wat r ocean currents?

Answer 1

An ocean current is any more or less permanent or continuous, directed movement of ocean water that flows in one of the Earth's oceans. The currents are generated from the forces acting upon the water like the earth's rotation, the wind, the temperature and salinity differences and the gravitation of the moon. The depth contours, the shoreline and other currents influence the current's direction and strength.

Ocean currents can flow for thousands of kilometers. They are very important in determining the climates of the continents, especially those regions bordering on the ocean. Perhaps the most striking example is the Gulf Stream, which makes northwest Europe much more temperate than any other region at the same latitude. Another example is the Hawaiian Islands, where the climate is somewhat cooler (sub-tropical) than the tropical latitudes in which they are located because of the California Current.

Surface ocean currents are generally wind driven and develop their typical clockwise spirals in the northern hemisphere and counter-clockwise rotation in the southern hemisphere because of the imposed wind stresses. In wind driven currents the Ekman spiral effect results in the currents flowing at an angle to the driving winds. The areas of surface ocean currents move somewhat with the seasons, this is most notable in equatorial currents.

Deep ocean currents are driven by density and temperature gradients. Thermohaline circulation, also known as the ocean's conveyor belt, refers to the deep ocean density-driven ocean basin currents. These currents that flow under the surface of the ocean, and are thus hidden from immediate detection, are called submarine rivers. These are currently being researched by floating devices, which maintain their depth according to slightly differing densities of waters. Upwelling and downwelling areas in the oceans are areas, where significant vertical movement of ocean water is observed.

Ocean currents are measured in Sverdrup with the symbol Sv, where 1 Sv is equivalent to 106 cubic meters per second.

Knowledge of surface ocean currents is essential in reducing costs of shipping, since they reduce fuel costs. In the sail-ship era knowledge was even more essential. A good example of this is the Agulhas current, which long prevented Portuguese sailors from reaching India. Even today, the round-the-world sailing competitors employ surface currents to their benefit.

Ocean currents are also very important in the dispersal of many life forms. A dramatic example is the life-cycle of the eel.

Answer 2

An ocean current is any more or less permanent or continuous, directed movement of ocean water that flows in one of the Earth's oceans. The currents are generated from the forces acting upon the water like the earth's rotation, the wind, the temperature and salinity differences and the gravitation of the moon. The depth contours, the shoreline and other currents influence the current's direction and strength.

Description

Ocean currents can flow for thousands of kilometers. They are very important in determining the climates of the continents, especially those regions bordering on the ocean. Perhaps the most striking example is the Gulf Stream, which makes northwest Europe much more temperate than any other region at the same latitude. Another example is the Hawaiian Islands, where the climate is somewhat cooler (sub-tropical) than the tropical latitudes in which they are located because of the California Current.

Surface ocean currents are generally wind driven and develop their typical clockwise spirals in the northern hemisphere and counter-clockwise rotation in the southern hemisphere because of the imposed wind stresses. In wind driven currents the Ekman spiral effect results in the currents flowing at an angle to the driving winds. The areas of surface ocean currents move somewhat with the seasons, this is most notable in equatorial currents.

Deep ocean currents are driven by density and temperature gradients. Thermohaline circulation, also known as the ocean's conveyor belt, refers to the deep ocean density-driven ocean basin currents. These currents that flow under the surface of the ocean, and are thus hidden from immediate detection, are called submarine rivers. These are currently being researched by floating devices, which maintain their depth according to slightly differing densities of waters. Upwelling and downwelling areas in the oceans are areas, where significant vertical movement of ocean water is observed.

Ocean currents are measured in Sverdrup with the symbol Sv, where 1 Sv is equivalent to 106 cubic meters per second.

Answer 3

Horizontal and vertical circulation system of ocean waters, produced by gravity, wind friction, and water density variation. Coriolis forces cause ocean currents to move clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere and deflect them about 45° from the wind direction. This movement creates distinctive currents called gyres. Major ocean currents include the Gulf Stream–North Atlantic–Norway Current in the Atlantic Ocean, the Peru (Humboldt) Current off South America, and the West Australia Current..

Answer 4

Ocean waters are constantly on the move. How they move influences climate and living conditions for plants and animals, even on land.

Currents flow in complex patterns affected by wind, the water's salinity and heat content, bottom topography, and the earth's rotation.

Answer 5

Ocean waters are constantly on the move. How they move influences climate and living conditions for plants and animals, even on land.

Currents flow in complex patterns affected by wind, the water's salinity and heat content, bottom topography, and the earth's rotation.

Upwelling brings cold, nutrient-rich water from the depths up to the surface. Earth's rotation and strong seasonal winds push surface water away from some western coasts, so water rises on the western edges of continents to replace it. Marine life thrives in these nutrient-rich waters §.

Deep water forms when sea water entering polar regions cools or freezes, becoming saltier and denser. Colder or saltier water tends to sink §.

A global "conveyor belt" set in motion when deep water forms in the North Atlantic, sinks, moves south, and circulates around Antarctica, and then moves northward to the Indian, Pacific, and Atlantic basins. It can take a thousand years for water from the North Atlantic to find its way into the North Pacific §.

Warm surface currents invariably flow from the tropics to the higher latitudes, driven mainly by atmospheric winds, as well as the earth's rotation.

Western boundary currents are good examples of warm surface currents: they are warm and fast, and they move from tropical to temperate latitudes §.

Cold surface currents come from polar and temperate latitudes, and they tend to flow towards the equator. Like the warm surface currents, they are driven mainly by atmospheric forces §. Gyres form when the major ocean currents connect. Water flows in a circular pattern--clockwise in the Northern Hemisphere, and counterclockwise in the Southern Hemisphere §.

The Gulf Stream surface current is a western boundary current, one of the strongest--warm, deep, fast, and relatively salty. It separates open-ocean water from coastal water.

The California current is an eastern boundary current. It's broad, slow, cool, and shallow. Eastern boundary currents are often associated with upwelling.

The Somali current, off Africa's eastern coast, is unusual because it reverses direction twice a year. From May to September it runs north; from November to March it runs south. As it flows northward, upwelling supports productive marine life, but productivity falls when the current begins to move southward.


Upwelling stirs the soup and serves up a stew of nutrients that have settled into deep water. (illustration coming soon)
The ocean is layered: warmer on top, cold at the bottom. Organisms move from one layer to another, and plant and animal remains containing nutrients "rain" down, but the layers stay fairly separate in all but a few places.

Coastal upwelling occurs against the western sides of continents in the Atlantic, Indian, and Pacific. There, colder water rises to replace warm surface water blown out to sea by strong offshore winds. Upwelling supports about half of the world's fisheries, although these cool waters account for only 10 percent of the surface area of the global ocean §.

http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/oceanography_currents_1.html

Answer 6

Look on a map it was real interesting. How the current comes out from Japan and circles around and under California.
They are different everywhere. Worth a look see.