The Drake Passage is the body of water between South America's Cape Horn , Chile, Argentina, and the South Shetland Islands of Antarctica . It connects the southwestern part of the Atlantic Ocean ( Scotia Sea ) with the southeastern part of the Pacific Ocean and extends into the Southern Ocean . The passage is named after the 16th-century English explorer and privateer Sir Francis Drake .
77-483: The Drake Passage is considered one of the most treacherous voyages for ships to make. The Antarctic Circumpolar Current , which runs through it, meets no resistance from any landmass, and waves top 40 feet (12 m), giving it a reputation for being "the most powerful convergence of seas". As the Drake Passage is the narrowest passage ( choke point ) around Antarctica, its existence and shape strongly influence
154-490: A closed Drake Passage, there is no North Atlantic Deep Water (NADW) cell, and no ACC. With a shallower Drake Passage, a weak ACC appears, but still no NADW cell. It has also been shown that present-day distribution of dissolved inorganic carbon can be obtained only with an open Drake Passage. Regarding the global surface temperature , an open (and sufficiently deep) Drake Passage cools the Southern Ocean and warms
231-538: A major effect on the global oceans due to deep currents like the Antarctic Circumpolar Current (ACC). This opening could have been a primary cause of changes in global circulation and climate, as well as the rapid expansion of Antarctic ice sheets , because, as Antarctica was encircled by ocean currents, it was cut off from receiving heat from warmer regions. The 800-kilometre-wide (500 mi) passage between Cape Horn and Livingston Island
308-561: A mean transport estimated at 100–150 Sverdrups (Sv, million m /s), or possibly even higher, making it the largest ocean current. The current is circumpolar due to the lack of any landmass connecting with Antarctica and this keeps warm ocean waters away from Antarctica, enabling that continent to maintain its huge ice sheet . Associated with the Circumpolar Current is the Antarctic Convergence , where
385-650: A much colder northern Europe and greater sea-level rise along the U.S. East Coast." Antarctic Circumpolar Current Antarctic Circumpolar Current ( ACC ) is an ocean current that flows clockwise (as seen from the South Pole) from west to east around Antarctica . An alternative name for the ACC is the West Wind Drift . The ACC is the dominant circulation feature of the Southern Ocean and has
462-678: A principal pathway of exchange among them. The current is strongly constrained by landform and bathymetric features. To trace it starting arbitrarily at South America, it flows through the Drake Passage between South America and the Antarctic Peninsula and then is split by the Scotia Arc to the east, with a shallow warm branch flowing to the north in the Falkland Current and a deeper branch passing through
539-475: A stratified fluid reaches an internal obstacle, a wave is created that can eventually break, mixing the fluid's layers. It has been estimated that the diapycnal diffusivity in the Drake Passage is ~20 times the value immediately to the west in the Pacific sector of the Antarctic Circumpolar Current (ACC). Much of the energy that is dissipated through internal wave breaking (around 20% of the wind energy put into
616-503: A wealth of other species . The ACC has been known to sailors for centuries; it greatly speeds up any travel from west to east, but makes sailing extremely difficult from east to west, although this is mostly due to the prevailing westerly winds . Jack London 's story "Make Westing" and the circumstances preceding the mutiny on the Bounty poignantly illustrate the difficulty it caused for mariners seeking to round Cape Horn westbound on
693-482: Is allowed by salinity dominating density stratification, due to the lower temperatures. Farther south still is the SACC, which is determined as the southernmost extent of Circumpolar deep water (temperature of about 2 °C at 400 m). This water mass flows along the shelfbreak of the western Antarctic Peninsula and thus marks the most southerly water flowing through Drake Passage and therefore circumpolar. The bulk of
770-418: Is an ocean current that flows clockwise (as seen from the South Pole) from west to east around Antarctica . An alternative name for the ACC is the West Wind Drift . The ACC is the dominant circulation feature of the Southern Ocean and has a mean transport estimated at 100–150 Sverdrups (Sv, million m /s), or possibly even higher, making it the largest ocean current. The current is circumpolar due to
847-410: Is driven by the strong westerly winds in the latitudes of the Southern Ocean. In latitudes where there are continents, winds blowing on light surface water can simply pile up light water against these continents. But in the Southern Ocean, the momentum imparted to the surface waters cannot be offset in this way. There are different theories on how the Circumpolar Current balances the momentum imparted by
