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98-660: The Bali Sea is sometimes grouped with the Flores Sea for oceanographic purposes; however, in some nautical charts , Bali Sea is written as a distinct sea for navigation. The sea has an area of 45,000 km (17,000 sq mi) and a maximum depth of 1,590 m (5,217 ft). The International Hydrographic Organization (IHO) defines the Bali Sea as being one of the waters of the East Indian Archipelago . The IHO defines its limits as follows: On

196-427: A acertar: mas partiam os nossos mareantes muy ensinados e prouidos de estromentos e regras de astrologia e geometria que sam as cousas que os cosmographos ham dadar apercebidas (...) e leuaua cartas muy particularmente rumadas e na ja as de que os antigos vsauam" (were not done by chance: but our seafarers departed well taught and provided with instruments and rules of astrology (astronomy) and geometry which were matters

294-1313: A continuation from Flores Sea to the Java Sea in the north. In oceanographic, Bali Sea is concerned with the Indonesian Throughflow coming from Pacific Ocean to the Indian Ocean , the flow of which are mostly passing through Bali Strait and Lombok Strait . In a recorded tsunami history, Bali Sea observed several tsunamis. The 1815 Tambora eruption (scale 7 of Volcanic Explosivity Index ) formed tsunamis on 22 September 1815 at coordinate 8°00′S 115°12′E  /  8.00°S 115.20°E  / -8.00; 115.20 and three years later (8 September 1818) from subsequent volcanic activities at coordinate 7°00′S 117°00′E  /  7.0°S 117.0°E  / -7.0; 117.0 . Two more tsunamis were recorded in 1857 and 1917 with maximum heights of 3 and 2 meters (9.8 and 6.6 ft) respectively. Oceanographic Oceanography (from Ancient Greek ὠκεανός ( ōkeanós )  ' ocean ' and γραφή ( graphḗ )  ' writing '), also known as oceanology , sea science , ocean science , and marine science ,

392-751: A high pressure (anticyclonic) systems such as the Azores-Bermuda high develops a gyre circulation with slow steady flows towards the equator in the interior. As discussed by Henry Stommel , these flows are balanced in the region of the western boundary, where a thin fast polewards flow called a western boundary current develops. Flow in the real ocean is more complex, but the Gulf Stream , Agulhas and Kuroshio are examples of such currents. They are narrow (approximately 100 km across) and fast (approximately 1.5 m/s). Equatorwards western boundary currents occur in tropical and polar locations, e.g.

490-563: A paper on reefs and the formation of atolls as a result of the second voyage of HMS Beagle in 1831–1836. Robert FitzRoy published a four-volume report of Beagle ' s three voyages. In 1841–1842 Edward Forbes undertook dredging in the Aegean Sea that founded marine ecology. The first superintendent of the United States Naval Observatory (1842–1861), Matthew Fontaine Maury devoted his time to

588-436: A result of heat storage in summer and release in winter; or of transport of heat from warmer locations: a particularly notable example of this is Western Europe , which is heated at least in part by the north atlantic drift . Surface winds tend to be of order meters per second; ocean currents of order centimeters per second. Hence from the point of view of the atmosphere, the ocean can be considered effectively stationary; from

686-513: A result, tiny variations in pressure can produce measurable currents. A slope of one part in one million in sea surface height, for example, will result in a current of 10 cm/s at mid-latitudes. The fact that the Coriolis effect is largest at the poles and weak at the equator results in sharp, relatively steady western boundary currents which are absent on eastern boundaries. Also see secondary circulation effects. Ekman transport results in

784-481: A subtropical ocean basin (the Sverdrup balance ). The return flow occurs in an intense, narrow, poleward western boundary current . Like the atmosphere, the ocean is far wider than it is deep, and hence horizontal motion is in general much faster than vertical motion. In the southern hemisphere there is a continuous belt of ocean, and hence the mid-latitude westerlies force the strong Antarctic Circumpolar Current . In

882-595: A sudden shift in the wind, such as the change of the trade winds at the beginning of the El Niño-Southern Oscillation . Coastal Kelvin waves follow shorelines and will always propagate in a counterclockwise direction in the Northern hemisphere (with the shoreline to the right of the direction of travel) and clockwise in the Southern hemisphere . Equatorial Kelvin waves propagate to

980-493: A time scale of decades. Known climate oscillations resulting from these interactions, include the Pacific decadal oscillation , North Atlantic oscillation , and Arctic oscillation . The oceanic process of thermohaline circulation is a significant component of heat redistribution across the globe, and changes in this circulation can have major impacts upon the climate. This is a coupled ocean / atmosphere wave that circles

