Ocean currents can be generated by wind, density differences in water masses caused by temperature and salinity variations, gravity, and events such as earthquakes. Currents are cohesive streams of seawater that circulate through the ocean.
In this manner, what is the meaning of the current?
Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms. The common symbol for current is the uppercase letter I.
What is the definition of electric current?
An electric current is a flow of electric charge. In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionised gas (plasma). Electric current is measured using a device called an ammeter.
A current, in a river or stream, is the flow of water influenced by gravity as the water moves downhill to reduce its potential energy. The current varies spatially as well as temporally within the stream, dependent upon the flow volume of water, stream gradient, and channel geometry.
It has positive and negative charges, which is expressed in coulomb. An electrical phenomenon is caused by flow of free electrons from one atom to another. The characteristics of current electricity are opposite to those of static electricity. Wires are made up of conductors such as copper or aluminum.
In these areas, the balance between gravity and Earth's spin causes geostrophic currents to flow. Deep ocean currents are caused by differences in water temperature and salinity (density).
Figure 14.14: The Coriolis Effect causes winds and currents to form circular patterns. The direction that they spin depend on the hemisphere that they are in. Currents on the surface are determined by three major factors: the major overall global wind patterns, the rotation of the Earth, and the shape of ocean basins.
Four Factors That Create Ocean Currents
- Wind. Wind is the single biggest factor in the creation of surface currents.
- Water Density. Another major factor in the creation of currents is water density, caused by the amount of salt in a body of water, and its temperature.
- Ocean Bottom Topography.
- Coriolis Effect.
The water at the ocean surface is moved primarily by winds that blow in certain patterns because of the Earth's spin and the Coriolis Effect. Winds are able to move the top 400 meters of the ocean creating surface ocean currents. Surface ocean currents form large circular patterns called gyres.
There are two type of Ocean Currents:
- Surface Currents--Surface Circulation.
- Deep Water Currents--Thermohaline Circulation.
- Primary Forces--start the water moving.
- The primary forces are:
- Secondary Forces--influence where the currents flow.
- Solar heating cause water to expand.
The ocean and atmosphere are connected. They work together to move heat and fresh water across the globe. Wind-driven and ocean-current circulations move warm water toward the poles and colder water toward the equator. The majority of the thermal energy at the Earth's surface is stored in the ocean.
Energy from the wind is quickly dissipated, so wind-driven currents slow down with depth, and finally die out within a few hundred meters of the surface. Surface currents are also triggered by gravity. Instead, the currents move at an angle to the force that generates them–a phenomenon called the Coriolis effect.
For the considerably longer periods– decades to millennia – which are relevant for climate change, the significantly larger heat capacity of the deep ocean is important. Ocean currents and mixing by winds and waves can transport and redistribute heat to deeper ocean layers.
There are five major ocean-wide gyres—the North Atlantic, South Atlantic, North Pacific, South Pacific, and Indian Ocean gyres. Each is flanked by a strong and narrow “western boundary current,” and a weak and broad “eastern boundary current” (Ross, 1995).
Warm Currents Cold Currents. Page 1. Warm Currents. Warm ocean currents flow away from the equatorial region on the western side of ocean basins. The Gulf Stream in the North Atlantic and the Kuroshio Current in the North Pacific are examples of warm currents.
Winds that blow along the shoreline—longshore winds—affect waves and, therefore, currents. Wave height is affected by wind speed, wind duration (or how long the wind blows), and fetch, which is the distance over water that the wind blows in a single direction.
According to the U.S. Geological Survey, most of that three percent is inaccessible. Over 68 percent of the fresh water on Earth is found in icecaps and glaciers, and just over 30 percent is found in ground water. Only about 0.3 percent of our fresh water is found in the surface water of lakes, rivers, and swamps.
Wind is the horizontal movement of air. All wind is caused by the uneven heating of Earth's surface, which sets convection currents in motion. Convection currents on a large scale cause global winds; convection currents on a small scale cause local winds.
Deep ocean currents (also known as Thermohaline Circulation) are caused by: The density of sea water varies globally due to differences in temperature and salinity. Surface water is heated by the sun, and warm water is less dense than cold water. The earth's rotation also influences deep ocean currents.
A current is like a vast river within the ocean, flowing from one place to another. These currents are caused by differences in temperature, differences in salinity, and by wind. Currents are responsible for a vast amount of movement of the water found in the Earth's oceans.
An electric current is a flow of electric charge. In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionised gas (plasma).
Beginning in the Caribbean and ending in the northern North Atlantic, the Florida Current leading into the Gulf Stream is a north flowing ocean current that reaches speeds in excess of 2.0m/s, particularly in the Florida Current region closest to the USA's eastern seaboard.