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The Gulf Stream, together with its northern extension the
North Atlantic Drift The North Atlantic Current (NAC), also known as North Atlantic Drift and North Atlantic Sea Movement, is a powerful warm western boundary current Boundary currents are ocean current An ocean current is a continuous, directed movement of sea ...
, is a warm and swift
Atlantic
Atlantic
ocean current An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contour ...
that originates in the
Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

Gulf of Mexico
and stretches to the tip of
Florida Florida is a U.S. state, state located in the Southeastern United States, Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia (U.S. state), Georg ...

Florida
and follows the eastern coastlines of the United States and
Newfoundland Newfoundland and Labrador (, ) is the easternmost provinces and territories of Canada, province of Canada, in the country's Atlantic Canada, Atlantic region. It is composed of the island of Newfoundland (island), Newfoundland and the continental ...
before crossing the Atlantic Ocean as the
North Atlantic Current The North Atlantic Current (NAC), also known as North Atlantic Drift and North Atlantic Sea Movement, is a powerful warm western boundary current Boundary currents are ocean current An ocean current is a continuous, directed movement of sea ...
. The process of
western intensification Boundary currents are ocean currents with dynamics determined by the presence of a coastline, and fall into two distinct categories: western boundary currents and eastern boundary currents. Eastern boundary currents Eastern boundary currents are r ...
causes the Gulf Stream to be a northwards accelerating current off the east coast of North America. At about , it splits in two, with the northern stream, the North Atlantic Drift, crossing to Northern Europe and the southern stream, the
Canary Current The Canary Current is a wind-driven surface current that is part of the North Atlantic Gyre. This eastern boundary current branches south from the North Atlantic Current and flows southwest about as far as Senegal where it turns west and later ...
, recirculating off West Africa. The Gulf Stream influences the climate of the east coast of North America from Florida to Newfoundland and the west coast of Europe. Although there has been recent debate,Climate Mythology: The Gulf Stream, European climate and Abrupt Change
/ref> there is consensus that the climate of Western Europe and Northern Europe is warmer than other areas of similar latitude because of the North Atlantic Current. It is part of the
North Atlantic Gyre The North Atlantic Gyre of the Atlantic Ocean is one of five great oceanic gyres. It is a circular ocean current An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, includin ...

North Atlantic Gyre
. Its presence has led to the development of strong
cyclone In meteorology, a cyclone () is a large scale air mass that rotates around a strong center of low atmospheric pressure, counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an ...
s of all types, both within the
atmosphere An atmosphere (from the greek words ἀτμός ''(atmos)'', meaning 'vapour', and σφαῖρα ''(sphaira)'', meaning 'ball' or 'sphere') is a layer or a set of layers of gases surrounding a planet or other material body, that is held in ...
and within the ocean. The Gulf Stream is also a significant potential source of renewable power generation.


History

European discovery of the Gulf Stream dates to the 1512 expedition of
Juan Ponce de León Juan Ponce de León (, , , ; 1474 – July 1521) was a Spanish Spanish may refer to: * Items from or related to Spain , * gl, Reino de España, * oc, Reiaume d'Espanha, , , image_flag = Bandera de España.svg , image_coat = E ...

Juan Ponce de León
, after which it became widely used by Spanish ships sailing from the
Caribbean The Caribbean (, ; es, Caribe; french: Caraïbes; ht, Karayib; also gcf, label=Antillean Creole, Kawayib; nl, Caraïben; Papiamento: ) is a region of the Americas that comprises the Caribbean Sea, its surrounding coasts, and its islands (some ...
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 Benjamin Franklin ( April 17, 1790) was an American polymath A polymath ( el, πολυμαθής, ', "having learned much"; Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-E ...

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 HM Customs (His or Her Majesty's Customs) was the national Customs service of Kingdom of England, England (and then of Kingdom of Great Britain, Great Britain from 1707, the United Kingdom from 1801) until a merger with the HM Excise, Department ...
: 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 Newport is a seaside city on Aquidneck Island in Newport County, Rhode Island. It is located in Narragansett Bay approximately southeast of Providence, Rhode Island, Providence, south of Fall River, Massachusetts, south of Boston, and northe ...
, despite the merchant ships leaving from London and having to sail down the
River Thames The River Thames ( ), known alternatively in parts as the The Isis, River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the Longest rivers of the United Kingdom, sec ...
and then the length of the
English Channel The English Channel,, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or (Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kana ...