1078-625: A voyage around the Cape of Good Hope in 1777, he mapped "the banks and currents at the Lagullas " . He was also the first to understand the nature of the intermittent current near the Isles of Scilly , (now known as Rennell's Current). The tides and currents of the ocean are distinct. Tides are the rise and fall of sea levels created by the combination of the gravitational forces of the Moon along with

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1176-424: A wide range of disciplines to deepen their understanding of the world’s oceans, incorporating insights from astronomy , biology , chemistry , geography , geology , hydrology , meteorology and physics . Humans first acquired knowledge of the waves and currents of the seas and oceans in pre-historic times. Observations on tides were recorded by Aristotle and Strabo in 384–322 BC. Early exploration of

1274-480: Is a turbulent and complex system which utilizes atmospheric measurement techniques such as eddy covariance to measure the rate of heat transfer expressed in the unit of or petawatts . Heat flux is the flow of energy per unit of area per unit of time. Most of the Earth's heat storage is within its seas with smaller fractions of the heat transfer in processes such as evaporation, radiation, diffusion, or absorption into

1372-651: Is due to the change in the regime of winds and currents: the North Atlantic gyre and the Equatorial counter current will push south along the northwest bulge of Africa, while the uncertain winds where the Northeast trades meet the Southeast trades (the doldrums) leave a sailing ship to the mercy of the currents. Together, prevalent current and wind make northwards progress very difficult or impossible. It

1470-740: Is entrained into the Circumpolar Current, and can be traced into the Indian and Pacific basins. Flow from the Arctic Ocean Basin into the Pacific, however, is blocked by the narrow shallows of the Bering Strait . Also see marine geology about that explores the geology of the ocean floor including plate tectonics that create deep ocean trenches. An idealised subtropical ocean basin forced by winds circling around

1568-457: Is formed in polar regions where cold salty waters sink in fairly restricted areas. This is the beginning of the thermohaline circulation . Oceanic currents are largely driven by the surface wind stress; hence the large-scale atmospheric circulation is important to understanding the ocean circulation. The Hadley circulation leads to Easterly winds in the tropics and Westerlies in mid-latitudes. This leads to slow equatorward flow throughout most of

1666-399: Is great, for both land and sea, the respective extremes such as mountains and trenches are rare. Because the vast majority of the world ocean's volume is deep water, the mean temperature of seawater is low; roughly 75% of the ocean's volume has a temperature from 0° – 5 °C (Pinet 1996). The same percentage falls in a salinity range between 34 and 35 ppt (3.4–3.5%) (Pinet 1996). There

1764-665: Is likely to affect marine organisms with calcareous shells, such as oysters, clams, sea urchins and corals, and the carbonate compensation depth will rise closer to the sea surface. Affected planktonic organisms will include pteropods , coccolithophorids and foraminifera , all important in the food chain . In tropical regions, corals are likely to be severely affected as they become less able to build their calcium carbonate skeletons, in turn adversely impacting other reef dwellers. The current rate of ocean chemistry change seems to be unprecedented in Earth's geological history, making it unclear how well marine ecosystems will adapt to

1862-499: Is primarily influenced by both these factors—colder, saltier water is denser than warmer, fresher water. This variation in density creates stratification in the ocean and is key to understanding ocean circulation patterns. Understanding the complex interactions between temperature, salinity, and density is essential for predicting ocean circulation patterns, climate change effects, and the health of marine ecosystems. These factors also influence marine life, as many species are sensitive to

1960-549: Is remembered in the navigation context for the determination of the loxodromic curve: the shortest course between two points on the surface of a sphere represented onto a two-dimensional map. When he published his "Treatise of the Sphere" (1537), mostly a commentated translation of earlier work by others, he included a treatise on geometrical and astronomic methods of navigation. There he states clearly that Portuguese navigations were not an adventurous endeavour: "nam se fezeram indo

2058-441: Is still quite a bit of variation, however. Surface temperatures can range from below freezing near the poles to 35 °C in restricted tropical seas, while salinity can vary from 10 to 41 ppt (1.0–4.1%). The vertical structure of the temperature can be divided into three basic layers, a surface mixed layer , where gradients are low, a thermocline where gradients are high, and a poorly stratified abyss. In terms of temperature,

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2156-442: Is that the phase velocity of each individual wave always has a westward component, but the group velocity can be in any direction. Usually the shorter Rossby waves have an eastward group velocity and the longer ones have a westward group velocity. The interaction of ocean circulation, which serves as a type of heat pump , and biological effects such as the concentration of carbon dioxide can result in global climate changes on

2254-444: Is the scientific study of the ocean , including its physics , chemistry , biology , and geology . It is an Earth science , which covers a wide range of topics, including ocean currents , waves , and geophysical fluid dynamics ; fluxes of various chemical substances and physical properties within the ocean and across its boundaries; ecosystem dynamics; and plate tectonics and seabed geology. Oceanographers draw upon

