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North Pacific Subtropical Gyre
The North Pacific Gyre (NPG) or North Pacific Subtropical Gyre (NPSG), located in the northern Pacific Ocean, is one of the five major oceanic gyres. This gyre covers most of the northern Pacific Ocean. It is the largest ecosystem on Earth, located between the equator and 50° N latitude, and comprising 20 million square kilometers. The gyre has a clockwise circular pattern and is formed by four prevailing ocean currents: the North Pacific Current to the north, the California Current to the east, the North Equatorial Current to the south, and the Kuroshio Current to the west. It is the site of an unusually intense collection of human-created marine debris, known as the Great Pacific Garbage Patch. The North Pacific Subtropical Gyre and the much smaller North Pacific Subpolar Gyre make up the two major gyre systems in the mid-latitudes of the Northern Pacific Ocean. This two-gyre circulation in the North Pacific is driven by the trade and westerly winds. This is one of the be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Pacific Subtropical Convergence Zone
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is related to the Old High German ''nord'', both descending from the Proto-Indo-European unit *''ner-'', meaning "left; below" as north is to left when facing the rising sun. Similarly, the other cardinal directions are also related to the sun's position. The Latin word ''borealis'' comes from the Greek '' boreas'' "north wind, north", which, according to Ovid, was personified as the wind-god Boreas, the father of Calais and Zetes. ''Septentrionalis'' is from ''septentriones'', "the seven plow oxen", a name of ''Ursa Major''. The Greek ἀρκτικός (''arktikós'') is named for the same constellation, and is the source of the English word ''Arctic''. Other languages have other derivations. For example, in Lezgian, ''kefer'' can mean b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticyclone
An anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere as viewed from above (opposite to a cyclone). Effects of surface-based anticyclones include clearing skies as well as cooler, drier air. Fog can also form overnight within a region of higher pressure. Mid-tropospheric systems, such as the subtropical ridge, deflect tropical cyclones around their periphery and cause a temperature inversion inhibiting free convection near their center, building up surface-based haze under their base. Anticyclones aloft can form within warm-core lows such as tropical cyclones, due to descending cool air from the backside of upper troughs such as polar highs, or from large-scale sinking such as a subtropical ridge. The evolution of an anticyclone depends upon variables such as its size, intensity, and extent of moist con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Atlantic Gyre
The South Atlantic Gyre is the Ocean gyre#Subtropical gyres, subtropical gyre in the south Atlantic Ocean. In the southern portion of the gyre, northwesterly (or southeastward-flowing) winds drive eastward-flowing currents that are difficult to distinguish from the northern boundary of the Antarctic Circumpolar Current. Like other oceanic gyres, it collects vast amounts of floating debris as a garbage patch. Southern boundary South of this gyre is the Antarctic Circumpolar Current. This current flows from West to East around Antarctica. Another name for this current is the West Wind Drift. This current allows Antarctica to maintain its huge ice sheet by keeping warm ocean waters away. At approximately 125 Sverdrup, Sv, this current is the largest ocean current. Western boundary The Brazil Current is the western boundary current of the gyre. It flows south along the Brazilian coast to the Rio de la Plata. The current is considerably weaker than its North Atlantic co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Current
An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, shoreline configurations, and interactions with other currents influence a current's direction and strength. Ocean currents are primarily horizontal water movements. An ocean current flows 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 makes northwest Europe much more temperate for its high latitude compared to other areas at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Atlantic Garbage Patch
The North Atlantic garbage patch is a garbage patch of man-made marine debris found floating within the North Atlantic Gyre, originally documented in 1972. Based on a 22-year research study conducted by the Sea Education Association, the patch is estimated to be hundreds of kilometers across in size, with a density of more than 200,000 pieces of debris per square kilometer. The source of the garbage originates from human waste traveling from the rivers into the ocean and mainly consists of microplastics. The garbage patch is a large risk to wildlife and humans through plastic consumption and entanglement. There have only been a few awareness and clean-up efforts for the North Atlantic garbage patch such as The Garbage Patch State at UNESCO and The Ocean Cleanup, as most of the research and cleanup efforts have been done for the Great Pacific garbage patch, a similar garbage patch in the Great Pacific. Characteristics Location and size The patch is located from 22°N to 38 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Pollution
Marine pollution occurs when substances used or spread by humans, such as industrial waste, industrial, agricultural pollution, agricultural and municipal solid waste, residential waste, particle (ecology), particles, noise, excess carbon dioxide or invasive organisms enter the ocean and cause harmful effects there. The majority of this waste (80%) comes from land-based activity, although Marine Transportation, marine transportation significantly contributes as well. Since most inputs come from land, either via the rivers, sewage or the atmosphere, it means that Continental shelf, continental shelves are more vulnerable to pollution. Air pollution is also a contributing factor by carrying off iron, carbonic acid, nitrogen, silicon, sulfur, pesticides or dust particles into the ocean. The pollution often comes from nonpoint source pollution, nonpoint sources such as agricultural surface runoff, runoff, wind-blown debris, and dust. These nonpoint sources are largely due to runoff th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem Of The North Pacific Subtropical Gyre