English Channel
before they sailed across the Atlantic, while the packets left from Falmouth in Cornwall? ''The First Salute: A View of the American Revolution'' New York: Ballantine Books, 1988. pp.221–222. Franklin asked Timothy Folger, a
Nantucket Island Nantucket is an island about by ferry south from Cape Cod, in the U.S. state of Massachusetts Massachusetts (, ), officially the Commonwealth of Massachusetts, is the most populous U.S. state, state in the New England region of the Unite ...
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 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 was published by Franklin in Philadelphia in 1786.


Properties

The Gulf Stream proper is a western-intensified current, driven largely by
wind stress In physical oceanography and fluid dynamics In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including aerodynamics (the stu ...
. The North Atlantic Drift, in contrast, is largely driven by
thermohaline circulation 350px, A summary of the path of the thermohaline circulation. Blue paths represent deep-water currents, while red paths represent surface currents. Thermohaline circulation (THC) is a part of the large-scale Ocean current, ocean circulation that ...

thermohaline circulation
. In 1958, oceanographer
Henry Stommel Henry "Hank" Melson Stommel (September 27, 1920 – January 17, 1992) was a major contributor to the field of physical oceanography. Beginning in the 1940s, he advanced theories about global ocean circulation patterns and the behavior of the Gulf ...
noted that "very little water from the Gulf of Mexico is actually in the stream". By carrying warm water northeast across the Atlantic, it makes Western Europe and especially Northern Europe warmer and milder than it otherwise would be.


Formation and behaviour

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 the
Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico a ...
, while a second, the
Antilles Current The Antilles Current is a highly variable surface ocean current of warm water that flows northeasterly past the island chain that separates the Caribbean The Caribbean (, ; es, Caribe; french: Caraïbes; ht, Karayib; also gcf, label= Antille ...

Antilles Current
, flows north and east of the
West Indies The West Indies are a subregion of North America, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea that includes 13 independent island country, island countries and 18 dependent territory, dependencies and other ter ...
. These two branches rejoin north of the
Straits of Florida 250px, The Straits of Florida The Straits of Florida, Florida Straits, or Florida Strait ( es, Estrecho de Florida) is a strait A strait is a naturally formed, narrow, typically navigable waterway that connects two larger bodies of water. M ...

Straits of Florida
. The
trade winds The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere ...
blow westwards in the tropics, and the
westerlies The westerlies, anti-trades, or prevailing westerlies, are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the high-pressure areas in the horse latitudes and trend to ...
blow eastwards at mid-latitudes. This wind pattern applies a stress to the subtropical ocean surface with negative
curl cURL (pronounced 'curl') is a computer software project providing a library A library is a curated collection of sources of information and similar resources, made accessible to a defined community for reference or borrowing. It provides ...
across the north Atlantic Ocean. The resulting Sverdrup transport is equatorward. Because of the conservation of
potential vorticity In fluid mechanics Fluid mechanics is the branch of physics concerned with the mechanics Mechanics (Ancient Greek, Greek: ) is the area of physics concerned with the motions of physical objects, more specifically the relationships among ...

potential vorticity
caused by the northwards-moving winds on the
subtropical ridge 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 is a high-pressure are ...
's western periphery and the increased relative vorticity of northwards moving water, transport is balanced by a narrow, accelerating polewards 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 Labrador Current is a cold current in the North Atlantic Ocean which flows from the Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is also known as ...

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 is 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 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
sverdrup In oceanography, the sverdrup (symbol: Sv) is a non-International System of Units, SI Metric_units#Volume_flow_rate, metric unit of Volumetric flow rate, flow, with equal to ; it is equivalent to the SI derived unit cubic hectometer per second (s ...
s) 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 the
Antarctic Circumpolar Current The Antarctic Circumpolar Current (ACC) is an ocean current An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, ca ...

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 Coastal erosion is the loss or displacement of land, or the long-term removal of sediment and rocks along the coastline due to the action of Wind wave, waves, Ocean current, currents, tides, wind-driven water, waterborne ice, or other impacts ...

coastal erosion
. The Gulf Stream is typically wide and to deep. The current velocity is fastest near the surface, with the maximum speed typically about . 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 File:10. Ладење при испарување.ogv, 280px, Demonstration of evaporative cooling. When the sensor is dipped in ethanol and then taken out to evaporate, the instrument shows progressively lower temperature as the ethanol evapor ...

evaporation
, cooling the water and increasing its
salinity File:IAPSO Standard Seawater.jpg, upInternational Association for the Physical Sciences of the Oceans (IAPSO) standard seawater. Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (se ...