2352-705: The Challenger expedition . Challenger , leased from the Royal Navy, was modified for scientific work and equipped with separate laboratories for natural history and chemistry . Under the scientific supervision of Thomson, Challenger travelled nearly 70,000 nautical miles (130,000 km) surveying and exploring. On her journey circumnavigating the globe, 492 deep sea soundings, 133 bottom dredges, 151 open water trawls and 263 serial water temperature observations were taken. Around 4,700 new species of marine life were discovered. The result

2450-695: The Australian Institute of Marine Science (AIMS), established in 1972 soon became a key player in marine tropical research. In 1921 the International Hydrographic Bureau , called since 1970 the International Hydrographic Organization , was established to develop hydrographic and nautical charting standards. Physical oceanography Physical oceanography is the study of physical conditions and physical processes within

2548-481: The Coriolis force . Roughly 97% of the planet's water is in its oceans, and the oceans are the source of the vast majority of water vapor that condenses in the atmosphere and falls as rain or snow on the continents. The tremendous heat capacity of the oceans moderates the planet's climate , and its absorption of various gases affects the composition of the atmosphere . The ocean's influence extends even to

2646-724: The Ishiguro Storm Surge Computer ) generally now replaced by numerical methods (e.g. SLOSH .) An oceanographic buoy array was established in the Pacific to allow prediction of El Niño events. 1990 saw the start of the World Ocean Circulation Experiment (WOCE) which continued until 2002. Geosat seafloor mapping data became available in 1995. Study of the oceans is critical to understanding shifts in Earth's energy balance along with related global and regional changes in climate ,

2744-1169: The Mediterranean Science Commission . Marine research institutes were already in existence, starting with the Stazione Zoologica Anton Dohrn in Naples, Italy (1872), the Biological Station of Roscoff, France (1876), the Arago Laboratory in Banyuls-sur-mer, France (1882), the Laboratory of the Marine Biological Association in Plymouth, UK (1884), the Norwegian Institute for Marine Research in Bergen, Norway (1900),

2842-619: The Norwegian Sea evaporative cooling is predominant, and the sinking water mass, the North Atlantic Deep Water (NADW), fills the basin and spills southwards through crevasses in the submarine sills that connect Greenland , Iceland and Britain . It then flows along the western boundary of the Atlantic with some part of the flow moving eastward along the equator and then poleward into the ocean basins. The NADW

2940-609: The Southern Ocean about every eight years. Since it is a wave-2 phenomenon (there are two peaks and two troughs in a latitude circle ) at each fixed point in space a signal with a period of four years is seen. The wave moves eastward in the direction of the Antarctic Circumpolar Current . Among the most important ocean currents are the: The ocean body surrounding the Antarctic is currently

3038-627: The Southern Ocean is of concern to ocean scientists because bottom water changes will effect currents, nutrients, and biota elsewhere. The international awareness of global warming has focused scientific research on this topic since the 1988 creation of the Intergovernmental Panel on Climate Change . Improved ocean observation, instrumentation, theory, and funding has increased scientific reporting on regional and global issues related to heat. Tide gauges and satellite altimetry suggest an increase in sea level of 1.5–3 mm/yr over

Bali Sea - Misplaced Pages Continue

3136-560: The biosphere and biogeochemistry . The atmosphere and ocean are linked because of evaporation and precipitation as well as thermal flux (and solar insolation ). Recent studies have advanced knowledge on ocean acidification , ocean heat content , ocean currents , sea level rise , the oceanic carbon cycle , the water cycle , Arctic sea ice decline , coral bleaching , marine heatwaves , extreme weather , coastal erosion and many other phenomena in regards to ongoing climate change and climate feedbacks . In general, understanding

3234-471: The continents . Their major restoring force is the change in Coriolis force with latitude . Their wave amplitudes are usually in the tens of meters and very large wavelengths . They are usually found at low or mid latitudes. There are two types of Rossby waves, barotropic and baroclinic . Barotropic Rossby waves have the highest speeds and do not vary vertically. Baroclinic Rossby waves are much slower. The special identifying feature of Rossby waves

3332-417: The convergence zones debris, foam and seaweed accumulates, while at the divergence zones plankton are caught and carried to the surface. If there are many plankton in the divergence zone fish are often attracted to feed on them. At the ocean-atmosphere interface, the ocean and atmosphere exchange fluxes of heat, moisture and momentum. The important heat terms at the surface are the sensible heat flux ,

3430-470: The ocean , especially the motions and physical properties of ocean waters. Physical oceanography is one of several sub-domains into which oceanography is divided. Others include biological , chemical and geological oceanography. Physical oceanography may be subdivided into descriptive and dynamical physical oceanography. Descriptive physical oceanography seeks to research the ocean through observations and complex numerical models, which describe

