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Distinctive white lines trace the flow of surface currents around the world.

Visualization showing global ocean currents from January 1, 2010, to December 31, 2012, at sea level, then at 2,000 m (6,600 ft) below sea level

Animation of circulation around ice shelves of Antarctica

An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences.^[1] Depth contours, shoreline configurations, and interactions with other currents influence a current's direction and strength. Ocean currents move both horizontally, on scales that can span entire oceans, as well as vertically, with vertical currents (upwelling and downwelling) playing an important role in the movement of nutrients and gases, such as carbon dioxide, between the surface and the deep ocean.

Ocean currents flow for great distances and together they create the global conveyor belt, which plays a dominant role in determining the climate of many of Earth's regions. More specifically, ocean currents influence the temperature of the regions through which they travel. For example, warm currents traveling along more temperate coasts increase the temperature of the area by warming the sea breezes that blow over them. Perhaps the most striking example is the Gulf Stream, which, together with its extension the North Atlantic Drift, makes northwest Europe much more temperate for its high latitude than other areas at the same latitude. Another example is Lima, Peru, whose cooler subtropical climate contrasts with that of its surrounding tropical latitudes because of the Humboldt Current.

The largest ocean current is the Antarctic Circumpolar Current (ACC), a wind-driven current which flows clockwise uninterrupted around Antarctica. The ACC connects all the ocean basins together, and also provides a link between the atmosphere and the deep ocean due to the way water upwells and downwells on either side of it.

Ocean currents are patterns of water movement that influence climate zones and weather patterns around the world. They are primarily driven by winds and by seawater density, although many other factors influence them – including the shape and configuration of the ocean basin they flow through. The two basic types of currents – surface and deep-water currents – help define the character and flow of ocean waters across the planet.

Causes

Ocean currents are driven by the wind, by the gravitational pull of the moon in the form of tides, and by the effects of variations in water density.^[4] Ocean dynamics define and describe the motion of water within the oceans.

Ocean temperature and motion fields can be separated into three distinct layers: mixed (surface) layer, upper ocean (above the thermocline), and deep ocean. Ocean currents are measured in units of sverdrup (Sv), where 1 Sv is equivalent to a volume flow rate of 1,000,000 m³ (35,000,000 cu ft) per second.

Surface ocean currents (in contrast to subsurface ocean currents), make up only 8% of all water in the ocean, are generally restricted to the upper 400 m (1,300 ft) of ocean water, and are separated from lower regions by varying temperatures and salinity which affect the density of the water, which in turn, defines each oceanic region. Because the movement of deep water in ocean basins is caused by density-driven forces and gravity, deep waters sink into deep ocean basins at high latitudes where the temperatures are cold enough to cause the density to increase. Surface currents are measured in units of meters per second (m/s) or in knots.^[1]

Wind-driven circulation

Surface oceanic currents are driven by wind currents, the large scale prevailing winds drive major persistent ocean currents, and seasonal or occasional winds drive currents of similar persistence to the winds that drive them,^[5] and the Coriolis effect plays a major role in their development.^[6] The Ekman spiral velocity distribution results in the currents flowing at an angle to the driving winds, and they develop typical clockwise spirals in the northern hemisphere and counter-clockwise rotation in the southern hemisphere.^[7] In addition, the areas of surface ocean currents move somewhat with the seasons; this is most notable in equatorial currents.

Deep ocean basins generally have a non-symmetric surface current, in that the eastern equator-ward flowing branch is broad and diffuse whereas the pole-ward flowing western boundary current is relatively narrow.

Thermohaline circulation

Large scale currents are driven by gradients in water density, which in turn depend on variations in temperature and salinity. This thermohaline circulation is also known as the ocean's conveyor belt. Where significant vertical movement of ocean currents is observed, this is known as upwelling and downwelling. The adjective thermohaline derives from thermo- referring to temperature and -haline referring to salt content, factors which together determine the density of seawater.

The thermohaline circulation is a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes.^[8]^[9] Wind-driven surface currents (such as the Gulf Stream) travel polewards from the equatorial Atlantic Ocean, cooling en route, and eventually sinking at high latitudes (forming North Atlantic Deep Water). This dense water then flows into the ocean basins. While the bulk of it upwells in the Southern Ocean, the oldest waters (with a transit time of around 1000 years)^[10] upwell in the North Pacific.^[11] Extensive mixing therefore takes place between the ocean basins, reducing differences between them and making the Earth's oceans a global system. On their journey, the water masses transport both energy (in the form of heat) and matter (solids, dissolved substances and gases) around the globe. As such, the state of the circulation has a large impact on the climate of the Earth. The thermohaline circulation is sometimes called the ocean conveyor belt, the great ocean conveyor, or the global conveyor belt. On occasion, it is imprecisely used to refer to the meridional overturning circulation, (MOC).

