land and sea breezes - mowerscience.orgmowerscience.org/ewexternalfiles/coastal upwelling.pdf ·...
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Land and Sea Breezes
Land and Sea Breezes
Deep Ocean Current!Cold water or salty water at the bottom
of the ocean can also travel in a current.
Deep Ocean Currents!These currents are caused by differences in
density rather than surface winds. !Usually “cold” in temperature (compared to
surface currents) !They are found near the bottom of the ocean !These currents flow much more slowly than
surface currents. They can take as long as 1,000 years to make a round trip from the pole to the equator and back.
Upwelling
! Surface and deep currents can mix when winds cause UPWELLING.
!Upwelling is the upward movement of cold water from the deep ocean.
!Winds blow away the warm surface water, and cold deep water replaces it
Upwelling! Upwelling brings tiny organisms, minerals, and
nutrients from the deeper layers of the water . ! The extra nutrients provide food to enormous
schools of fish!
Upwelling
Upwelling and Fishing! The most important fishing spots in the
world are found where upwelling occurs. Why?
El Niño! El Niño prevents upwelling because warm winds
are blown TOWARD the coast of South America ! This pushes the deep, cold, nutrient-rich water
downward and many fish lose their food source
Normal—Upwelling El Niño—Downwelling
The End
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