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44-520: The Gulf Stream is a warm Atlantic Ocean current. Gulf Stream or Gulfstream may also refer to: Gulf Stream The Gulf Stream influences 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

88-648: 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 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

132-527: A horse. An incorrect translation could therefore have produced the term "horse latitudes". The heating of the earth at the thermal equator leads to large amounts of convection along the Intertropical Convergence Zone . This air mass rises and then diverges, moving away from the equator in both northerly and southerly directions. As the air moves towards the mid-latitudes on both sides of the equator, it cools and sinks. This creates

176-420: A period of time without income. If they got advances from the ship's paymaster, they would incur debt. This period was called the "dead horse" time, and it usually lasted a month or two. The seaman's ceremony was to celebrate having worked off the "dead horse" debt. As west-bound shipping from Europe usually reached the subtropics at about the time the "dead horse" was worked off, the latitude became associated with

220-539: A ridge of high pressure near the 30th parallel in both hemispheres. At the surface level, the sinking air diverges again with some returning to the equator, creating the Hadley cell which during summer is reinforced by other climatological mechanisms such as the Rodwell–Hoskins mechanism . Many of the world's deserts are caused by these climatological high-pressure areas . The subtropical ridge moves poleward during

264-497: 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

308-490: A strong current . This was suggested by Edward Taube in his article "The Sense of 'Horse' in the Horse Latitudes". He argued the maritime use of 'horsed' described a ship that was being carried along by an ocean current or tide in the manner of a rider on horseback. The term had been in use since the end of the seventeenth century. Furthermore, The India Directory in its entry for Fernando de Noronha , an island off

352-457: Is a high-pressure area at the divergence of trade winds and the westerlies . A likely and documented explanation is that the term is derived from the "dead horse" ritual of seamen (see Beating a dead horse ). In this practice, the seaman paraded a straw-stuffed effigy of a horse around the deck before throwing it overboard. Seamen were paid partly in advance before a long voyage, and they frequently spent their pay all at once, resulting in

396-556: 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 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

440-566: 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

484-463: Is fastest near 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

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528-695: Is strongly correlated with the progression of the monsoon trough or Intertropical Convergence Zone . Most tropical cyclones form on the side of the subtropical ridge closer to the equator, then move poleward past the ridge axis before recurving into the main belt of the Westerlies. When the subtropical ridge shifts due to ENSO, so will the preferred tropical cyclone tracks. Areas west of Japan and Korea tend to experience far fewer September–November tropical cyclone impacts during El Niño and neutral years, while mainland China experiences much greater landfall frequency during La Niña years. During El Niño years,

572-509: 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 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

616-748: 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 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

660-477: The Atlantic multidecadal oscillation 's mode is favorable to tropical cyclone development (1995–present), it amplifies the subtropical ridge across the central and eastern Atlantic. When the subtropical ridge in the northwest Pacific is stronger than normal, it leads to a wet monsoon season for Asia. The subtropical ridge position is linked to how far northward monsoon moisture and thunderstorms extend into

704-685: 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 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

748-588: 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

792-549: The Atlantic combined, which total 0.6 sverdrups. It is weaker, however, than 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

836-672: 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

880-676: 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

924-489: The Southern Hemisphere. The subtropical ridge starts migrating poleward in late spring reaching its zenith in early autumn before retreating equatorward during the late fall, winter, and early spring. The equatorward migration of the subtropical ridge during the cold season is due to increasing north-south temperature differences between the poles and tropics. The latitudinal movement of the subtropical ridge

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968-532: The United States. The subtropical ridge across North America typically migrates far enough northward to begin monsoon conditions across the Desert Southwest from July to September. When the subtropical ridge is farther north than normal towards the Four Corners , monsoon thunderstorms can spread northward into Arizona . When the high pressure moves south, its circulation cuts off the moisture, and

