Currents

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Currents

• What are currents?

- Rivers of circulating water

• Causes

- Wind
- Rotating Earth
- Density Changes
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Surface Ocean Currents

• Broad, slow drifts never cross equator

• Wind generated circular gyres

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• Coriolis Effect

• The effect of Earths rotation on the direction
  of winds and currents.

• Northern Hemisphere - clockwise Right

• Southern Hemisphere -counterclockwise Left

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• Gulf Stream

- North Atlantic
- Brings warm water from equator north along
east coast of North America.

• Sometimes form eddies circulating water
  that pinches off from the current

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IMPORTANCE OF SURF. CURRENTS
NAVIGATION
MIGRATION
WEATHER
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Localized Surface Currents

• Longshore Current.
• Flows parallel to shore move sediment

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RIP CURRENT
- Caused by converging longshore currents
- Very dangerous Red Flag
- DO NOT fight rip current swim parallel to
shore to get out of channel
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Effects of currents on climate

• Climate average weather conditions of an area
  over many years.
• Currents move cold and warm water around the
  globe
• A surface current warms or cools the air above
  it, influencing the climate of the land near the
  coast.
• El Nino, an abnormal climate event that occurs
  every 2 to 7 years in the Pacific Ocean.

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Deep Ocean Currents

• Flow beneath surface cross equator

• Separated from surface currents by boundary
  called a Thermohaline (difference in densities)

• Move North to South

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Importance Of Deep Currents

• Upwelling
• Brings deep water to surf.
• Circulates nutrients up
• Moves plankton larvae