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#1732764889977924-410: Is driven by the strong westerly winds in the latitudes of the Southern Ocean. In latitudes where there are continents, winds blowing on light surface water can simply pile up light water against these continents. But in the Southern Ocean, the momentum imparted to the surface waters cannot be offset in this way. There are different theories on how the Circumpolar Current balances the momentum imparted by
1001-550: Is mostly due to the prevailing westerly winds . Jack London 's story "Make Westing" and the circumstances preceding the mutiny on the Bounty poignantly illustrate the difficulty it caused for mariners seeking to round Cape Horn westbound on the clipper ship route from New York to California. The eastbound clipper route , which is the fastest sailing route around the world, follows the ACC around three continental capes – Cape Agulhas (Africa), South East Cape (Australia), and Cape Horn (South America). The current creates
1078-527: Is reported to have opened to water circulation 33.5 million years ago (Ma). The timing of the opening of the Drake Passage, between South America and the Antarctic Peninsula, is more disputed; tectonic and sediment evidence show that it could have been open as early as pre-34 Ma, estimates of the opening of the Drake passage are between 20 and 40 Ma. The isolation of Antarctica by
1155-404: Is reported to have opened to water circulation 33.5 million years ago (Ma). The timing of the opening of the Drake Passage, between South America and the Antarctic Peninsula, is more disputed; tectonic and sediment evidence show that it could have been open as early as pre-34 Ma, estimates of the opening of the Drake passage are between 20 and 40 Ma. The isolation of Antarctica by
1232-596: Is the shortest crossing from Antarctica to another landmass. The boundary between the Atlantic and Pacific Oceans is sometimes taken to be a line drawn from Cape Horn to Snow Island (130 kilometres (81 mi) north of mainland Antarctica), though the International Hydrographic Organization defines it as the meridian that passes through Cape Horn: 67° 16′ W. Both lines lie within the Drake Passage. The other two passages around
1309-573: The "Mar de Hoces (Sea of Hoces)" in Spanish maps and sources, while almost always in the rest of the Spanish-speaking countries it is mostly known as “Pasaje de Drake” (Argentina, mainly), “Paso Drake” or to a lesser extent: “Mar de Drake” (both in Chile, mainly). The passage received its English name from Sir Francis Drake during his raiding expedition . After passing in 1578 through
1386-551: The Antarctic Circumpolar Current , which carries a huge volume of water through the passage and around Antarctica. The passage hosts whales, dolphins, and seabirds including giant petrels , other petrels , albatrosses , and penguins . The presence of the Drake Passageway allows the three main ocean basins (Atlantic, Pacific and Indian) to be connected via the Antarctic Circumpolar current (ACC),
1463-407: The Antarctic Peninsula constrain the ACC in the Drake Passage; the convenience of measuring the ACC across the passage lays in the clear boundaries of the current in that stripe. Even after the advent of satellite altimetry data, direct observations in the Drake Passage have not lost their exceptionality. The relative shallowness and narrowness of the passage makes it particularly suitable to assess
1540-685: The Macquarie Ridge south of New Zealand. The ACC varies with time. Evidence of this is the Antarctic Circumpolar Wave , a periodic oscillation that affects the climate of much of the southern hemisphere. There is also the Antarctic oscillation , which involves changes in the location and strength of Antarctic winds. Trends in the Antarctic Oscillation have been hypothesized to account for an increase in
1617-413: The Macquarie Ridge south of New Zealand. The ACC varies with time. Evidence of this is the Antarctic Circumpolar Wave , a periodic oscillation that affects the climate of much of the southern hemisphere. There is also the Antarctic oscillation , which involves changes in the location and strength of Antarctic winds. Trends in the Antarctic Oscillation have been hypothesized to account for an increase in
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#17327648899771694-518: The Ross and Weddell Gyres . The ACC connects the Atlantic , Pacific , and Indian Oceans, and serves as a principal pathway of exchange among them. The current is strongly constrained by landform and bathymetric features. To trace it starting arbitrarily at South America, it flows through the Drake Passage between South America and the Antarctic Peninsula and then is split by the Scotia Arc to
