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56-736: In turn it is chiefly subdivided into the Gulf Stream flowing northward along the west; its often conflated continuation, the North Atlantic Current across the north; the Canary Current flowing southward along the east; and the Atlantic's North Equatorial Current in the south. The gyre has a pronounced thermohaline circulation , bringing salty water west from the Mediterranean Sea and then north to form

112-524: A consequence, the resulting Gulf Stream is a strong ocean current. It transports water at a rate of 30 million cubic metres per second (30 sverdrups ) through the Florida Straits. As it passes south of Newfoundland, this rate increases to 150 sverdrups. The volume of the Gulf Stream dwarfs all rivers that empty into the Atlantic combined, which total 0.6 sverdrups. It is weaker, however, than

168-632: A counterclockwise pattern. Hurricanes and tropical storms (massive low-pressure systems) spin counterclockwise in the Northern Hemisphere. The shadow of a sundial moves clockwise on latitudes north of the subsolar point and anticlockwise to the south. During the day at these latitudes, the Sun tends to rise to its maximum at a southerly position. Between the Tropic of Cancer and the Equator,

224-597: A density increase and convection in the water column. Open ocean convection occurs in deep plumes and is particularly strong in winter when the sea-air temperature difference is largest. Of the 6 sverdrup (Sv) of dense water that flows southward over the GSR (Greenland-Scotland Ridge), 3 Sv does so via the Denmark Strait forming Denmark Strait Overflow Water (DSOW). 0.5-1 Sv flows over the Iceland-Faroe ridge and

280-437: A shallow frontal zone , forced by the Gulf Stream, during the cold season . Subtropical cyclones also tend to be generated near the Gulf Stream. About 75% of such systems documented between 1951 and 2000 formed near this warm-water current, with two annual peaks of activity occurring during May and October. Cyclones within the ocean itself form under the Gulf Stream, extending as deep as 3,500 m (11,500 ft) beneath

336-764: Is a debate about the extent to which convection in the Labrador Sea plays a role in AMOC circulation, particularly in the connection between Labrador sea variability and AMOC variability. Observational studies have been inconclusive about whether this connection exists. New observations with the OSNAP array show little contribution from the Labrador Sea to overturning, and hydrographic observations from ships dating back to 1990 show similar results. Nevertheless, older estimates of LSW formation using different techniques suggest larger overturning. As with many oceanographic patterns,

392-566: Is denser and colder (or more precisely, water that is still liquid at a lower temperature). In the North Atlantic Ocean, the water becomes so dense that it begins to sink down through less salty and less dense water. (The convective action is similar to a lava lamp .) This downdraft of cold, dense water becomes a part of the North Atlantic Deep Water , a southgoing stream. Very little seaweed lies within

448-418: Is equatorward. Because of the conservation of potential vorticity caused by the northward-moving winds on the subtropical ridge 's western periphery and the increased relative vorticity of northward-moving water, transport is balanced by a narrow, accelerating poleward current. This flows along the western boundary of the ocean basin, outweighing the effects of friction with the western boundary current, and

504-489: Is known as the Labrador Current . The conservation of potential vorticity also causes bends along the Gulf Stream, which occasionally break off as the Gulf Stream's position shifts, forming separate warm and cold eddies. This overall process, known as western intensification, causes currents on the western boundary of an ocean basin, such as the Gulf Stream, to be stronger than those on the eastern boundary. As

560-537: Is largely driven by thermohaline circulation . Its carrying warm water northeast across the Atlantic makes Western Europe and especially Northern Europe warmer and milder than it otherwise would be. A river of sea water, called the Atlantic North Equatorial Current , flows westwards off the coast of Central Africa. When this current interacts with the northeastern coast of South America, the current forks into two branches. One passes into

616-557: Is taken as the period from the June solstice through to the September equinox (typically on 23 September UTC). The dates vary each year due to the difference between the calendar year and the astronomical year . Within the Northern Hemisphere, oceanic currents can change the weather patterns that affect many factors within the north coast. Such events include El Niño–Southern Oscillation . Trade winds blow from east to west just above