Since the 2000s an international program called Argo has been mapping the temperature and salinity structure of the ocean with a fleet of automated platforms that float with the ocean currents. The information gathered will help explain the role the oceans play in the earth's climate.^[12]

Coupling data collected by NASA/JPL by several different satellite-borne sensors, researchers have been able to "break through" the ocean's surface to detect "Meddies" – super-salty warm-water eddies that originate in the Mediterranean Sea and then sink more than a half-mile underwater in the Atlantic Ocean. The Meddies are shown in red in this scientific figure.

Distribution

Currents of the Arctic Ocean

Baffin Island Current – Arctic Ocean current
Beaufort Gyre – Wind-driven ocean current in the Arctic Ocean polar region
East Greenland Current – Current from Fram Strait to Cape Farewell off the eastern coat of Greenland
East Iceland Current – Cold water ocean current that forms as a branch of the East Greenland Current
Labrador Current – Cold current in the Atlantic ocean along the coasts of Labrador, Newfoundland and Nova Scotia
North Icelandic Jet – Deep-reaching current that flows along the continental slope of Iceland
Norwegian Current – Current that flows northeasternly along the Atlantic coast of Norway
Transpolar Drift Stream – An ocean current of the Arctic Ocean
West Greenland Current – Weak cold water current that flows to the north along the west coast of Greenland
West Spitsbergen Current – Warm, salty current that runs poleward just west of Spitsbergen

Currents of the Atlantic Ocean

Angola Current – Temporary ocean surface current
Antilles Current – Ocean current
Atlantic meridional overturning circulation – System of surface and deep currents in the Atlantic Ocean
Azores Current – Ocean current in the North Atlantic Ocean
Benguela Current – Ocean current in the South Atlantic
Brazil Current – Warm current that flows south along the Brazilian south coast to the mouth of the Río de la Plata
Canary Current – Wind-driven surface current that is part of the North Atlantic Gyre
Cape Horn Current – Cold water current that flows west-to-east around Cape Horn
Caribbean Current – Atlantic Ocean current
East Greenland Current – Current from Fram Strait to Cape Farewell off the eastern coat of Greenland
East Iceland Current – Cold water ocean current that forms as a branch of the East Greenland Current
Equatorial Counter Current – Shallow eastward flowing current found in the Atlantic, Indian, and Pacific Oceans
Falkland Current – Northward cold water Atlantic Ocean current
Florida Current – Thermal ocean current
Guinea Current – A slow warm water current that flows to the east along the Guinea coast of West Africa
Gulf Stream – Warm Atlantic Ocean current
Irminger Current – north Atlantic current setting westward off the southwest coast of Iceland
Labrador Current – Cold current in the Atlantic ocean along the coasts of Labrador, Newfoundland and Nova Scotia
Lomonosov Current – Deep current in the Atlantic Ocean. from the coast of Brazil to the Gulf of Guinea
Loop Current – Ocean current between Cuba and Yucatán Peninsula
North Atlantic Current – Current of the Atlantic Ocean
North Brazil Current – North Atlantic ocean current
North Equatorial Current – Current in the Pacific and Atlantic Oceans
Norwegian Current – Current that flows northeasternly along the Atlantic coast of Norway
Portugal Current – Weak ocean current that flows south along the coast of Portugal
South Atlantic Current – Eastward ocean current, fed by the Brazil Current
South Equatorial Current – Ocean current in the Pacific, Atlantic, and Indian Ocean
West Greenland Current – Weak cold water current that flows to the north along the west coast of Greenland
West Spitsbergen Current – Warm, salty current that runs poleward just west of Spitsbergen

Currents of the Indian Ocean

Agulhas Current – Western boundary current of the southwest Indian Ocean that flows down the east coast of Africa
Agulhas Return Current – Ocean current in the southern Indian Ocean
East Madagascar Current – Oceanic flow feature near Madagascar
Equatorial Counter Current – Shallow eastward flowing current found in the Atlantic, Indian, and Pacific Oceans
Indian Monsoon Current – Seasonally-varying ocean current regime found in the tropical regions of the northern Indian Ocean
Indonesian Throughflow – Ocean current
Leeuwin Current – Ocean current off Western Australia
Madagascar Current – Ocean current in the West Indian Ocean
Mozambique Current – Warm ocean current in the Indian Ocean
North Madagascar Current – Ocean current near Madagascar that flows into the South Equatorial Current
Somali Current – Ocean boundary current that flows along the coast of Somalia and Oman in the Western Indian Ocean
South Equatorial Current – Ocean current in the Pacific, Atlantic, and Indian Ocean
Southwest Madagascar Coastal Current – Warm poleward ocean current flowing in the south-west of Madagascar
West Australian Current – Cool oceanic current

