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Agulhas Leakage
The Agulhas Leakage is an inflow of anomalously warm and saline water from the Indian Ocean into the Atlantic Ocean, South Atlantic due to the limited latitudinal extent of the African continent compared to the southern extension of the Subtropical gyre, subtropical super gyre in the Indian Ocean. The process occurs during the Retroflect, retroflection of the Agulhas Current via shedding of Warm core ring, anticyclonic Agulhas Rings, Eddy (fluid dynamics), cyclonic eddies and direct inflow. The leakage contributes to the Atlantic meridional overturning circulation, Atlantic Meridional Overturning Circulation (AMOC) by supplying its upper limb, which has direct #Climate change, climate implications. Pathway The Agulhas Current carries around 70 Sverdrup, Sv southward towards 32°S. When the current passes the southern African tip, it changes direction and returns to the Indian Ocean. However, part of it (around 2-15 Sv) leaks into the Southern Atlantic. The leakage is mainly driven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), Australia to the east. To the south it is bounded by the Southern Ocean or Antarctica, depending on the definition in use. The Indian Ocean has large marginal or regional seas, including the Andaman Sea, the Arabian Sea, the Bay of Bengal, and the Laccadive Sea. Geologically, the Indian Ocean is the youngest of the oceans, and it has distinct features such as narrow continental shelf, continental shelves. Its average depth is 3,741 m. It is the warmest ocean, with a significant impact on global climate due to its interaction with the atmosphere. Its waters are affected by the Indian Ocean Walker circulation, resulting in unique oceanic currents and upwelling patterns. The Indian Ocean is ecologically diverse, with important ecosystems such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Water Route
Cold is the presence of low temperature, especially in the atmosphere. In common usage, cold is often a subjective perception. A lower bound to temperature is absolute zero, defined as 0.00K on the Kelvin scale, an absolute thermodynamic temperature scale. This corresponds to on the Celsius scale, on the Fahrenheit scale, and on the Rankine scale. Since temperature relates to the thermal energy held by an object or a sample of matter, which is the kinetic energy of the random motion of the particle constituents of matter, an object will have less thermal energy when it is colder and more when it is hotter. If it were possible to cool a system to absolute zero, all motion of the particles in a sample of matter would cease and they would be at complete rest in the classical sense. The object could be described as having zero thermal energy. Microscopically in the description of quantum mechanics, however, matter still has zero-point energy even at absolute zero, because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotope Ratio
The term stable isotope has a meaning similar to stable nuclide, but is preferably used when speaking of nuclides of a specific element. Hence, the plural form stable isotopes usually refers to isotopes of the same element. The relative abundance of such stable isotopes can be measured experimentally (isotope analysis), yielding an isotope ratio that can be used as a research tool. Theoretically, such stable isotopes could include the radiogenic daughter products of radioactive decay, used in radiometric dating. However, the expression stable-isotope ratio is preferably used to refer to isotopes whose relative abundances are affected by isotope fractionation in nature. This field is termed stable isotope geochemistry. Stable-isotope ratios Measurement of the ratios of naturally occurring stable isotopes (isotope analysis) plays an important role in isotope geochemistry, but stable isotopes (mostly hydrogen, carbon, nitrogen, oxygen and sulfur) are also finding uses in ecologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globorotalia Menardii
''Globorotalia menardii'' is a perforate foraminiferan, about in size. It is a single-celled animal large enough to be seen with a naked eye and is found in the fossil record back to the Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), .... References Globothalamea Protists described in 1865 Foraminifera species Radiolarian species {{foram-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoceanography
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 the scientific community to assess the role of the oceanic processes in the global climate by the re-construction of past climate at various intervals. Paleoceanographic research is also intimately tied to paleoclimatology. Source and methods of information Paleoceanography makes use of so-called proxy methods as a way to infer information about the past state and evolution of the world's oceans. Several geochemical proxy tools include long-chain organic molecules (e.g. alkenones), stable and radioactive isotopes, and trace metals. Additionally, sediment cores rich with fossils and shells (tests) can also be useful; the field of paleoceanography is closely related to sedimentology and paleontology. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instability