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672-654: Is theorised to hold true across the Atlantic in surface layers. The North Atlantic garbage patch is a garbage patch of man-made marine debris found floating within the North Atlantic Gyre, originally documented in 1972. A 22-year research study conducted by the Sea Education Association estimates the patch to be hundreds of kilometers across, with a density of more than 200,000 pieces of debris per square kilometer. The garbage originates from human-created waste traveling from rivers into

728-609: The Antarctic Circumpolar Current . Given the strength and proximity of the Gulf Stream, beaches along the East Coast of the United States may be more vulnerable to large sea-level anomalies, which significantly impact rates of coastal erosion . The Gulf Stream is typically 100 km (62 mi) wide and 800 to 1,200 m (2,600 to 3,900 ft) deep. The current velocity is fastest near

784-673: The Caribbean Sea , while a second, the Antilles Current , flows north and east of the West Indies . These two branches rejoin north of the Straits of Florida. The trade winds blow westwards in the tropics, and the westerlies blow eastwards at mid-latitudes. This wind pattern applies a stress to the subtropical ocean surface with negative curl across the north Atlantic Ocean. The resulting Sverdrup transport

840-550: The North Atlantic Current . The process of western intensification causes the Gulf Stream to be a northward-accelerating current off the east coast of North America. Around 40°0′N 30°0′W  /  40.000°N 30.000°W  / 40.000; -30.000 , it splits in two, with the northern stream, the North Atlantic Drift, crossing to Northern Europe and the southern stream, the Canary Current , recirculating off West Africa. The Gulf Stream influences

896-625: The North Atlantic Deep Water . The gyre traps anthropogenic (human-made) marine debris in its natural garbage or flotsam patch , in the same way the North Pacific Gyre has the Great Pacific Garbage Patch . At the heart of the gyre is the Sargasso Sea , noted for its still waters and quite dense seaweed accumulations. Low air temperatures at high latitudes cause substantial sea-air heat flux, driving

952-465: The Northern temperate zone . The changes in these regions between summer and winter are generally mild, rather than extreme hot or cold. However, a temperate climate can have very unpredictable weather. Tropical regions (between the Tropic of Cancer and the Equator, 0° latitude) are generally hot all year round and tend to experience a rainy season during the summer months, and a dry season during

1008-583: The last glacial period ended about 10,000 years ago. Earth is currently in an interglacial period of the Quaternary , called the Holocene . The glaciations that occurred during the glacial period covered many areas of the Northern Hemisphere. The Arctic is a region around the North Pole (90° latitude ). Its climate is characterized by cold winters and cool summers. Precipitation mostly comes in

1064-421: The seawater . Interannual trends have established that carbon dioxide concentrations within this gyre are increasing at a similar rate to that occurring in the atmosphere . This discovery concurs with that made in the North Pacific Gyre . The North Atlantic Gyre also undergoes temperature changes via atmospheric wave patterns. The North Atlantic Oscillation (NAO) is one such pattern. During its positive phase,

1120-588: The western coastal islands of Scotland . A noticeable effect of the Gulf Stream and the strong westerly winds on Europe occurs along the Norwegian coast . Northern parts of Norway lie close to the Arctic zone, most of which is covered with ice and snow in winter. However, almost all of Norway's coast remains free of ice and snow throughout the year. The warming effect provided by the Gulf Stream has allowed fairly large settlements to be developed and maintained on

1176-672: The Caribbean and then either move in a northward direction and curve towards the eastern coast of the United States or stay on a north-westward track and enter the Gulf of Mexico . Such storms have the potential to create strong winds and extensive damage to the United States' Southeast coastal areas . Hurricane Sandy in 2012 was a recent example of a hurricane tracking along the Gulf Stream and gaining strength. Strong extratropical cyclones have been shown to deepen significantly along

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1232-678: The East flank of Reykjanes Ridge, through the Charlie Gibbs Fracture Zone and then northward to join DSOW. These waters are sometimes referred to as Nordic Seas Overflow Water (NSOW). NSOW flows cyclonically following the surface route of the SPG (sub-polar gyre) around the Labrador Sea and further entrains Labrador Sea Water (LSW). Characteristically fresh Labrador Sea Water (LSW) is formed at intermediate depths by deep convection in

