1. 200 m
1000 m
Fig (EFB)

2. Ocean Productivity and Circulation:
Winds
countercurrents
Ekman spirals
Langmuir cells

3. Fig (EFB)

4. Ekman Spiral
form in hours to
days
Fig (EFB)

5. Langmuir Cells
form in minutes to
hours
Fig (EFB)

6. Ocean Productivity and Circulation:
Winds
countercurrents
Ekman spirals
Langmuir cells
2. Thermohaline circulation
lower temperature + greater salinity = greatest density

8. Ocean Productivity and Circulation:
Winds
countercurrents
Ekman spirals
Langmuir cells
2. Thermohaline circulation
3. Upwelling

9. Upwelling
Upwelling

10. Normal Conditions H H
March – July position of high pressure zones
Cold-water upwelling intensifies

11. August - December position of high pressure zones
Normal Conditions H H
August - December position of high pressure zones
Warm waters dominate inshore

12. Davidson Current
El Niño Current

13. Davidson Current
El Niño Current
Aug-Dec shift

14. H H
March shift in El Niño Southern Oscillation (ENSO)
Cold-water upwelling absent

16. ENSO Early Warning Signs
Higher SSTs, track Kelvin wave W to E
Absence of cold-water upwelling on
California coast
Unusual marine organisms
barracudas, mako sharks, tropical fish to north
Failure of nesting seabirds

17. ENSO Global Impacts Droughts in interior continents:
Southwest U.S., SE Asia, Australia, S. Africa
Floods in coastal CA, Peru
More tropical storms, hurricanes
in Pacific
Decline in fisheries

18. H H
March shift in La Niña year following ENSO event
Cold-water upwelling intensified

19. La Niña Global Impacts Intensified cold-water upwelling
More tropical storms, hurricanes
in Atlantic
Increase in fisheries

21. ENSO in Antarctica = more sea ice = more productivity