1771-411: The clipper ship route from New York to California. The eastbound clipper route , which is the fastest sailing route around the world, follows the ACC around three continental capes – Cape Agulhas (Africa), South East Cape (Australia), and Cape Horn (South America). The current creates the Ross and Weddell Gyres . The ACC connects the Atlantic , Pacific , and Indian Oceans, and serves as
1848-707: The mid-ocean ridge in the Southeast Pacific. The current is accompanied by three fronts : the Subantarctic front (SAF), the Polar front (PF), and the Southern ACC front (SACC). Furthermore, the waters of the Southern Ocean are separated from the warmer and saltier subtropical waters by the subtropical front (STF). The northern boundary of the ACC is defined by the northern edge of the SAF, this being
1925-459: The ACC transport is carried in this front, which is defined as the latitude at which a subsurface salinity minimum or a thick layer of unstratified Subantarctic mode water first appears, allowed by temperature dominating density stratification. Still further south lies the PF, which is marked by a transition to very cold, relatively fresh, Antarctic Surface Water at the surface. Here a temperature minimum
2002-714: The Arc more to the east before also turning to the north. Passing through the Indian Ocean, the current first retroflects the Agulhas Current to form the Agulhas Return Current before it is split by the Kerguelen Plateau , and then moving northward again. Deflection is also seen as it passes over the mid-ocean ridge in the Southeast Pacific. The current is accompanied by three fronts :
2079-415: The Circumpolar Current may directly transport momentum downward in the water column. This is because such flows can produce a net southward flow in the troughs and a net northward flow over the ridges without requiring any transformation of density. In practice both the thermohaline and the eddy/meander mechanisms are likely to be important. The current flows at a rate of about 4 km/h (2.5 mph) over
2156-415: The Circumpolar Current may directly transport momentum downward in the water column. This is because such flows can produce a net southward flow in the troughs and a net northward flow over the ridges without requiring any transformation of density. In practice both the thermohaline and the eddy/meander mechanisms are likely to be important. The current flows at a rate of about 4 km/h (2.5 mph) over
2233-594: The Drake Passage to the equator, mainly in the Atlantic and Pacific Oceans. This value is not far from the Gulf Stream transport in the Florida Strait (33 Sv), but is an order of magnitude lower than the transport of the ACC (100–150 Sv). Water transported from the Southern Ocean to the Northern Hemisphere contributes to the global mass balance and permits the meridional circulation across
2310-468: The Furious Fifties blow around Antarctica and drive the Antarctic Circumpolar Current (ACC). As a result of Ekman Transport , water gets transported northward from the ACC (on the left-hand side while facing the stream direction). Using a Lagrangian approach , water parcels passing through the Drake Passage can be followed in their journey in the oceans. Around 23 Sv of water is transported from
2387-477: The Southern Ocean, transformation of these waters into light surface waters, and a transformation of waters in the opposite direction to the north. Such theories link the magnitude of the Circumpolar Current with the global thermohaline circulation , particularly the properties of the North Atlantic. Alternatively, ocean eddies , the oceanic equivalent of atmospheric storms, or the large-scale meanders of
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2464-413: The Southern Ocean, transformation of these waters into light surface waters, and a transformation of waters in the opposite direction to the north. Such theories link the magnitude of the Circumpolar Current with the global thermohaline circulation , particularly the properties of the North Atlantic. Alternatively, ocean eddies , the oceanic equivalent of atmospheric storms, or the large-scale meanders of
2541-578: The Strait of Magellan with Marigold , Elizabeth , and his flagship Golden Hind , Drake entered the Pacific Ocean and was blown far south in a tempest. Marigold was lost and Elizabeth abandoned the fleet. Only Drake's Golden Hind entered the passage. This incident demonstrated to the English that there was open water south of South America. In 1616, Dutch navigator Willem Schouten became