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 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 Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity Homogeneity and heterogeneity are concepts often used in the sciences and statistics Statistics ...

convective
action is similar to a
lava lamp A lava lamp is a decorative lamp, invented in 1963 by British entrepreneur Edward Craven Walker, the founder of the lighting company Mathmos. The lamp consists of a bolus of a special coloured wax mixture inside a glass vessel, the remainder o ...

lava lamp
.) This downdraft of cold, dense water becomes a part of the
North Atlantic Deep Water North Atlantic Deep Water (NADW) is a deep water mass formed in the North Atlantic Ocean. Thermohaline circulation 350px, A summary of the path of the thermohaline circulation. Blue paths represent deep-water currents, while red paths represent ...
, a southgoing stream. Very little
seaweed Seaweed, or macroalgae, refers to thousands of species of Macroscopic scale, macroscopic, Multicellular organism, multicellular, ocean, marine algae. The term includes some types of ''Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta ...

seaweed
lies within the current, although seaweed lies in clusters to its east. In April 2018, two studies published in ''Nature'' found the Gulf Stream to be at its weakest for at least 1,600 years.


Localized effects

The Gulf Stream is influential on the climate of the Florida peninsula. The portion off the Florida coast, referred to as the
Florida Current The Florida Current is a thermal ocean current that flows from the Straits of Florida around the Florida Peninsula and along the southeastern coast of the United States before joining the Gulf Stream Current near Cape Hatteras Cape Hatteras is ...
, maintains an average water temperature of at least during the winter. 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. Also, the Gulf Stream's proximity to
Nantucket Nantucket is an island about by ferry south from Cape Cod Cape Cod is a geographic cape extending into the Atlantic Ocean from the southeastern corner of mainland Massachusetts Massachusetts (, ), officially the Commonwealth of Massa ...

Nantucket
,
Massachusetts Massachusetts (, ), officially the Commonwealth of Massachusetts, is the most populous state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * T ...

Massachusetts
adds to its
biodiversity Biodiversity is the biological variety and Genetic variability, variability of life, life on Earth. Biodiversity is a measure of variation at the Genetics, genetic, species, and ecosystem level. Terrestrial biodiversity is usually greater near t ...
, 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 the mainland. The North Atlantic Current of the Gulf Stream, along with similar warm air currents, helps keep
Ireland Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island upright=1.15, Great_Britain.html"_;"title="Ireland_(left)_and_Great_Britain">Ireland_(left)_and_Great_Britain_(right),_are_large_islands_of_north-west_Europe image:Small_Island_in ...

Ireland
and the western coast of
Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the List of European islands by area, largest European island, and the List of i ...

Great Britain
a couple of degrees warmer than the east. However, the difference is most dramatic in the western coastal islands of Scotland. A noticeable effect of the Gulf Stream and the strong westerly winds (driven by the warm water of the Gulf Stream) on Europe occurs along the Norwegian coast. Northern parts of
Norway Norway, officially the Kingdom of Norway,Names in the official and recognised languages: Bokmål Bokmål (, ; literally "book tongue") is an official written standard for the Norwegian language, alongside Nynorsk. Bokmål is the preferred ...

Norway
lie close to the
Arctic The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Alaska (United States), Canada, Finland, Greenland (Danish Realm, Den ...

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 the coast of
Northern Norway Northern Norway ( nb, Nord-Norge, , nn, Nord-Noreg; se, Davvi-Norga) is a geographical Regions of Norway, region of Norway, consisting of the two northernmost counties Nordland and Troms og Finnmark, in total about 35% of the Norwegian mainland ...
, including
Tromsø Tromsø (, , ; se, Romsa ; fkv, Tromssa; sv, Tromsö) is a List of municipalities of Norway, municipality in Troms og Finnmark Counties of Norway, county, Norway. The administrative centre of the municipality is the Tromsø (city), city of Trom ...