1288-547: The GSR (Greenland-Scotland Ridge) overflows. Most of the diverted LSW however splits off before the CGFZ (Charlie-Gibbs Fracture Zone) and remains in the western SPG. LSW production is highly dependent on sea-air heat flux and yearly production typically ranges from 3–9 Sv. ISOW is produced in proportion to the density gradient across the Iceland-Scotland Ridge and as such is sensitive to LSW production which affects

1344-625: The Gulf Stream will not shut down in a warming climate. While the Gulf Stream is expected to slow down as the Atlantic Meridional Overturning Circulation (AMOC) weakens, it will not collapse, even if the AMOC were to collapse. Nevertheless, this slowing down will have significant effects, including a rise in sea level along the North American coast, reduced precipitation in the midlatitudes, changing patterns of strong precipitation around Europe and

1400-484: The North Atlantic Gyre experiences seasonal changes. Stramma and Siedler (1988) determined that the gyre expands and contracts with a seasonal variance; however, the magnitude of volume transport does not seem to change significantly. During the Northern Hemisphere winter season, the gyre follows a more zonal pattern; that is, it expands in the east-west direction and thins in the north-south direction. As

1456-630: The Northern Hemisphere, together with about two-thirds of Africa and a small part of South America . During the 2.5 million years of the Pleistocene , numerous cold phases called glacials ( Quaternary ice age ), or significant advances of continental ice sheets, in Europe and North America , occurred at intervals of approximately 40,000 to 100,000 years. The long glacial periods were separated by more temperate and shorter interglacials which lasted about 10,000–15,000 years. The last cold episode of

1512-613: The Solar System as Earth's North Pole . Due to Earth's axial tilt of 23.439281°, there is a seasonal variation in the lengths of the day and night. There is also a seasonal variation in temperatures, which lags the variation in day and night. Conventionally, winter in the Northern Hemisphere is taken as the period from the December solstice (typically December 21 UTC ) to the March equinox (typically March 20 UTC), while summer

1568-734: The Sun can be seen to the north, directly overhead, or to the south at noon, depending on the time of year. In the Southern Hemisphere, the midday Sun is predominantly in the north. When viewed from the Northern Hemisphere, the Moon appears inverted compared to a view from the Southern Hemisphere. The North Pole faces away from the Galactic Center of the Milky Way . This results in the Milky Way being sparser and dimmer in

1624-522: The capacity to transport the distinct biological, chemical, and physical properties of their originating waters to the new waters into which they travel. Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator . For other planets in the Solar System , north is defined as being in the same celestial hemisphere relative to the invariable plane of

1680-634: The central Labrador Sea, particularly during winter storms. This convection is not deep enough to penetrate into the NSOW layer which forms the deep waters of the Labrador Sea. LSW joins NSOW to move southward out of the Labrador Sea: while NSOW easily passes under the NAC at the North-West Corner, some LSW is retained. This diversion and retention by the SPG explains its presence and entrainment near

1736-492: The climate of the coastal areas of the East Coast of the United States from Florida to southeast Virginia (near 36°N latitude), and to a greater degree, the climate of Northwest Europe. A consensus exists that the climate of Northwest Europe is warmer than other areas of similar latitude at least partially because of the strong North Atlantic Current. It is part of the North Atlantic Gyre . Its presence has led to

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1792-607: The coast of Northern Norway , including Tromsø , the third-largest city north of the Arctic Circle. Weather systems warmed by the Gulf Stream drift into Northern Europe, also warming the climate behind the Scandinavian Mountains . The possibility of a Gulf Stream collapse has been covered by some news publications. The IPCC Sixth Assessment Report addressed this issue specifically, and found that based on model projections and theoretical understanding,

1848-622: The current, although seaweed lies in clusters to its east. In April 2018, two studies published in the British scientific journal Nature found the Gulf Stream to be at its weakest for at least 1,600 years. The Gulf Stream is influential on the climate of the Florida peninsula . The portion off the Florida coast, referred to as the Florida Current , maintains an average water temperature of at least 24 °C (75 °F) during

1904-555: The development of strong cyclones of all types, both within the atmosphere and within the ocean. European discovery of the Gulf Stream dates to the 1512 expedition of Juan Ponce de León , after which it became widely used by Spanish ships sailing from the Caribbean to Spain. A summary of Ponce de León's voyage log on April 22, 1513, noted, "A current such that, although they had great wind, they could not proceed forwards, but backwards and it seems that they were proceeding well; at