Currents of the Pacific Ocean

Alaska Current – Warm-water current flowing nortwards along the coast of British Columbia and the Alaska Panhandle
Aleutian Current – Eastward-flowing ocean current which lies north of the North Pacific Current;
California Current – Pacific Ocean current
Cape Horn Current – Cold water current that flows west-to-east around Cape Horn
Cromwell Current – Eastward-flowing subsurface current that extends along the equator in the Pacific Ocean
Davidson Current – Countercurrent of the Pacific Ocean
East Australian Current – Currents of the Pacific Ocean
East Korea Warm Current – Ocean current in the Sea of Japan
Equatorial Counter Current – Shallow eastward flowing current found in the Atlantic, Indian, and Pacific Oceans
Humboldt Current – Current of the Pacific Ocean
Indonesian Throughflow – Ocean current
Kamchatka Current – Pacific Ocean current
Kuroshio Current – North flowing ocean current on the west side of the North Pacific Ocean
Mindanao Current – Narrow, southward-flowing ocean current along the southeastern coast of the Philippines
Mindanao Eddy – Semi-permanent cold-ring eddy formed in the retroflection area of the Mindanao Current.
North Equatorial Current – Current in the Pacific and Atlantic Oceans
North Korea Cold Current – Cold water current in the Sea of Japan
North Pacific Current – Ocean current, Japan to British Columbia
Oyashio Current – Cold subarctic ocean current in the Pacific Ocean
South Equatorial Current – Ocean current in the Pacific, Atlantic, and Indian Ocean
Subtropical Countercurrent – Narrow eastward ocean current in the central North Pacific Ocean
Tasman Front – Pacific Ocean current
Tasman Outflow – Deepwater current that flows from the Pacific Ocean past Tasmania into the Indian Ocean

Currents of the Southern Ocean

Antarctic Circumpolar Current – Ocean current that flows clockwise from west to east around Antarctica
Tasman Outflow – Deepwater current that flows from the Pacific Ocean past Tasmania into the Indian Ocean
Kerguelen deep western boundary current^[2]^[3]

Oceanic gyres

Beaufort Gyre – Wind-driven ocean current in the Arctic Ocean polar region
Indian Ocean Gyre – Major oceanic gyre in the Indian Ocean
North Atlantic Gyre – Major circular system of ocean currents
North Pacific Gyre – Major circulating system of ocean currents
Ross Gyre – Circulating system of ocean currents in the Ross Sea
South Atlantic Gyre – Subtropical gyre in the south Atlantic Ocean
South Pacific Gyre – Major circulating system of ocean currents
Weddell Gyre – One of two gyres within the Southern Ocean

Effects on climate and ecology

Ocean currents are important in the study of marine debris, and vice versa. These currents also affect temperatures throughout the world. For example, the ocean current that brings warm water up the north Atlantic to northwest Europe also cumulatively and slowly blocks ice from forming along the seashores, which would also block ships from entering and exiting inland waterways and seaports, hence ocean currents play a decisive role in influencing the climates of regions through which they flow.^[13] Cold ocean water currents flowing from polar and sub-polar regions bring in a lot of plankton that are crucial to the continued survival of several key sea creature species in marine ecosystems. Since plankton are the food of fish, abundant fish populations often live where these currents prevail.

Ocean currents are also very important in the dispersal of many life forms. An example is the life-cycle of the European Eel.

Ocean currents and climate change

As atmospheric temperatures continue to rise, this is anticipated to have various effects on the strength of surface ocean currents, wind-driven circulation and dispersal patterns.^[14]^[15]^[16] Ocean currents play a significant role in influencing climate, and shifts in climate, in turn, impact ocean currents.^[15] Over the last century, reconstructed sea surface temperature data reveal that western boundary currents are heating at double the rate of the global average.^[17] These observations indicate that the western boundary currents are likely intensifying due to this change in temperature, and may continue to grow stronger in the near future.^[15] Studies investigating international ocean current patterns have also suspected that anthropogenic climate change has accelerated upper ocean currents by 77%.^[16] Faster upper ocean currents are often associated with increased vertical stratification, as well as faster and stronger zonal currents.^[16]

In addition to water surface temperatures, the wind systems are a crucial determinant of ocean currents.^[18] Wind wave systems influence oceanic heat exchange, the condition of the sea surface, and can alter ocean currents.^[19] In the North Atlantic, equatorial Pacific, and Southern Ocean, increased wind speeds as well as significant wave heights have been attributed to climate change and natural processes combined.^[19] In the East Australian Current, global warming has also been accredited to increased wind stress curls, which intensify these currents, and may even indirectly increase sea levels, due to the additional warming created by stronger currents.^[20]

