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Upwelling
| Fisheries glossary |
- The process by which water, usually cold and nutrient-rich, rises from a deeper to a shallower depth. this is often a result of offshore surface water flow, particularly when persistent wind blows parallel to a coastland and the resultant ekman transport
- The oceans are layered; with sunwarmed water on top, and colder water containing 343 upwelling nutrients and dissolved gases below. upwelling is a phenomenon that brings this deeper water to the surface. when nutrients rise towards the sunlight, microscopic plants (phytoplankton) combine them with carbon dioxide and solar energy by photosynthesis. the organic compounds thus produced form the basis of the oceanic food chain. oceanographers have identified many different forms of this phenomenon, the more significant of which are: • coastal upwelling: coriolis effect causes winddriven currents to move to the right of winds in the northern hemisphere. thus winds blowing south along an eastern land-ocean boundary, or north along a western one, drive surface water away from the coast, allowing cold, nutrient-rich deep water to rise and replace it. in the southern hemisphere, these directions are reversed. some of the world’s most productive fishing grounds are in regions where coastal upwelling occurs. • equatorial upwelling: a related phenomenon. the equatorial surface current flows from east to west in both the atlantic and pacific basins. coriolis force turns the flow away from the equator (north to the right, south to the left) once again clearing a path for colder water to rise from the depths. as phytoplankton feast on the rising nutrients they bloom, causing the water to become green and murky—to the extent that space travelers can visually locate the pacific equatorial region by a line of high phytoplankton concentration. • dynamic uplift: occurs in response to variations in coastal ocean currents and is independent of coastal wind conditions. • tidal pumping: strong tidal currents produce upwelling through amplification and associated topographic turbulence. during flood tide, oceanic water mixes with and transfers part of its nutrient load to the shelf water before being removed again during ebb tide. each flood tide brings another load of nutrients, and the resulting enrichment can be substantial. marine life on the great barrier reef benefits greatly from tidal pumping, as do similar geographical settings where tidal currents are amplified in channels between islands. • eddy formation:western boundary currents spawn several eddies per year, each of which maintains its identity for two years or longer. warm core eddies are characterized by a deep thermocline in the centre and shallow thermocline around the eddy fringe. as they impinge on the continental slope, the thermocline is lifted up, having the same effect as when the main current impinges on the shelf.
- The raising of benthic nutrients to the surface waters. this occurs in regions where the flow of water brings currents of differing temperatures together, and increases productivity of the ecosystem.
- A rising of nutrient-rich water toward the sea surface.
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Апвеллинг, русский
(от англ . up - наверх и well - хлынуть), подъем вод из глубины водоема к поверхности. вызывается устойчиво дующими ветрами, которые сгоняют поверхностные воды в сторону открытого моря, а взамен на поверхность поднимаются воды нижележащих слоев.
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Particularly, английский
Persistent, английский
- Стойкий
- A постоянный (ант. sporadic, transient)
- Упорный; устойчивый; стойкий
Containing, английский
Phenomenon, английский
- 1. a fact or situation which can be observed 2. someone or something that is considered to be extraordinary and marvellous
- A condition with various possible causes in which the blood supply to the fingers and toes is restricted and they become cold, white and numb. also called dead man’s fingers, vasospasm [described 1862. after maurice raynaud (1834–81), french physician.] rbc rbc abbr red blood cell rcgp rcgp abbr royal college of general practitioners rcn rcn abbr royal college of nursing rcog rcog abbr royal college of obstetricians and gynaecologists rcp rcp abbr royal college of physicians
- In diabetes mellitus, a swing to a high level of glucose in the blood from an extremely low level, usually occurring after an untreated insulin reaction during the night. it is caused by the release of stress hormones to counter low glucose levels.
- Явление; эффект
Microscopic, английский
- Observable only with the aid of a microscope.
- Objects or organisms that are too small to be seen with the naked eye.
Phytoplankton, английский
- Tiny, free-floating, photosynthetic organisms in aquatic systems.
- Tiny, free-floating, photosynthetic organisms in aquatic systems. they include diatoms, desmids, and dinoflagellates.
- Microscopic planktonic plants.
- Photosynthetic plankton
Photosynthesis, английский
- The fundamental chemical process in which green plants (and blue-green algae) utilize the energy of sunlight or other light to convert carbon dioxide and water into carbohydrates, with the green pigment chlorophyll acting as the energy converter. this pro
- The production of carbohydrates in plants, algae and some bacteria using the energy of light. co is used as the carbon source. annex i glossary, acronyms, chemical symbols and prefi xes photovoltaics (pv): the technology of converting light energy directly into electricity by mobilizing electrons in solid state devices. the specially prepared thin sheet semiconductors are called pv cells. see solar energy.
- Process whereby phototrophic organisms convert solar energy into chemical energy that can then be used to build carbohydrates
Identified, английский
Significant, английский
- Значительный
- A значимый (о суффиксе и т.п. ) (ант. non-significant) | n означающее, сигнификант
Hemisphere, английский
- One of names of air space under the circus cupola; a space in which aerial acts are performed.
- Half of a sphere
- N анат. полушарие (го- ловного мозга и мозжечка ) asymmetry cerebral ~ полушарие головного мозга left ~ левое полушарие (ант. right ~) right ~ правое полушарие (ант. left ~)
- Half the surface of a globe. the celestial equator divides the heavens into two hemispheres—the northern and the southern.
- Полусфера
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Hatchery, английский
- The process of cultivating and breeding a large number of juveniles in an enclosed environment. the juveniles are then released into lakes, rivers or fish farm enclosures.
- A facility where fish eggs are hatched and the fry raised, especially to stock lakes, streams, and ponds.
Trophic level, английский
- The position that a species occupies in a food chain. the species it eats are at a lower trophic level, and the species that eats it are at a higher trophic level.
- (gk. trophos, feeder) a step in the movement of energy through an ecosystem, represented by a particular set of organisms (see biomass). 10 10
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