1960-433: The downstream density More indirectly, increased LSW production is associated with a strengthened SPG and hypothesized to be anti-correlated with ISOW This interplay confounds any simple extension of a reduction in individual overflow waters to a reduction in AMOC. LSW production is understood to have been minimal prior to the 8.2 ka event, with the SPG thought to have existed before in a weakened, non-convective state. There

2016-685: The end, it was known that the current was more powerful than the wind." Benjamin Franklin became interested in the North Atlantic Ocean circulation patterns. In 1768, while in England, Franklin heard a curious complaint from the Colonial Board of Customs : "Why did it take British packets several weeks longer to reach New York from England than it took an average American merchant ship to reach Newport, Rhode Island , despite

2072-669: The equator. The winds pull surface water with them, creating currents, which flow westward due to the Coriolis effect . The currents then bend to the right, heading north. At about 30 degrees north latitude, a different set of winds, the westerlies , push the currents back to the east, producing a closed clockwise loop. Its surface is 60.7% water, compared with 80.9% water in the case of the Southern Hemisphere , and it contains 67.3% of Earth's land. The continents of North America and mainland Eurasia are located entirely in

2128-589: The form of snow. Areas inside the Arctic Circle (66°34′ latitude) experience some days in summer when the Sun never sets, and some days during the winter when it never rises. The duration of these phases varies from one day for locations right on the Arctic Circle to several months near the Pole, which is the middle of the Northern Hemisphere. Between the Arctic Circle and the Tropic of Cancer (23°26′ latitude) lies

2184-413: The gyre warms. This is due to a weakening of the westerly winds , resulting in reduced wind stress and heat exchange , providing a greater period of time for the gyre water temperatures to rise. Measured samples of aerosols , marine particles, and water in the gyre from 1990–92 include examining lead isotope ratios. Certain isotopes are hallmarks of pollution essentially from Europe and

2240-476: The mainland in winter just 30 miles to the north. North of Nantucket Island along the New England coast northward to the eastern Canadian coast the cold Labrador Current is found. The North Atlantic Current of the Gulf Stream, along with similar warm air currents, helps keep Ireland and the western coast of Great Britain a few degrees warmer than the east. However, the difference is most dramatic in

2296-684: The merchant ships leaving from London and having to sail down the River Thames and then the length of the English Channel before they sailed across the Atlantic, while the packets left from Falmouth in Cornwall?" Franklin asked his cousin Timothy Folger, a Nantucket Island whaling captain, for an answer. Folger explained that merchant ships routinely crossed the current—which was identified by whale behaviour, measurement of

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2352-430: The near Middle East by trade winds ; other contamination was primarily caused by American emissions. The surface layers of the Sargasso Sea were read for such concentrations. 42–57% of the contamination came from American industrial and automotive sources, despite the reduction in the production and use of leaded gasoline in the United States. Since 1992 lead has clearly reducing concentrations – this

2408-525: The ocean and mainly consists of microplastics . The garbage patch is a large risk to wildlife (and to humans) through plastic consumption and entanglement. Gulf Stream The Gulf Stream is a warm and swift Atlantic ocean current that originates in the Gulf of Mexico and flows through the Straits of Florida and up the eastern coastline of the United States, then veers east near 36°N latitude (North Carolina) and moves toward Northwest Europe as

2464-513: The ocean's surface. The Gulf Stream periodically forms rings resulting from a meander of the Gulf Stream being closed off from an alternate route distinctive from that meander, creating an independent eddy. These eddies have two types - cold-core rings, which rotate cyclonically (counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere), and warm-core rings, which rotate anticyclonically. These rings have

2520-917: The remaining 2–2.5 Sv returns through the Faroe-Shetland Channel; these two flows form Iceland Scotland Overflow Water (ISOW). The majority of flow over the Faroe-Shetland ridge flows through the Faroe-Bank Channel and soon joins that which flowed over the Iceland-Faroe ridge, to flow southward at depth along the Eastern flank of the Reykjanes Ridge. As ISOW overflows the GSR (Greenland-Scotland Ridge), it turbulently entrains intermediate density waters such as Sub-Polar Mode water and Labrador Sea Water. This grouping of water-masses then moves geostrophically southward along