As ocean circulation changes due to climate, typical distribution patterns are also changing. The dispersal patterns of marine organisms depend on oceanographic conditions, which as a result, influence the biological composition of oceans.^[14] Due to the patchiness of the natural ecological world, dispersal is a species survival mechanism for various organisms.^[21] With strengthened boundary currents moving toward the poles, it is expected that some marine species will be redirected to the poles and greater depths.^[14]^[22] The strengthening or weakening of typical dispersal pathways by increased temperatures are expected to not only impact the survival of native marine species due to inability to replenish their meta populations but also may increase the prevalence of invasive species.^[14] In Japanese corals and macroalgae, the unusual dispersal pattern of organisms toward the poles may destabilize native species.^[23]

Economic importance

Knowledge of surface ocean currents is essential in reducing costs of shipping, since traveling with them reduces fuel costs. In the wind powered sailing-ship era, knowledge of wind patterns and ocean currents was even more essential. Using ocean currents to help their ships into harbor and using currents such as the gulf stream to get back home.^[24] The lack of understanding of ocean currents during that time period is hypothesized to be one of the contributing factors to exploration failure. The gulf stream and the Canary current keep western European countries warmer and less variable, while at the same latitude North America's weather was colder.^[25] A good example of this is the Agulhas Current (down along eastern Africa), which long prevented sailors from reaching India.

In recent times, around-the-world sailing competitors make good use of surface currents to build and maintain speed. Ocean currents can also be used for marine power generation, with areas of Japan, Florida and Hawaii being considered for test projects. The utilization of currents today can still impact global trade, it can reduce the cost and emissions of shipping vessels.^[26] Ocean currents can also impact the fishing industry, examples of this include the Tsugaru, Oyashio and Kuroshio currents all of which influence the western North Pacific temperature, which has been shown to be a habitat predictor for the Skipjack tuna.^[27] It has also been shown that it is not just local currents that can affect a country's economy, but neighboring currents can influence the viability of local fishing industries.^[28]