3528-481: The 29 days Cabral took from Cape Verde up to landing in Monte Pascoal , Brazil. The Danish expedition to Arabia 1761–67 can be said to be the world's first oceanographic expedition, as the ship Grønland had on board a group of scientists, including naturalist Peter Forsskål , who was assigned an explicit task by the king, Frederik V , to study and describe the marine life in the open sea, including finding

3626-655: The Azores), bringing what is now Brazil into the Portuguese area of domination. The knowledge gathered from open sea exploration allowed for the well-documented extended periods of sail without sight of land, not by accident but as pre-determined planned route; for example, 30 days for Bartolomeu Dias culminating on Mossel Bay , the three months Gama spent in the South Atlantic to use the Brazil current (southward), or

3724-720: The East Greenland and Labrador currents, in the Atlantic and the Oyashio . They are forced by winds circulation around low pressure (cyclonic). The Gulf Stream, together with its northern extension, North Atlantic Current , is a powerful, warm, and swift Atlantic Ocean current that originates in the Gulf of Mexico , exits through the Strait of Florida, and follows the eastern coastlines of the United States and Newfoundland to

3822-664: The East coast to Tg Bantenan, the Southeast extreme of the island. On the South. A line from Tanjong Banenan through the Southern points of Balt [ sic ] and Noesa Islands to Tanjong Bt Gendang, the Southwest extreme of Lombok , and its South coast to Tanjong Ringgit the Southeast extreme, thence a line to Tanjong Mangkoen ( 9°01′S 116°43′E  /  9.017°S 116.717°E  / -9.017; 116.717 )

3920-597: The Gulf Stream's cause. Franklin and Timothy Folger printed the first map of the Gulf Stream in 1769–1770. Information on the currents of the Pacific Ocean was gathered by explorers of the late 18th century, including James Cook and Louis Antoine de Bougainville . James Rennell wrote the first scientific textbooks on oceanography, detailing the current flows of the Atlantic and Indian oceans. During

4018-801: The Laboratory für internationale Meeresforschung, Kiel, Germany (1902). On the other side of the Atlantic, the Scripps Institution of Oceanography was founded in 1903, followed by the Woods Hole Oceanographic Institution in 1930, the Virginia Institute of Marine Science in 1938, the Lamont–Doherty Earth Observatory at Columbia University in 1949, and later the School of Oceanography at University of Washington . In Australia ,

Bali Sea - Misplaced Pages Continue

4116-595: The North. A line from the Western Paternoster Island to the East point of Sepandjang and thence through this island to the West point of Gedeh Bay on the South coast of Kangean ( 7°01′S 115°18′E  /  7.017°S 115.300°E  / -7.017; 115.300 ). On the West. A line from the West point of Gedeh Bay, Kangean Island, to Tg Sedano, the Northeast extreme of Java and down

4214-614: The Southwest extreme of Soembawa . On the East. The West and North coasts of Soembawa as far East as Tanjong Sarokaja ( 8°22′S 117°10′E  /  8.367°S 117.167°E  / -8.367; 117.167 ), thence the Western limit of Flores Sea [A line from Tg Sarokaja to the Western Paternoster island ( 7°26′S 117°08′E  /  7.433°S 117.133°E  / -7.433; 117.133 )]. The circulation and mass water properties in Bali Sea are

4312-506: The Sun (the Sun just in a much lesser extent) and are also caused by the Earth and Moon orbiting each other. 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 . Sir James Clark Ross took the first modern sounding in deep sea in 1840, and Charles Darwin published

4410-552: The cause of mareel , or milky seas. For this purpose, the expedition was equipped with nets and scrapers, specifically designed to collect samples from the open waters and the bottom at great depth. Although Juan Ponce de León in 1513 first identified the Gulf Stream , and the current was well known to mariners, Benjamin Franklin made the first scientific study of it and gave it its name. Franklin measured water temperatures during several Atlantic crossings and correctly explained

4508-641: The centre for oceanographic research well into the 20th century. Murray was the first to study marine trenches and in particular the Mid-Atlantic Ridge , and map the sedimentary deposits in the oceans. He tried to map out the world's ocean currents based on salinity and temperature observations, and was the first to correctly understand the nature of coral reef development. In the late 19th century, other Western nations also sent out scientific expeditions (as did private individuals and institutions). The first purpose-built oceanographic ship, Albatros ,

4606-464: The composition of volcanic rocks through seafloor metamorphism , as well as to that of volcanic gases and magmas created at subduction zones . From sea level, the oceans are far deeper than the continents are tall; examination of the Earth's hypsographic curve shows that the average elevation of Earth's landmasses is only 840 metres (2,760 ft), while the ocean's average depth is 3,800 metres (12,500 ft). Though this apparent discrepancy

