Ocean Circulation

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Ocean Circulation
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Fig. 3.19
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Ocean circulation

• Primarily wind-driven
• 1. Major winds

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ATMOSPHERICCIRCULATION PATTERNS
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Coriolis Effect

• A. Cause

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Changes in rotational speed of Earth as one
approaches the poles
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Coriolis Effect

• A. Cause
• B. Effect on ocean circulation
• 1. Northern hemisphere
• Clockwise
• 2. Southern hemisphere counter-clockwise

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Ocean circulation

• Total cause of currents and gyres
• Winds Coriolis position of landmasses

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Fig. 3.19
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Ekman transport

• The net transport of nutrients carried by
  currents.
• Caused by the difference between the winds and
  water movement.

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Fig. 3.18
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Ekman transport

• Net movement

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Fig. 14.29
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Upwelling

• Can be Coastal
• Equatorial

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Fig. 14.31
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Upwelling

• 1. Coastal upwelling

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Fig. 14.30
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California coastal sea surface temp
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Upwelling

• 1. Coastal upwelling
• 2. Equatorial upwelling

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Equatorial upwelling - Fig. 14.33
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Fig. 14.31
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El Niño
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El Niño effects on upwelling
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El Niño effects on upwelling
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Worldwide effect of the 1997 El Niño - Fig. 14.35
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El Niño

• Caused by Southern Oscillation

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Movement of high pressure system - the Southern
Oscillation - Fig. 14.34
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Impact of southern oscillation on regional winds
( consequently, ocean currents)
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How the southern oscillaton causes El Niño.
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Thermohaline circulation

• Thermohaline circulation is distinct layers of
  water which result from differences in density.
• Density differences are caused by differences in
  water temperature and salinity.

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Fig. 3.33
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Thermohaline circulation