Types of Ocean Currents

Surface currents

• Wind-driven
• Similar to pattern of major wind belts
• Primarily horizontal motion
• Transfers heat from tropical to polar regions (and cold from polar to tropical regions)
• Affects coastal climates

Deep currents

• Driven by differences in density caused by differences in temperature and salinity
• Vertical and horizontal motions
• Provides oxygen to deep sea

Measuring surface currents

Direct methods
• Floating device tracked through time
• Fixed current meter
  
  
Indirect methods
• Pressure gradients
• Radar altimeters
• Doppler flow meter

Measuring deep currents

Floating devices tracked through time

Chemical tracers
• Tritium
• Chlorofluorocarbons
  
  
Characteristic temperature and salinity