Oceanic currents are driven by three main factors:
- The rise and fall of the tides. Tides create a current in the oceans, which are strongest near the shore, and in bays and estuaries along the coast.
- Wind. Winds drive currents that are at or near the ocean’s surface.
- Thermohaline circulation.
What are the four factors that influence ocean currents?
Oceanic currents are driven by three main factors:
- The rise and fall of the tides. Tides create a current in the oceans, which are strongest near the shore, and in bays and estuaries along the coast.
- Wind. Winds drive currents that are at or near the ocean’s surface.
- Thermohaline circulation.
Which factor most directly affects the flow of ocean currents?
Tides caused by the gravitational pull of the Moon and the Sun also play role in the forming of oceanic currents. The factors that can modify the currents are direction and shape of coastlines, bottom reliefs of the ocean basins, seasonal variations and rotation of the earth. Ocean circulation is driven by winds and by differences in water density.
What are the causes and effects of ocean currents?
The following are the effects that are caused by the ocean surface circulation currents:
- Rainfall: The circulation current can affect the amount of a rainfall within a certain region. ...
- Storm: Another effect from the current is creating powerful ocean storms. ...
- Wind Patterns: Surface currents can affect the winds too. ...
- Climate: Ocean currents heavily affect the overall climate over a certain region. ...
Which of these factors control ocean currents?
Tides caused by the gravitational pull of the Moon and the Sun also play role in the forming of oceanic currents. The factors that can modify the currents are direction and shape of coastlines, bottom reliefs of the ocean basins, seasonal variations and rotation of the earth. Ocean circulation is driven by winds and by differences in water density.
What causes ocean currents?
Thus, the difference in the temperature of the ocean waters causes ocean currents. They are convectional currents giving rise to a transfer of heat energy in the ocean waters from the areas of excess to the areas of deficit heat energy. The factors relating to the earth’s nature and its rotation include the gravitational force ...
How does temperature affect ocean currents?
The main effect of temperature differences on the earth occurs in a north-south direction i.e. from equator to poles. Warm equatorial waters therefore move slowly along the surface towards the poles while heavier cold waters of the polar areas creep slowly towards the Equator along the bottom of the sea. Thus, the difference in the temperature of the ocean waters causes ocean currents. They are convectional currents giving rise to a transfer of heat energy in the ocean waters from the areas of excess to the areas of deficit heat energy.
How does salinity affect the density of ocean water?
Oceanic salinity affects the density of ocean water and density variation causes ocean currents. Salinity increases the density of ocean water. If two areas having equal temperature are characterized by varying salinity, the area of high salinity will have greater density than the area of low salinity. The denser water sinks and moves as subsurface current whereas less saline water moves towards greater saline water as surface current. In other words, ocean currents on the water surface are generated from the areas of less salinity to the areas of greater salinity. Such system of surface and subsurface currents caused by salinity variation is originated in open and enclosed seas. For example, the current flowing from the Atlantic Ocean to the Mediterranean Sea via Gibraltar Strait is caused because of the difference in salinity.
Why does the Mediterranean Sea sink?
Consequently, water sinks in the Mediterranean Sea. In order to compensate the loss of water Atlantic water flows as surface current into the Mediterranean Sea. The sinking water in the Mediterranean Sea moves as subsurface current towards the Atlantic Ocean. Similarly, such system of surface and subsurface currents is generated between the Red Sea and the Arabian Sea via Bab-el- Mandeb Strait.
Why is the ocean moving below the surface?
There is movement of ocean water below the water surface in the form of subsurface current from colder polar areas to warmer equatorial areas in order to balance the loss of water in the equatorial areas. Thus, the poleward surface current and Equatorward subsurface currents form a complete circulatory system of ocean water.
What are the factors that affect Earth's rotation?
The factors relating to the earth’s nature and its rotation include the gravitational force and deflective force by earth’s rotation also known as Coriolis force.
Which ocean currents form a circulatory system?
Thus, the poleward surface current and Equatorward subsurface currents form a complete circulatory system of ocean water. The Gulf Stream and Kuroshio warm currents moving from equator towards north are examples of such currents.
How are ocean currents driven?
Surface currents in the ocean are driven by global wind systems that are fueled by energy from the sun. Patterns of surface currents are determined by wind direction, Coriolis forces from the Earth’s rotation, and the position of landforms that interact with the currents. Surface wind-driven currents generate upwelling currents in conjunction with landforms, creating deepwater currents.
What causes deepwater currents?
Currents may also be caused by density differences in water masses due to temperature (thermo) and salinity (haline) variations via a process known as thermohaline circulation. These currents move water masses through ...
What are the two main types of currents in the ocean?
There are two distinct current systems in the ocean—surface circulation, which stirs a relatively thin upper layer of the sea, and deep circulation , which sweeps along the deep-sea floor. Download image (jpg, 38.6 KB).
What causes turbidity in the ocean?
Earthquakes may also trigger rapid downslope movement of water-saturated sediments, creating strong turbidity currents.
Why do ocean currents slow down?
As ocean water warms to greater depths, and temperatures climb in the polar regions , major ocean currents may slow down or even stop.
Which direction do ocean currents flow?
Major current systems typically flow clockwise in the northern hemisphere and counterclockwise in the southern hemisphere, in circular patterns that often trace the coastlines.
What percentage of ocean currents are surface currents?
Surface Currents amount to only 8-10% of the global oceanic current flow. Deep ocean currents: Differences in water density, resulting from the variability of water temperature (Thermo) and salinity (haline), also cause ocean currents. This process is known as thermohaline circulation.
How are ocean currents classified?
The ocean currents may be classified based on their depth as surface currents and deep water currents:
What are the determinants of climate?
From helping to keep our planet warm, to influencing precipitation patterns around the world, to playing a critical role in the global carbon cycle- ocean currents are one of the major determinants of weather and climatological conditions.
Where do ocean currents originate?
In other words, ocean currents on the water surface are generated from the areas of less salinity to the areas of greater salinity. Such a system of surface and subsurface currents caused by salinity variation is originated in open and enclosed seas.
Why is it important to know the surface ocean currents?
Knowledge of surface ocean currents is essential in reducing the costs of shipping since travelling with them reduces fuel costs.