2618-414: The Subantarctic front (SAF), the Polar front (PF), and the Southern ACC front (SACC). Furthermore, the waters of the Southern Ocean are separated from the warmer and saltier subtropical waters by the subtropical front (STF). The northern boundary of the ACC is defined by the northern edge of the SAF, this being the most northerly water to pass through Drake Passage and therefore be circumpolar. Much of
2695-459: The amount of sea ice is lowest, and in August–September the sea ice is at its greatest extent. Ice levels have been monitored by satellite since 1973. Upwelling of deep water under the sea ice brings substantial amounts of nutrients. As the ice melts, the melt water provides stability and the critical depth is well below the mixing depth, which allows for a positive net primary production . As
2772-400: The amount of sea ice is lowest, and in August–September the sea ice is at its greatest extent. Ice levels have been monitored by satellite since 1973. Upwelling of deep water under the sea ice brings substantial amounts of nutrients. As the ice melts, the melt water provides stability and the critical depth is well below the mixing depth, which allows for a positive net primary production . As
2849-463: The circulation of water around Antarctica and the global oceanic circulation , as well as the global climate. The bathymetry of the Drake Passage plays an important role in the global mixing of oceanic water. In 1525, Spanish navigator Francisco de Hoces discovered the Drake Passage while sailing south from the entrance of the Strait of Magellan . Because of this, the Drake Passage is referred to as
2926-489: The cold Antarctic waters meet the warmer waters of the subantarctic , creating a zone of upwelling nutrients. These nurture high levels of phytoplankton with associated copepods and krill , and resultant food chains supporting fish, whales, seals , penguins, albatrosses , and a wealth of other species . The ACC has been known to sailors for centuries; it greatly speeds up any travel from west to east, but makes sailing extremely difficult from east to west, although this
3003-418: The continent. Diatom production continues through the summer, and populations of krill are sustained, bringing large numbers of cetaceans , cephalopods , seals, birds, and fish to the area. Phytoplankton blooms are believed to be limited by irradiance in the austral (southern hemisphere) spring, and by biologically available iron in the summer. Much of the biology in the area occurs along the major fronts of
3080-418: The continent. Diatom production continues through the summer, and populations of krill are sustained, bringing large numbers of cetaceans , cephalopods , seals, birds, and fish to the area. Phytoplankton blooms are believed to be limited by irradiance in the austral (southern hemisphere) spring, and by biologically available iron in the summer. Much of the biology in the area occurs along the major fronts of
3157-572: The current is credited by many researchers with causing the glaciation of Antarctica and global cooling in the Eocene epoch. Oceanic models have shown that the opening of these two passages limited polar heat convergence and caused a cooling of sea surface temperatures by several degrees; other models have shown that CO 2 levels also played a significant role in the glaciation of Antarctica. Antarctic sea ice cycles seasonally, in February–March
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3234-463: The current is credited by many researchers with causing the glaciation of Antarctica and global cooling in the Eocene epoch. Oceanic models have shown that the opening of these two passages limited polar heat convergence and caused a cooling of sea surface temperatures by several degrees; other models have shown that CO 2 levels also played a significant role in the glaciation of Antarctica. Antarctic sea ice cycles seasonally, in February–March
3311-524: The current, the Subtropical, Subantarctic, and the Antarctic Polar fronts, these are areas associated with well defined temperature changes. Size and distribution of phytoplankton are also related to fronts. Microphytoplankton (>20 μm) are found at fronts and at sea ice boundaries, while nanophytoplankton (<20 μm) are found between fronts. Studies of phytoplankton stocks in
3388-399: The current, the Subtropical, Subantarctic, and the Antarctic Polar fronts, these are areas associated with well defined temperature changes. Size and distribution of phytoplankton are also related to fronts. Microphytoplankton (>20 μm) are found at fronts and at sea ice boundaries, while nanophytoplankton (<20 μm) are found between fronts. Studies of phytoplankton stocks in
3465-423: The east, with a shallow warm branch flowing to the north in the Falkland Current and a deeper branch passing through the Arc more to the east before also turning to the north. Passing through the Indian Ocean, the current first retroflects the Agulhas Current to form the Agulhas Return Current before it is split by the Kerguelen Plateau , and then moving northward again. Deflection is also seen as it passes over