2576-427: The seasons move from winter to summer, the gyre shifts south by a few degrees latitude. This occurs concurrently with the displacement of the northeastern part of the gyre. It has been concluded that zonal deviations within the gyre remain small while north and south of the gyre they are large. Data collected in the Sargasso Sea region in the western part of the North Atlantic Gyre has led to analytical evidence that

2632-447: The surface, with the maximum speed typically about 2.5 m/s (5.6 mph). As it travels north, the warm water transported by the Gulf Stream undergoes evaporative cooling. The cooling is wind-driven; wind moving over the water causes evaporation , cooling the water and increasing its salinity and density. When sea ice forms, salts are left out of the ice, a process known as brine exclusion. These two processes produce water that

2688-534: The tropics, and stronger storms in the North Atlantic. The warm water and temperature contrast along the edge of the Gulf Stream often increase the intensity of cyclones, tropical or otherwise. Tropical cyclone generation normally requires water temperatures in excess of 26.5 °C (79.7 °F). Tropical cyclone formation is common over the Gulf Stream, especially in July. Storms travel westward through

2744-403: The variability of this gyre is linked to wintertime convective mixing . According to Bates (2001), a seasonal variation of 8-10 °C in surface temperature occurs alongside a fluctuation in the mixed layer depth between the Northern Hemisphere winter and summer seasons. The depth rises from 200 meters in winter to about 10 meters in summer. Nutrients remain below the euphotic zone for most of

2800-452: The warm waters of the Gulf Stream, tropical fish are often encountered off the East Coast as they search for food, including several species of Batoidea , Dolphin , Barracuda , and Triggerfish . The Gulf Stream's proximity to Nantucket , Massachusetts , adds to its biodiversity , because it is the northern limit for southern varieties of plant life, and the southern limit for northern plant species, Nantucket being warmer during winter than

2856-421: The water's temperature, and changes in the water's colour—while the mail packet captains ran against it. Franklin had Folger sketch the path of the current on a chart of the Atlantic and add notes on how to avoid the current when sailing from England to America. Franklin then forwarded the chart to Anthony Todd, secretary of the British Post Office. Franklin's Gulf Stream chart was printed in 1769 in London, but it

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2912-448: The weather patterns that affect many factors within the north coast. For the same reason, flows of air down toward the northern surface of the Earth tend to spread across the surface in a clockwise pattern. Thus, clockwise air circulation is characteristic of high pressure weather cells in the Northern Hemisphere. Conversely, air rising from the northern surface of the Earth (creating a region of low pressure) tends to draw air toward it in

2968-426: The winter months. In the Northern Hemisphere, objects moving across or above the surface of the Earth tend to turn to the right because of the Coriolis effect . As a result, large-scale horizontal flows of air or water tend to form clockwise-turning gyres . These are best seen in ocean circulation patterns in the North Atlantic and North Pacific oceans. Within the Northern Hemisphere, oceanic currents can change

3024-468: The winter, and often 29 °C (84 °F) in summer and fall. East winds moving over this warm water move warm air from over the Gulf Stream inland, helping to keep temperatures milder across the state than elsewhere across the Southeastern United States during the winter. The Gulf Stream carries a wide variety of tropical fish and organisms northward along the East Coast from Florida to extreme southeast Massachusetts in spring and summer. Following

3080-400: The year, resulting in low primary production . Yet during winter convective mixing, nutrients penetrate the euphotic zone, causing a short-lived phytoplankton bloom in the spring. This then lifts the mixed-layer depth to 10 meters. The changes in oceanic biology and vertical mixing between winter and summer in the North Atlantic Gyre seasonally alter the total amount of carbon dioxide in

3136-431: Was mostly ignored by British sea captains. A copy of the chart was printed in Paris circa 1770–1773, and a third version was published by Franklin in Philadelphia in 1786. The Gulf Stream proper is a western-intensified current, driven largely by wind stress . In 1958, oceanographer Henry Stommel noted, "very little water from the Gulf of Mexico is actually in the stream". The North Atlantic Current , in contrast,

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