4704-460: The context of the physical, chemical and geological characteristics of their ocean environment. Chemical oceanography is the study of the chemistry of the ocean. Whereas chemical oceanography is primarily occupied with the study and understanding of seawater properties and its changes, ocean chemistry focuses primarily on the geochemical cycles . The following is a central topic investigated by chemical oceanography. Ocean acidification describes

4802-511: The cosmographers would provide (...) and they took charts with exact routes and no longer those used by the ancient). His credibility rests on being personally involved in the instruction of pilots and senior seafarers from 1527 onwards by Royal appointment, along with his recognized competence as mathematician and astronomer. The main problem in navigating back from the south of the Canary Islands (or south of Boujdour ) by sail alone,

4900-542: The currents and winds of the Atlantic, is demonstrated by the understanding of the seasonal variations, with expeditions setting sail at different times of the year taking different routes to take account of seasonal predominate winds. This happens from as early as late 15th century and early 16th: Bartolomeu Dias followed the African coast on his way south in August 1487, while Vasco da Gama would take an open sea route from

4998-456: The decade long period between Bartolomeu Dias finding the southern tip of Africa, and Gama's departure; additionally, there are indications of further travels by Bartolomeu Dias in the area. The most significant consequence of this systematic knowledge was the negotiation of the Treaty of Tordesillas in 1494, moving the line of demarcation 270 leagues to the west (from 100 to 370 leagues west of

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5096-406: The decrease in ocean pH that is caused by anthropogenic carbon dioxide (CO 2 ) emissions into the atmosphere . Seawater is slightly alkaline and had a preindustrial pH of about 8.2. More recently, anthropogenic activities have steadily increased the carbon dioxide content of the atmosphere; about 30–40% of the added CO 2 is absorbed by the oceans, forming carbonic acid and lowering

5194-582: The direction of travel of the layers of water slowly move farther and farther to the right as they get deeper in the Northern Hemisphere, and to the left in the Southern Hemisphere. In most cases, the very bottom layer of water affected by the wind is at a depth of 100 m – 150 m and is traveling about 180 degrees, completely opposite of the direction that the wind is blowing. Overall, the net transport of water would be 90 degrees from

5292-414: The east in the Northern and Southern hemispheres , using the equator as a guide . Kelvin waves are known to have very high speeds, typically around 2–3 meters per second. They have wavelengths of thousands of kilometers and amplitudes in the tens of meters. Rossby waves , or planetary waves are huge, slow waves generated in the troposphere by temperature differences between the ocean and

5390-506: The equator towards the poles, thereby reducing the temperature gradients that would exist in the absence of fluid motion. Perhaps three quarters of this heat is carried in the atmosphere; the rest is carried in the ocean. The atmosphere is heated from below, which leads to convection, the largest expression of which is the Hadley circulation . By contrast the ocean is heated from above, which tends to suppress convection. Instead ocean deep water

5488-567: The extra heat stored in the ocean from changes in Earth's energy balance . The increase in the ocean heat play an important role in sea level rise , because of thermal expansion . Ocean warming accounts for 90% of the energy accumulation associated with global warming since 1971. Paleoceanography is the study of the history of the oceans in the geologic past with regard to circulation, chemistry, biology, geology and patterns of sedimentation and biological productivity. Paleoceanographic studies using environment models and different proxies enable

5586-433: The first all-woman oceanographic expedition. Until that time, gender policies restricted women oceanographers from participating in voyages to a significant extent. From the 1970s, there has been much emphasis on the application of large scale computers to oceanography to allow numerical predictions of ocean conditions and as a part of overall environmental change prediction. Early techniques included analog computers (such as

5684-422: The first woman to have earned a PhD (at Scripps) in the United States, completed a major work on diatoms that remained the standard taxonomy in the field until well after her death in 1999. In 1940, Cupp was let go from her position at Scripps. Sverdrup specifically commended Cupp as a conscientious and industrious worker and commented that his decision was no reflection on her ability as a scientist. Sverdrup used

5782-455: The fluid motions as precisely as possible. Dynamical physical oceanography focuses primarily upon the processes that govern the motion of fluids with emphasis upon theoretical research and numerical models. These are part of the large field of Geophysical Fluid Dynamics (GFD) that is shared together with meteorology . GFD is a sub field of Fluid dynamics describing flows occurring on spatial and temporal scales that are greatly influenced by

5880-466: The impact of these natural cycles on the lifestyle and livelihood of Native Hawaiians tending coastal fishponds. Aia ke ola ka hana meaning . . . Life is in labor . Tidal resonance occurs in the Bay of Fundy since the time it takes for a large wave to travel from the mouth of the bay to the opposite end, then reflect and travel back to the mouth of the bay coincides with the tidal rhythm producing