3542-513: The first to sail around Cape Horn and through the Drake Passage. On December 25, 2019, a crew of six explorers successfully rowed across the passage, becoming the first in history to do so. This accomplishment became the subject of a 2020 documentary, The Impossible Row . The Drake Passage opened when Antarctica separated from South America due to plate tectonics , however, there is much debate about when this occurred, with estimates ranging from 49 to 17 million years ago (Ma). The opening had
3619-414: The front. Some research has been conducted on Antarctic phytoplankton as a carbon sink . Areas of open water left from ice melt are good areas for phytoplankton blooms. The phytoplankton takes carbon from the atmosphere during photosynthesis. As the blooms die and sink, the carbon can be stored in sediments for thousands of years. This natural carbon sink is estimated to remove 3.5 million tonnes from
3696-414: The front. Some research has been conducted on Antarctic phytoplankton as a carbon sink . Areas of open water left from ice melt are good areas for phytoplankton blooms. The phytoplankton takes carbon from the atmosphere during photosynthesis. As the blooms die and sink, the carbon can be stored in sediments for thousands of years. This natural carbon sink is estimated to remove 3.5 million tonnes from
3773-448: The global climate. Major features of the modern ocean’s temperature and salinity fields, including the overall thermal asymmetry between the hemispheres, the relative saltiness of deep water formed in the northern hemisphere, and the existence of a transequatorial conveyor circulation, develop after Drake Passage is opened. The importance of an open Drake Passage extends farther than the Southern Ocean latitudes. The Roaring Forties and
3850-635: The global extra-tropical circulation at ≈ 10^4 kilometers". The current helps preserve wooden shipwrecks by preventing wood-boring " ship worms " from reaching targets such as Ernest Shackleton 's ship, the Endurance . The "State of the cryosphere" report found, that the Antarctic Circumpolar Current became weaker. By 2050 it expected to lose 20% of its strenght with "widespread impacts on ocean circulation and climate." The Weddell Sea Bottom Water has lost 30% of its volume in
3927-496: The global extra-tropical circulation at ≈ 10^4 kilometers". The current helps preserve wooden shipwrecks by preventing wood-boring " ship worms " from reaching targets such as Ernest Shackleton 's ship, the Endurance . The "State of the cryosphere" report found, that the Antarctic Circumpolar Current became weaker. By 2050 it expected to lose 20% of its strenght with "widespread impacts on ocean circulation and climate." The Weddell Sea Bottom Water has lost 30% of its volume in
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#17327648899774004-425: The global thermohaline circulation; without internal mixing, cooler water would never rise above warmer water, and there would be no density ( buoyancy )-driven circulation. However, mixing in the interior of most of the ocean is thought to be ten times weaker than required to support the global circulation. It has been hypothesised that the extra-mixing can be ascribed to breaking of internal waves ( Lee waves ). When
4081-526: The high latitudes of the Northern Hemisphere. The isolation of Antarctica by the ACC (that can flow only with an open Drake Passage) is credited by many researchers with causing the glaciation of the continent and global cooling in the Eocene epoch. Diapycnal mixing is the process by which different layers of a stratified fluid mix. It directly affects vertical gradients, thus it is of great importance to all gradient-driven types of transport and circulation (including thermohaline circulation ). Mixing drives
4158-533: The lack of any landmass connecting with Antarctica and this keeps warm ocean waters away from Antarctica, enabling that continent to maintain its huge ice sheet . Associated with the Circumpolar Current is the Antarctic Convergence , where the cold Antarctic waters meet the warmer waters of the subantarctic , creating a zone of upwelling nutrients. These nurture high levels of phytoplankton with associated copepods and krill , and resultant food chains supporting fish, whales, seals , penguins, albatrosses , and
4235-491: The latest 32 years, and the Antarctic Bottom Water is expected to shrunk. This will impact ocean circulation, nutrients, heat content and carbon sequestration. UNESCO mentions that the report in the first time "notes a growing scientific consensus that melting Greenland and Antarctic ice sheets, among other factors, may be slowing important ocean currents at both poles, with potentially dire consequences for