Tromsø
, the third largest city north of the Arctic Circle. Weather systems warmed by the Gulf Stream drift into
Northern Europe Northern Europe is a loosely defined Geography, geographical and cultural region in Europe. Narrower definitions may describe Northern Europe as being roughly north of the southern coast of the Baltic Sea, which is about 54°N, or may be based o ...
, also warming the climate behind the
Scandinavian mountains#REDIRECT Scandinavian Mountains The Scandinavian Mountains or the Scandes is a mountain range that runs through the Scandinavian Peninsula. The Scandinavian Mountains are often erroneously thought to be equivalent to the Scandinavian Caledonide ...
.


Effect on cyclone formation

The warm water and temperature contrast along the edge of the Gulf Stream often increase the intensity of cyclones,
tropical The tropics are the region of Earth surrounding the Equator. They are delimited in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S; these latitudes correspond to ...
or otherwise. Tropical cyclone generation normally requires water temperatures in excess of . Tropical cyclone formation is common over the Gulf Stream, especially in the month of July. Storms travel westwards through the Caribbean and then either move in a northwards direction and curve towards the eastern coast of the United States or stay on a north-westwards track and enter the
Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

Gulf of Mexico
. Such storms have the potential to create strong winds and extensive damage to the United States' Southeast Coastal Areas.
Hurricane Sandy Hurricane Sandy (unofficially referred to as Superstorm Sandy) was the deadliest, the most destructive, and the strongest tropical cyclone, hurricane of the 2012 Atlantic hurricane season. The storm inflicted nearly $70 billion (2012 USD) ...
in 2012 was a recent example of a hurricane passing over the Gulf Stream and gaining strength.The Making of a Superstorm
/ref> Strong
extratropical cyclone Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of pr ...
s have been shown to deepen significantly along a shallow frontal zone, forced by the Gulf Stream, during the .
Subtropical cyclone A subtropical cyclone is a weather system that has some characteristics of a tropical and an extratropical cyclone. As early as the 1950s, meteorologists were uncertain whether they should be characterized as tropical or extratropical cyclone ...
s also tend to generate near the Gulf Stream. 75 percent of such systems documented between 1951 and 2000 formed near this warm water current, with two annual peaks of activity occurring during the months of May and October. Cyclones within the ocean form under the Gulf Stream, extending as deep as beneath the ocean's surface.


Possible renewable power source

The theoretical maximum energy dissipation from the Gulf Stream by turbines is in the range of 20–60 GW. One suggestion, which could theoretically supply power comparable to several nuclear power plants, would deploy a field of underwater turbines placed 300 metres (980 ft) under the centre of the core of the Gulf Stream.
Ocean thermal energy Ocean Thermal Energy Conversion (OTEC) uses the ocean thermal gradient between cooler deep and warmer shallow or surface seawaters to run a heat engine and produce useful Work (physics), work, usually in the form of electricity. OTEC can operate ...
could also be harnessed to produce electricity using the temperature difference between cold deep water and warm surface water.Jeremy Elton Jacquot
Gulf Stream's Tidal Energy Could Provide Up to a Third of Florida's Power.
Retrieved on 2008-09-21.


Gulf Stream Rings

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. Of these eddies, there are two types: cold core rings, which rotate cyclonically, and warm core rings, which rotate anti cyclonically. These rings have the capacity to transport the distinct biological, chemical, and physical properties of their originating waters to the new waters into which they travel.


See also

* Arctic dipole anomaly *
Boundary current Boundary currents are ocean current An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature an ...
*
Humboldt Current The Humboldt Current, also called the Peru Current, is a cold, low-salinity ocean current that flows north along the western coast of South America.Montecino, Vivian, and Carina B. Lange. "The Humboldt Current System: Ecosystem components and proce ...
* Latitude of the Gulf Stream and the Gulf Stream north wall index *
North Atlantic oscillation#REDIRECT North Atlantic oscillation {{Redirect category shell, 1= {{R from other capitalisation ...
*
Shutdown of thermohaline circulation A shutdown or slowdown of the thermohaline circulation is a hypothesized Effects of global warming, effect of global warming on a major ocean circulation. A 2015 study suggested that the Atlantic meridional overturning circulation (AMOC) has w ...


References


Further reading


Corona Magazine Issue 124: Science
(German, Transported amount of power) * (Increased temperature and salinity in the Nordic Seas.)


External links


Current map of the Gulf Stream
{{Authority control Currents of the Atlantic Ocean Atlantic Ocean Effects of climate change Regional climate effects Natural environment