References

^ ^a ^b "What is a current?". NOAA's National Ocean Service. 2009-03-01. Retrieved 2023-03-14.
^ ^a ^b "Massive Southern Ocean current discovered". ScienceDaily. Apr 27, 2010.
^ ^a ^b Yasushi Fukamachi, Stephen Rintoul; et al. (Apr 2010). "Strong export of Antarctic Bottom Water east of the Kerguelen plateau". Nature Geoscience. 3 (5): 327–331. Bibcode:2010NatGe...3..327F. doi:10.1038/NGEO842. hdl:2115/44116. S2CID 67815755.
^ National Oceanic and Atmospheric Administration (16 June 2024). "What is a current?". oceanservice.noaa.gov. Retrieved 2024-09-03.
^ "Current". www.nationalgeographic.org. National Geographic. 2 September 2011. Retrieved 7 January 2021.
^ "Ocean Currents of the World: Causes". 29 August 2020. Retrieved 2020-11-20.
^ National Ocean Service (March 25, 2008). "Surface Ocean Currents". noaa.gov. National Oceanic and Atmospheric Administration. Archived from the original on July 6, 2017. Retrieved 2017-06-13.
^ Rahmstorf, S (2003). "The concept of the thermohaline circulation" (PDF). Nature. 421 (6924): 699. Bibcode:2003Natur.421..699R. doi:10.1038/421699a. PMID 12610602. S2CID 4414604.
^ Lappo, SS (1984). "On reason of the northward heat advection across the Equator in the South Pacific and Atlantic ocean". Study of Ocean and Atmosphere Interaction Processes. Moscow Department of Gidrometeoizdat (in Mandarin): 125–9.
^ The global ocean conveyor belt is a constantly moving system of deep-ocean circulation driven by temperature and salinity; What is the global ocean conveyor belt?
^ Primeau, F (2005). "Characterizing transport between the surface mixed layer and the ocean interior with a forward and adjoint global ocean transport model" (PDF). Journal of Physical Oceanography. 35 (4): 545–64. Bibcode:2005JPO....35..545P. doi:10.1175/JPO2699.1. S2CID 130736022.
^ Scripps Institution of Oceanography, UC San Diego. "Argo". Argo. Archived from the original on 1 September 2024. Retrieved 2024-09-05.
^ "What Is the Gulf Stream? | NOAA SciJinks – All About Weather". scijinks.gov. Retrieved 2024-04-15.
^ ^a ^b ^c ^d Wilson, Laura J.; Fulton, Christopher J.; Hogg, Andrew McC; Joyce, Karen E.; Radford, Ben T. M.; Fraser, Ceridwen I. (2016-05-02). "Climate-driven changes to ocean circulation and their inferred impacts on marine dispersal patterns". Global Ecology and Biogeography. 25 (8): 923–939. Bibcode:2016GloEB..25..923W. doi:10.1111/geb.12456. ISSN 1466-822X.
^ ^a ^b ^c Miller, Johanna L. (2017). "Ocean currents respond to climate change in unexpected ways". Physics Today. 70 (1): 17–18.
^ ^a ^b ^c Peng, Qihua; Xie, Shang-Ping; Wang, Dongxiao; Huang, Rui Xin; Chen, Gengxin; Shu, Yeqiang; Shi, Jia-Rui; Liu, Wei (2022-04-22). "Surface warming–induced global acceleration of upper ocean currents". Science Advances. 8 (16): eabj8394. Bibcode:2022SciA....8J8394P. doi:10.1126/sciadv.abj8394. ISSN 2375-2548. PMC 9020668. PMID 35442733.
^ Wu, Lixin; Cai, Wenju; Zhang, Liping; Nakamura, Hisashi; Timmermann, Axel; Joyce, Terry; McPhaden, Michael J.; Alexander, Michael; Qiu, Bo; Visbeck, Martin; Chang, Ping; Giese, Benjamin (2012-01-29). "Enhanced warming over the global subtropical western boundary currents". Nature Climate Change. 2 (3): 161–166. Bibcode:2012NatCC...2..161W. doi:10.1038/nclimate1353. hdl:1912/5125. ISSN 1758-6798.
^ Constantin, Adrian (2021-01-02). "Frictional effects in wind-driven ocean currents". Geophysical & Astrophysical Fluid Dynamics. 115 (1): 1–14. Bibcode:2021GApFD.115....1C. doi:10.1080/03091929.2020.1748614. ISSN 0309-1929.
^ ^a ^b Dobrynin, Mikhail; Murawski, Jens; Baehr, Johanna; Ilyina, Tatiana (2015-02-15). "Detection and Attribution of Climate Change Signal in Ocean Wind Waves". Journal of Climate. 28 (4): 1578–1591. Bibcode:2015JCli...28.1578D. doi:10.1175/JCLI-D-13-00664.1. ISSN 0894-8755.
^ Cai, W.; Shi, G.; Cowan, T.; Bi, D.; Ribbe, J. (2005-12-10). "The response of the Southern Annular Mode, the East Australian Current, and the southern mid-latitude ocean circulation to global warming". Geophysical Research Letters. 32 (23). Bibcode:2005GeoRL..3223706C. doi:10.1029/2005GL024701. ISSN 0094-8276.
^ Kininmonth, Stuart (2011-04-11). "Dispersal connectivity and reserve selection for marine conservation". Ecological Modelling. 222 (7): 1272–1282. Bibcode:2011EcMod.222.1272K. doi:10.1016/j.ecolmodel.2011.01.012.
^ Vergés, Adriana; Steinberg, Peter D.; Hay, Mark E.; Poore, Alistair G. B.; Campbell, Alexandra H.; Ballesteros, Enric; Heck, Kenneth L.; Booth, David J.; Coleman, Melinda A.; Feary, David A.; Figueira, Will; Langlois, Tim; Marzinelli, Ezequiel M.; Mizerek, Toni; Mumby, Peter J. (2014-08-22). "The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts". Proceedings of the Royal Society B: Biological Sciences. 281 (1789): 20140846. doi:10.1098/rspb.2014.0846. ISSN 0962-8452. PMC 4100510. PMID 25009065.
^ Kumagai, Naoki H.; García Molinos, Jorge; Yamano, Hiroya; Takao, Shintaro; Fujii, Masahiko; Yamanaka, Yasuhiro (2018-09-04). "Ocean currents and herbivory drive macroalgae-to-coral community shift under climate warming". Proceedings of the National Academy of Sciences. 115 (36): 8990–8995. Bibcode:2018PNAS..115.8990K. doi:10.1073/pnas.1716826115. ISSN 0027-8424. PMC 6130349. PMID 30126981.
^ "Atlantic Ocean - Exploration, Currents, Marine Life | Britannica". www.britannica.com. Retrieved 2024-04-20.
^ US Department of Commerce, National Oceanic and Atmospheric Administration. "Boundary Currents - Currents: NOAA's National Ocean Service Education". oceanservice.noaa.gov. Retrieved 2024-04-20.
^ Chang, Yu-Chia; Tseng, Ruo-Shan; Chen, Guan-Yu; Chu, Peter C.; Shen, Yung-Ting (November 2013). "Ship Routing Utilizing Strong Ocean Currents". The Journal of Navigation. 66 (6): 825–835. doi:10.1017/S0373463313000441. ISSN 0373-4633.
^ Ramesh, Nandini; Rising, James A.; Oremus, Kimberly L. (2019-06-21). "The small world of global marine fisheries: The cross-boundary consequences of larval dispersal". Science. 364 (6446): 1192–1196. Bibcode:2019Sci...364.1192R. doi:10.1126/science.aav3409. ISSN 0036-8075.
^ Talley, Lynne D. (April 1, 1995). "North Pacific Intermediate Water in the Kuroshio/Oyashio Mixed Water Region". American Meteorological Society. 25 (4): 475–501. Bibcode:1995JPO....25..475T. doi:10.1175/1520-0485(1995)025<0475:NPIWIT>2.0.CO;2 – via AMS Publications.