4312-417: The latest 32 years, and the Antarctic Bottom Water is expected to shrunk. This will impact ocean circulation, nutrients, heat content and carbon sequestration. UNESCO mentions that the report in the first time "notes a growing scientific consensus that melting Greenland and Antarctic ice sheets, among other factors, may be slowing important ocean currents at both poles, with potentially dire consequences for
4389-464: The most northerly water to pass through Drake Passage and therefore be circumpolar. Much of the ACC transport is carried in this front, which is defined as the latitude at which a subsurface salinity minimum or a thick layer of unstratified Subantarctic mode water first appears, allowed by temperature dominating density stratification. Still further south lies the PF, which is marked by a transition to very cold, relatively fresh, Antarctic Surface Water at
4466-464: The ocean each year. 3.5 million tonnes of carbon taken from the ocean and atmosphere is equivalent to 12.8 million tonnes of carbon dioxide. An expedition in May 2008 by 19 scientists studied the geology and biology of eight Macquarie Ridge sea mounts, as well as the Antarctic Circumpolar Current to investigate the effects of climate change of the Southern Ocean. The circumpolar current merges
4543-415: The ocean each year. 3.5 million tonnes of carbon taken from the ocean and atmosphere is equivalent to 12.8 million tonnes of carbon dioxide. An expedition in May 2008 by 19 scientists studied the geology and biology of eight Macquarie Ridge sea mounts, as well as the Antarctic Circumpolar Current to investigate the effects of climate change of the Southern Ocean. The circumpolar current merges
4620-511: The ocean) is dissipated in the Southern Ocean. In short, without the coarse topography in the depths of the Drake Passage, oceanic internal mixing would be weaker, and the global circulation would be affected. Worldwide satellite measurements of oceanic properties have been available since the 1980s. Before then, data could be only gathered through oceanic ships taking direct measurements. The Antarctic Circumpolar Current (ACC) has been (and is) surveyed making repeated transects. South America and
4697-493: The oceans. Several studies have linked the current shape of the Drake Passage to an effective Atlantic meridional overturning circulation (AMOC). Models have been run with different widths and depths of the Drake Passage, and consequent changes in the global oceanic circulation and temperature distribution have been analyzed: It appears that the "conveyor belt" of the global thermohaline circulation appears only in presence of an open Drake Passage, subject to wind forcing . With
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#17327648899774774-400: The sea ice recedes epontic algae dominate the first phase of the bloom, and a strong bloom dominate by diatoms follows the ice melt south. Another phytoplankton bloom occurs more to the north near the Antarctic Convergence , here nutrients are present from thermohaline circulation . Phytoplankton blooms are dominated by diatoms and grazed by copepods in the open ocean, and by krill closer to
4851-400: The sea ice recedes epontic algae dominate the first phase of the bloom, and a strong bloom dominate by diatoms follows the ice melt south. Another phytoplankton bloom occurs more to the north near the Antarctic Convergence , here nutrients are present from thermohaline circulation . Phytoplankton blooms are dominated by diatoms and grazed by copepods in the open ocean, and by krill closer to
4928-487: The southern extremity of South America — the Strait of Magellan and the Beagle Channel — have frequent narrows , leaving little maneuvering room for a ship, as well as unpredictable winds and tidal currents. Most sailing ships thus prefer the Drake Passage, which is open water for hundreds of miles. No significant land sits at the latitudes of the Drake Passage. This is important to the unimpeded eastward flow of
5005-595: The southern sea have shown that the Antarctic Circumpolar Current is dominated by diatoms, while the Weddell Sea has abundant coccolithophorids and silicoflagellates. Surveys of the SW Indian Ocean have shown phytoplankton group variation based on their location relative to the Polar Front, with diatoms dominating South of the front, and dinoflagellates and flagellates in higher populations North of
5082-411: The southern sea have shown that the Antarctic Circumpolar Current is dominated by diatoms, while the Weddell Sea has abundant coccolithophorids and silicoflagellates. Surveys of the SW Indian Ocean have shown phytoplankton group variation based on their location relative to the Polar Front, with diatoms dominating South of the front, and dinoflagellates and flagellates in higher populations North of
