Topic: Currents and Ocean Circulation

Theme: Change

Key Concepts:

Currents and Climate

• The North Atlantic Deep-Water conveyor belt has switched off and on in the past. Periods when it has not operated seem to be associated with colder climates, expecially in Europe. The change to a warmer climate takes place abruptly when the conveyor is switched on.
  


• A change in climate induced by global warming leads to increased melting of the Greenland ice sheet, which scientists theorize could lead to a large influx of fresh water that:
  
• Might intensify the cold Labrador Current allowing it to push the warmer Gulf Stream current further south and/or
  


• Create a decrease in water density, which could change the vertical density gradient and affect thermohaline circulation in the North Atlantic.