Coastal Upwelling
- Ekman transport pushes water away from coast, sea surface slopes towards cost
- Water from typically 50-200 m depth replaces surface water; cold, nutrient-rich!
- Upwelling areas rich in plankton & fisheries
Seasonal changes in upwelling and down- welling occur as prevailing wind directions change with seasons. Examples: west coast of the U.S. San Francisco summer fog); coast of Peru & NW Africa
Langmuir Circulation
- First observed 1938 by Irving Langmuir: straight rows of seaweed parallel to the wind direction
- Light to moderate winds create horizontal convection cells
- All floating seaweed, plankton are concentrated near surface in convergence zones
- Convergence zones can be seen by accumulation of drifting material or turbidity
- Detailed physical explanation and description still pending
