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Ocean Currents
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. Depth contours, shoreline configurations, and interactions with other currents influence a current's direction and strength. Ocean currents move both horizontally, on scales that can span entire oceans, as well as vertically, with vertical currents (upwelling and downwelling) playing an important role in the movement of nutrients and gases, such as carbon dioxide, between the surface and the deep ocean. Ocean currents flow 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northwest Europe
Northwestern Europe, or Northwest Europe, is a loosely defined subregion of Europe, overlapping Northern Europe, Northern and Western Europe. The term is used in geographic, history, and military contexts. Geographic definitions Geography, Geographically, Northwestern Europe is given by some sources as a region which includes Great Britain, Ireland, Belgium, the Netherlands, Luxembourg, Northern France, parts of or all of Germany, Denmark, Norway, Sweden, and Iceland. In some works, Switzerland, Finland, and Austria are also included as part of Northwestern Europe. Under the Interreg program, funded by the European Regional Development Fund, "North-West Europe" (NWE) is a region of European Territorial Cooperation that includes Belgium, Ireland, Luxembourg, Switzerland, the Netherlands and parts of France and Germany. Ethnography During the Reformation, some parts of Northwestern Europe converted to Protestantism, in a manner which differentiated the region from its Catholic C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ekman Spiral
Ekman transport is part of Ekman motion theory, first investigated in 1902 by Vagn Walfrid Ekman. Winds are the main source of energy for ocean circulation, and Ekman transport is a component of wind-driven ocean current. Ekman transport occurs when ocean surface waters are influenced by the friction force acting on them via the wind. As the wind blows it casts a friction force on the ocean surface that drags the upper 10-100m of the water column with it. However, due to the influence of the Coriolis effect, as the ocean water moves it is subject to a force at a 90° angle from the direction of motion causing the water to move at an angle to the wind direction. The direction of transport is dependent on the hemisphere: in the northern hemisphere, transport veers clockwise from wind direction, while in the southern hemisphere it veers anticlockwise.Colling, pp 42-44 This phenomenon was first noted by Fridtjof Nansen, who recorded that ice transport appeared to occur at an angle to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volume Flow Rate
In physics and engineering, in particular fluid dynamics, the volumetric flow rate (also known as volume flow rate, or volume velocity) is the volume of fluid which passes per unit time; usually it is represented by the symbol (sometimes \dot V). Its SI unit is cubic metres per second (m3/s). It contrasts with '' mass flow rate'', which is the other main type of fluid flow rate. In most contexts a mention of "rate of fluid flow" is likely to refer to the volumetric rate. In hydrometry, the volumetric flow rate is known as '' discharge''. The volumetric flow rate across a unit area is called '' volumetric flux'', as defined by Darcy's law and represented by the symbol . Conversely, the integration of a volumetric flux over a given area gives the volumetric flow rate. Units The SI unit is cubic metres per second (m3/s). Another unit used is standard cubic centimetres per minute (SCCM). In US customary units and imperial units, volumetric flow rate is often expressed as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sverdrup
In oceanography, the sverdrup (symbol: Sv) is a non- SI metric unit of volumetric flow rate, with equal to . It is equivalent to the SI derived unit cubic hectometer per second (symbol: hm3/s or hm3⋅s−1): is equal to . It is used almost exclusively in oceanography to measure the volumetric rate of transport of ocean currents. It is named after Harald Sverdrup. One sverdrup is about five times what is carried at the estuary by the world's largest river, the Amazon. In the context of ocean currents, a volume of one million cubic meters may be imagined as a "slice" of ocean with dimensions × × (width × length × thickness) or a cube with dimensions × × . At this scale, these units can be more easily compared in terms of width of the current (several km), depth (hundreds of meters), and current speed (as meters per second). Thus, a hypothetical current wide, (m) deep, and moving at would be transporting of water. The sverdrup is distinct from the SI siever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Unit