External links

Current global map of sea surface currents

[NOAAs_National_Ocean_Service_2009-1] "What is a current?". NOAA's National Ocean Service. 2009-03-01. Retrieved 2023-03-14.

[Massive-2] "Massive Southern Ocean current discovered". ScienceDaily. Apr 27, 2010.

[Fukamachi-3] Yasushi Fukamachi, Stephen Rintoul; et al. (Apr 2010). "Strong export of Antarctic Bottom Water east of the Kerguelen plateau". Nature Geoscience. 3 (5): 327–331. Bibcode:2010NatGe...3..327F. doi:10.1038/NGEO842. hdl:2115/44116. S2CID 67815755.

[4] National Oceanic and Atmospheric Administration (16 June 2024). "What is a current?". oceanservice.noaa.gov. Retrieved 2024-09-03.

[NatGeo_Current-5] "Current". www.nationalgeographic.org. National Geographic. 2 September 2011. Retrieved 7 January 2021.

[6] "Ocean Currents of the World: Causes". 29 August 2020. Retrieved 2020-11-20.

[NNOAACurrents-7] National Ocean Service (March 25, 2008). "Surface Ocean Currents". noaa.gov. National Oceanic and Atmospheric Administration. Archived from the original on July 6, 2017. Retrieved 2017-06-13.

[8] Rahmstorf, S (2003). "The concept of the thermohaline circulation" (PDF). Nature. 421 (6924): 699. Bibcode:2003Natur.421..699R. doi:10.1038/421699a. PMID 12610602. S2CID 4414604.

[9] Lappo, SS (1984). "On reason of the northward heat advection across the Equator in the South Pacific and Atlantic ocean". Study of Ocean and Atmosphere Interaction Processes. Moscow Department of Gidrometeoizdat (in Mandarin): 125–9.

[10] The global ocean conveyor belt is a constantly moving system of deep-ocean circulation driven by temperature and salinity; What is the global ocean conveyor belt?

[11] Primeau, F (2005). "Characterizing transport between the surface mixed layer and the ocean interior with a forward and adjoint global ocean transport model" (PDF). Journal of Physical Oceanography. 35 (4): 545–64. Bibcode:2005JPO....35..545P. doi:10.1175/JPO2699.1. S2CID 130736022.

[12] Scripps Institution of Oceanography, UC San Diego. "Argo". Argo. Archived from the original on 1 September 2024. Retrieved 2024-09-05.

[13] "What Is the Gulf Stream? | NOAA SciJinks – All About Weather". scijinks.gov. Retrieved 2024-04-15.

[:0-14] Wilson, Laura J.; Fulton, Christopher J.; Hogg, Andrew McC; Joyce, Karen E.; Radford, Ben T. M.; Fraser, Ceridwen I. (2016-05-02). "Climate-driven changes to ocean circulation and their inferred impacts on marine dispersal patterns". Global Ecology and Biogeography. 25 (8): 923–939. Bibcode:2016GloEB..25..923W. doi:10.1111/geb.12456. ISSN 1466-822X.

[:1-15] Miller, Johanna L. (2017). "Ocean currents respond to climate change in unexpected ways". Physics Today. 70 (1): 17–18.

[:2-16] Peng, Qihua; Xie, Shang-Ping; Wang, Dongxiao; Huang, Rui Xin; Chen, Gengxin; Shu, Yeqiang; Shi, Jia-Rui; Liu, Wei (2022-04-22). "Surface warming–induced global acceleration of upper ocean currents". Science Advances. 8 (16): eabj8394. Bibcode:2022SciA....8J8394P. doi:10.1126/sciadv.abj8394. ISSN 2375-2548. PMC 9020668. PMID 35442733.

[17] Wu, Lixin; Cai, Wenju; Zhang, Liping; Nakamura, Hisashi; Timmermann, Axel; Joyce, Terry; McPhaden, Michael J.; Alexander, Michael; Qiu, Bo; Visbeck, Martin; Chang, Ping; Giese, Benjamin (2012-01-29). "Enhanced warming over the global subtropical western boundary currents". Nature Climate Change. 2 (3): 161–166. Bibcode:2012NatCC...2..161W. doi:10.1038/nclimate1353. hdl:1912/5125. ISSN 1758-6798.

[18] Constantin, Adrian (2021-01-02). "Frictional effects in wind-driven ocean currents". Geophysical & Astrophysical Fluid Dynamics. 115 (1): 1–14. Bibcode:2021GApFD.115....1C. doi:10.1080/03091929.2020.1748614. ISSN 0309-1929.

