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Ekman Current Meter
{{short description, Mechanical flowmeter invented by Vagn Walfrid Ekman, a Swedish oceanographer, in 1903 The Ekman current meter is a mechanical flowmeter invented by Vagn Walfrid Ekman, a Swedish oceanographer, in 1903. It comprises a propeller with a mechanism to record the number of revolutions, a compass and a recorder with which to record the direction, and a vane that orients the instrument so the propeller faces the current. It is mounted on a free-swinging vertical axis suspended from a wire and has a weight attached below. The balanced propeller, with four to eight blades, rotates inside a protective ring. The position of a lever controls the propeller. In down position the propeller is stopped and the instrument is lowered, after reaching the desired depth a weight called a messenger is dropped to move the lever into the middle position which allows the propeller to turn freely. When the measurement has been taken another weight is dropped to push the lever to its high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ekman Meter
Ekman is a Swedish surname. Notable people with the surname include: *Carl Gustaf Ekman (1872–1945), Swedish politician *Carl Daniel Ekman (1845–1904), Swedish chemical engineer *Erik Leonard Ekman (1883–1931), Swedish botanist * Fam Ekman (born 1946), Swedish-Norwegian children's writer and illustrator *Gösta Ekman (junior) (1939–2017), Swedish actor *Gösta Ekman (senior) (1890–1938) Swedish actor *Hasse Ekman (1915–2004), Swedish film director and actor * Hedda Ekman (1860–1929), Swedish writer and photographer *Ida Ekman (1875–1942), Finnish soprano *Kajsa Ekis Ekman, (born 1980), Swedish journalist and writer *Kerstin Ekman (born 1933), Swedish novelist *Nils Ekman (born 1976), Swedish ice hockey player *Paul Ekman (born 1934), American psychologist *Robert Wilhelm Ekman (1808–1873), Finnish painter *Sheldon V. Ekman (1920–1982), United States Tax Court judge * Sven P. Ekman (1876–1964), Swedish zoologist *Ulf Ekman (born 1950), Swedish clergyman *Vagn Wal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Current Meter
A current meter is an oceanographic device for flow measurement by mechanical, tilt, acoustical or electrical means. Different reference frames In physics, one distinguishes different reference frames depending on where the observer is located, this is the basics for the Lagrangian and Eulerian specification of the flow field in fluid dynamics: The observer can be either in the Moving frame (as for a Lagrangian drifter) or in a resting frame. * Lagrangian current meters measure the displacement of an oceanographic drifter, an unmoored buoy or a non-anchored ship's actual position to the position predicted by dead reckoning. * Eulerian current meters measure current passing a resting current meter. Types Mechanical Mechanical current meters are mostly based on counting the rotations of a propeller and are thus rotor current meters. A mid-20th-century realization is the Ekman current meter which drops balls into a container to count the number of rotations. The Roberts r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowmeter
Flow measurement is the quantification of bulk fluid movement. Flow can be measured in a variety of ways. The common types of flowmeters with industrial applications are listed below: * a) Obstruction type (differential pressure or variable area) * b) Inferential (turbine type) * c) Electromagnetic * d) Positive displacement meter, Positive-displacement flowmeters, which accumulate a fixed volume of fluid and then count the number of times the volume is filled to measure flow. * e) Fluid dynamic (vortex shedding) * f) Anemometer * g) Ultrasonic * h) Mass flowmeter (Coriolis force). Flow measurement methods other than positive-displacement flowmeters rely on forces produced by the flowing stream as it overcomes a known constriction, to indirectly calculate flow. Flow may be measured by measuring the velocity of fluid over a known area. For very large flows, tracer methods may be used to deduce the flow rate from the change in concentration of a dye or radioisotope. Kinds and uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagn Walfrid Ekman
Vagn Walfrid Ekman (3 May 1874 – 9 March 1954) was a Swedish oceanographer. Born in Stockholm to Fredrik Laurentz Ekman, himself an oceanographer, he became committed to oceanography while studying physics at the University of Uppsala and, in particular, on hearing Vilhelm Bjerknes lecture on fluid dynamics. During the expedition of the ''Fram'', Fridtjof Nansen had observed that icebergs tend to drift not in the direction of the prevailing wind but at an angle of 20°-40° to the right. Bjerknes invited Ekman, still a student, to investigate the problem. Later, in 1905, Ekman published his theory of the Ekman spiral which explains the phenomenon in terms of the balance between frictional effects in the ocean and the Coriolis force, which arises from moving objects in a rotating environment, like planetary rotation. On completing his doctorate in Uppsala in 1902, Ekman joined the International Laboratory for Oceanographic Research, Oslo where he worked for seven years, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, Finland to the east, and is connected to Denmark in the southwest by a bridgetunnel across the Öresund. At , Sweden is the largest Nordic country, the third-largest country in the European Union, and the fifth-largest country in Europe. The capital and largest city is Stockholm. Sweden has a total population of 10.5 million, and a low population density of , with around 87% of Swedes residing in urban areas in the central and southern half of the country. Sweden has a nature dominated by forests and a large amount of lakes, including some of the largest in Europe. Many long rivers run from the Scandes range through the landscape, primarily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanographer
Oceanography (), also known as oceanology and ocean science, is the scientific study of the oceans. It is an Earth science, which covers a wide range of topics, including ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and physical properties within the ocean and across its boundaries. These diverse topics reflect multiple disciplines that oceanographers utilize to glean further knowledge of the world ocean, including astronomy, biology, chemistry, climatology, geography, geology, hydrology, meteorology and physics. Paleoceanography studies the history of the oceans in the geologic past. An oceanographer is a person who studies many matters concerned with oceans, including marine geology, physics, chemistry and biology. History Early history Humans first acquired knowledge of the waves and currents of the seas and oceans in pre-historic times. Observations on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic 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] |
Ekman Spiral
The oceanic, wind driven Ekman spiral is the result of a force balance created by a shear stress force, Coriolis force and the water drag. This force balance gives a resulting current of the water different from the winds. In the ocean, there are two places where the Ekman spiral can be observed. At the surface of the ocean, the shear stress force corresponds with the wind stress force. At the bottom of the ocean, the shear stress force is created by friction with the ocean floor. This phenomenon was first observed at the surface by the Norwegian oceanographer Fridtjof Nansen during his Fram expedition. He noticed that icebergs did not drift in the same direction as the wind. His student, the Swedish oceanographer Vagn Walfrid Ekman, was the first person to physically explain this process. Bottom Ekman Spiral In order to derive the properties of an Ekman spiral a look is taken at a uniform, horizontal geostrophic interior flow in a homogeneous fluid. This flow will by denoted by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ekman Water Bottle
The Ekman water bottle is a sea water temperature sample device. The cylinder is dropped at the desired depth, the trap door below is opened to let the water enter and then closed tightly. This can be repeated at different depths as each sample goes to a different chamber of the insulated bottle. by Geophysic institut of the () It was used for greater depths during the research cruises of 1903 and 1904. The first instruments made, however, were too delicate; after being used for some time, the brass rods which pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Oceanography
Physical oceanography is the study of physical conditions and physical processes within 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 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