A unit of measurement, or unit of measure, is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a multiple of the unit of measurement. For example, a length is a physical quantity. The metre (symbol m) is a unit of length that represents a definite predetermined length. For instance, when referencing "10 metres" (or 10 m), what is actually meant is 10 times the definite predetermined length called "metre". The definition, agreement, and practical use of units of measurement have played a crucial role in human endeavour from early ages up to the present. A multitude of systems of units used to be very common. Now there is a global standard, the International System of Units (SI), the modern form of the metric system. In trade, weights and measures are often a subject of governmental regulation, to ensure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Dynamics
Ocean dynamics define and describe the flow of water within the oceans. Ocean temperature and motion fields can be separated into three distinct layers: mixed (surface) layer, upper ocean (above the thermocline), and deep ocean. Ocean dynamics has traditionally been investigated by sampling from instruments in situ. The mixed layer is nearest to the surface and can vary in thickness from 10 to 500 meters. This layer has properties such as temperature, salinity and dissolved oxygen which are uniform with depth reflecting a history of active turbulence (the atmosphere has an analogous planetary boundary layer). Turbulence is high in the mixed layer. However, it becomes zero at the base of the mixed layer. Turbulence again increases below the base of the mixed layer due to shear instabilities. At extratropical latitudes this layer is deepest in late winter as a result of surface cooling and winter storms and quite shallow in summer. Its dynamics is governed by turbulent mixing as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or " tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see '' Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides a day—is a third regular category. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CSIRO ScienceImage 11128 The Bathymetry Of The Kerguelen Plateau In The Southern Ocean Governs The Course Of The New Current Part Of The Global Network Of Ocean Currents
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) is an Australian Government agency that is responsible for scientific research and its commercial and industrial applications. CSIRO works with leading organisations around the world. From its headquarters in Canberra, CSIRO maintains more than 50 sites across Australia as well as in France and the United States, employing over 6,500 people. Federally funded scientific research in Australia began in 1916 with the creation of the Advisory Council of Science and Industry. However, the council struggled due to insufficient funding. In 1926, research efforts were revitalised with the establishment of the Council for Scientific and Industrial Research (CSIR), which strengthened national science leadership and increased research funding. CSIR grew rapidly, achieving significant early successes. In 1949, legislative changes led to the renaming of the organisation as Commonwealth Scientific and Industrial Research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Basin
In hydrology, an oceanic basin (or ocean basin) is anywhere on Earth that is covered by seawater. Geologically, most of the ocean basins are large Structural basin, geologic basins that are below sea level. Most commonly the ocean is divided into basins following the continents distribution: the Atlantic Ocean, North and South Atlantic (together approximately 75 million km2/ 29 million mi2), Pacific Ocean, North and South Pacific (together approximately 155 million km2/ 59 million mi2), Indian Ocean (68 million km2/ 26 million mi2) and Arctic Ocean (14 million km2/ 5.4 million mi2). Also recognized is the Southern Ocean (20 million km2/ 7 million mi2). All ocean basins collectively cover 71% of the Earth's surface, and together they contain almost 97% of all water on the planet. They have an average depth of almost 4 km (about 2.5 miles). Definitions of boundaries Boundaries based on continents ''"Limits of Oceans and Seas"'',International Hydrographic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humboldt Current
The Humboldt Current, also called the Peru Current, is a cold, low-salinity ocean current that flows north along the western coast of South America.Montecino, Vivian, and Carina B. Lange. "The Humboldt Current System: Ecosystem components and processes, fisheries, and sediment studies." ''Progress in Oceanography'' 83.1 (2009): 65-79. doi:10.1016/j.pocean.2009.07.041 It is an eastern boundary current flowing in the direction of the equator, and extends offshore. The Humboldt Current is named after the German naturalist Alexander von Humboldt even though it was discovered by José de Acosta 250 years before Humboldt. In 1846, von Humboldt reported measurements of the cold-water current in his book ''Cosmos''. The current extends from southern Chile (~ 45th parallel south) to northern Peru (~ 4th parallel south) where cold, upwelled, waters intersect warm tropical waters to form the Equatorial Front. Sea surface temperatures off the coast of Peru, around 5th parallel south, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