5159-399: The strongest oceanic current, with an estimated transport of 100–150 Sv ( Sverdrups , million m/s). This flow is the only large-scale exchange occurring between the global oceans, and the Drake passage is the narrowest passage on its flow around Antarctica. As such, a significant amount of research has been done in understanding how the shape of the Drake passage ( bathymetry and width) affects
5236-471: The surface. Here a temperature minimum is allowed by salinity dominating density stratification, due to the lower temperatures. Farther south still is the SACC, which is determined as the southernmost extent of Circumpolar deep water (temperature of about 2 °C at 400 m). This water mass flows along the shelfbreak of the western Antarctic Peninsula and thus marks the most southerly water flowing through Drake Passage and therefore circumpolar. The bulk of
5313-434: The transport is carried in the middle two fronts. The total transport of the ACC at Drake Passage is estimated to be around 135 Sv, or about 135 times the transport of all the world's rivers combined. There is a relatively small addition of flow in the Indian Ocean, with the transport south of Tasmania reaching around 147 Sv, at which point the current is probably the largest on the planet. The circumpolar current
5390-434: The transport is carried in the middle two fronts. The total transport of the ACC at Drake Passage is estimated to be around 135 Sv, or about 135 times the transport of all the world's rivers combined. There is a relatively small addition of flow in the Indian Ocean, with the transport south of Tasmania reaching around 147 Sv, at which point the current is probably the largest on the planet. The circumpolar current
5467-494: The transport of the Circumpolar Current over the past two decades. Published estimates of the onset of the Antarctic Circumpolar Current vary, but it is commonly considered to have started at the Eocene / Oligocene boundary. The isolation of Antarctica and formation of the ACC occurred with the openings of the Tasmanian Passage and the Drake Passage . The Tasmanian Seaway separates East Antarctica and Australia, and
5544-427: The transport of the Circumpolar Current over the past two decades. Published estimates of the onset of the Antarctic Circumpolar Current vary, but it is commonly considered to have started at the Eocene / Oligocene boundary. The isolation of Antarctica and formation of the ACC occurred with the openings of the Tasmanian Passage and the Drake Passage . The Tasmanian Seaway separates East Antarctica and Australia, and
5621-519: The validity of horizontally and vertically changing quantities (such as velocity in Ekman's theory ). In addition, the strength of the ACC makes meanders and pinching cold-core cyclonic rings easier to observe. Wildlife in the Drake Passage includes the following species: 58°35′S 65°54′W / 58.583°S 65.900°W / -58.583; -65.900 Antarctic Circumpolar Current Antarctic Circumpolar Current ( ACC )
5698-469: The waters of the Atlantic, Indian, and Pacific Oceans and carries up to 150 times the volume of water flowing in all of the world's rivers. The study found that any damage on the cold-water corals nourished by the current will have a long-lasting effect. After studying the circumpolar current it is clear that it strongly influences regional and global climate as well as underwater biodiversity. The subject has been characterized recently as "the spectral peak of
5775-469: The waters of the Atlantic, Indian, and Pacific Oceans and carries up to 150 times the volume of water flowing in all of the world's rivers. The study found that any damage on the cold-water corals nourished by the current will have a long-lasting effect. After studying the circumpolar current it is clear that it strongly influences regional and global climate as well as underwater biodiversity. The subject has been characterized recently as "the spectral peak of
5852-557: The winds. The increasing eastward momentum imparted by the winds causes water parcels to drift outward from the axis of the Earth's rotation (in other words, northward) as a result of the Coriolis force . This northward Ekman transport is balanced by a southward, pressure-driven flow below the depths of the major ridge systems. Some theories connect these flows directly, implying that there is significant upwelling of dense deep waters within
5929-450: The winds. The increasing eastward momentum imparted by the winds causes water parcels to drift outward from the axis of the Earth's rotation (in other words, northward) as a result of the Coriolis force . This northward Ekman transport is balanced by a southward, pressure-driven flow below the depths of the major ridge systems. Some theories connect these flows directly, implying that there is significant upwelling of dense deep waters within
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