Ocean Circulation

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Ocean Circulation

• 16.1

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16.1 Ocean Circulation

• Ocean current is the mass of ocean water that
  flows from one place to another.
• Two types of ocean currents
• Surface currents
• Density currents

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1. Surface Currents

• Surface currents are movements of water that flow
  horizontally in the upper part of the oceans
  surface.

How do you think that a surface current
develops?
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Ocean Surface Currents
Gyres Clockwise rotation north of equator
Gyres Counter clockwise rotation south of
equator
Gyres are huge circular-moving current systems
that dominate the surfaces of the oceans
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Coriolis Effect

• The Coriolis effect is the deflection of
  currents away from their original course as a
  result of Earths rotation.

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2. Density Currents

• Density currents are deep water currents that
  occur below the surface currents.
• Density currents move vertically.

Density currents occur in cold, salty water.
Surface currents
Density currents
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The Composition of Seawater
The Ocean Conveyor Belt moderates earths climate.
When currents from equator move into north and
south poles, they transfer heat from warmer to
cooler areas on Earth.
As cold water currents from north and south
poles travel toward the equator, they help
moderate warm temperatures of adjacent land areas.
Equator
Red warm water Blue cold water
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The Composition of Seawater

• A Conveyor Belt

In a simplified model, ocean circulation is
similar to a conveyor belt that travels from the
Atlantic Ocean, through the Indian and Pacific
Oceans, and back again.
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The Composition of Seawater
1. Upwelling is the rise of cold water from
deeper layers to replace warmer surface water.
2. Upwelling brings greater concentrations of
dissolved nutrients, to the ocean surface.
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Effects of Upwelling
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El Nino

• Normal Year
• Offshore winds
• Good fishing

• El Nino Year
• Rain
• Poor fishing