In dynamical systems instability means that some of the outputs or internal states increase with time, without bounds. Not all systems that are not stable are unstable; systems can also be marginally stable or exhibit limit cycle behavior. In structural engineering, a structural beam or column can become unstable when excessive compressive load is applied. Beyond a certain threshold, structural deflections magnify stresses, which in turn increases deflections. This can take the form of buckling or crippling. The general field of study is called structural stability. Atmospheric instability is a major component of all weather systems on Earth. Instability in control systems In the theory of dynamical systems, a state variable in a system is said to be unstable if it evolves without bounds. A system itself is said to be unstable if at least one of its state variables is unstable. In continuous time control theory, a system is unstable if any of the roots of its charac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Westerlies
The westerlies, anti-trades, or prevailing westerlies, are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the high-pressure areas in the horse latitudes (about 30 degrees) and trend towards the poles and steer extratropical cyclones in this general manner. Tropical cyclones which cross the subtropical ridge axis into the westerlies recurve due to the increased westerly flow. The winds are predominantly from the southwest in the Northern Hemisphere and from the northwest in the Southern Hemisphere. The westerlies are strongest in the winter hemisphere and times when the pressure is lower over the poles, while they are weakest in the summer hemisphere and when pressures are higher over the poles. The westerlies are particularly strong, especially in the Southern Hemisphere (called also 'Brave West winds' at striking Chile, Argentina, Tasmania and New Zealand), in areas where land is absent, bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inertia
Inertia is the natural tendency of objects in motion to stay in motion and objects at rest to stay at rest, unless a force causes the velocity to change. It is one of the fundamental principles in classical physics, and described by Isaac Newton in his Newton%27s_laws_of_motion#First, first law of motion (also known as The Principle of Inertia). It is one of the primary manifestations of mass, one of the core quantitative properties of physical systems. Newton writes: In his 1687 work ''Philosophiæ Naturalis Principia Mathematica'', Newton defined inertia as a property: History and development Early understanding of inertial motion Joseph NeedhamProfessor John H. Lienhard points out the Mozi (book), Mozi – based on a Chinese text from the Warring States period (475–221 BCE) – as having given the first description of inertia. Before the European Renaissance, the prevailing theory of motion in western philosophy was that of Aristotle (384–322 BCE). On the surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Agulhas
Cape Agulhas (; , "Cape of Needles") is a rocky headland in Western Cape, South Africa. It is the geographic southern tip of Africa and the beginning of the traditional dividing line between the Atlantic and Indian oceans according to the International Hydrographic Organization. It is approximately half a degree of latitude, or , farther south than the Cape of Good Hope. Historically, the cape has been known to sailors as a major hazard on the traditional clipper route. It is sometimes regarded as one of the great capes. It was most commonly known in English as Cape L'Agulhas until the 20th century. The town of L'Agulhas is near the cape. Geography Cape Agulhas is located in the Overberg region, 170 kilometres (105 mi) southeast of Cape Town. The cape was named by Portuguese navigators, who called it ''Cabo das Agulhas''— Portuguese for "Cape of Needles"—after noticing that around the year 1500 the direction of magnetic north (and therefore the compass ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Stress
In physical oceanography and fluid dynamics, the wind stress is the shear stress exerted by the wind on the free surface, surface of large bodies of water – such as oceans, seas, estuary, estuaries and lakes. When wind is blowing over a water surface, the wind applies a wind force on the water surface. The wind stress is the component of this wind force that is parallel to the surface per unit area. Also, the wind stress can be described as the flux of horizontal momentum applied by the wind on the water surface. The wind stress causes a deformation of the water body whereby wind waves are generated. Also, the wind stress drives ocean currents and is therefore an important driver of the large-scale ocean circulation. The wind stress is affected by the wind speed, the shape of the wind waves and the atmospheric stratification. It is one of the components of the air–sea interaction, with others being the atmospheric pressure on the water surface, as well as the exchange of energy a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Boundary Current
Boundary currents are ocean currents with dynamics determined by the presence of a coastline, and fall into two distinct categories: western boundary currents and eastern boundary currents. Eastern boundary currents Eastern boundary currents are relatively shallow, broad and slow-flowing. They are found on the eastern side of oceanic basins (adjacent to the western coasts of continents). Subtropical eastern boundary currents flow equatorward, transporting cold water from higher latitudes to lower latitudes; examples include the Benguela Current, the Canary Current, the Humboldt (Peru) Current, and the California Current. Coastal upwelling often brings nutrient-rich water into eastern boundary current regions, making them productive areas of the ocean. Western boundary currents Western boundary currents may themselves be divided into sub-tropical or low-latitude western boundary currents. Sub-tropical western boundary currents are warm, deep, narrow, and fast-flowing currents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
