1. Introduction to Ocean Circulation - Geography 163 Wind-driven circulation of major gyres & surface currents Buoyancy-driven circulation linking the major gyres & the global conveyor belt Coastal circulations & land-ocean interactions Build from physical principles (w/out math)

2. Approach First principles do “work” Build descriptions from first principles Do not bludgeon students with calculus Work with available data sets

6. Why do we care? Climate –Global heat & water cycles –Weather & weather/climate prediction Global biogeography & biogeochemistry –Species ranges & adaptation to global change –Fossil fuel CO 2 sequestration Marine resources –Renewable (fisheries) –Non-renewable (oil, etc.)

7. IPCC [2007] Global Climate Change

8. Global Heat Transport How can it be constant?

9. Global Heat Transport

10. 10 15 W = 1 Petawatt

11. El Niño

14. SST Departures ( o C) in the Tropical Pacific During the Last 4 Weeks During the last 4-weeks, equatorial SSTs were more than 1.0°C above average between 165°E and 120°W and near the western S. American coast.

15. Niño Region SST Departures ( o C) Recent Evolution The latest weekly SST departures are: Niño 4 1.0ºC Niño 3.4 1.1ºC Niño 3 0.7ºC Niño 1+2 0.1ºC

16. Recent Evolution of Equatorial Pacific SST Departures ( o C) Longitude Time Since the beginning of June 2009, SST anomalies have been at least +0.5°C across most of the equatorial Pacific. During December 2009, positive SST anomalies increased across much of the equatorial Pacific. From late December 2009 to mid- February 2010, positive SST anomalies decreased across portions of the central and east-central Pacific. Recently, positive SST anomalies have decreased over the central Pacific.

17. NPP & Climate NPP = Net Primary Production rate of C fixed by phytoplankton Chlorophyll is found in all plants & phytoplankton Averages are from persistently warm ocean (SST> 15C) From Behrenfeld et al. [2006]

18. NPP & Climate

19. Biogeography

20. Biogeographical Boundaries

21. Biogeography

22. CO 2 Sequestration It’s gotta go somewhere...

23. CO 2 Sequestration This is where.

24. Climate & Fish Pacific Decadal Oscillation Warm phase - southern Cool phase - northern We’re now in a cool phase…

25. Introduction to Ocean Circulation - Geography 163 Wind-driven circulation of major gyres & surface currents Buoyancy-driven circulation linking the major gyres & the global conveyor belt Coastal circulations & land-ocean interactions

26. Scales Ocean basins are wide & shallow –Typical scales are 10 4 km across and 5 km deep –“Spit on a basketball” Aspect ratio has important implications –Horizontal velocities are >> vertical velocities –Horizontal property changes are << vertical ones

27. Global Bathymetry

28. Hyposgraphic Curve

29. Wind-Driven Gyres

30. Global Ocean Circulation

32. Global Wind Climate

33. Conveyor Belt

34. Net Air-Sea Heat Flux

35. Atlantic Temperature eWOCE gallery – www.ewoce.org

36. Atlantic Salinity

37. Atlantic Oxygen

38. Atlantic Phosphate

39. Coastal Upwelling

41. July 1992 AVHRR Ch 4

42. Summary Importance of large-scale ocean circulation –climate, biogeochemistry, marine resources Characteristic “Types” of Ocean Circulation –Patterns of circulation can be generalized for different regions –Suggests that dynamical processes are the same –Wind-driven, Buoyancy-driven & Coastal Scales - “spit on a basketball”