[:3-19] Dobrynin, Mikhail; Murawski, Jens; Baehr, Johanna; Ilyina, Tatiana (2015-02-15). "Detection and Attribution of Climate Change Signal in Ocean Wind Waves". Journal of Climate. 28 (4): 1578–1591. Bibcode:2015JCli...28.1578D. doi:10.1175/JCLI-D-13-00664.1. ISSN 0894-8755.

[20] Cai, W.; Shi, G.; Cowan, T.; Bi, D.; Ribbe, J. (2005-12-10). "The response of the Southern Annular Mode, the East Australian Current, and the southern mid-latitude ocean circulation to global warming". Geophysical Research Letters. 32 (23). Bibcode:2005GeoRL..3223706C. doi:10.1029/2005GL024701. ISSN 0094-8276.

[21] Kininmonth, Stuart (2011-04-11). "Dispersal connectivity and reserve selection for marine conservation". Ecological Modelling. 222 (7): 1272–1282. Bibcode:2011EcMod.222.1272K. doi:10.1016/j.ecolmodel.2011.01.012.

[22] Vergés, Adriana; Steinberg, Peter D.; Hay, Mark E.; Poore, Alistair G. B.; Campbell, Alexandra H.; Ballesteros, Enric; Heck, Kenneth L.; Booth, David J.; Coleman, Melinda A.; Feary, David A.; Figueira, Will; Langlois, Tim; Marzinelli, Ezequiel M.; Mizerek, Toni; Mumby, Peter J. (2014-08-22). "The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts". Proceedings of the Royal Society B: Biological Sciences. 281 (1789): 20140846. doi:10.1098/rspb.2014.0846. ISSN 0962-8452. PMC 4100510. PMID 25009065.

[23] Kumagai, Naoki H.; García Molinos, Jorge; Yamano, Hiroya; Takao, Shintaro; Fujii, Masahiko; Yamanaka, Yasuhiro (2018-09-04). "Ocean currents and herbivory drive macroalgae-to-coral community shift under climate warming". Proceedings of the National Academy of Sciences. 115 (36): 8990–8995. Bibcode:2018PNAS..115.8990K. doi:10.1073/pnas.1716826115. ISSN 0027-8424. PMC 6130349. PMID 30126981.

[24] "Atlantic Ocean - Exploration, Currents, Marine Life | Britannica". www.britannica.com. Retrieved 2024-04-20.