5978-400: The instructor billet vacated by Cupp to employ Marston Sargent, a biologist studying marine algae, which was not a new research program at Scripps. Financial pressures did not prevent Sverdrup from retaining the services of two other young post-doctoral students, Walter Munk and Roger Revelle . Cupp's partner, Dorothy Rosenbury, found her a position teaching high school, where she remained for

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6076-426: The latent heat flux, the incoming solar radiation and the balance of long-wave ( infrared ) radiation . In general, the tropical oceans will tend to show a net gain of heat, and the polar oceans a net loss, the result of a net transfer of energy polewards in the oceans. The oceans' large heat capacity moderates the climate of areas adjacent to the oceans, leading to a maritime climate at such locations. This can be

6174-537: The latitude of Sierra Leone , spending three months in the open sea of the South Atlantic to profit from the southwards deflection of the southwesterly on the Brazilian side (and the Brazilian current going southward - Gama departed in July 1497); and Pedro Álvares Cabral (departing March 1500) took an even larger arch to the west, from the latitude of Cape Verde, thus avoiding the summer monsoon (which would have blocked

6272-478: The main factors determining ocean currents. The thermohaline circulation (THC) ( thermo- referring to temperature and -haline referring to salt content ) connects the ocean basins and is primarily dependent on the density of sea water . It is becoming more common to refer to this system as the 'meridional overturning circulation' because it more accurately accounts for other driving factors beyond temperature and salinity. Oceanic heat content (OHC) refers to

6370-479: The net transport of surface water 90 degrees to the right of the wind in the Northern Hemisphere, and 90 degrees to the left of the wind in the Southern Hemisphere. As the wind blows across the surface of the ocean, it "grabs" onto a thin layer of the surface water. In turn, that thin sheet of water transfers motion energy to the thin layer of water under it, and so on. However, because of the Coriolis Effect,

6468-554: The northeast before crossing the Atlantic Ocean. The Kuroshio Current is an ocean current found in the western Pacific Ocean off the east coast of Taiwan and flowing northeastward past Japan , where it merges with the easterly drift of the North Pacific Current . It is analogous to the Gulf Stream in the Atlantic Ocean, transporting warm, tropical water northward towards the polar region. Ocean heat flux

6566-473: The northern hemisphere the land masses prevent this and the ocean circulation is broken into smaller gyres in the Atlantic and Pacific basins. The Coriolis effect results in a deflection of fluid flows (to the right in the Northern Hemisphere and left in the Southern Hemisphere). This has profound effects on the flow of the oceans. In particular it means the flow goes around high and low pressure systems, permitting them to persist for long periods of time. As

6664-404: The northern latitudes where the westerly winds will bring the seafarers towards the western coasts of Europe. The secrecy involving the Portuguese navigations, with the death penalty for the leaking of maps and routes, concentrated all sensitive records in the Royal Archives, completely destroyed by the Lisbon earthquake of 1775 . However, the systematic nature of the Portuguese campaign, mapping

6762-533: The ocean into distinct layers. Salinity, a measure of the concentration of dissolved salts in seawater, typically ranges between 34 and 35 parts per thousand (ppt) in most of the world’s oceans. However, localized factors such as evaporation, precipitation, river runoff, and ice formation or melting cause significant variations in salinity. These variations are often most evident in coastal areas and marginal seas. The combination of temperature and salinity variations leads to changes in seawater density. Seawater density

6860-423: The ocean surface, by the presence of the waves, changes the wind near the surface. The ocean can gain moisture from rainfall , or lose it through evaporation . Evaporative loss leaves the ocean saltier; the Mediterranean and Persian Gulf for example have strong evaporative loss; the resulting plume of dense salty water may be traced through the Straits of Gibraltar into the Atlantic Ocean . At one time, it

6958-512: The ocean's layers are highly latitude -dependent; the thermocline is pronounced in the tropics, but nonexistent in polar waters (Marshak 2001). The halocline usually lies near the surface, where evaporation raises salinity in the tropics, or meltwater dilutes it in polar regions. These variations of salinity and temperature with depth change the density of the seawater, creating the pycnocline . The temperature of ocean water varies significantly across different regions and depths. As mentioned,

7056-480: The ocean's physical attributes including temperature-salinity structure, mixing, surface waves , internal waves, surface tides , internal tides , and currents . The following are central topics investigated by physical oceanography. Since the early ocean expeditions in oceanography, a major interest was the study of ocean currents and temperature measurements. The tides , the Coriolis effect , changes in direction and strength of wind , salinity, and temperature are

7154-412: The oceans was primarily for cartography and mainly limited to its surfaces and of the animals that fishermen brought up in nets, though depth soundings by lead line were taken. The Portuguese campaign of Atlantic navigation is the earliest example of a systematic scientific large project, sustained over many decades, studying the currents and winds of the Atlantic. The work of Pedro Nunes (1502–1578)

