Ocean Currents

By Legendary Teacher

Currents are ocean waters that travel in huge circular patterns.  Currents mix the waters of the world together and affect where ocean plants and animals live.  They also affect the movement of ships around the world.  Three things cause currents:  wind patterns, temperature, and salinity.

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By Legendary Teacher

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Many large currents are created by winds that blow in the same direction year round.  One of these currents is the Gulf Stream.  The Gulf Stream runs along the east coast of the United States.  It is located in the Atlantic Ocean and is one of the strongest currents known.  It is like a river of warm water flowing on top of deeper cold water.

​Wind

By Legendary Teacher

​Tempature

​Near the equator the sun heats up the surface of the ocean causing a change in the water temperature.  As water heats up it becomes lighter and rises to the surface.  As the heated water rises to the surface colder water sinks to the bottom.  This up and down movement of hot and cold water creates currents.

By Legendary Teacher

​Salinity

​As water evaporates and leaves behind salt, the water becomes heavier and will sink.  Less salty water rises and the rising and sinking will create currents.

By Legendary Teacher

​Other Facts

Currents are also influenced by the rotation of the Earth called the Coriolis effect. This causes currents to flow clockwise in the northern hemisphere and counter clockwise in the southern hemisphere.

One other factor impacting ocean currents is the gravitational pull of the Moon and the Sun.

Do currents impact the climate? Ocean currents can have a significant impact on climate. In some areas warm water is moved from the equator to a colder region causing the region to be warmer. One example of this is the Gulfstream current. It pulls warm water from the equator to the coast of Western Europe. As a result, areas such as the United Kingdom are typically much warmer than areas at the same northern latitude in North America.

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