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@@ Line 32: / Line 32: @@
 {{main|Thermohaline circulation}}
 {{Further|Deep ocean water}}
-Large scale currents are driven by gradients in water [[density]], which in turn depend on variations in temperature and salinity. This [[thermohaline circulation]] is also known as the ocean's conveyor belt. Where significant vertical movement of ocean currents is observed, this is known as [[upwelling]] and [[downwelling]]. An international program called [[Argo (oceanography)|Argo]] began researching deep ocean currents with a fleet of underwater robots in the 2000s.
+Large scale currents are driven by gradients in water [[density]], which in turn depend on variations in temperature and salinity. This [[thermohaline circulation]] is also known as the ocean's conveyor belt. Where significant vertical movement of ocean currents is observed, this is known as [[upwelling]] and [[downwelling]]. The adjective ''thermohaline'' derives from ''[[wikt:thermo-|thermo-]]'' referring to [[temperature]] and ''{{nowrap|-haline}}'' referring to [[salinity|salt content]], factors which together determine the density of seawater.
-The thermohaline circulation is a part of the large-scale ocean circulation that is driven by global [[density gradient]]s created by surface heat and freshwater [[flux]]es.<ref>{{cite journal|last=Rahmstorf|first=S|title=The concept of the thermohaline circulation|journal=Nature|volume=421|page=699|year=2003|url=http://www.pik-potsdam.de/~stefan/Publications/Nature/nature_concept_03.pdf|pmid=12610602|issue=6924|doi=10.1038/421699a|bibcode = 2003Natur.421..699R |s2cid=4414604|doi-access=free}}</ref><ref>{{cite journal|last=Lappo|first=SS|title=On reason of the northward heat advection across the Equator in the South Pacific and Atlantic ocean|journal=Study of Ocean and Atmosphere Interaction Processes|year=1984|pages=125–9|publisher=Moscow Department of Gidrometeoizdat (in Mandarin)}}</ref> The adjective ''thermohaline'' derives from ''[[wikt:thermo-|thermo-]]'' referring to [[temperature]] and ''{{nowrap|-haline}}'' referring to [[salinity|salt content]], factors which together determine the density of seawater. [[Wind]]-driven surface currents (such as the [[Gulf Stream]]) travel [[Polar regions of Earth|polewards]] from the equatorial [[Atlantic Ocean]], cooling en route, and eventually sinking at high [[latitude]]s (forming [[North Atlantic Deep Water]]). This dense water then flows into the [[ocean basin]]s. While the bulk of it [[upwelling|upwells]] in the [[Southern Ocean]], the oldest waters (with a transit time of around 1000 years)<ref>The global ocean conveyor belt is a constantly moving system of deep-ocean circulation driven by temperature and salinity; [http://oceanservice.noaa.gov/facts/conveyor.html What is the global ocean conveyor belt?]</ref> upwell in the North Pacific.<ref>{{cite journal|doi=10.1175/JPO2699.1|last=Primeau|first=F|title=Characterizing transport between the surface mixed layer and the ocean interior with a forward and adjoint global ocean transport model|journal=Journal of Physical Oceanography|volume=35|issue=4|pages=545–64|year=2005|bibcode=2005JPO....35..545P|s2cid=130736022 |url=https://escholarship.org/content/qt5f76r4wn/qt5f76r4wn.pdf?t=n3tp5j}}</ref> Extensive mixing therefore takes place between the ocean basins, reducing differences between them and making the Earth's oceans a global system. On their journey, the water masses transport both energy (in the form of heat) and matter (solids, dissolved substances and gases) around the globe. As such, the state of the circulation has a large impact on the [[climate]] of the Earth. The thermohaline circulation is sometimes called the ocean conveyor belt, the great ocean conveyor, or the global conveyor belt. On occasion, it is imprecisely used to refer to the [[meridional overturning circulation]], (MOC).
+The thermohaline circulation is a part of the large-scale ocean circulation that is driven by global [[density gradient]]s created by surface heat and freshwater [[flux]]es.<ref>{{cite journal|last=Rahmstorf|first=S|title=The concept of the thermohaline circulation|journal=Nature|volume=421|page=699|year=2003|url=http://www.pik-potsdam.de/~stefan/Publications/Nature/nature_concept_03.pdf|pmid=12610602|issue=6924|doi=10.1038/421699a|bibcode = 2003Natur.421..699R |s2cid=4414604|doi-access=free}}</ref><ref>{{cite journal|last=Lappo|first=SS|title=On reason of the northward heat advection across the Equator in the South Pacific and Atlantic ocean|journal=Study of Ocean and Atmosphere Interaction Processes|year=1984|pages=125–9|publisher=Moscow Department of Gidrometeoizdat (in Mandarin)}}</ref> [[Wind]]-driven surface currents (such as the [[Gulf Stream]]) travel [[Polar regions of Earth|polewards]] from the equatorial [[Atlantic Ocean]], cooling en route, and eventually sinking at high [[latitude]]s (forming [[North Atlantic Deep Water]]). This dense water then flows into the [[ocean basin]]s. While the bulk of it [[upwelling|upwells]] in the [[Southern Ocean]], the oldest waters (with a transit time of around 1000 years)<ref>The global ocean conveyor belt is a constantly moving system of deep-ocean circulation driven by temperature and salinity; [http://oceanservice.noaa.gov/facts/conveyor.html What is the global ocean conveyor belt?]</ref> upwell in the North Pacific.<ref>{{cite journal|doi=10.1175/JPO2699.1|last=Primeau|first=F|title=Characterizing transport between the surface mixed layer and the ocean interior with a forward and adjoint global ocean transport model|journal=Journal of Physical Oceanography|volume=35|issue=4|pages=545–64|year=2005|bibcode=2005JPO....35..545P|s2cid=130736022 |url=https://escholarship.org/content/qt5f76r4wn/qt5f76r4wn.pdf?t=n3tp5j}}</ref> Extensive mixing therefore takes place between the ocean basins, reducing differences between them and making the Earth's oceans a global system. On their journey, the water masses transport both energy (in the form of heat) and matter (solids, dissolved substances and gases) around the globe. As such, the state of the circulation has a large impact on the [[climate]] of the Earth. The thermohaline circulation is sometimes called the ocean conveyor belt, the great ocean conveyor, or the global conveyor belt. On occasion, it is imprecisely used to refer to the [[meridional overturning circulation]], (MOC).
+Since the 2000s an international program called [[Argo (oceanography)|Argo]] has been mapping the temperature and salinity structure of the ocean with a fleet of automated platforms that float with the ocean currents. The information gathered will help explain the role the oceans play in the earth's climate.<ref>{{Cite web |last=Scripps Institution of Oceanography, UC San Diego |title=Argo |url=https://argo.ucsd.edu/ |archive-url=https://web.archive.org/web/20240901191501/https://argo.ucsd.edu/ |archive-date=1 September 2024 |access-date=2024-09-05 |website=Argo |language=en-US}}</ref>
 [[File:Meddes-20060320-browse.jpg|thumb|Coupling data collected by NASA/JPL by several different satellite-borne sensors, researchers have been able to "break through" the ocean's surface to detect "Meddies" – super-salty warm-water eddies that originate in the Mediterranean Sea and then sink more than a half-mile underwater in the Atlantic Ocean. The Meddies are shown in red in this scientific figure.]]

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