7252-467: The only continuous body of water where there is a wide latitude band of open water. It interconnects the Atlantic , Pacific and Indian oceans, and provide an uninterrupted stretch for the prevailing westerly winds to significantly increase wave amplitudes. It is generally accepted that these prevailing winds are primarily responsible for the circumpolar current transport. This current is now thought to vary with time, possibly in an oscillatory manner. In

7350-501: The orbital motion of the Moon results in tidal patterns that vary over the course of a month. The ebb and flow of the tides produce a cyclical current along the coast, and the strength of this current can be quite dramatic along narrow estuaries. Incoming tides can also produce a tidal bore along a river or narrow bay as the water flow against the current results in a wave on the surface. Tide and Current (Wyban 1992) clearly illustrates

7448-524: The original direction of the wind. Langmuir circulation results in the occurrence of thin, visible stripes, called windrows on the surface of the ocean parallel to the direction that the wind is blowing. If the wind is blowing with more than 3 m s , it can create parallel windrows alternating upwelling and downwelling about 5–300 m apart. These windrows are created by adjacent ovular water cells (extending to about 6 m (20 ft) deep) alternating rotating clockwise and counterclockwise. In

7546-402: The pH (now below 8.1 ) through ocean acidification. The pH is expected to reach 7.7 by the year 2100. An important element for the skeletons of marine animals is calcium , but calcium carbonate becomes more soluble with pressure, so carbonate shells and skeletons dissolve below the carbonate compensation depth . Calcium carbonate becomes more soluble at lower pH, so ocean acidification

7644-455: The past 100 years. The IPCC predicts that by 2081–2100, global warming will lead to a sea level rise of 260 to 820 mm. The rise and fall of the oceans due to tidal effects is a key influence upon the coastal areas. Ocean tides on the planet Earth are created by the gravitational effects of the Sun and Moon . The tides produced by these two bodies are roughly comparable in magnitude, but

7742-420: The point of view of the ocean, the atmosphere imposes a significant wind stress on its surface, and this forces large-scale currents in the ocean. Through the wind stress, the wind generates ocean surface waves ; the longer waves have a phase velocity tending towards the wind speed . Momentum of the surface winds is transferred into the energy flux by the ocean surface waves. The increased roughness of

7840-705: The polar regions and Africa , so too did the mysteries of the unexplored oceans. The seminal event in the founding of the modern science of oceanography was the 1872–1876 Challenger expedition . As the first true oceanographic cruise, this expedition laid the groundwork for an entire academic and research discipline. In response to a recommendation from the Royal Society , the British Government announced in 1871 an expedition to explore world's oceans and conduct appropriate scientific investigation. Charles Wyville Thomson and Sir John Murray launched

7938-474: The rest of her career. (Russell, 2000) Sverdrup, Johnson and Fleming published The Oceans in 1942, which was a major landmark. The Sea (in three volumes, covering physical oceanography, seawater and geology) edited by M.N. Hill was published in 1962, while Rhodes Fairbridge 's Encyclopedia of Oceanography was published in 1966. The Great Global Rift, running along the Mid Atlantic Ridge,

8036-523: The return route from the western coast of Africa (sequentially called 'volta de Guiné' and 'volta da Mina'); and the references to the Sargasso Sea (also called at the time 'Mar da Baga'), to the west of the Azores , in 1436, reveals the western extent of the return route. This is necessary, under sail, to make use of the southeasterly and northeasterly winds away from the western coast of Africa, up to

8134-410: The route taken by Gama at the time he set sail). Furthermore, there were systematic expeditions pushing into the western Northern Atlantic (Teive, 1454; Vogado, 1462; Teles, 1474; Ulmo, 1486). The documents relating to the supplying of ships, and the ordering of sun declination tables for the southern Atlantic for as early as 1493–1496, all suggest a well-planned and systematic activity happening during

8232-619: The scientific community to assess the role of the oceanic processes in the global climate by the reconstruction of past climate at various intervals. Paleoceanographic research is also intimately tied to palaeoclimatology. The earliest international organizations of oceanography were founded at the turn of the 20th century, starting with the International Council for the Exploration of the Sea created in 1902, followed in 1919 by

8330-504: The sea floor. The majority of the ocean heat flux is through advection or the movement of the ocean's currents. For example, the majority of the warm water movement in the south Atlantic is thought to have originated in the Indian Ocean. Another example of advection is the nonequatorial Pacific heating which results from subsurface processes related to atmospheric anticlines. Recent warming observations of Antarctic bottom water in

8428-400: The shifting conditions of the near future. Of particular concern is the manner in which the combination of acidification with the expected additional stressors of higher ocean temperatures and lower oxygen levels will impact the seas. Geological oceanography is the study of the geology of the ocean floor including plate tectonics and paleoceanography . Physical oceanography studies