1012-587: The break in the subtropical ridge tends to lie near 130°E , which would favor the Japanese archipelago, while in La Niña years the formation of tropical cyclones, along with the subtropical ridge position, shift west, which increases the threat to China. In the Atlantic basin, the subtropical ridge position tends to lie about 5 degrees farther south during El Niño years, which leads to a more southerly recurvature for tropical cyclones during those years. When

1056-478: The capacity to transport the distinct biological, chemical, and physical properties of their originating waters to the new waters into which they travel. Subtropical ridge The horse latitudes are the latitudes about 30 degrees north and south of the Equator . They are characterized by sunny skies, calm winds, and very little precipitation. They are also known as subtropical ridges or highs. It

1100-519: The ceremony. An alternative theory, of sufficient popularity to serve as an example of folk etymology , is that the term horse latitudes originates from when the Spanish transported horses by ship to their colonies in the West Indies and Americas. Ships often became becalmed in mid-ocean in this latitude, thus severely prolonging the voyage; the resulting water shortages made it impossible for

1144-607: 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,

1188-579: The coast of Brazil, mentions it had been visited frequently by ships "occasioned by the currents having horsed them to the westward". A further explanation is that this naming first appeared in the English translation of a German book where Rossbreiten was incorrectly understood as Pferdbreiten . The 'Ross latitudes' were named after the Englishman who described them first but could have been mistranslated, as Pferd and Ross are German synonyms for

1232-439: The crew to keep the horses alive, and they would throw the dead or dying animals overboard. A third explanation, which simultaneously explains both the northern and southern horse latitudes and does not depend on the length of the voyage or the port of departure, is based on maritime terminology: a ship was said to be 'horsed' when, although there was insufficient wind for sail, the vessel could make good progress by latching on to

1276-622: 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

1320-1012: The horse latitudes are the main cause for the existence of the world's major hot deserts, such as the Sahara Desert in Africa, the Arabian and Syrian deserts in the Middle East, the Mojave and Sonoran deserts in the southwestern United States and northern Mexico, all in the Northern Hemisphere; and the Atacama Desert , the Namib Desert , the Kalahari Desert , and the Australian Desert in

1364-403: The hot, dry continental airmass returns from the northwest, and therefore the atmosphere dries out across the Desert Southwest, causing a break in the monsoon regime. In summer, On the subtropical ridge's western edge (generally on the eastern coast of continents), the high-pressure cell pushes poleward a southerly flow (northerly in the southern hemisphere) of tropical air. In the United States,

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1408-476: 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

1452-513: 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

1496-521: 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 the water's temperature, and changes in the water's colour—while the mail packet captains ran against it. Franklin had Folger sketch

1540-586: 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 was mostly ignored by British sea captains. A copy of the chart was printed in Paris circa 1770–1773, and a third version

1584-591: The subtropical ridge Bermuda High helps create the hot, sultry summers with daily thunderstorms with buoyant airmasses typical of the Gulf of Mexico and the East Coast of the United States . This flow pattern also occurs on the eastern coasts of continents in other subtropical climates such as South China, southern Japan, central-eastern South America Pampas , southern Queensland and, KwaZulu-Natal province in South Africa. When surface winds become light,

1628-404: The subtropical ridge varies in position and strength, it can enhance or depress monsoon regimes around their low-latitude periphery. The horse latitudes are associated with the subtropical anticyclone. The belt in the Northern Hemisphere is sometimes called the "calms of Cancer " and that in the Southern Hemisphere the "calms of Capricorn ". The consistently warm, dry, and sunny conditions of

1672-473: The summer, reaching its highest latitude in early autumn, before moving back during the cold season. The El Niño–Southern Oscillation (ENSO) can displace the northern hemisphere subtropical ridge, with La Niña allowing for a more northerly axis for the ridge, while El Niños show flatter, more southerly ridges. The change of the ridge position during ENSO cycles changes the tracks of tropical cyclones that form around their equatorward and western peripheries. As

1716-460: 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 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

1760-534: 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

1804-452: 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

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1848-508: The western boundary of an ocean basin, such as the Gulf Stream, to be stronger than those on the eastern boundary. As 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

1892-548: 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

1936-653: 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, 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

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