep water and so AABW and AAIW penetrate far into the basin.

There is a local source of intermediate water around India which forms as a result of monsoonal heating and evaporation forming a more saline intermediate water mass which flows southward away from the sub-continent.

Question: The Gulf Stream, a warm ocean current, flows from the North American continent to where?
Answer: British Isles