8526-440: The specific temperature and salinity ranges of their habitats. Energy for the ocean circulation (and for the atmospheric circulation) comes from solar radiation and gravitational energy from the Sun and Moon. The amount of sunlight absorbed at the surface varies strongly with latitude, being greater at the equator than at the poles, and this engenders fluid motion in both the atmosphere and ocean that acts to redistribute heat from

8624-486: The study of marine meteorology, navigation , and charting prevailing winds and currents. His 1855 textbook Physical Geography of the Sea was one of the first comprehensive oceanography studies. Many nations sent oceanographic observations to Maury at the Naval Observatory, where he and his colleagues evaluated the information and distributed the results worldwide. Knowledge of the oceans remained confined to

8722-530: The submersible DSV  Alvin . In the 1950s, Auguste Piccard invented the bathyscaphe and used the bathyscaphe Trieste to investigate the ocean's depths. The United States nuclear submarine Nautilus made the first journey under the ice to the North Pole in 1958. In 1962 the FLIP (Floating Instrument Platform), a 355-foot (108 m) spar buoy, was first deployed. In 1968, Tanya Atwater led

8820-400: The topmost few fathoms of the water and a small amount of the bottom, mainly in shallow areas. Almost nothing was known of the ocean depths. The British Royal Navy 's efforts to chart all of the world's coastlines in the mid-19th century reinforced the vague idea that most of the ocean was very deep, although little more was known. As exploration ignited both popular and scientific interest in

8918-414: The vast majority of ocean water (around 75%) lies between 0° and 5°C, mostly in the deep ocean, where sunlight does not penetrate. The surface layers, however, experience far greater variability. In polar regions, surface temperatures can drop below freezing, while in tropical and subtropical regions, they may reach up to 35°C. This thermal stratification results in a vertical temperature gradient that divides

9016-434: The world ocean through further scientific study enables better stewardship and sustainable utilization of Earth's resources. The Intergovernmental Oceanographic Commission reports that 1.7% of the total national research expenditure of its members is focused on ocean science. The study of oceanography is divided into these five branches: Biological oceanography investigates the ecology and biology of marine organisms in

9114-534: Was believed that evaporation / precipitation was a major driver of ocean currents; it is now known to be only a very minor factor. A Kelvin wave is any progressive wave that is channeled between two boundaries or opposing forces (usually between the Coriolis force and a coastline or the equator ). There are two types, coastal and equatorial. Kelvin waves are gravity driven and non-dispersive . This means that Kelvin waves can retain their shape and direction over long periods of time. They are usually created by

9212-736: Was built in 1882. In 1893, Fridtjof Nansen allowed his ship, Fram , to be frozen in the Arctic ice. This enabled him to obtain oceanographic, meteorological and astronomical data at a stationary spot over an extended period. In 1881 the geographer John Francon Williams published a seminal book, Geography of the Oceans . Between 1907 and 1911 Otto Krümmel published the Handbuch der Ozeanographie , which became influential in awakening public interest in oceanography. The four-month 1910 North Atlantic expedition headed by John Murray and Johan Hjort

9310-604: Was discovered by Maurice Ewing and Bruce Heezen in 1953 and mapped by Heezen and Marie Tharp using bathymetric data; in 1954 a mountain range under the Arctic Ocean was found by the Arctic Institute of the USSR. The theory of seafloor spreading was developed in 1960 by Harry Hammond Hess . The Ocean Drilling Program started in 1966. Deep-sea vents were discovered in 1977 by Jack Corliss and Robert Ballard in

9408-627: Was the Report Of The Scientific Results of the Exploring Voyage of H.M.S. Challenger during the years 1873–76 . Murray, who supervised the publication, described the report as "the greatest advance in the knowledge of our planet since the celebrated discoveries of the fifteenth and sixteenth centuries". He went on to found the academic discipline of oceanography at the University of Edinburgh , which remained

9506-521: Was the most ambitious research oceanographic and marine zoological project ever mounted until then, and led to the classic 1912 book The Depths of the Ocean . The first acoustic measurement of sea depth was made in 1914. Between 1925 and 1927 the "Meteor" expedition gathered 70,000 ocean depth measurements using an echo sounder, surveying the Mid-Atlantic Ridge. In 1934, Easter Ellen Cupp ,

9604-476: Was to overcome this problem and clear the passage to India around Africa as a viable maritime trade route, that a systematic plan of exploration was devised by the Portuguese. The return route from regions south of the Canaries became the ' volta do largo' or 'volta do mar '. The 'rediscovery' of the Azores islands in 1427 is merely a reflection of the heightened strategic importance of the islands, now sitting on

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