Atmosphere-Ocean Climate Interactions

What is upwelling?

To understand upwelling, you must know that the rotation of the Earth causes moving objects to deflect along their paths - to the right in the Northern Hemisphere, and to the left in the Southern Hemisphere. This phenomenon - known as the Coriolis effect - acts on airplanes, artillery shells, and even ocean currents. The Coriolis effect combines with the predominantly equatorward (southward- blowing in the Northern Hemisphere) winds along the west coasts of the continents to create an offshore surface current. The upwelling process moves cooler nutrient-rich water up toward the surface to replace the original surface water. The primary effects of coastal upwelling are to maintain relatively cool water along the west coast of all continents, and to provide fertilization to surface waters - a key to the high biological productivity of these coastal regions. Upwelling also occurs along the equator and in the open ocean away from the eastern boundaries, but coastal upwelling is the most familiar and most ecologically important form of this process. PFEL provides estimates of upwelling along our coast and elsewhere for research purposes.

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