The North Pacific Subtropical Gyre (NPSG) is the largest contiguous ecosystem on earth. In oceanography, a subtropical gyre is a ring-like system of ocean currents rotating clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere caused by the Coriolis Effect. They generally form in large open ocean areas that lie between land masses. The NPSG is the largest of the gyres as well as the largest ecosystem on our planet. Like other subtropical gyres, it has a high-pressure zone in its center. Circulation around the center is clockwise around this high-pressure zone. Subtropical gyres make up 40% of the Earth’s surface and play critical roles in carbon fixation and nutrient cycling.Poretsky, 2009 This particular gyre covers most of the Pacific Ocean and comprises four prevailing ocean currents: the North Pacific Current to the north, the California Current to the east, the North Equatorial Current to the south, and the Kuroshio Current to the west. Its lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtropical Countercurrent
The subtropical countercurrent (STCC) is a narrow eastward ocean current in the central North Pacific Ocean (20–30°N) where the Sverdrup theory predicts a broad westward flow. It originates in the western North Pacific around 20°N, and flows eastward against the northeast trade winds and stretches northeastward to the north of Hawaii. It is accompanied by a subsurface temperature and density front called the subtropical front, in thermal wind relation with the STCC. Furthermore, the STCC maintains a sea surface temperature front during winter and spring. During April and May when the SST front is still strong, the seasonal warming makes the region conductive to atmospheric convection, and surface wind stress curls turn weakly positive along the front on the background of negative curls that drive the subtropical gyre In oceanography, a gyre () is any large system of circulating ocean currents, particularly those involved with large wind movements. Gyres are caused by the Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upwelling
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton. The biomass of phytoplankton and the presence of cool water in those regions allow upwelling zones to be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll-a. The increased availability of nutrients in upwelling regions results in high levels of primary production and thus fishery production. Approximately 25% of the total global marine fish catches come from five upwellings, which occupy only 5% of the total ocean area.Jennings, S., Kaiser, M.J., Reynolds, J.D. (2001) "Marine Fisheries Ecology." Oxford: Blackwell Science Ltd. Upwellings that are driven by coastal currents or diverging open oc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclone
In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an anticyclone). Cyclones are characterized by inward-spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale (the synoptic scale). Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes, and dust devils lie within smaller mesoscale. Upper level cyclones can exist without the presence of a surface low, and can pinch off from the base of the tropical upper tropospheric trough during the summer months in the Northern Hemisphere. Cyclones have also been seen on extraterrestrial planets, such as Mars, Jupiter, and Neptune. Cyclogenesis is the process of cyclone formation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harald Sverdrup (oceanographer)
Harald Ulrik Sverdrup (15 November 1888 – 21 August 1957) was a Norwegian oceanographer and meteorologist. He was director of Scripps Institution of Oceanography and director of the Norwegian Polar Institute. Background He was born at Sogndal in Sogn og Fjordane, Norway. He was the son of Lutheran theologian Edvard Sverdrup (1861–1923) and Maria Vollan (1865–1891). His sister Mimi Sverdrup Lunden (1894–1955) was an educator and author. His brother Leif Sverdrup (1898–1976) was a General with the U.S. Army Corps of Engineers. His brother Einar Sverdrup (1895–1942) was CEO of Store Norske Spitsbergen Kulkompani. Sverdrup was a student at Bergen Cathedral School in 1901 before graduating in 1906 at Kongsgård School in Stavanger. He graduated cand. real. in 1914 from University of Oslo. He studied under Vilhelm Bjerknes and earned his Dr. Philos. at the University of Leipzig in 1917. Career He was the scientific director of the North Polar expeditio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostrophic Wind
In atmospheric science, geostrophic flow () is the theoretical wind that would result from an exact balance between the Coriolis force and the pressure gradient force. This condition is called '' geostrophic equilibrium'' or ''geostrophic balance'' (also known as ''geostrophy''). The geostrophic wind is directed parallel to isobars (lines of constant pressure at a given height). This balance seldom holds exactly in nature. The true wind almost always differs from the geostrophic wind due to other forces such as friction from the ground. Thus, the actual wind would equal the geostrophic wind only if there were no friction (e.g. above the atmospheric boundary layer) and the isobars were perfectly straight. Despite this, much of the atmosphere outside the tropics is close to geostrophic flow much of the time and it is a valuable first approximation. Geostrophic flow in air or water is a zero-frequency inertial wave. Origin A useful heuristic is to imagine air starting from rest, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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